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Background: The comparison of coronary computed tomography angiography plaques and perivascular adipose tissue (PVAT) between patients with acute myocardial infarction (AMI) posttreatment and patients with stable coronary artery disease is poorly understood. Our objective was to evaluate the differences in coronary computed tomography angiography-quantified plaque and PVAT characteristics in patients post-AMI and identify signs of residual inflammation., Methods and Results: We analyzed 205 patients (age, 59.77±9.24 years; 92.20% men) with AMI ≤1 month and matched them with 205 patients with stable coronary artery disease (age, 60.52±10.04 years; 90.24% men) based on age, sex, and cardiovascular risk factors. Coronary computed tomography angiography scans were assessed for nonculprit plaque and vessel characteristics, plaque volumes by composition, high-risk plaques, and PVAT mean attenuation. Both patient groups exhibited similar noncalcified plaque volumes (383.35±313.23 versus 378.63±426.25 mm 3 , P =0.899). However, multivariable analysis revealed that patients post-AMI had a greater patient-wise noncalcified plaque volume ratio (estimate, 0.089 [95% CI, 0.053-0.125], P <0.001), largely attributed to a higher fibrofatty and necrotic core volume ratio, along with higher peri-lesion PVAT mean attenuation (estimate, 3.968 [95% CI, 2.556-5.379], P <0.001). When adjusted for vessel length, patients post-AMI had more high-risk plaques (estimate, 0.417 [95% CI, 0.298-0.536], P <0.001) per patient., Conclusions: Patients post-AMI displayed heightened noncalcified plaque components, largely due to fibrofatty and necrotic core content, more high-risk plaques, and increased PVAT mean attenuation on a per-patient level, highlighting the necessity for refined risk assessment in patients with AMI after treatment.

Myocardial infarction (MI), one of the leading causes of death worldwide, urgently needs further understanding of the pathological process and effective therapies. SO 2 in endoplasmic reticulum in several cardiovascular diseases has been reported to be particularly important. However, the role of endogenous SO 2 in endoplasmic reticulum in treating myocardial infarction is still ambiguous and needs to be elucidated. Herein, we developed TPA-HI-SO 2 as the first endoplasmic reticulum-targeting fluorescent agent for specific imaging and detection of sulfur dioxide derivatives both in vitro and in vivo. TPA-HI-SO 2 shows a highly sensitive and selective response to SO 2 derivatives over other anions in aqueous solution with a satisfactory response time and detection limit. Furthermore, TPA-HI-SO 2 decreased the SO 2 concentration in H9C2 cells treated with H 2 O 2 and in an MI mouse model. Most importantly, TPA-HI-SO 2 protects H9C2 cells from H 2 O 2 -induced apoptosis and obviously protects against myocardial infarction in vivo through neutralization of endogenous SO 2 . Taken together, we developed the first ER-targeting ratiometric fluorescent probe for endogenous SO 2 with excellent biocompatibility, high selectivity and sensitivity in this paper. More importantly, we demonstrated an obvious increase of the endogenous SO 2 concentration in a myocardial infarction mouse model for the first time, which suggests that neutralization of endogenous SO 2 in endoplasmic reticulum could be a promising therapeutic strategy for myocardial infarction., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

Background: Accumulation of CXCR4 (C-X-C motif chemokine receptor 4)-positive immune cells after acute myocardial infarction (AMI) can be visualized by positron emission tomography. For a broader clinical application, there is a need for CXCR4-directed radiotracers labeled with isotopes that can be used with single-photon emission computed tomography (SPECT). We report on the detection of CXCR4 expression after AMI in humans using the novel tracer [ 99m Tc]-PentixaTec., Methods: In this retrospective analysis, 9 patients with AMI after mechanical revascularization underwent myocardial inflammation imaging with [ 99m Tc]-PentixaTec SPECT/computed tomography and rest perfusion SPECT imaging. Tracer uptake in the infarcted area, spleen, bone marrow, and blood pool were used for semiquantitative analysis and calculation of signal-to-background ratios. The extent and intensity of SPECT-derived inflammatory changes were compared with serological markers and perfusion defects., Results: CXCR4-directed SPECT was positive in all patients. Increased CXCR4 expression was only detected in areas with diminished perfusion corresponding to the affected vessel in coronary angiography, with a signal-to-background ratio (infarcted area-to-blood pool) of 2.36±0.74. Uptake in bone marrow and spleen showed a significant correlation with CXCR4 expression in the infarcted areas (r=0.73 and P =0.03 for spleen and r=0.81 and P =0.008 for bone marrow, respectively). The extent and intensity of SPECT-derived inflammatory changes showed no significant association with serum troponin, CK (creatine kinase), leukocyte, or CRP (C-reactive protein) levels., Conclusions: This is the first report of in vivo CXCR4 imaging after AMI using a 99m Tc-labeled tracer. Increased CXCR4 expression was observed locally in the infarcted region and was related to a systemic inflammatory response in the reticuloendothelial system. This proof-of-concept investigation demonstrates the general feasibility of evaluating the inflammation-related CXCR4 expression in the myocardium after AMI using conventional scintigraphy or SPECT and might, thus, broaden its worldwide application in clinical practice., Competing Interests: All the authors certify that they have no affiliations with or involvement in any organization or entity with any financial interest or nonfinancial interest in the subject matter or materials discussed in this article.

Purpose: Generating polar map (PM) from [ 68 Ga]Ga-DOTA-FAPI-04 PET images is challenging and inaccurate using existing automatic methods that rely on the myocardial anatomical integrity in PET images. This study aims to enhance the accuracy of PM generated from [ 68 Ga]Ga-DOTA-FAPI-04 PET images and explore the potential value of PM in detecting reactive fibrosis after myocardial infarction and assessing its relationship with cardiac function., Methods: We proposed a deep-learning-based method that fuses multi-modality images to compensate for the cardiac structural information lost in [ 68 Ga]Ga-DOTA-FAPI-04 PET images and accurately generated PMs. We collected 133 pairs of [ 68 Ga]Ga-DOTA-FAPI-04 PET/MR images from 87 ST-segment elevated myocardial infarction patients for training and evaluation purposes. Twenty-six patients were selected for longitudinal analysis, further examining the clinical value of PM-related imaging parameters., Results: The quantitative comparison demonstrated that our method was comparable with the manual method and surpassed the commercially available software-PMOD in terms of accuracy in generating PMs for [ 68 Ga]Ga-DOTA-FAPI-04 PET images. Clinical analysis revealed the effectiveness of [ 68 Ga]Ga-DOTA-FAPI-04 PET PM in detecting reactive myocardial fibrosis. Significant correlations were demonstrated between the difference of baseline PM FAPI% and PM LGE%, and the change in cardiac function parameters (all p < 0.001), including LVESV% (r = 0.697), LVEDV% (r = 0.621) and LVEF% (r = -0.607)., Conclusion: The [ 68 Ga]Ga-DOTA-FAPI-04 PET PMs generated by our method are comparable to manually generated and sufficient for clinical use. The PMs generated by our method have potential value in detecting reactive fibrosis after myocardial infarction and were associated with cardiac function, suggesting the possibility of enhancing clinical diagnostic practices., Trial Registration: ClinicalTrials.gov (NCT04723953). Registered 26 January 2021., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Adverse left ventricular remodeling (ALVR) and subsequent heart failure after myocardial infarction (MI) remain a major cause of patient morbidity and mortality worldwide. Overt inflammation has been identified as the common pathway underlying myocardial fibrosis and development of ALVR post-MI. With its ability to simultaneously provide information about cardiac structure, function, perfusion, and tissue characteristics, cardiac magnetic resonance (CMR) is well poised to inform prognosis and guide early surveillance and therapeutics in high-risk cohorts. Further, established and evolving CMR-derived biomarkers may serve as clinical endpoints in prospective trials evaluating the efficacy of novel anti-inflammatory and antifibrotic therapies. This review provides an overview of post-MI ALVR and illustrates how CMR may help clinical adoption of novel therapies via mechanistic or prognostic imaging markers., Competing Interests: Funding Support and Author Disclosures Dr Gissler was supported by the IMM-PACT-Programme for Clinician Scientists, Department of Medicine II, Medical Center–University of Freiburg and Faculty of Medicine, University of Freiburg, funded by the Deutsche Forschungsgemeinschaft—413517907. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2024 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Histological analysis with 2,3,5-triphenyltetrazolium chloride (TTC) staining is the most frequently used tool to detect myocardial ischemia/reperfusion injury. However, its practicality is often challenged by poor image quality in gross histology, leading to an equivocal infarct-boundary delineation and potentially compromised measurement accuracy. Here, we introduce several crucial refinements in staining protocol and sample processing, which enable TTC images to be analyzed with light microscopy. The refined protocol involves a two-step TTC staining process (perfusion and immersion) and subsequent Zamboni fixation to differentiate myocardial viability and necrosis, and use of Coomassie brilliant blue to label area-at-risk. After the duo-staining steps were completed, the heart sample was embedded and sliced transversally by a cryostat into a series of thin sections (50 µm) for microscopic analysis. The refined TTC (redTTC) assay yielded remarkably high-quality images with striking color intensity and sharply defined boundaries, permitting unambiguous and reliable delineation of the infarct and area-at-risk. In the same animals, the redTTC assay showed good agreement with the in-vivo gold standard measurements (LGE and MEMRI). Meanwhile, redTTC imaging allows tracking of viable cardiomyocytes at cellular resolution, and with this enhanced capability, we convincingly demonstrated the pro-survival action of stem cells based-therapy. Therefore, the redTTC assay represents a significant technical advance that permits precise detection of the true extent of cardiac injury and cardiomyocyte viability. This approach is cost-effective and may be adapted for use in diverse applications, making it highly appealing to many laboratories performing ischemia/reperfusion injury experiments., (© 2024. The Author(s).)

