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Background: Current guidelines consider atrial fibrillation (AF) type as the prognostic factor for a recommendation of catheter ablation. We aimed to determine whether LA and LA appendage (LAA) volumes measured using multislice computed tomography (MSCT) were related to long-term outcomes in AF following radiofrequency catheter ablation (RFCA). Methods: We evaluated 152 consecutive patients with drug-refractory AF (median age, 55.8 ± 9.6 years), including 110 male patients, who underwent RFCA in a single center. All patients underwent MSCT imaging for anatomical assessment. The endpoint of this study was documented AF recurrence after RFCA. Results: The overall procedure success rate was 77.6% (n = 118) during a mean follow-up period of 12.6 months. The LA volume was significantly larger for those who experienced AF recurrence after RFCA than for the patients without recurrent AF after the procedure (153.8 ± 29.9 mL vs. 139.2 ± 34.1 mL, p = 0.025). However, LAA volumes were nearly equivalent between the patients with and without AF recurrence after RFCA (16.2 ± 6.3 mL and 14.7 ± 6.5 mL, respectively; p = 0.235). LA volume ≥ 153.2 mL was the optimal cutoff value for estimating AF recurrence after RFCA, with 94% sensitivity and 66% specificity. LA volume remained an independent predictor of both AF recurrence and permanent AF. Conclusions: LA volume as assessed by MSCT might be helpful for identifying patients likely to achieve successful AF ablation. LA volume ≥ 153.2 mL, but not LAA volume, showed good accuracy in predicting AF recurrence after RFCA. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate whether plaque characteristics as assessed by coronary computed tomography angiography (CCTA) were associated with the presence of a thin-cap fibroatheroma (TCFA)-a precursor of plaque rupture-defined by optical coherence tomography (OCT) in a section-to-section-level comparison.Methods: From 28 symptomatic patients, 31 coronary lesions were evaluated on 727 cross-sections co-registered by both CCTA and OCT. CCTA plaque characteristics included low attenuation plaque (LAP, <30 HU), napkin ring sign (NRS), positive remodelling (PR, remodelling index ≥1.10), and spotty calcification and plaque area and plaque burden. By OCT, presence of TCFA, lumen area and arc of lipid were determined.Results: OCT revealed a TCFA in 69 (9.4%) sections from 19 (61.2 %) lesions. In per-section analysis, OCT-TCFA showed higher frequency of CCTA-detected LAP (58.0% vs. 18.5%), NRS (31.9% vs. 8.8%) and PR (68.1% vs. 48.0%) and greater plaque burden (70.6% vs. 61.9%) as compared to sections without OCT-TCFA (all p < 0.05). In multivariable analysis, LAP (odds ratio [OR] 4.05, p < 0.001) and NRS (OR 2.47, p = 0.005) were associated with OCT-TCFA. CCTA-measured lumen area correlated well with OCT-measured lumen area (R = 0.859, limits of agreement -0.5 ± 3.7 mm2).Conclusions: LAP and NRS in CCTA were associated with the presence of OCT-defined TCFA in a section-to-section comparison.Key Points: • CT-defined LAP and NRS were associated with OCT-defined TCFA • OCT-TCFA showed higher frequency of LAP, NRS, PR and greater plaque burden • Non-calcified plaque area was correlated with OCT-measured lipid arc. [ABSTRACT FROM AUTHOR]

Lesion morphology poorly predicts functional significance of intermediate coronary artery stenosis. The aim of this study was to determine whether a coronary artery-based myocardial segmentation method that quantifies subtended myocardium can improve the diagnostic accuracy of intravascular ultrasound (IVUS)-derived parameters for detecting ischemia-producing lesions. Coronary computed tomography angiography, IVUS, and fractional flow reserve (FFR) data were analyzed in 101 non-left main lesions (20% to 80% angiographic stenosis). Using the coronary artery-based myocardial segmentation method, total left ventricular myocardial volume (Vtotal), myocardial volume subtended by the stenotic coronary segment (Vsub), and Vratio (the ratio of the Vsub to the Vtotal) were assessed. Both Vsub >30.7 cm(3) and Vratio >25.4% were determinants of FFR ≤0.75 (area under the curve = 0.696 and 0.744). Overall, an IVUS-measured minimum lumen area (IVUS-MLA) ≤2.83 mm(2) predicted FFR ≤0.75 with a sensitivity 88% and specificity 73%. Among lesions with IVUS-MLA ≤2.83 mm(2) and FFR >0.75, 89% showed Vsub <30.7 cm(3). In 50 lesions with Vsub >30.7 cm(3), an IVUS-MLA ≤2.85 mm(2) predicted FFR ≤0.75 with sensitivity 85%, specificity 92%, positive predictive value 92%, and negative predictive value 85%. Conversely, in 51 lesions with a Vsub ≤30.7 cm(3), IVUS-MLA ≤2.67 mm(2) showed sensitivity 100%, specificity 69%, positive predictive value 38%, and negative predictive value 100% for predicting FFR ≤0.75. Body surface area, reference lumen diameter, and vessel area had modest correlations with Vsub. In those lesion subsets, IVUS-MLA ≈2.8 mm(2) accurately predicted an FFR ≤0.75, whereas the clinical relevance of assessing and treating lesions with a smaller myocardial territory may be limited (ClinicalTrials.gov number NCT1696006). [ABSTRACT FROM AUTHOR]

There are several methods for treating aortic stenosis including transcatheter valve implantation (TAVI) and surgical aortic valve replacement. Among these, TAVI is highly recommended for elderly patients with high surgical risk or a life expectancy of less than 10 yr. However, recent research findings indicate that thrombosis after TAVI leads to the malfunction of TAVI leaflets, which increases the risk of stroke and heart attack. Since the mechanism of thrombus formation is unclear, this study aimed to investigate the sinus hemodynamics after TAVI in different configurations using particle image velocimetry. The results showed that compared with SAV, the TAV resulted in a relatively low velocity at the sinus owing to the native leaflet and skirt of the TAV. The native leaflet length, covering over 75% of TAV, significantly increased the flow stasis and particle residence. In addition, a larger sinus diameter corresponded to a larger stasis area of the same length as that of the native leaflet. According to this study, patients with long native leaflets in their aortic sinus are at a higher risk of developing thrombosis and may require a higher deployment during treatment. [ABSTRACT FROM AUTHOR]