Emergency computed tomography (CT) often does not allow for comprehensive coronary artery assessment. However, CT may reveal pathological myocardial hypoperfusion suggestive of acute myocardial infarction (AMI), especially in patients presenting with a different diagnostic hypothesis. CT hypoperfusion is known to be associated with myocardial infarction, however the diagnostic value of CT hypoperfusion for the detection of AMI is still not well evaluated. This was a single-centre retrospective study including patients who underwent invasive coronary angiography (ICA) due to suspected AMI based on incidental perfusion defects upon emergency CT imaging between 2018 and 2023. A total of 22 patients (mean age 66.3 ± 10.8 years, 11 female) were included in this analysis. The diagnosis of AMI was established in all cases leading to ICA. Culprit coronary artery lesions with an indication of percutaneous coronary intervention were detected in all patients who underwent ICA. Spearmann correlation for hypoperfused segments on CT imaging and the corresponding vascular territory upon ICA was significantly substantial (ρ = 0.73, p = < 0.001). The higher the number of affected myocardial segments, the faster ICA was initiated. Mean time between the suspicion of AMI on CT imaging and ICA was 196 (29-4044) minutes. Myocardial hypoperfusion on emergency CT imaging should be considered as AMI until proven otherwise, independent of the clinical scenario leading to performance of CT imaging and whether imaging was performed for the exclusion of non-cardiac pathologies. Early initiation of further diagnostic workup may potentially avoid delays to invasive treatment and reduce the CT-to-catheter-time. Our study explicitly underlines that myocardial hypoperfusion upon contrast enhanced CT imaging needs to be considered as sign of acute myocardial infarction and indicates targeted clinical workup to rule out this diagnosis and to shorten the timeframe from imaging diagnosis to interventional treatment., (© 2024. The Author(s).)

Aims: There is lack of agreement on late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) imaging processing for guiding ventricular tachycardia (VT) ablation. We aim at developing and validating a systematic processing approach on LGE-CMR images to identify VT corridors that contain critical VT isthmus sites., Methods and Results: This is a translational study including 18 pigs with established myocardial infarction and inducible VT undergoing in vivo characterization of the anatomical and functional myocardial substrate associated with VT maintenance. Clinical validation was conducted in a multicentre series of 33 patients with ischaemic cardiomyopathy undergoing VT ablation. Three-dimensional LGE-CMR images were processed using systematic scanning of 15 signal intensity (SI) cut-off ranges to obtain surface visualization of all potential VT corridors. Analysis and comparisons of imaging and electrophysiological data were performed in individuals with full electrophysiological characterization of the isthmus sites of at least one VT morphology. In both the experimental pig model and patients undergoing VT ablation, all the electrophysiologically defined isthmus sites (n = 11 and n = 19, respectively) showed overlapping regions with CMR-based potential VT corridors. Such imaging-based VT corridors were less specific than electrophysiologically guided ablation lesions at critical isthmus sites. However, an optimized strategy using the 7 most relevant SI cut-off ranges among patients showed an increase in specificity compared to using 15 SI cut-off ranges (70 vs. 62%, respectively), without diminishing the capability to detect VT isthmus sites (sensitivity 100%)., Conclusion: Systematic imaging processing of LGE-CMR sequences using several SI cut-off ranges may improve and standardize procedure planning to identify VT isthmus sites., Competing Interests: Conflict of interest: none declared., (© The Author(s) 2024. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Background: Plaque quantification from coronary computed tomography angiography has emerged as a valuable predictor of cardiovascular risk. Deep learning can provide automated quantification of coronary plaque from computed tomography angiography. We determined per-patient age- and sex-specific distributions of deep learning-based plaque measurements and further evaluated their risk prediction for myocardial infarction in external samples., Methods: In this international, multicenter study of 2803 patients, a previously validated deep learning system was used to quantify coronary plaque from computed tomography angiography. Age- and sex-specific distributions of coronary plaque volume were determined from 956 patients undergoing computed tomography angiography for stable coronary artery disease from 5 cohorts. Multicenter external samples were used to evaluate associations between coronary plaque percentiles and myocardial infarction., Results: Quantitative deep learning plaque volumes increased with age and were higher in male patients. In the combined external sample (n=1847), patients in the ≥75th percentile of total plaque volume (unadjusted hazard ratio, 2.65 [95% CI, 1.47-4.78]; P =0.001) were at increased risk of myocardial infarction compared with patients below the 50th percentile. Similar relationships were seen for most plaque volumes and persisted in multivariable analyses adjusting for clinical characteristics, coronary artery calcium, stenosis, and plaque volume, with adjusted hazard ratios ranging from 2.38 to 2.50 for patients in the ≥75th percentile of total plaque volume., Conclusions: Per-patient age- and sex-specific distributions for deep learning-based coronary plaque volumes are strongly predictive of myocardial infarction, with the highest risk seen in patients with coronary plaque volumes in the ≥75th percentile., Competing Interests: Dr Miller has received consulting fees and research support from Pfizer. S. Cadet, Dr Slomka, Dr Dey, and Dr Berman received software royalties from Cedars-Sinai Medical Center and report equity in APQ Health Inc. outside of the current work. Dr Berman, Dr Slomka, and Dr Dey hold a patent (US8885905B2/WO2011069120A1, Method and System for Plaque Characterization). Dr Grodecki reports grants or contracts from the Foundation for Polish Science and Polish Society of Cardiology. Dr Kwan reports partial effort support from the Doris Duke Charitable Foundation Grant. Dr Kuronuma is supported by grants from The Society of Nuclear Medicine and Molecular Imaging Wagner-Torizuka Fellowship and Nihon University School of Medicine Alumni Association. S. Cadet reports financial support from the Miriam and Sheldon G Adelson Medical Research Foundation Grant. Dr Nicholls reports grants or contracts from AstraZeneca, New Amsterdam Pharma, Amgen, Anthera, Eli Lilly, Esperion, Novartis, Cerenis, The Medicines Company, Resverlogix, InfraReDx, Roche, Sanofi-Regeneron, and LipoScience; and consulting fees from AstraZeneca, Amarin, Akcea, Eli Lilly, Anthera, Omthera, Merck, Takeda, Resverlogix, Sanofi-Regeneron, CSL Behring, Esperion, and Boehringer Ingelheim. Dr Dweck reports consulting fees from Novartis, Jupiter Bioventures, and Silence Therapeutics; and payment or honoraria from Pfizer and Novartis. Dr Newby reports a grant from the British Heart Foundation (RE/24/130012, CH/09/002, and RG/F/22/110093) and Wellcome Trust. Dr Williams has given talks for Canon Medical Systems, Siemens Healthineers and Novartis. The other authors report no conflicts.

Background: Lipid content in untreated nonobstructive coronary artery lesions is associated with adverse clinical outcomes, and residual in-stent or stent edge lipid may worsen outcomes after percutaneous coronary intervention (PCI)., Methods: Near-infrared spectroscopy-intravascular ultrasound was performed before and after PCI in patients with myocardial infarction. We evaluated the impact of lipid assessed by near-infrared spectroscopy (maximal lipid core burden index over 4 mm [maxLCBI 4mm ]) along with intravascular ultrasound information including residual plaque burden on in-stent or edge-related major adverse cardiac events (MACE) in de novo PCI-treated culprit coronary artery lesions. The primary end point was culprit lesion-related MACE (CL-MACE), defined as cardiac death, myocardial infarction, or unstable or progressive angina either requiring revascularization or with rapid lesion progression and classified as in-stent or stent edge-related., Results: During a median follow-up of 3.8 years, 25 CL-MACE (11 stent edge-related, 13 in-stent, and 1 in-lesion without a stent) occurred in 1041 PCI-treated lesions in 768 patients. Pre-PCI or post-PCI measures of lipid content were not related to in-stent CL-MACE. However, stent edge-related CL-MACE was increased if both the post-PCI stent edge maxLCBI 4mm was greater than the upper quartile (108.7) and the stent edge plaque burden was >50% (adjusted odds ratio, 4.11 [95% CI, 1.12-15.2]; P =0.03)., Conclusions: In PROSPECT II (Providing Regional Observations to Study Predictors of Events in the Coronary Tree), CL stent implantation leaving behind greater stent edge-related lipid and uncovered plaque burden was associated with an increased risk of stent edge-related CL-MACE during follow-up. In contrast, CL lipid content was not related to in-stent CL-MACE., Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02171065., Competing Interests: Dr Maehara is a consultant to Boston Scientific, Philips, and SpectraWave; and speaker honoraria from Nipro. Dr Matsumura is a consultant to Boston Scientific and Terumo. Dr Maeng is supported by a grant from the Novo Nordisk Foundation (grant number NNF22OC0074083); has received lecture and advisory board fees from AstraZeneca, Bayer, Boehringer Ingelheim, Bristol-Myers Squibb, and Novo Nordisk; has received research grants from Philips, Bayer, and Novo Nordisk; has research contracts with Novo Nordisk, Janssen, and Philips; and is a minor shareholder in Verve Therapeutics, Eli Lilly, and Novo Nordisk. Dr Engstrøm has received advisory board fees from Novo Nordisk, Abbot Vascular, and Opsens; and speakers fee from Abbott Vascular. Dr Fröbert has received grants from Sanofi Pasteur. Dr Persson has received unrestricted grants from Abbott. Dr Jensen has received institutional unrestricted research grants from Biotronik, BioSensors, and OrbusNeich. Dr Held has received Advisory board fees from Novo Nordisk, AstraZeneca, Boehringer Ingelheim, Coala Life, and Pharmacosmos; research grants from Pfizer; and lecture fees from Bayer. Dr Mintz has received honoraria from Boston Scientific, Philips, Abbott, SpectraWave, and Gentuity. Dr Ali has received institutional grant support from Abbott, Abiomed, Acist Medical, Amgen, Boston Scientific, Cathworks, Canon, Conavi, Heartflow, Inari, Medtronic Inc, National Institutes of Health, Nipro, Opsens Medical, Medis, Philips, Shockwave, Siemens, Spectrawave, and Teleflex Inc; consultant honoraria from Abiomed, AstraZeneca, Boston Scientific, Cathworks, Opsens, Philips, and Shockwave; and equity in Elucid, Lifelink, Spectrawave, Shockwave, and VitalConnect. Dr Stone has received speaker honoraria from Medtronic, Pulnovo, Infraredx, Abiomed, Amgen, and Boehringer Ingelheim; has served as a consultant to Abbott, Daiichi Sankyo, Ablative Solutions, CorFlow, Cardiomech, Robocath, Miracor, Vectorious, Apollo Therapeutics, Elucid Bio, Cardiac Success, Valfix, TherOx, HeartFlow, Neovasc, Ancora, Occlutech, Impulse Dynamics, Adona Medical, Millennia Biopharma, Oxitope, HighLife, Elixir, Remote Cardiac Enablement, and Aria; and has equity/options from Cardiac Success, Ancora, Cagent, Applied Therapeutics, Biostar family of funds, SpectraWave, Orchestra Biomed, Aria, Valfix, and Xenter. Dr Stone’s employer, Mount Sinai Hospital, receives research grants from Shockwave, Abbott, Abiomed, Bioventrix, Cardiovascular Systems Inc, Phillips, Biosense-Webster, Vascular Dynamics, Pulnovo, and V-wave. Dr Erlinge has received speakers fees from Amgen, AstraZeneca, Bayer, and Chiesi; and advisory board fees from Bayer, Boehringer Ingelheim, and Sanofi. The other authors report no conflicts.

The peptide hormone ghrelin is produced in cardiomyocytes and acts through the myocardial growth hormone secretagogue receptor (GHSR) to promote cardiomyocyte survival. Administration of ghrelin may have therapeutic effects on post-myocardial infarction (MI) outcomes. Therefore, there is a need to develop molecular imaging probes that can track the dynamics of GHSR in health and disease to better predict the effectiveness of ghrelin-based therapeutics. We designed a high-affinity GHSR ligand labeled with 18 F for imaging by PET and characterized its in vivo properties in a canine model of MI. Methods: We rationally designed and radiolabeled with 18 F a quinazolinone derivative ([ 18 F]LCE470) with subnanomolar binding affinity to GHSR. We determined the sensitivity and in vivo and ex vivo specificity of [ 18 F]LCE470 in a canine model of surgically induced MI using PET/MRI, which allowed for anatomic localization of tracer uptake and simultaneous determination of global cardiac function. Uptake of [ 18 F]LCE470 was determined by time-activity curve and SUV analysis in 3 regions of the left ventricle-area of infarct, territory served by the left circumflex coronary artery, and remote myocardium-over a period of 1.5 y. Changes in cardiac perfusion were tracked by [ 13 N]NH 3 PET. Results: The receptor binding affinity of LCE470 was measured at 0.33 nM, the highest known receptor binding affinity for a radiolabeled GHSR ligand. In vivo blocking studies in healthy hounds and ex vivo blocking studies in myocardial tissue showed the specificity of [ 18 F]LCE470, and sensitivity was demonstrated by a positive correlation between tracer uptake and GHSR abundance. Post-MI changes in [ 18 F]LCE470 uptake occurred independently of perfusion tracer distributions and changes in global cardiac function. We found that the regional distribution of [ 18 F]LCE470 within the left ventricle diverged significantly within 1 d after MI and remained that way throughout the 1.5-y duration of the study. Conclusion: [ 18 F]LCE470 is a high-affinity PET tracer that can detect changes in the regional distribution of myocardial GHSR after MI. In vivo PET molecular imaging of the global dynamics of GHSR may lead to improved GHSR-based therapeutics in the treatment of post-MI remodeling., (© 2024 by the Society of Nuclear Medicine and Molecular Imaging.)

Purpose: Biomaterial and stem cell delivery are promising approaches to treating myocardial infarction. However, the mechanical and biochemical mechanisms underlying the therapeutic benefits require further clarification. This study aimed to assess the deformation of stem cells injected with the biomaterial into the infarcted heart., Methods: A microstructural finite element model of a mid-wall infarcted myocardial region was developed from ex vivo microcomputed tomography data of a rat heart with left ventricular infarct and intramyocardial biomaterial injectate. Nine cells were numerically seeded in the injectate of the microstructural model. The microstructural and a previously developed biventricular finite element model of the same rat heart were used to quantify the deformation of the cells during a cardiac cycle for a biomaterial elastic modulus (E inj ) ranging between 4.1 and 405,900 kPa., Results: The transplanted cells' deformation was largest for E inj = 7.4 kPa, matching that of the cells, and decreased for an increase and decrease in E inj . The cell deformation was more sensitive to E inj changes for softer (E inj ≤ 738 kPa) than stiffer biomaterials., Conclusions: Combining the microstructural and biventricular finite element models enables quantifying micromechanics of transplanted cells in the heart. The approach offers a broader scope for in silico investigations of biomaterial and cell therapies for myocardial infarction and other cardiac pathologies., Competing Interests: Declarations. Competing Interests: The authors declare that they have no competing interests., (© 2024. The Author(s).)

Combined [ 18 F]FDG PET-cardiac MRI imaging (PET/CMR) is a useful tool to assess myocardial viability and cardiac function in patients with acute myocardial infarction (AMI). Here, we evaluated the prognostic value of PET/CMR in a porcine closed-chest reperfused AMI (rAMI) model. Late gadolinium enhancement by PET/CMR imaging displayed tracer uptake defect at the infarction site by 3 days after the rAMI in the majority of the animals (group Match, n = 28). Increased [ 18 F]FDG uptake at the infarcted area (metabolism/contractility mismatch) with reduced tracer uptake in the remote viable myocardium (group Mismatch, n = 12) 3 days after rAMI was observed in the animals with larger infarct size and worse left ventricular ejection fraction (LVEF) (34 ± 8.7 vs 42.0 ± 5.2%), with lower LVEF also at the 1-month follow-up (35.8 ± 9.5 vs 43.0 ± 6.3%). Transcriptome analyses by bulk and single-nuclei RNA sequencing of the infarcted myocardium and border zones (n = 3 of each group, and 3 sham-operated controls) revealed a strong inflammatory response with infiltration of monocytes and macrophages in the infarcted and border areas in Mismatch animals. Our data indicate a high prognostic relevance of combined PET/MRI in the subacute phase of rAMI for subsequent impairment of heart function and underline the adverse effects of an excessive activation of the innate immune system in the initial phase after rAMI., (© 2024. The Author(s).)

Patients with acute coronary artery disease (CAD) exhibit reduced global and regional strain and strain rate (S/SR). However, knowledge about segmental S/SR in stable CAD patients is still limited. This study aimed to investigate whether resting segmental S/SR measurements differ in patients with chronic chest pain who have normal coronary arteries or stenotic coronary arteries, and to compare these measurements to those in patients with revascularized myocardial infarction (MI). We prospectively enrolled 510 patients with chronic chest pain referred for coronary computed tomography angiography (CCTA) and 102 patients revascularized after MI. All participants underwent transthoracic echocardiography featuring S/SR analysis. In addition to the patients with MI, patients with suspected CAD based on CCTA findings subsequently underwent invasive coronary angiography (CAG). We assessed global longitudinal strain (GLS) and averaged segmental peak longitudinal strain during systole (PLS), peak systolic strain rate (SRs), peak early diastolic strain rate (SRe), and post systolic shortening (PSS). We also determined functionally reduced segment percentages using differing S/SR cut-off values. There were significant disparities in all average segmental S/SR metrics between the No-CAD and MI groups. SRe was the only S/SR metric that differed significantly between the No-CAD and PCI groups. Differences in SRe, PLS and GLS measurements were observed between the No-CAD and CABG groups. The proportion of diminished segmental S/SR mirrored these findings. For the percentage of pathological segments with varying cut-off values, segmental SRe below 1.5 s - 1 displayed the most marked difference among the four groups (p < 0.001). Revascularized MI patients or those referred to CABG present with diminished segmental S/SR values. However, among patients with chronic chest pain, only segmental SRe discerns subtle disparities between the No-CAD and the PCI group. The diagnostic accuracy of SRe warrants further exploration in subsequent studies., (© 2024. The Author(s).)