• For repairing segmental arteries in open surgical repair, two types of patient-specific graft reconstruction guides were applied clinically. • Designing the patient-specific guides with a conventional method is labor-intensive, time-consuming, and tedious tasks. • We developed the automatic modeling method and evaluated accuracy and modeling time with conventional modeling method. • The automatic modeling was demonstrated to reduce the modeling time with reasonable accuracy. Because repairing visceral and segmental arteries in open surgical repair for thoracoabdominal aortic aneurysms is essential, two types of patient-specific graft reconstruction guides for reconstruction in the operating room have been developed that are applied clinically. However, designing the patient-specific guides is a time-consuming, laborious task. The aim of this study was to develop an automatic modeling method and to evaluate its accuracy. In 10 patients with thoracoabdominal aortic aneurysms, computer-aided designing was performed with conventional and automatic modeling methods for aortic reconstruction guides as follows: 1) a visualizing guide that presented the accurate shape of the aortic graft, visualizing the main aortic body and major blood vessels; and 2) a marking guide wherein the vessels in the visualizing guide were replaced by the protruding marking regions detectable by tactile sense. The script-based automatic guide modeling program was developed using an application programming interface presented in the 3-matic software with Python. For accuracy, the absolute mean differences of both modeling methods were assessed using Hausdorff distance. The modeling between conventional and automatic modeling methods was compared and evaluated using the Wilcoxon signed-rank test. The absolute mean difference between the conventional and automatic modeling methods were 6.05 ± 4.86 µm for the visualizing guide and 5.51 ± 4.85 µm for the marking guide. For the visualizing guide, the modeling time of the automatic modeling method was reduced by approximately more than thirtyfold than the conventional modeling method (p<0.001). The marking guide was reduced about fortyfold (p<0.001). Compared to the conventional method, the automatic modeling method was demonstrated to reduce the modeling time with reasonable accuracy, which could lead to a more efficient modeling and clinical application. [ABSTRACT FROM AUTHOR]

Background: In Langerhans cell histiocytosis (LCH) evaluation of the extent of disease is one of the major predictors of patient outcome. Historically this is undertaken using plain radiography and bone scintigraphy. Recently, whole-body (WB) MRI has been reported to be useful in detecting skeletal and extraskeletal metastases in both adults and children.Objective: To evaluate the usefulness of WB MRI in patients with LCH in comparison with plain radiography and bone scintigraphy.Materials and Methods: In nine children (1-7 years of age; mean 3.3 years) who had a pathological diagnosis of LCH and had either plain radiography or bone scintigraphy for comparison, 43 WB MR examinations were performed. Skeletal and extraskeletal lesions of the disease on WB MRI were compared with those on plain radiography and bone scintigraphy.Results: LCH showed unifocal single-system involvement in one patient, multifocal single-system involvement in three, and multifocal multisystem disease in five. WB MRI identified additional skeletal lesions in three (38%) of eight patients, compared with plain radiography, and in two (25%) of eight, compared with bone scintigraphy. WB MRI detected extraskeletal lesions of the disease in five (56%) of the nine patients exclusively, except for one patient whose lung lesions were also detected on plain radiography. In two patients, treatment was changed according to WB MRI findings.Conclusion: WB MRI is a useful initial and follow-up diagnostic method to assess the extent of LCH because WB MRI not only identifies more skeletal lesions of the disease than do plain radiography and bone scintigraphy, but also detects extraskeletal lesions of the disease. [ABSTRACT FROM AUTHOR]

Medical therapy for aortic stenosis (AS) remains an elusive goal. This study sought to establish whether evogliptin, a dipeptidyl peptidase-4 inhibitor, could reduce AS progression. A total of 228 patients (age 67 ± 11 years; 33% women) with AS were randomly assigned to receive placebo (n = 75), evogliptin 5 mg (n = 77), or evogliptin 10 mg (n = 76). The primary endpoint was the 96-week change in aortic valve calcium volume (AVCV) on computed tomography. Secondary endpoints included the 48-week change in active calcification volume measured using 18F-sodium fluoride positron emission tomography (18F-NaF PET). There were no significant differences in the 96-week changes in AVCV between evogliptin 5 mg and placebo (−5.27; 95% CI: −55.36 to 44.82; P = 0.84) or evogliptin 10 mg and placebo (−18.83; 95% CI: −32.43 to 70.10; P = 0.47). In the placebo group, the increase in AVCV between 48 weeks and 96 weeks was higher than that between baseline and 48 weeks (136 mm3; 95% CI: 108–163 vs 102 mm3; 95% CI: 75–129; P = 0.0485). This increasing trend in the second half of the study was suppressed in both evogliptin groups. The 48-week change in active calcification volume on 18F-NaF PET was significantly lower in both the evogliptin 5 mg (−1,325.6; 95% CI: −2,285.9 to −365.4; P = 0.008) and 10-mg groups (−1,582.2; 95% CI: −2,610.8 to −553.5; P = 0.0038) compared with the placebo group. This exploratory study did not demonstrate the protective effect of evogliptin on AV calcification. Favorable 18F-NaF PET results and possible suppression of aortic valve calcification with longer medication use in the evogliptin groups suggest the need for larger confirmatory trials. (A Multicenter, Double-blind, Placebo-controlled, Stratified-randomized, Parallel, Therapeutic Exploratory Clinical Study to Evaluate the Efficacy and Safety of DA-1229 in Patients With Calcific Aortic Valve Disease; NCT04055883) [ABSTRACT FROM AUTHOR]