Background: The prognostic efficacy of a coronary computed tomography angiography (CCTA)-derived myocardial radiomics model in patients with chronic myocardial infarction (MI) is unclear., Methods: In this retrospective study, a cohort of 236 patients with chronic MI who underwent both CCTA and cardiac magnetic resonance (CMR) examinations within 30 days were enrolled and randomly divided into training and testing datasets at a ratio of 7:3. The clinical endpoints were major adverse cardiovascular events (MACE), defined as all-cause death, myocardial reinfarction and heart failure hospitalization. The entire three-dimensional left ventricular myocardium on CCTA images was segmented as the volume of interest for the extraction of radiomics features. Five models, namely the clinical model, CMR model, clinical+CMR model, CCTA-radiomics model, and clinical+CCTA-radiomics model, were constructed using multivariate Cox regression. The prognostic performances of these models were evaluated through receiver operating characteristic curve analysis and the index of concordance (C-index)., Results: Fifty-one (20.16%) patients experienced MACE during a median follow-up of 1439.5 days. The predictive performance of the CCTA-radiomics model surpassed that of the clinical model, CMR model, and clinical+CMR model in both the training (area under the curve (AUC) of 0.904 vs. 0.691, 0.764, 0.785; C-index of 0.88 vs. 0.71, 0.75, 0.76, all p values <0.001) and testing (AUC of 0.893 vs. 0.704, 0.851, 0.888; C-index of 0.86 vs. 0.73, 0.85, 0.85, all p values <0.05) datasets., Conclusions: The CCTA-based myocardial radiomics model is a valuable tool for predicting adverse outcomes in chronic MI, providing incremental value to conventional clinical and CMR parameters., Competing Interests: Declaration of competing interest All authors disclosed no relevant conflicts., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: Regional Wall Motion Abnormality (RWMA) serves as an early indicator of myocardial infarction (MI), the global leader in mortality. Accurate and early detection of RWMA is vital for the successful treatment of MI. Current automated echocardiography analyses typically concentrate on peak values from left ventricular (LV) displacement curves, based on LV contour annotations or key frames during the heart's systolic or diastolic phases within a single echocardiographic cycle. This approach may overlook the rich motion field features available in multi-cycle cardiac data, which could enhance RWMA detection., Methods: In this research, we put forward an innovative approach to detect RWMA by harnessing motion information across multiple echocardiographic cycles and multi-views. Our methodology synergizes U-Net-based segmentation with optical flow algorithms for detailed cardiac structure delineation, and Temporal Convolutional Networks (ConvNet) to extract nuanced motion features. We utilize a variety of machine learning and deep learning classifiers on both A2C and A4C views echocardiograms to enhance detection accuracy. A three-phase algorithm-originating from the HMC-QU dataset-incorporates U-Net for segmentation, followed by optical flow for cardiac wall motion field features. Temporal ConvNet, inspired by the Temporal Segment Network (TSN), is then applied to interpret these motion field features, independent of traditional cardiac parameter curves or specific key phase frame inputs., Results: Employing five-fold cross-validation, our SVM classifier demonstrated high performance, with a sensitivity of 93.13%, specificity of 83.61%, precision of 88.52%, and an F1 score of 90.39%. When compared with other studies using the HMC-QU datasets, these Fig s stand out, underlining our method's effectiveness. The classifier also attained an overall accuracy of 89.25% and Area Under the Curve (AUC) of 95%, reinforcing its potential for reliable RWMA detection in echocardiographic analysis., Conclusions: This research not only demonstrates a novel technique but also contributes a more comprehensive and precise tool for early myocardial infarction diagnosis., Competing Interests: NO authors have competing interests., (Copyright: © 2024 Kasim et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Background: Late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) is a standard technique for diagnosing myocardial infarction (MI), which, however, poses risks due to gadolinium contrast usage. Techniques enabling MI assessment based on contrast-free CMR are desirable to overcome the limitations associated with contrast enhancement., Methods: We introduce a novel deep generative learning method, termed cine-generated enhancement (CGE), which transforms standard contrast-free cine CMR into LGE-equivalent images for MI assessment. CGE features with multislice spatiotemporal feature extractor, enhancement contrast modulation, and sophisticated loss function. Data from 430 patients with acute MI from 3 centers were collected. After image quality control, 1525 pairs (289 patients) of center I were used for training, and 293 slices (52 patients) of the same center were reserved for internal testing. The 40 patients (401 slices) of the other 2 centers were used for external testing. The CGE robustness was further tested in 20 normal subjects in a public cine CMR data set. CGE images were compared with LGE for image quality assessment and MI quantification regarding scar size and transmurality., Results: The CGE method produced images of superior quality to LGE in both internal and external data sets. There was a significant ( P <0.001) correlation between CGE and LGE measurements of scar size (Pearson correlation, 0.79/0.80; intraclass correlation coefficient, 0.79/0.77) and transmurality (Pearson correlation, 0.76/0.64; intraclass correlation coefficient, 0.76/0.63) in internal/external data set. Considering all data sets, CGE demonstrated high sensitivity (91.27%) and specificity (95.83%) in detecting scars. Realistic enhancement images were obtained for the normal subjects in the public data set without false positive subjects., Conclusions: CGE achieved superior image quality to LGE and accurate scar delineation in patients with acute MI of both internal and external data sets. CGE can significantly simplify the CMR examination, reducing scan times and risks associated with gadolinium-based contrasts, which are crucial for acute patients., Competing Interests: None.

Competing Interests: Dr Zhang has authorship rights for patent WO2021044153: Enhancement of Medical Images. W.Y.R. Fok reports no conflicts.

Background: While left ventricular ejection fraction (LVEF) is the primary variable utilized for prognosis following myocardial infarction (MI), it is relatively indiscriminate for survival in patients with mildly reduced (> 40%) or preserved LVEF (> 50%). Improving risk stratification in patients with mildly reduced or preserved LVEF remains an unmet need, and could be achieved by using a combination approach using prognostically validated measures of left-ventricular (LV) size, geometry, and function., Aims: The aim of this study was to compare the prognostic utility of a Combined Echo-Score for predicting all-cause (ACM) and cardiac mortality (CM) following MI to LVEF alone, including the sub-groups with LVEF > 40% and LVEF > 50%., Methods: Retrospective data on 3094 consecutive patients with MI from 2013 to 2021 who had inpatient echocardiography were included, including both patients with ST-elevation MI (n = 869 [28.1%]) and non-ST-elevation MI (n = 2225 [71.9%]). Echo-Score consisted of LVEF < 40% (2 points) or LVEF < 50% (1 point), and 1 point each for left atrial volume index > 34 mL/m 2 , septal E/e' > 15, abnormal LV mass-index, tricuspid regurgitation velocity > 2.8 m/s, and abnormal LV end-systolic volume-index. Simple addition was used to derive a score out of 7., Results: At a median follow-up of 4.5 years there were 445 deaths (130 cardiac deaths). On Cox proportional-hazards multivariable analysis incorporating significant clinical and echocardiographic predictors, Echo-Score was an independent predictor of both ACM (HR 1.34, p < .001) and CM (HR 1.59, p < .001). Inter-model comparisons of model 𝛘 2 , Harrel's C and Somer's D, and Receiver operating curves confirmed the superior prognostic value of Echo-Score for both endpoints compared to LVEF. In the subgroups with LVEF > 40% and LVEF > 50%, Echo-Score was similarly superior to LVEF for predicting ACM and CM., Conclusions: An Echo-Score composed of prognostically validated LV parameters is superior to LVEF alone for predicting survival in patients with MI, including the subgroups with mildly reduced and preserved LVEF. This could lead to improved patient risk stratification, better-targeted therapies, and potentially more efficient use of device therapies. Further studies should be considered to define the benefit of further investigation and treatment in high-risk subgroups., (© 2024 The Author(s). Echocardiography published by Wiley Periodicals LLC.)

Competing Interests: Beijing Luhe Hospital received free ferumoxytol sponsorship from Chia Tai Tianqing Pharmaceutical Group Co, Ltd. The authors report no conflict.

Background: Epicardial adipose tissue (EAT) accumulation plays a key role in the progression myocardial infarction (MI) and diabetes. Diabetic patients have elevated risk of major adverse cardiac events (MACEs) compared to non-diabetic patients. We aimed to investigate the prognostic value of EAT volume in MI patients with and without diabetes., Methods: This study included 458 MI patients who underwent cardiac computed tomography (CT) imaging and received successful stent implantation. EAT volume was quantified with cardiac CT imaging. Sub-study stratification of patients by diabetes status was further analyzed. Cox proportional hazards regression models were applied to evaluate the association between EAT volume and MACEs., Results: Diabetes was identified in 135 of the 458 patients (29.5%). EAT volume was significantly higher in diabetes than non-diabetes. During a median follow-up of 1154 days, MACEs occurred more frequently in patients with versus without diabetes. EAT volume was independent predictor of MACEs in all MI patients after adjustment for risk factors, and showed good predictive value in the evaluation of MACEs. Moreover, EAT volume was also significantly associated with MACEs after adjustment for risk factors in diabetes and non-diabetes in the subgroup analysis., Conclusion: MI patients with diabetes had higher EAT volume and experienced higher rate of MACEs compared to non-diabetes. EAT volume is an independent risk of prognosis of MI, regardless of the diabetes status., Competing Interests: Declaration of Competing Interest The authors of this manuscript declare no conflict of interest., (Copyright © 2024 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.)

Objective: Epicardial adipose tissue (EAT) quantity is associated with poor cardiovascular outcomes. However, the quality of EAT may be of incremental prognostic value. Cardiac magnetic resonance (CMR) is the gold standard for tissue characterization but has never been applied for EAT quality assessment. We aimed to investigate EAT quality measured on CMR T1 mapping as a predictor of poor outcomes in an all-comer cohort., Methods: We investigated the association of EAT area and EAT T1 times (EAT-T1) with a composite endpoint of nonfatal myocardial infarction, heart failure hospitalization, and all-cause death., Results: A total of 966 participants were included (47.2% female; mean age: 58.4 years) in this prospective observational CMR registry. Mean EAT area and EAT-T1 were 7.3 cm 2 and 268 ms, respectively. On linear regression, EAT-T1 was not associated with markers of obesity, dyslipidemia, or comorbidities such as diabetes (p > 0.05 for all). During a follow-up of 57.7 months, a total of 280 (29.0%) events occurred. EAT-T1 was independently associated (adjusted hazard ratio per SD: 1.202; 95% CI: 1.022-1.413; p = 0.026) with the composite endpoint when adjusted for established clinical risk., Conclusions: EAT quality (as assessed via CMR T1 times), but not EAT quantity, is independently associated with a composite endpoint of nonfatal myocardial infarction, heart failure hospitalization, and all-cause death., (© 2024 The Author(s). Obesity published by Wiley Periodicals LLC on behalf of The Obesity Society.)

Determining the location of myocardial infarction is crucial for clinical management and therapeutic stratagem. However, existing diagnostic tools either sacrifice ease of use or are limited by their spatial resolution. Addressing this, we aim to refine myocardial infarction localization via surface potential reconstruction of the ventricles in 12-lead electrocardiograms (ECG). A notable obstacle is the ill-posed nature of such reconstructions. To overcome this, we introduce the frequency-enhanced geometric-constrained iterative network (FGIN). FGIN begins by mining the latent features from ECG data across both time and frequency domains. Subsequently, it increases the data dimensionality of ECG and captures intricate features using convolutional layers. Finally, FGIN incorporates ventricular geometry as a constraint on surface potential distribution. It allocates variable weights to distinct edges. Experimental validation of FGIN confirms its efficacy over synthetic and clinical datasets. On the synthetic dataset, FGIN outperforms seven existing reconstruction methods, attaining the highest Pearson Correlation Coefficient of 0.8624, the lowest Root Mean Square Error of 0.1548, and the highest Structural Similarity Index Measure of 0.7988. On the clinical public dataset (2007 PhysioNet/Computers in Cardiology Challenge), FGIN achieves better localization results than other approaches, according to the clinical standard 17-segment model, achieving an average Segment Overlap of 87.2%. Clinical trials on 50 patients demonstrate FGIN's effectiveness, showing an average accuracy of 91.6% and an average Segment Overlap of 88.2%.