Research on cardiovascular diseases using CT-derived strain is gaining momentum, yet there is a paucity of information regarding reference standard values beyond echocardiography, particularly in cardiac chambers other than the left ventricle (LV). We aimed to compile CT-derived strain values from the four cardiac chambers in healthy adults and assess the impact of age and sex on myocardial strains. This study included 101 (mean age: 55.2 ± 9.0 years, 55.4% men) consecutive healthy individuals who underwent multiphase cardiac CT. CT-derived cardiac strains, including LV global and segmental longitudinal, circumferential, and transverse strains, left atrial (LA), right atrial (RA), and right ventricle (RV) strains were measured by the commercially available software. Strain values were classified and compared by their age and sex. The normal range of CT-derived LV global longitudinal strain (GLS), global circumferential strain (GCS), and global radial strain (GRS) were −20.2 ± 2.7%, −27.9 ± 4.1%, and 49.4 ± 12.1%, respectively. For LA, reservoir strain, pump strain, and conduit strain were 28.6 ± 8.5%, 13.2 ± 6.4%, and 15.5 ± 8.6%, respectively. The GLS of RA and RV were 27.9 ± 10.9% and −22.0 ± 5.7%, respectively. The absolute values of GLS of RA and RV of women were higher than that in men (32.4 ± 11.4 vs. 24.3 ± 9.1 and −25.2 ± 4.7 vs. −19.4 ± 5.0, respectively; p<0.001, both). Measurement of CT-derived strain in four cardiac chambers is feasible. The reference ranges of CT strains in four cardiac chambers can be used for future studies of various cardiac diseases using the cardiac strains. [ABSTRACT FROM AUTHOR]

Four-dimensional flow magnetic resonance imaging (4D flow MRI) offers a powerful tool for visualizing fluid flows, critical for both diagnosing cardiovascular diseases and analyzing engineering fluid dynamics. Despite its potential in medical research, the clinical applicability of 4D flow MRI often faces challenges due to inherent noise. To mitigate this, we introduce the split-and-overlap singular value decomposition (SOSVD) filter, a distinctive noise reduction approach. Unlike traditional singular value decomposition methods, the SOSVD filter partitions the primary data matrix into overlapping subdomains and then applies singular value decomposition to each subdomain, preserving only the dominant mode for noise attenuation. Evaluations on simulated and experimental flow data within a square duct revealed a significant decrease in root mean square noise metrics. Moreover, when applied to in vivo aortic data, the SOSVD filter enhanced various flow determinants, including divergence, velocity gradients, streamlines, and velocity coherence. Thus, the SOSVD method presents a promising avenue for augmenting noise reduction in 4D flow MRI, potentially elevating diagnostic accuracy and enriching cardiovascular disease research. [ABSTRACT FROM AUTHOR]

Objective: Patients who undergo transcatheter aortic valve replacement (TAVR) are at risk for new-onset arrhythmia (NOA) that may require permanent pacemaker (PPM) implantation, resulting in decreased cardiac function. We aimed to investigate the factors that are associated with NOA after TAVR and to compare pre- and post-TAVR cardiac functions between patients with and without NOA using CT-derived strain analyses. Methods: We included consecutive patients who underwent pre- and post-TAVR cardiac CT scans six months after TAVR. New-onset left bundle branch block, atrioventricular block, and atrial fibrillation/flutter lasting over 30 days after the procedure and/or the need for PPM diagnosed within 1 year after TAVR were regarded as NOA. Implant depth and left heart function and strains were analyzed using multi-phase CT images and compared between patients with and without NOA. Results: Of 211 patients (41.7% men; median 81 years), 52 (24.6%) presented with NOA after TAVR, and 24 (11.4%) implanted PPM. Implant depth was significantly deeper in the NOA group than in the non-NOA group (− 6.7 ± 2.4 vs. − 5.6 ± 2.6 mm; p = 0.009). Left ventricular global longitudinal strain (LV GLS) and left atrial (LA) reservoir strain were significantly improved only in the non-NOA group (LV GLS, − 15.5 ± 4.0 to − 17.3 ± 2.9%; p < 0.001; LA reservoir strain, 22.3 ± 8.9 to 26.5 ± 7.6%; p < 0.001). The mean percent change of the LV GLS and LA reservoir strains was evident in the non-NOA group (p = 0.019 and p = 0.035, respectively). Conclusions: A quarter of patients presented with NOA after TAVR. Deep implant depth on post-TAVR CT scans was associated with NOA. Patients with NOA after TAVR had impaired LV reserve remodeling assessed by CT-derived strains. Clinical relevance statement: New-onset arrhythmia (NOA) following transcatheter aortic valve replacement (TAVR) impairs cardiac reverse remodeling. CT-derived strain analysis reveals that patients with NOA do not show improvement in left heart function and strains, highlighting the importance of managing NOA for optimal outcomes. Key Points: • New-onset arrhythmia following transcatheter aortic valve replacement (TAVR) is a concern that interferes with cardiac reverse remodeling. • Comparison of pre-and post-TAVR CT-derived left heart strain provides insight into the impaired cardiac reverse remodeling in patients with new-onset arrhythmia following TAVR. • The expected reverse remodeling was not observed in patients with new-onset arrhythmia following TAVR, given that CT-derived left heart function and strains did not improve. [ABSTRACT FROM AUTHOR]