Coronary artery disease continues to be the leading cause of death globally. Identifying patients who are at risk of coronary artery disease remains a public health priority. At present, the focus of cardiovascular disease prevention relies heavily on probabilistic risk scoring despite no randomized controlled trials demonstrating their efficacy. The concept of using imaging to guide preventative therapy is not new, but has previously focused on indirect measures such as carotid intima-media thickening or coronary artery calcification. In recent trials, patients found to have coronary artery disease on computed tomography (CT) coronary angiography were more likely to be started on preventative therapy and had lower rates of cardiac events. This led to the design of the SCOT-HEART 2 (Scottish Computed Tomography of the Heart 2) trial, which aims to determine whether screening with the use of CT coronary angiography is more clinically effective than cardiovascular risk scoring to guide the use of primary preventative therapies and reduce the risk of myocardial infarction., Competing Interests: Funding Support and Author Disclosures Dr McDermott is supported by a British Heart Foundation Clinical Research Training Fellowship (FS/CRTF/23/24491). Drs Mills and Newby are supported by a Chair Award, Programme Grant, and Research Excellence Award (CH/F/21/90010, CH/09/002/26360, RG/20/10/34966, RG/F/22/110093, RE/24/130012) from the British Heart Foundation. The SCOT-HEART 2 trial is funded by the British Heart Foundation (CS/18/4/34074). Dr Williams is supported by the British Heart Foundation (FS/ICRF/20/26002); and has given talks for Canon Medical Systems, Siemens Healthineers, and Novartis. Dr Mills has received research grants, honoraria, or consultancy fees from Abbott Diagnostics, Roche Diagnostics, Siemens Healthineers, LumiraDx, and Pyros Laboratories. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Ventricular tachycardia (VT), which can lead to sudden cardiac death, occurs frequently in patients after myocardial infarction. Radiofrequency catheter ablation (RFA) is a modestly effective treatment of VT, but it has limitations and risks. Cardiac magnetic resonance (CMR)-based heart digital twins have emerged as a useful tool for identifying VT circuits for RFA treatment planning. However, the CMR resolution used to reconstruct these digital twins may impact VT circuit predictions, leading to incorrect RFA treatment planning., Objectives: This study sought to predict RFA targets in the arrhythmogenic substrate using heart digital twins reconstructed from both clinical and high-resolution 2-dimensional CMR datasets and compare the predictions., Methods: High-resolution (1.35 × 1.35 × 3 mm), or oversampled resolution (Ov-Res), short-axis late gadolinium-enhanced CMR was acquired by combining 2 subsequent clinical resolution (Clin-Res) (1.35 × 1.35 × 6 mm) short-axis late gadolinium-enhanced CMR scans from 6 post-myocardial infarction patients undergoing VT ablation and used to reconstruct a total of 3 digital twins (1 Ov-Res, 2 Clin-Res) for each patient. Rapid pacing was used to assess VT circuits and identify the optimal ablation targets in each digital twin. VT circuits predicted by the digital twins were compared with intraprocedural electroanatomic mapping data and used to identify emergent VT., Results: The Ov-Res digital twins reduced partial volume effects and better predicted unique VT circuits compared with the Clin-Res digital twins (66.6% vs 54.5%; P < 0.01). Only the Ov-Res digital twin successfully identified emergent VT after a failed initial ablation., Conclusions: Digital twin infarct geometry and VT circuit predictions depend on the magnetic resonance resolution. Ov-Res digital twins better predict VT circuits and emergent VT, which may improve RFA outcomes., Competing Interests: Funding Support and Author Disclosures The authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2024 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Purpose: The aim of this study was to investigate the contrast mechanisms of Contrast-enhanced steady-state free-precession (CE-SSFP) through the utilization of Bloch simulations in an experimental porcine model and in patients with acute myocardial infarction., Methods: Six pigs and ten patients with myocardial infarction underwent CMR and tissue characterization at 1.5 T whereas a Bloch simulation framework was utilized to simulate the CE-SSFP signal formation and compare it against the actual CE-SSFP signal acquired from the experimental porcine model and the patient population. The relaxation times of remote, salvaged, and infarcted myocardium were calculated after the injection of gadolinium, at the time of CE-SSFP acquisition. Simulations were performed using the same CE-SSFP pulse sequence as used on the scanner on a set of spins with the calculated relaxation times from the CMR scans., Results: The normalized signal intensities of salvaged and infarcted myocardium obtained with simulations were lower than the corresponding normalized signal intensities obtained in vivo in pigs (p < 0.05, 134% vs 153%) and in patients (p < 0.05, 126% vs 145%). The results from simulations showed a linear relationship to the results obtained in the experimental porcine model (r 2  = 0.61) and in patients (r 2  = 0.69)., Conclusion: The T1 and T2 values of remote, salvaged, and infarcted myocardium only partly explain the signal intensities in CE-SSFP images. Bloch simulations suggest that there may be more elements that contribute to the CE-SSFP contrast. Integration of other aspects of the MR experiment into the simulation model could further help to fully unravel the mechanisms of CE-SSFP., Competing Interests: Declaration of competing interest Christos G. Xanthis and Anthony H. Aletras are founders of Corsmed AB., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Cholesterol crystals (CCs) are recognized as a risk factor for vulnerable atherosclerotic plaque rupture (PR) and major adverse cardiovascular events. However, their predictive factors and association with plaque vulnerability in patients with acute myocardial infarction (AMI) remain insufficiently explored. Therefore, This study aims to investigate the association between CCs and plaque vulnerability in culprit lesions of AMI patients, identify the factors influencing CCs formation, and develop a predictive model for CCs., Methods: A total of 431 culprit lesions from AMI patients who underwent pre-intervention optical coherence tomography (OCT) imaging were analyzed. Patients were divided into groups based on the presence or absence of CCs and PR. The relationship between CCs and plaque vulnerability was evaluated. A risk nomogram for predicting CCs was developed using the least absolute shrinkage and selection operator and logistic regression analysis., Results: CCs were identified in 64.5 % of patients with AMI. The presence of CCs was associated with a higher prevalence of vulnerable plaque features, such as thin-cap fibroatheroma (TCFA), PR, macrophage infiltration, neovascularization, calcification, and thrombus, compared to patients without CCs. The CCs model demonstrated an area under the curve (AUC) of 0.676 for predicting PR. Incorporating CCs into the TCFA model (AUC = 0.656) significantly enhanced predictive accuracy, with a net reclassification improvement index of 0.462 (95 % confidence interval [CI]: 0.263-0.661, p < 0.001) and an integrated discrimination improvement index of 0.031 (95 % CI: 0.013-0.048, p = 0.001). Multivariate regression analysis identified the atherogenic index of plasma (odds ratio [OR] = 2.417), TCFA (OR = 1.759), macrophage infiltration (OR = 3.863), neovascularization (OR = 2.697), calcification (OR = 1.860), and thrombus (OR = 2.430) as independent risk factors for CCs formation. The comprehensive model incorporating these factors exhibited reasonable discriminatory ability, with an AUC of 0.766 (95 % CI: 0.717-0.815) in the training set and 0.753 (95 % CI: 0.704-0.802) in the internal validation set, reflecting good calibration. Decision curve analysis suggested that the model has potential clinical utility within a threshold probability range of approximately 18 % to 85 %., Conclusions: CCs were associated with plaque vulnerability in the culprit lesions of AMI patients. Additionally, this study identified key factors influencing CCs formation and developed a predictive model with potential clinical applicability., Competing Interests: Declaration of competing interest None., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Background: Little is known about the underlying factors contributing to unfavourable clinical outcomes in patients with diabetes mellitus (DM) complicated by new-onset acute myocardial infarction (AMI). The aim of this study was to investigate the impact of DM on the pathophysiologic features and prognosis of patients with new-onset AMI following successful revascularization by utilizing cardiac magnetic resonance (CMR)., Methods: Consecutive patients diagnosed with new-onset AMI between June 2022 and January 2024 were included. All patients underwent culprit vessel revascularization upon admission and CMR imaging 3-7 days later. The primary clinical endpoint of this study was the occurrence of major adverse cardiac and cerebrovascular events (MACCEs), for which the average follow-up was 10 months., Results: A total of 72 patients were divided into a DM group ( n  = 23) and a non-DM group ( n  = 49). Multivariate logistic regression analysis revealed that DM was an independent risk factor for the occurrence of microvascular obstruction. Multivariate linear regression analysis found that DM was the influencing factor of global radial strain (B = -4.107, t = -2.328, p  = 0.023), while fasting blood glucose influenced infarct segment myocardial radial strain (B = -0.622, t = -2.032, p  = 0.046). DM independently contributed to the risk of MACCEs following successful revascularization in patients with AMI ( p  < 0.05)., Conclusion: Comprehensive phenotypic characterization of myocardial injury and microcirculatory status could enable reliable identification of high-risk MACCEs in DM patients with new-onset AMI following successful revascularization.

Competing Interests: Conflict of interest: None declared.

Late gadolinium enhancement (LGE) is a widely used magnetic resonance imaging method for assessing cardiac disease. However, the relationship between different LGE signal thresholds and microscopic tissue staining images is unclear. In this study, we performed cardiovascular MRI on myocardial infarction (MI) model rats and evaluated the relationship between LGE with different signal thresholding methods and tissue staining images. We prepared 16 rats that underwent MRI 14-18 days following a surgery to create an MI model. We captured cine and LGE images of the cardiac short-axis and longitudinal two- and four-chamber views. The mean ± 2SD, ± 3SD, and ± 5SD of the pixel values in the non-infarcted area were defined as the LGE area. We compared areas of Sirius red staining, determined by the color tone, with their respective LGE areas at end-diastole and end-systole. We observed that the LGE area calculated as the mean ± 2SD of the non-infarcted area at end-diastole demonstrated a significant positive correlation with the area of Sirius red staining (Pearson's correlation coefficient in both: 0.81 [p < 0.01]). Therefore, the LGE area calculated as the mean ± 2SD of the non-infarcted area at end-diastole best reflected the MI area in tissue staining., (© 2024. The Author(s).)