Purpose: In multiphase coronary CT angiography (CTA), a series of CT images are taken at different levels of radiation dose during the examination. Although this reduces the total radiation dose, the image quality during the low‐dose phases is significantly degraded. Recently, deep neural network approaches based on supervised learning technique have demonstrated impressive performance improvement over conventional model‐based iterative methods for low‐dose CT. However, matched low‐ and routine‐dose CT image pairs are difficult to obtain in multiphase CT. To address this problem, we aim at developing a new deep learning framework. Method: We propose an unsupervised learning technique that can remove the noise of the CT images in the low‐dose phases by learning from the CT images in the routine dose phases. Although a supervised learning approach is not applicable due to the differences in the underlying heart structure in two phases, the images are closely related in two phases, so we propose a cycle‐consistent adversarial denoising network to learn the mapping between the low‐ and high‐dose cardiac phases. Results: Experimental results showed that the proposed method effectively reduces the noise in the low‐dose CT image while preserving detailed texture and edge information. Moreover, thanks to the cyclic consistency and identity loss, the proposed network does not create any artificial features that are not present in the input images. Visual grading and quality evaluation also confirm that the proposed method provides significant improvement in diagnostic quality. Conclusions: The proposed network can learn the image distributions from the routine‐dose cardiac phases, which is a big advantage over the existing supervised learning networks that need exactly matched low‐ and routine‐dose CT images. Considering the effectiveness and practicability of the proposed method, we believe that the proposed can be applied for many other CT acquisition protocols. [ABSTRACT FROM AUTHOR]

Background: Primary cardiac sarcomas are rare and their clinicopathologic features are heterogeneous. Among them, particularly intimal sarcoma is a diagnostic challenge due to nonspecific histologic features. Recently, MDM2 amplification reported to be a characteristic genetic event in the intimal sarcoma. In this study, we aimed to identify the types and incidence of primary cardiac sarcomas that occurred over 25 years in tertiary medical institutions, and to find clinicopatholgical significance through reclassification of diagnoses using additional immunohistochemistry (IHC). Methods: We reviewed the primary cardiac sarcoma cases between January 1993 and June 2018 at Asan Medical Center, South Korea, with their clinicopathologic findings, and reclassified the subtypes, especially using IHC for MDM2 and then, analyzed the significance of prognosis. Results: Forty‐eight (6.8%) cases of a primary cardiac sarcoma were retrieved. The tumors most frequently involved the right atrium (n = 25, 52.1%), and the most frequent tumor subtype was angiosarcoma (n = 23, 47.9%). Seven cases (53.8%) were newly reclassified as an intimal sarcoma by IHC for MDM2. Twenty‐nine (60.4%) patients died of disease (mean, 19.8 months). Four patients underwent a heart transplantation and had a median survival of 26.8 months. This transplantation group tended to show good clinical outcomes in the earlier stages, but this was not statistically significant (p = 0.318). MDM2 positive intimal sarcoma showed the better overall survival (p = 0.003) than undifferentiated pleomorphic sarcoma. Adjuvant treatment is beneficial for patient survival (p < 0.001), particularly in angiosarcoma (p < 0.001), but not in intimal sarcoma (p = 0.154). Conclusion: Our study supports the use of adjuvant treatment in primary cardiac sarcoma, as it was associated with a significantly better overall survival rate. Further consideration of tumor histology may be important in determining the optimal use of adjuvant treatment for different types of sarcomas. Therefore, accurate diagnosis by MDM2 test is important condsidering patient's prognosis and treatment. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate commercial deep learning–based software for fully automated coronary artery calcium (CAC) scoring on non-electrocardiogram (ECG)-gated low-dose CT (LDCT) with different slice thicknesses compared with manual ECG-gated calcium-scoring CT (CSCT). Methods: This retrospective study included 567 patients who underwent both LDCT and CSCT. All LDCT images were reconstructed with a 2.5-mm slice thickness (LDCT2.5-mm), and 453 LDCT scans were reconstructed with a 1.0-mm slice thickness (LDCT1.0-mm). Automated CAC scoring was performed on CSCT (CSCTauto), LDCT1.0-mm, and LDCT2.5-mm images. The reliability of CSCTauto, LDCT1.0-mm, and LDCT2.5-mm was compared with manual CSCT scoring (CSCTmanual) using intraclass correlation coefficients (ICCs) and Bland-Altman analysis. Agreement, in CAC severity category, was analyzed using weighted kappa statistics. Diagnostic performance at various Agatston score cutoffs was also calculated. Results: CSCTauto, LDCT1.0-mm, and LDCT2.5-mm demonstrated excellent agreement with CSCTmanual (ICC [95% confidence interval, CI]: 1.000 [1.000, 1.000], 0.937 [0.917, 0.952], and 0.955 [0.946, 0.963], respectively). The mean difference with 95% limits of agreement was lower with LDCT1.0-mm than with LDCT2.5-mm (19.94 [95% CI, −244.0, 283.9] vs. 45.26 [−248.2, 338.7]). Regarding CAC severity, LDCT1.0-mm achieved almost perfect agreement, and LDCT2.5-mm achieved substantial agreement (kappa [95% CI]: 0.809 [0.776, 0.838], 0.776 [0.740, 0.809], respectively). Diagnostic performance for detecting Agatston score ≥ 400 was also higher with LDCT1.0-mm than with LDCT2.5-mm (F1 score, 0.929 vs. 0.855). Conclusions: Fully automated CAC-scoring software with both CSCT and LDCT yielded excellent reliability and agreement with CSCTmanual. LDCT1.0-mm yielded more accurate Agatston scoring than LDCT2.5-mm using fully automated commercial software. Key Points: • Total Agatston scores and all vessels of CSCTauto, LDCT1.0-mm, and LDCT2.5-mmdemonstrated excellent agreement with CSCTmanual(all ICC > 0.85). • The diagnostic performance for detecting all Agatston score cutoffs was better with LDCT1.0-mmthan with LDCT2.5-mm. • This automated software yielded a lower degree of underestimation compared with methods described in previous studies, and the degree of underestimation was lower with LDCT1.0-mmthan with LDCT2.5-mm. [ABSTRACT FROM AUTHOR]

Objectives: To validate an artificial intelligence (AI)–based fully automatic coronary artery calcium (CAC) scoring system on non-electrocardiogram (ECG)–gated low-dose chest computed tomography (LDCT) using multi-institutional datasets with manual CAC scoring as the reference standard. Methods: This retrospective study included 452 subjects from three academic institutions, who underwent both ECG-gated calcium scoring computed tomography (CSCT) and LDCT scans. For all CSCT and LDCT scans, automatic CAC scoring (CAC_auto) was performed using AI-based software, and manual CAC scoring (CAC_man) was set as the reference standard. The reliability and agreement of CAC_auto was evaluated and compared with that of CAC_man using intraclass correlation coefficients (ICCs) and Bland-Altman plots. The reliability between CAC_auto and CAC_man for CAC severity categories was analyzed using weighted kappa (κ) statistics. Results: CAC_auto on CSCT and LDCT yielded a high ICC (0.998, 95% confidence interval (CI) 0.998–0.999 and 0.989, 95% CI 0.987–0.991, respectively) and a mean difference with 95% limits of agreement of 1.3 ± 37.1 and 0.8 ± 75.7, respectively. CAC_auto achieved excellent reliability for CAC severity (κ = 0.918–0.972) on CSCT and good to excellent but heterogenous reliability among datasets (κ = 0.748–0.924) on LDCT. Conclusions: The application of an AI-based automatic CAC scoring software to LDCT shows good to excellent reliability in CAC score and CAC severity categorization in multi-institutional datasets; however, the reliability varies among institutions. Key Points: • AI-based automatic CAC scoring on LDCT shows excellent reliability with manual CAC scoring in multi-institutional datasets. • The reliability for CAC score–based severity categorization varies among datasets. • Automatic scoring for LDCT shows a higher false-positive rate than automatic scoring for CSCT, and most common causes of a false-positive are image noise and artifacts for both CSCT and LDCT. [ABSTRACT FROM AUTHOR]

Background: A certain proportion of patients with severe aortic stenosis (AS) present with discordant grading between different diagnostic modalities, which raises uncertainty about the true severity of AS. The aim of this study was to compare the aortic valve area (AVA) measured on CT and echocardiography and demonstrate the factors affecting AVA discrepancies. Methods: Between June 2011 and March 2016, 535 consecutive patients (66.83±8.80 years, 297 men) with AS who underwent pre-operative cardiac CT and echocardiography for aortic valve replacement were retrospectively included. AVA was obtained by AVA on echocardiography (AVAecho) and CT (AVACT) using a measurement of the left ventricular outflow tract on each modality and correlations between those measures were evaluated. Logistic regression analysis was performed to identify factors affecting the discordance for grading severe AS. Results: The AVACT and AVAecho showed a high correlation (r: 0.79, P <0.001) but AVACT was larger than the AVAecho (difference 0.26 cm2, P <0.001). By using the cut-off values of AVACT (<1.2 cm2) and AVAecho (<1.0 cm2) for diagnosing severe AS, the BSA (odds ratio [OR]: 68.03, 95% confidence interval [CI]: 5.45–849.99; P = 0.001), AVAecho (OR: 1.19, 95%CI: 1.14–1.24; P <0.001), tricuspid valve morphology (OR: 2.83, 95%CI: 1.23–6.50; P = 0.01), and normalized annulus area (OR: 1.02; 95%CI:1.02–1.03; P <0.001) were significant factors associated with the discordance between the AVAecho and AVACT. Conclusion: Patients with larger BSA, AVAecho, and annulus, and tricuspid valve morphology were associated with the AVA discordance between the echocardiography and CT. Complementary use of CT with echocardiography for grading severe AS could be helpful in such conditions. [ABSTRACT FROM AUTHOR]

Background: It is unknown whether the direct oral anticoagulant edoxaban can reduce leaflet thrombosis and the accompanying cerebral thromboembolic risk after transcatheter aortic valve replacement. In addition, the causal relationship of subclinical leaflet thrombosis with cerebral thromboembolism and neurological or neurocognitive dysfunction remains unclear.Methods: We conducted a multicenter, open-label randomized trial comparing edoxaban with dual antiplatelet therapy (aspirin plus clopidogrel) in patients who had undergone successful transcatheter aortic valve replacement and did not have an indication for anticoagulation. The primary end point was an incidence of leaflet thrombosis on 4-dimensional computed tomography at 6 months. Key secondary end points were the number and volume of new cerebral lesions on brain magnetic resonance imaging and the serial changes of neurological and neurocognitive function between 6 months and immediately after transcatheter aortic valve replacement.Results: A total of 229 patients were included in the final intention-to-treat population. There was a trend toward a lower incidence of leaflet thrombosis in the edoxaban group compared with the dual antiplatelet therapy group (9.8% versus 18.4%; absolute difference, -8.5% [95% CI, -17.8% to 0.8%]; P=0.076). The percentage of patients with new cerebral lesions on brain magnetic resonance imaging (edoxaban versus dual antiplatelet therapy, 25.0% versus 20.2%; difference, 4.8%; 95% CI, -6.4% to 16.0%) and median total new lesion number and volume were not different between the 2 groups. In addition, the percentages of patients with worsening of neurological and neurocognitive function were not different between the groups. The incidence of any or major bleeding events was not different between the 2 groups. We found no significant association between the presence or extent of leaflet thrombosis with new cerebral lesions and a change of neurological or neurocognitive function.Conclusions: In patients without an indication for long-term anticoagulation after successful transcatheter aortic valve replacement, the incidence of leaflet thrombosis was numerically lower with edoxaban than with dual antiplatelet therapy, but this was not statistically significant. The effects on new cerebral thromboembolism and neurological or neurocognitive function were also not different between the 2 groups. Because the study was underpowered, the results should be considered hypothesis generating, highlighting the need for further research.Registration: URL: https://www.Clinicaltrials: gov. Unique identifier: NCT03284827. [ABSTRACT FROM AUTHOR]