This study focuses on identifying anatomical markers with predictive capacity for long-term myocardial infarction (MI) in focal coronary artery disease (CAD). Eighty future culprit lesions (FCL) and 108 non-culprit lesions (NCL) from 80 patients underwent 3D quantitative coronary angiography. The minimum lumen area (MLA), minimum lumen ratio (MLR), and vessel fractional flow reserve (vFFR) were evaluated. MLR was defined as the ratio between MLA and the cross-sectional area at the proximal lesion edge, with lower values indicating more abrupt luminal narrowing. Significant differences were observed between FCL and NCL in MLR (0.41 vs. 0.53, p < 0.001). MLR correlated inversely with translesional vFFR (r =  - 0.26, p = 0.0004) and was the strongest predictor of MI at 5 years (AUC = 0.75). Lesions with MLR < 0.40 had a fourfold increased MI incidence at 5 years. MLR is a robust predictor of future adverse coronary events., (© 2024. The Author(s).)

Purpose To investigate whether infarct-to-remote myocardial contrast can be optimized by replacing generic fitting algorithms used to obtain native T1 maps with a data-driven machine learning pixel-wise approach in chronic reperfused infarct in a canine model. Materials and Methods A controlled large animal model (24 canines, equal male and female animals) of chronic myocardial infarction with histologic evidence of heterogeneous infarct tissue composition was studied. Unsupervised clustering techniques using self-organizing maps and t -distributed stochastic neighbor embedding were used to analyze and visualize native T1-weighted pixel-intensity patterns. Deep neural network models were trained to map pixel-intensity patterns from native T1-weighted image series to corresponding pixels on late gadolinium enhancement (LGE) images, yielding visually enhanced noncontrast maps, a process referred to as data-driven native mapping (DNM). Pearson correlation coefficients and Bland-Altman analyses were used to compare findings from the DNM approach against standard T1 maps. Results Native T1-weighted images exhibited distinct pixel-intensity patterns between infarcted and remote territories. Granular pattern visualization revealed higher infarct-to-remote cluster separability with LGE labeling as compared with native T1 maps. Apparent contrast-to-noise ratio from DNM (mean, 15.01 ± 2.88 [SD]) was significantly different from native T1 maps (5.64 ± 1.58; P < .001) but similar to LGE contrast-to-noise ratio (15.51 ± 2.43; P = .40). Infarcted areas based on LGE were more strongly correlated with DNM compared with native T1 maps ( R 2 = 0.71 for native T1 maps vs LGE; R 2 Chronic Myocardial Infarction, Cardiac MRI, Data-Driven Native Contrast Mapping P < .001). Conclusion Native T1-weighted pixels carry information that can be extracted with the proposed DNM approach to maximize image contrast between infarct and remote territories for enhanced visualization of chronic infarct territories. Keywords: Chronic Myocardial Infarction, Cardiac MRI, Data-Driven Native Contrast Mapping Supplemental material is available for this article. © RSNA, 2024.

Background: The structural and functional characteristics of the heart in patients with diabetes mellitus (DM) and without myocardial infarction (MI) are not fully understood., Methods: We retrospectively analysed the data of patients with left ventricular ejection fraction (LVEF) ≥ 40% who underwent contrast-enhanced cardiac magnetic resonance imaging (CMR), which was also used to exclude MI, at two hospitals. Volumetric data and extracellular volume fraction (ECVf) of the myocardium evaluated using CMR were compared between patients with and without DM, and their association with diastolic function was evaluated., Results: Among 322 analysed patients, 53 had DM. CMR revealed that the left ventricular mass index (LVMi) and ECVf were increased while LVEF was decreased in patients with DM after adjusting for patient characteristics (all P < 0.05). A stronger positive correlation was observed between LVMi and the early diastolic transmitral flow velocity to early diastolic mitral annular velocity ratio (E/e') in patients with DM than in those without DM (correlation coefficient [R] = 0.46, p = 0.001; R = 0.15, p = 0.021, respectively; p for interaction = 0.011). ECVf correlated with E/e' only in patients with DM (R = 0.61, p = 0.004)., Conclusions: Patients with DM have increased LVMi and ECVf. Importantly, there was a difference between patients with and without DM in the relationship between these structural changes and E/e', with a stronger relationship in patients with DM. Furthermore, DM is associated with mildly reduced LVEF even in the absence of MI., Competing Interests: Declaration of competing interest M.K. received research grants from KOWA company, Ltd. and FUJIREBIO Inc. Y.A. received scholarship grants from Abbott Medical Japan and Terumo. T.F. received a research grant from General Electric. Y.S. received an honorarium from Astra-Zeneca, Nippon Boehringer-Ingelheim Co., Ltd., Daiichi-Sankyo Company, and Novartis., (Copyright © 2024. Published by Elsevier B.V.)

Background: Despite improved treatments for acute myocardial infarction (AMI), myocardial fibrosis remains a key driver of adverse left ventricular (LV) remodeling and increased mortality. Fibroblast activation and proliferation significantly contribute to this process by enhancing cardiac fibrosis, which can lead to detrimental changes in LV structure. This study evaluates the effectiveness of 99m Tc-labeled fibroblast activation protein inhibitor ( 99m Tc-HFAPi) SPECT imaging in predicting LV remodeling over 12 months in post-AMI patients., Methods: A cohort of 58 AMI patients (46 males, median age 61 [53, 67] years) underwent baseline 99m Tc-HFAPi imaging (5 ± 2 days post-MI), perfusion imaging (6 ± 2 days post-MI), and echocardiography (2 ± 2 days post-MI). Additionally, 15 patients had follow-up 99m Tc-HFAPi and perfusion imaging, while 30 patients had follow-up echocardiography. Myocardial 99m Tc-HFAPi activity was assessed at the patient level. LV remodeling was defined as a ≥10% increase in LV end-diastolic diameter (LVEDD) or LV end-systolic diameter (LVESD) from baseline to follow-up echocardiography., Results: AMI patients displayed localized but non-uniform 99m Tc-HFAPi uptake, exceeding perfusion defects. Baseline 99m Tc-HFAPi activity exhibited significant correlations with BNPmax, LDHmax, cTNImax, and WBCmax, inversely correlating with LVEF. After 12 months, 11 patients (36.66%) experienced LV remodeling. Univariate regression analysis demonstrated an association between baseline 99m Tc-HFAPi uptake extent and LV remodeling (OR = 2.14, 95%CI, 1.04, 4.39, P = 0.038)., Conclusions: 99m Tc-HFAPi SPECT imaging holds promise in predicting LV remodeling post-MI, providing valuable insights for patient management and prognosis., (Copyright © 2024 American Society of Nuclear Cardiology. Published by Elsevier Inc. All rights reserved.)

Myocardial infarction (MI) is a life-threatening medical emergency resulting in coronary microvascular dysregulation and heart muscle damage. One of the primary characteristics of MI is capillary loss, which plays a significant role in the progression of this cardiovascular condition. In this study, we utilized optical coherence tomography angiography (OCTA) to image coronary microcirculation in fixed rat hearts, aiming to analyze coronary microvascular impairment post-infarction. Various angiographic metrics are presented to quantify vascular features, including the vessel area density, vessel complexity index, vessel tortuosity index, and flow impairment. Pathological differences identified from OCTA analysis are corroborated with histological analysis. The quantitative assessments reveal a significant decrease in microvascular density in the capillary-sized vessels and an enlargement for the arteriole/venule-sized vessels. Further, microvascular tortuosity and complexity exhibit an increase after myocardial infarction. The results underscore the feasibility of using OCTA to offer qualitative microvascular details and quantitative metrics, providing insights into coronary vascular network remodeling during disease progression and response to therapy.

Background: Previous studies have initially reported accompanying elevated 2-deoxy-2[ 18 F]fluoro-D-glucose ([ 18 F]F-FDG) inflammatory activity in the remote area and its prognostic value after acute myocardial infarction (AMI). Non-invasive characterization of the accompanying inflammation in the remote myocardium may be of potency in guiding future targeted theranostics. [ 68 Ga]Ga-Pentixafor targeting chemokine receptor 4 (CXCR4) on the surface of inflammatory cells is currently one of the promising inflammatory imaging agents. In this study, we sought to focus on the longitudinal evolution of [ 68 Ga]Ga-Pentixafor activities in the remote myocardium following AMI and its association with cardiac function., Methods: Twelve AMI rats and six Sham rats serially underwent [ 68 Ga]Ga-Pentixafor imaging at pre-operation, and 5, 7, 14 days post-operation. Maximum and mean standard uptake value (SUV) and target-to-background ratio (TBR) were assessed to indicate the uptake intensity. Gated [ 18 F]F-FDG imaging and immunofluorescent staining were performed to obtain cardiac function and responses of pro-inflammatory and reparative macrophages, respectively., Results: The uptake of [ 68 Ga]Ga-Pentixafor in the infarcted myocardium peaked at day 5 (all P = 0.003), retained at day 7 (all P = 0.011), and recovered at day 14 after AMI (P > 0.05), paralleling with the rise-fall pro-inflammatory M1 macrophages (P < 0.05). Correlated with the peak activity in the infarct territory, [ 68 Ga]Ga-Pentixafor uptake in the remote myocardium on day 5 early after AMI significantly increased (AMI vs. Sham: SUVmean, SUVmax, and TBRmean: all P < 0.05), and strongly correlated with contemporaneous EDV and/or ESV (SUVmean and TBRmean: both P < 0.05). The transitory remote activity recovered as of day 7 post-AMI (AMI vs. Sham: P > 0.05)., Conclusions: Corresponding with the peaked [ 68 Ga]Ga-Pentixafor activity in the infarcted myocardium, the activity in the remote region elevated accordingly and led to contemporaneous left ventricular remodelling early after AMI. Further studies are warranted to clarify its clinical application potential., (© 2024. The Author(s), under exclusive licence to World Molecular Imaging Society.)