Aortic valve calcium scoring by cardiac computed tomographic (CT) has been recommended as an alternative to classify the AS (aortic stenosis) severity, but it is unclear that whether CT findings would have additional value to discriminate significant AS subtypes including high gradient severe AS, classic low-flow, low gradient (LF-LG) AS, paradoxical LF-LG AS, and moderate AS. In this study, we examined the preoperative clinical and cardiac CT findings of different subtypes of AS in patients with surgical aortic valve replacement (AVR) and evaluated the subtype classification as a factor affecting post-surgical outcomes. This study included 511 (66.9 ± 8.8 years, 55% men) consecutive patients with severe AS who underwent surgical AVR. Aortic valve area (AVA) was obtained by echocardiography (AVAecho) and by CT (AVACT) using each modalities measurement of the left ventricular outflow tract. Patients with AS were classified as (1) high-gradient severe (n = 438), (2) classic LF-LG (n = 18), and (3) paradoxical LF-LG (n = 55) based on echocardiography. In all patients, 455 (89.0%) patients were categorized as severe AS according to the AVACT. However, 56 patients were re-classified as moderate AS (43 [9.8%] high-gradient severe AS, 5 [27.8%] classic LF-LG AS, and 8 [14.5%] paradoxical LF-LG AS) by AVACT. The classic LF-LG AS group presented larger AVACT and aortic annulus than those in high-gradient severe AS group and one third of them had AVACT ≥ 1.2 cm2. After multivariable adjustment, old age (hazard ratio [HR], 1.04, P = 0.049), high B-type natriuretic peptide (BNP) (HR, 1.005; P < 0.001), preoperative atrial fibrillation (HR, 2.75; P = 0.003), classic LF-LG AS (HR, 5.53, P = 0.004), and small aortic annulus on CT (HR, 0.57; P = 0.002) were independently associated with major adverse cardiac and cerebrovascular events (MACCE) after surgical AVR. [ABSTRACT FROM AUTHOR]

Objectives: Cardiovascular border (CB) analysis is the primary method for detecting and quantifying the severity of cardiovascular disease using posterior-anterior chest radiographs (CXRs). This study aimed to develop and validate a deep learning–based automatic CXR CB analysis algorithm (CB_auto) for diagnosing and quantitatively evaluating valvular heart disease (VHD). Methods: We developed CB_auto using 816 normal and 798 VHD CXRs. For validation, 640 normal and 542 VHD CXRs from three different hospitals and 132 CXRs from a public dataset were assigned. The reliability of the CB parameters determined by CB_auto was evaluated. To evaluate the differences between parameters determined by CB_auto and manual CB drawing (CB_hand), the absolute percentage measurement error (APE) was calculated. Pearson correlation coefficients were calculated between CB_hand and echocardiographic measurements. Results: CB parameters determined by CB_auto yielded excellent reliability (intraclass correlation coefficient > 0.98). The 95% limits of agreement for the cardiothoracic ratio were 0.00 ± 0.04% without systemic bias. The differences between parameters determined by CB_auto and CB_hand as defined by the APE were < 10% for all parameters except for carinal angle and left atrial appendage. In the public dataset, all CB parameters were successfully drawn in 124 of 132 CXRs (93.9%). All CB parameters were significantly greater in VHD than in normal controls (all p < 0.05). All CB parameters showed significant correlations (p < 0.05) with echocardiographic measurements. Conclusions: The CB_auto system empowered by deep learning algorithm provided highly reliable CB measurements that could be useful not only in daily clinical practice but also for research purposes. Key Points: • A deep learning–based automatic CB analysis algorithm for diagnosing and quantitatively evaluating VHD using posterior-anterior chest radiographs was developed and validated. • Our algorithm (CB_auto) yielded comparable reliability to manual CB drawing (CB_hand) in terms of various CB measurement variables, as confirmed by external validation with datasets from three different hospitals and a public dataset. • All CB parameters were significantly different between VHD and normal control measurements, and echocardiographic measurements were significantly correlated with CB parameters measured from normal control and VHD CXRs. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate whether bicuspid anatomy affects the discrepancy between CT-derived annular size and intraoperative size. We retrospectively analyzed annular measurements in 667 patients who underwent surgical aortic valve replacement (AVR). Preoperative CT measurements of the aortic annulus were compared to surgically implanted valve sizes. To evaluate whether the bicuspid valve affects the differences between CT annulus diameter and surgical AVR size, patients with diameter larger by > 10% (CT-Lg group) on CT, compared to surgical AVR size, were compared with those having size difference < 10% (CT-Sim group). Propensity score matching yielded 183 matched patients from each group. Bicuspid aortic valve annulus parameters significantly correlated with surgical aortic valve size (r = 0.52–0.71; for all, p < 0.01). The most representative measurements corresponded to surgical aortic valve size were area-derived diameters in tricuspid aortic valve (r = 0.69, p < 0.001) and bicuspid without raphe (r = 0.71, p < 0.001), and perimeter-derived diameter in bicuspid with raphe (r = 0.63, p < 0.001). After propensity score matching, native valve type was not different between CT-Sim and CT-Lg groups. In multivariable analysis, the difference between CT-derived diameter and surgical AVR size was affected by the operator factor and types of prosthesis. Bicuspid aortic annulus diameters measured on CT showed a significant correlation with surgical aortic valve size. The difference between CT-derived diameter and surgical AVR size is affected by operator factor and the types of prosthesis but not affected by the bicuspid valve. [ABSTRACT FROM AUTHOR]

In thoracoabdominal aortic aneurysm repair, repairing the visceral and segmental arteries is challenging. Although there is a pre-hand-sewn and multi-branched graft based on the conventional image-based technique, it has shortcomings in precisely positioning and directing the visceral and segmental arteries. Here, we introduce two new reconstruction techniques using patient-specific 3D-printed graft reconstruction guides: (1) model-based technique that presents the projected aortic graft, visualizing the main aortic body and its major branches and (2) guide-based technique in which the branching vessels in the visualization model are replaced by marking points identifiable by tactile sense. We demonstrate the effectiveness by evaluating conventional and new techniques based on accuracy, marking time requirement, reproducibility, and results of survey to surgeons on the perceived efficiency and efficacy. The graft reconstruction guides cover the segmentation, design, fabrication, post-processing, and clinical application of open surgical repair of thoracoabdominal aneurysm, and proved to be efficient for accurately reconstructing customized grafts. [ABSTRACT FROM AUTHOR]

Background: Cardiovascular diseases (CVDs) are difficult to diagnose early and have risk factors that are easy to overlook. Early prediction and personalization of treatment through the use of artificial intelligence (AI) may help clinicians and patients manage CVDs more effectively. However, to apply AI approaches to CVDs data, it is necessary to establish and curate a specialized database based on electronic health records (EHRs) and include pre-processed unstructured data.Methods: To build a suitable database (CardioNet) for CVDs that can utilize AI technology, contributing to the overall care of patients with CVDs. First, we collected the anonymized records of 748,474 patients who had visited the Asan Medical Center (AMC) or Ulsan University Hospital (UUH) because of CVDs. Second, we set clinically plausible criteria to remove errors and duplication. Third, we integrated unstructured data such as readings of medical examinations with structured data sourced from EHRs to create the CardioNet. We subsequently performed natural language processing to structuralize the significant variables associated with CVDs because most results of the principal CVD-related medical examinations are free-text readings. Additionally, to ensure interoperability for convergent multi-center research, we standardized the data using several codes that correspond to the common data model. Finally, we created the descriptive table (i.e., dictionary of the CardioNet) to simplify access and utilization of data for clinicians and engineers and continuously validated the data to ensure reliability.Results: CardioNet is a comprehensive database that can serve as a training set for AI models and assist in all aspects of clinical management of CVDs. It comprises information extracted from EHRs and results of readings of CVD-related digital tests. It consists of 27 tables, a code-master table, and a descriptive table.Conclusions: CardioNet database specialized in CVDs was established, with continuing data collection. We are actively supporting multi-center research, which may require further data processing, depending on the subject of the study. CardioNet will serve as the fundamental database for future CVD-related research projects. [ABSTRACT FROM AUTHOR]

The abnormal growth of tissue, called pannus, is frequently found in patients who have an implanted prosthetic heart valve. Its growth is related to the valve dysfunction and disturbed blood flow in the aorta. We performed in vitro experiments to demonstrate the effects of pannus formation on hemodynamics and valvular function. The results showed that the opening angle of the heart valve changes depending on the size and shape of the pannus. The circular pannus decreased the maximum opening angle of the heart valve. Although the opening motion of the valve was not affected by the semi-circular pannus, one of the valve leaflets obstructed by the semi-circular pannus had a closing dysfunction during the cardiac cycle, implying aortic insufficiency and regurgitation in the patients with this type of pannus formation. The experimentally measured pressure gradient and velocity-based transvalvular pressure gradient estimation increased with the growth of the pannus, although a discrepancy between the two estimations was observed. [ABSTRACT FROM AUTHOR]

To perform comprehensive in vitro experiments using six-directional icosahedral flow encoding (ICOSA6) 4D flow magnetic resonance imaging (MRI) under various scan conditions to analyze the robustness of velocity and turbulence quantification. In vitro flow phantoms with steady flow rates of 10 and 20 L/min were scanned using both conventional 4D flow MRI and ICOSA6. Experiments focused on comparisons between ICOSA6 and conventional four point (4P) methods, and the effects of contrast agents, velocity encoding range (Venc), and scan direction on velocity and turbulence quantification. The results demonstrated that 1) ICOSA6 improves the velocity-to-noise ratio (VNR) of velocity estimation by 33% (on average) and results in similar turbulent kinetic energy (TKE) estimation as the 4P method. 2) Measurements with a contrast agent resulted in more than a 2.5 fold increase in average VNR. However, the improvement of total TKE quantification was not obvious. 3) TKE estimation was less affected by Venc and the scan direction, whereas turbulence production (TP) estimation was largely affected by these measurement conditions. The effects of Venc and scan direction accounted for less than 11.63% of TKE estimation, but up to 33.89% of TP estimation. The ICOSA6 scheme is compatible with conventional 4D flow MRI for velocity and TKE measurement. Contrast agents are effective at increasing VNR, but not signal-to-noise ratio for TKE quantification. The effects of Venc and scan direction influence total TP more than total TKE. [ABSTRACT FROM AUTHOR]

Some patients with a bileaflet mechanical heart valve (BMHV) show significant increases in the transvalvular pressure drop and abnormal leaflet motion due to a pannus (an abnormal fibrovascular tissue) formed on the ventricular side, even in the absence of physical contact between the pannus and leaflets. We investigate the effects of the pannus shape (circular or semi-circular ring), implantation location and height on the leaflet motion, flow structure and transvalvular pressure drop using numerical simulations. The valve model considered resembles a 25 mm masters HP valve. The mean systolic pressure drop is significantly increased with increasing pannus height, irrespective of its implantation orientation. Near the peak inflow rate, the flow behind the pannus becomes highly turbulent, and the transvalvular pressure drop is markedly increased by the pannus. At the end of valve opening and the start of valve closing, oscillatory motions of the leaflets occur due to periodic shedding of vortex rings behind the pannus, and their amplitudes become large with increasing pannus height. When the pannus shape is asymmetric (e.g., a semi-circular ring) and its height reaches about 0.1D (D (= 25 mm) is the diameter of an aorta), abnormal leaflet motions occur: two leaflets move asymmetrically, and valve closing is delayed in time or incomplete, which increases the regurgitation volume. The peak energy loss coefficients due to panni are obtained from simulation data and compared with those predicted by a one-dimensional model. The comparison indicates that the one-dimensional model is applicable for the BMHV with and without pannus. [ABSTRACT FROM AUTHOR]