Background: Early invasive revascularization guided by moderate to severe ischemia did not improve outcomes over medical therapy alone, underlying the need to identify high-risk patients for a more effective invasive referral. CMR could determine the myocardial extent and matching locations of ischemia and infarction., Objectives: This study sought to investigate if CMR peri-infarct ischemia is associated with adverse events incremental to known risk markers., Methods: Consecutive patients were included in an expanded cohort of the multicenter SPINS (Stress CMR Perfusion Imaging in the United States) study. Peri-infarct ischemia was defined by the presence of any ischemic segment neighboring an infarcted segment by late gadolinium enhancement imaging. Primary outcome events included acute myocardial infarction and cardiovascular death, whereas secondary events included any primary events, hospitalization for unstable angina, heart failure hospitalization, and late coronary artery bypass surgery., Results: Among 3,915 patients (age: 61.0 ± 12.9 years; 54.7% male), ischemia, infarct, and peri-infarct ischemia were present in 752 (19.2%), 1,123 (28.8%), and 382 (9.8%) patients, respectively. At 5.3 years (Q1-Q3: 3.9-7.2 years) of median follow-up, primary and secondary events occurred in 406 (10.4%) and 745 (19.0%) patients, respectively. Peri-infarct ischemia was the strongest multivariable predictor for primary and secondary events (HR adjusted : 1.72 [95% CI: 1.23-2.41] and 1.71 [95% CI: 1.32-2.20], respectively; both P < 0.001), adjusted for clinical risk factors, left ventricular function, ischemia extent, and infarct size. The presence of peri-infarct ischemia portended to a >6-fold increased annualized primary event rate compared to those with no infarct and ischemia (6.5% vs 0.9%)., Conclusions: Peri-infarct ischemia is a novel and robust prognostic marker of adverse cardiovascular events., Competing Interests: Funding Support and Author Disclosures SPINS was funded in part by the Society for Cardiovascular Magnetic Resonance. The Society for Cardiovascular Magnetic Resonance was supported by a joint research grant from Bayer AG and Siemens Medical Systems. The authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2024 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Objective: In this study, we explored the determinants of ventricular aneurysm development following acute myocardial infarction (AMI), thereby prompting timely interventions to enhance patient prognosis., Methods: In this retrospective cohort analysis, we evaluated 297 AMI patients admitted to the First People's Hospital of Changzhou. The study was structured as follows. Comprehensive baseline data collection included hematological evaluations, ECG, echocardiography, and coronary angiography upon admission. Within 3 months post-AMI, cardiac ultrasounds were administered to detect ventricular aneurysm development. Univariate and multivariate logistic regression analysis were employed to pinpoint the determinants of ventricular aneurysm formation. Subsequently, a predictive model was formulated for ventricular aneurysm post-AMI. Moreover, the diagnostic efficacy of this model was appraised using the ROC curves., Results: In our analysis of 291 AMI patients, spanning an age range of 32-91 years, 247 were male (84.9%). At the conclusion of a 3-month observational period, the cohort bifurcated into two subsets: 278 patients without ventricular aneurysm and 13 with evident ventricular aneurysm. Distinguishing features of the ventricular aneurysm subgroup were markedly higher values for age, B-type natriuretic peptide(BNP), Left atrium(LA), Left ventricular end-diastolic dimension (LEVDD), left ventricular end systolic diameter (LVEWD), E-wave velocity (E), Left atrial volume (LAV), E/A ratio (E/A), E/e ratio (E/e), ECG with elevated adjacent four leads(4 ST-Elevation), and anterior wall myocardial infarction(AWMI) compared to their counterparts (p < 0.05). Among the singular predictive factors, total cholesterol (TC) emerged as the most significant predictor for ventricular aneurysm development, exhibiting an AUC of 0.704. However, upon crafting a multifactorial model that incorporated gender, TC, an elevated ST-segment in adjacent four leads, and anterior wall infarction, its diagnostic capability: notably surpassed that of the standalone TC, yielding an AUC of 0.883 (z = -9.405, p = 0.000) as opposed to 0.704. Multivariate predictive model included gender, total cholesterol, ST elevation in 4 adjacent leads, anterior myocardial infarction, the multivariate predictive model showed better diagnostic efficacy than single factor index TC (AUC: 0. 883 vs. 0.704,z =-9.405, p = 0.000), it also improved predictive power for correctly reclassifying ventricular aneurysm occurrence in patients with AMI, NRI = 28.42% (95% CI: 6.29-50.55%; p = 0.012). Decision curve analysis showed that the use of combination model had a positive net benefit., Conclusion: Lipid combined with ECG model after myocardial infarction could be used to predict the formation of ventricular aneurysm and aimed to optimize and adjust treatment strategies., (© 2024. The Author(s).)

The EMMY trial was a multicentre, investigator-initiated, placebo-controlled, double-blind trial, which enrolled 476 patients immediately following AMI and the first study demonstrating a significant reduction in NT-proBNP-levels as well as significant improvements in cardiac structure and function in patients after acute myocardial infarction treated with empagliflozin vs. placebo. However, hardly any data are available investigating the prognostic role of baseline electrocardiogram metrics in SGLT2-inhibitor-treated patients. This post-hoc analysis investigated the association of baseline ECG metrics collected in one centre of the trial (181 patients) with changes in structural and functional cardiac parameters as well as cardiac biomarkers in response to Empagliflozin treatment. A total of 181 patients (146 men; mean age 58 ± 14 years) were included. Median PQ-interval was 156 (IQR 144-174) milliseconds (ms), QRS width 92 (84-98) ms, QTc interval 453 (428-478) ms, Q-wave duration 45 (40-60) ms, Q-wave amplitude 0.40 (0.30-0.70) millivolt (mV), and heart rate was 71 (64-85) bpm. For functional cardiac parameters (LVEF and E/e') of the entire cohort, a greater decrease of E/e' from baseline to week 26 was observed in shorter QRS width (P = 0.005).Structural cardiac endpoints were only found to have a significant positive correlation between LVEDD and Q wave duration (P = 0.037). Higher heart rate was significantly correlated with better response in LVEF (P = 0.001), E/e' (P = 0.021), and NT-proBNP (P = 0.005). Empagliflozin-treatment showed no interaction with the results. Baseline ECG characteristics post AMI are neither predictive for beneficial NTproBNP effects of Empagliflozin post AMI, nor for functional or structural changes within 26 weeks post AMI., (© 2024. The Author(s).)

Two-dimensional ultrasound (2DUS) echocardiography is the main noninvasive method used to evaluate cardiac function in animal models of myocardial infarction (MI). However, 2DUS echocardiography does not capture regional differences in cardiac contractility since it relies on planar images to estimate left ventricular (LV) geometry and global function. Thus, the current study was designed to evaluate the efficacy of a newly developed 4-dimensional ultrasound (4DUS) method in detecting cardiac functional differences between two models of MI, permanent ligation (PL), and ischemia/reperfusion (I/R) in rats. We found that only 4DUS was able to detect LV global functional differences between the two models and that 4DUS-derived surface area strain accurately detected infarcted regions within the myocardium that correlated well with histological infarct size analysis. We also found that 4DUS-derived strain, which includes circumferential, longitudinal, and surface area strain, correlated with the peak positive of the first derivative of left ventricular pressure (+dP/dt max ). In conclusion, 4DUS strain echocardiography effectively assesses myocardial mechanics following experimentally induced ischemia in rats and accurately estimates infarct size as early as 1 day after injury. 4DUS also correlates well with +dP/dt max , a widely used marker of cardiac contractility., (© 2024 The Author(s). Physiological Reports published by Wiley Periodicals LLC on behalf of The Physiological Society and the American Physiological Society.)

Introduction and Objectives: Myocardial infarction with non-obstructive coronary arteries (MINOCA) is responsible for about 10% of all acute myocardial infarctions (AMI). Therapeutic strategies and prognosis depend on the underlying etiology, and a multimodal approach is essential. The objectives of this study were to characterize the group of patients diagnosed with MINOCA and to valuate the diagnostic yield of cardiovascular magnetic resonance (CMR)., Methods: This was a retrospective, observational, and analytical study, including 516 patients admitted for a non-ST-elevation MI and with no significant coronary disease on coronary angiography between January 2016 and September 2021., Results: After the inclusion criteria, 163 patients remained of the 516 admitted to the study. They were divided into four groups based on the CMR results: MINOCA (n=51), Takotsubo syndrome (n=37), myocarditis (n=33), and without diagnosis (n=42). Most patients diagnosed with MINOCA were female with a mean age of 61.06±13.83 years. CMR identified the diagnosis in 74.2% of patients admitted for suspected acute MI, in which coronary angiography showed the absence of significant obstructions. The median time between hospital admission and CMR was significantly shorter in the groups that had a diagnosis compared with the group with no diagnosis (p=0.038), with a significant increase in diagnostic profitability if CMR was performed up to 14 days after admission (p=0.022). There were no deaths of cardiovascular etiology during the follow-up period., Conclusions: CMR was fundamental as it identified the diagnosis in three out of four patients; it should be performed in the first 14 days., (Copyright © 2024. Publicado por Elsevier España, S.L.U.)

Cardiac digital twins (CDTs) have the potential to offer individualized evaluation of cardiac function in a non-invasive manner, making them a promising approach for personalized diagnosis and treatment planning of myocardial infarction (MI). The inference of accurate myocardial tissue properties is crucial in creating a reliable CDT of MI. In this work, we investigate the feasibility of inferring myocardial tissue properties from the electrocardiogram (ECG) within a CDT platform. The platform integrates multi-modal data, such as cardiac MRI and ECG, to enhance the accuracy and reliability of the inferred tissue properties. We perform a sensitivity analysis based on computer simulations, systematically exploring the effects of infarct location, size, degree of transmurality, and electrical activity alteration on the simulated QRS complex of ECG, to establish the limits of the approach. We subsequently present a novel deep computational model, comprising a dual-branch variational autoencoder and an inference model, to infer infarct location and distribution from the simulated QRS. The proposed model achieves mean Dice scores of 0.457 ±0.317 and 0.302 ±0.273 for the inference of left ventricle scars and border zone, respectively. The sensitivity analysis enhances our understanding of the complex relationship between infarct characteristics and electrophysiological features. The in silico experimental results show that the model can effectively capture the relationship for the inverse inference, with promising potential for clinical application in the future. The code is available at https://github.com/lileitech/MI&#95;inverse&#95;inference.

Microvascular injury immediately following reperfusion therapy in acute myocardial infarction (MI) has emerged as a driving force behind major adverse cardiovascular events in the postinfarction period. Although postmortem investigations and animal models have aided in developing early understanding of microvascular injury following reperfusion, imaging, particularly serial noninvasive imaging, has played a central role in cultivating critical knowledge of progressive damage to the myocardium from the onset of microvascular injury to months and years after in acute MI patients. This review summarizes the pathophysiological features of microvascular injury and downstream consequences, and the contributions noninvasive imaging has imparted in the development of this understanding. It also highlights the interventional trials that aim to mitigate the adverse consequences of microvascular injury based on imaging, identifies potential future directions of investigations to enable improved detection of disease, and demonstrates how imaging stands to play a major role in the development of novel therapies for improved management of acute MI patients., Competing Interests: Funding Support and Author Disclosures This work was funded in part by National Institutes of Health (HL133407, HL136578, and HL147133) to Dr Dharmakumar. Dr Dharmakumar has an ownership interest in Cardio-Theranostics, LLC. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2024 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Angiogenesis is an essential part of the cardiac repair process after myocardial infarction, but its spatiotemporal dynamics remain to be fully deciphered. 68 Ga-NODAGA-Arg-Gly-Asp (RGD) is a PET tracer targeting α v β 3 integrin expression, which is a marker of angiogenesis. Methods: In this prospective single-center trial, we aimed to monitor angiogenesis through myocardial integrin α v β 3 expression in 20 patients with ST-segment elevation myocardial infarction (STEMI). In addition, the correlations between the expression levels of myocardial α v β 3 integrin and the subsequent changes in 82 Rb PET/CT parameters, including rest and stress myocardial blood flow (MBF), myocardial flow reserve (MFR), and wall motion abnormalities, were assessed. The patients underwent 68 Ga-NODAGA-RGD PET/CT and rest and stress 82 Rb-PET/CT at 1 wk, 1 mo, and 3 mo after STEMI. To assess 68 Ga-NODAGA-RGD uptake, the summed rest 82 Rb and 68 Ga-NODAGA-RGD images were coregistered, and segmental SUVs were calculated (RGD SUV). Results: At 1 wk after STEMI, 19 participants (95%) presented increased 68 Ga-NODAGA-RGD uptake in the infarcted myocardium. Seventeen participants completed the full imaging series. The values of the RGD SUV in the infarcted myocardium were stable 1 mo after STEMI (1 wk vs. 1 mo, 1.47 g/mL [interquartile range (IQR), 1.37-1.64 g/mL] vs. 1.47 g/mL [IQR, 1.30-1.66 g/mL]; P = 0.9), followed by a significant partial decrease at 3 mo (1.32 g/mL [IQR, 1.12-1.71 g/mL]; P = 0.011 vs. 1 wk and 0.018 vs. 1 mo). In segment-based analysis, positive correlations were found between RGD SUV at 1 wk and the subsequent changes in stress MBF (Spearman ρ: r = 0.17, P = 0.0033) and MFR (Spearman ρ: r = 0.31, P < 0.0001) at 1 mo. A negative correlation was found between RGD SUV at 1 wk and the subsequent changes in wall motion abnormalities at 3 mo (Spearman ρ: r = - 0.12, P = 0.035). Conclusion: The present study found that α v β 3 integrin expression is significantly increased in the infarcted myocardium 1 wk after STEMI. This expression remains stable after 1 mo and partially decreases after 3 mo. Initial α v β 3 integrin expression at 1 wk is significantly weakly correlated with subsequent improvements in stress MBF, MFR, and wall motion analysis., (© 2024 by the Society of Nuclear Medicine and Molecular Imaging.)

Aims: Evidence on the association between subclinical atherosclerosis (SA) and cardiovascular (CV) events in low-risk populations is scant. To study the association between SA burden and an ischaemic scar (IS), identified by cardiac magnetic resonance (CMR), as a surrogate of CV endpoint, in a low-risk population., Methods and Results: A cohort of 712 asymptomatic middle-aged individuals from the Progression of Early SA (PESA-CNIC-Santander) study (median age 51 years, 84% male, median SCORE2 3.37) were evaluated on enrolment and at 3-year follow-up with 2D/3D vascular ultrasound (VUS) and coronary artery calcification scoring (CACS). A cardiac magnetic study (CMR) was subsequently performed and IS defined as the presence of subendocardial or transmural late gadolinium enhancement (LGE). On CMR, 132 (19.1%) participants had positive LGE, and IS was identified in 20 (2.9%) participants. Individuals with IS had significantly higher SCORE2 at baseline and higher CACS and peripheral SA burden (number of plaques by 2DVUS and plaque volume by 3DVUS) at both SA evaluations. High CACS and peripheral SA (number of plaques) burden were independently associated with the presence of IS, after adjusting for SCORE2 [OR for 3rd tertile, 8.31; 95% confidence interval (CI) 2.85-24.2; P < 0.001; and 2.77; 95% CI, 1.02-7.51; P = 0.045, respectively] and provided significant incremental diagnostic value over SCORE2., Conclusion: In a low-risk middle-aged population, SA burden (CAC and peripheral plaques) was independently associated with a higher prevalence of IS identified by CMR. These findings reinforce the value of SA evaluation to early implement preventive measures., Clinical Trial Registration: Progression of Early Subclinical Atherosclerosis (PESA) Study Identifier: NCT01410318., Competing Interests: Conflict of interest. J.S.-G. is an employee of Philips Healthcare. All other authors have reported that they have no relationships to disclose relevant to the content of this paper., (© The Author(s) 2024. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Imaging modalities for percutaneous coronary intervention (PCI), such as intravascular ultrasound (IVUS) or optical coherence tomography (OCT), have increased in the current PCI era. However, their clinical benefits in acute myocardial infarction (AMI) have not been fully elucidated. This study investigated the long-term outcomes of image-guided PCI in patients with AMI using data from the Korean Acute Myocardial Infarction Registry. A total of 9,271 patients with AMI, who underwent PCI with second-generation drug-eluting stents between November 2011 and December 2015, were retrospectively examined, and target lesion failure (TLF) at 3 years (defined as the composite of cardiac death, target vessel myocardial infarction, and ischemia-driven target lesion revascularization) was evaluated. From the registry, 2,134 patients (23.0%) underwent image-guided PCI (IVUS-guided: n = 1,919 [20.6%]; OCT-guided: n = 215 patients [2.3%]). Based on propensity score matching, image-guided PCI was associated with a significant reduction in TLF (hazard ratio: 0.76; 95% confidence interval: 0.59-0.98, p = 0.035). In addition, the TLF incidence in the OCT-guided PCI group was comparable to that in the IVUS-guided PCI group (5.3% vs 4.7%, p = 0.903). Image-guided PCI, including IVUS and OCT, is associated with favorable clinical outcomes in patients with AMI at 3 years post-intervention. Additionally, OCT-guided PCI is not inferior to IVUS-guided PCI in patients with AMI., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Kwon et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Purpose: To evaluate the intracavity left ventricular (LV) blood flow kinetic energy (KE) parameters using four-dimensional (4D) flow cardiovascular magnetic resonance (CMR) in patients with acute myocardial infarction (AMI)., Methods: Thirty AMI patients and twenty controls were examined via CMR, which included cine imaging, late gadolinium enhancement (LGE) and global heart 4D flow imaging. The KE parameters were indexed to LV end-diastolic volume (EDV) to obtain average, systolic and diastolic KE as well as the proportion of LV in-plane KE (%). These parameters were compared between the AMI patients and controls and between the two subgroups., Results: Analysis of the LV blood flow KE parameters at different levels of the LV cavity and in different segments of the same level showed that the basal level had the highest blood flow KE while the apical level had the lowest in the control group. There were no significant differences in diastolic KE, systolic in-plane KE and diastolic in-plane KE between the anterior wall and posterior wall (p > 0.05), only the systolic KE had a significant difference between them (p < 0.05). Compared with those in the control group, the average (10.7 ± 3.3 µJ/mL vs. 14.7 ± 3.6 µJ/mL, p < 0.001), systolic (14.6 ± 5.1 µJ/mL vs. 18.9 ± 3.9 µJ/mL, p = 0.003) and diastolic KE (7.9 ± 2.5 µJ/mL vs. 10.6 ± 3.8 µJ/mL, p = 0.018) were significantly lower in the AMI group. The average KE in the infarct segment was lower than that in the noninfarct segment in the AMI group (49.5 ± 18.7 µJ/mL vs. 126.3 ± 50.7 µJ/mL, p < 0.001), while the proportion of systolic in-plane KE increased significantly (61.8%±11.5 vs. 42.9%±14.4, p = 0.001)., Conclusion: The 4D Flow MRI technique can be used to quantitatively evaluate LV regional hemodynamic parameters. There were differences in the KE parameters of LV blood flow at different levels and in different segments of the same level in healthy people. In AMI patients, the average KE of the infarct segment decreased, while the proportion of systolic in-plane KE significantly increased., (© 2024. The Author(s).)