Background: Homocysteine has been known as a risk factor for cardiovascular disease. This study sought to evaluate the influence of homocysteine on the risk of subclinical coronary atherosclerosis in asymptomatic individuals. Methods: We reviewed 3,186 asymptomatic individuals (mean age 53.8 ± 8.0 years, 2,202 men [69.1%]) with no prior history of coronary artery disease who voluntarily underwent coronary computed tomographic angiography (CCTA) and laboratory tests as part of a general health examination. The subjects were stratified into tertiles according to their homocysteine levels. The degree and extent of subclinical coronary atherosclerosis were assessed by CCTA. Logistic regression analysis was used to determine the association between homocysteine levels and subclinical coronary atherosclerosis. Results: The prevalence of significant coronary artery stenosis, any atherosclerotic, calcified, mixed, and non-calcified plaques increased with homocysteine tertiles (all p < 0.05). However, after adjustment for cardiovascular risk factors, there were no statistically significant differences in the adjusted odds ratios (ORs) for any atherosclerotic plaque (OR 1.06; 95% CI [confidence interval] 0.85–1.32; p = 0.610), calcified plaques (OR 1.17; 95% CI 0.92–1.48; p = 0.199), non-calcified plaques (OR 0.80; 95% CI 0.61–1.04; p = 0.089), and mixed plaques (OR 1.42; 95% CI 0.96–2.11; p = 0.077) between the third and first homocysteine tertiles. In addition, the adjusted OR for significant coronary artery stenosis (OR 0.92; 95% CI 0.63–1.36; p = 0.687) did not differ between the first and third tertiles. Conclusions: In asymptomatic individuals, homocysteine is not associated with an increased risk of subclinical coronary atherosclerosis. [ABSTRACT FROM AUTHOR]

Background: Atherosclerotic cardiovascular (CV) events commonly occur in individuals with a low CV risk burden. This study evaluated the ability of the triglyceride glucose (TyG) index to predict subclinical coronary artery disease (CAD) in asymptomatic subjects without traditional CV risk factors (CVRFs). Methods: This retrospective, cross-sectional, and observational study evaluated the association of TyG index with CAD in 1250 (52.8 ± 6.5 years, 46.9% male) asymptomatic individuals without traditional CVRFs (defined as systolic/diastolic blood pressure ≥ 140/90 mmHg; fasting glucose ≥126 mg/dL; total cholesterol ≥240 mg/dL; low-density lipoprotein cholesterol ≥160 mg/dL; high-density lipoprotein cholesterol < 40 mg/dL; body mass index ≥25.0 kg/m2; current smoking; and previous medical history of hypertension, diabetes, or dyslipidemia). CAD was defined as the presence of any coronary plaque on coronary computed tomographic angiography. The participants were divided into three groups based on TyG index tertiles. Results: The prevalence of CAD increased with elevating TyG index tertiles (group I: 14.8% vs. group II: 19.3% vs. group III: 27.6%; P < 0.001). Multivariate logistic regression models showed that TyG index was associated with an increased risk of CAD (odds ratio [OR] 1.473, 95% confidence interval [CI] 1.026–2.166); especially non-calcified (OR 1.581, 95% CI 1.002–2.493) and mixed plaques (OR 2.419, 95% CI 1.051–5.569) (all P < 0.05). The optimal TyG index cut-off for predicting CAD was 8.44 (sensitivity 47.9%; specificity 68.5%; area under the curve 0.600; P < 0.001). The predictive value of this cut-off improved after considering the non-modifiable factors of old age and male sex. Conclusions: TyG index is an independent marker for predicting subclinical CAD in individuals conventionally considered healthy. [ABSTRACT FROM AUTHOR]

There are limited data on the association between serum uric acid (SUA) level and subclinical coronary atherosclerosis. This study investigated the influence of SUA level on subclinical coronary atherosclerosis, as detected by coronary computed tomography angiography (CCTA), in an asymptomatic population. We evaluated 6431 asymptomatic individuals (mean age 53.6 ± 7.6 years, 4691 men [72.9%]) with no prior history of coronary artery disease, who voluntarily underwent laboratory tests and CCTA as part of a general health examination. The participants were stratified into quartiles according to their SUA levels. Coronary atherosclerotic plaques (calcified, mixed, and non-calcified plaques) were assessed using CCTA. Logistic regression analysis was used to determine the association between SUA levels and subclinical coronary atherosclerosis. The prevalence of any atherosclerotic, calcified, mixed, and non-calcified plaques increased with SUA quartiles (all p < 0.001). After adjustment for cardiovascular risk factors, there were no statistically significant differences in the adjusted odds ratios for calcified plaque (1.19; 95% CI 0.98–1.46; p = 0.080) and mixed plaque (1.25; 95% CI 0.94–1.67; p = 0.132) in the fourth SUA quartile compared to the first quartile. However, the adjusted odds ratios for any atherosclerotic plaque (1.39; 95% CI 1.16–1.68; p < 0.001) and non-calcified plaque (1.38; 95% CI 1.11–1.72; p = 0.004) were significantly higher in the fourth SUA quartile. In asymptomatic individuals, high SUA level was an independent predictor of non-calcified plaques, suggesting an increased cardiovascular risk. Image 1 • The association between serum uric acid and CAD showed conflicting results. • High serum uric acid level is an independent predictor of non-calcified vulnerable plaque. • Screening for CAD might be considered in individuals with hyperuricemia. [ABSTRACT FROM AUTHOR]

To use adenosine-induced stress CT myocardial perfusion imaging (CT-MPI) to determine normal reference values for left ventricle (LV) wall thickness (WT) and motion parameters. This study included 106 Korean subjects (52 men and 54 women) who underwent CT-MPI due to chest pain, but were not found to have any detectable mild or severe coronary artery disease or myocardial perfusion defect. The following quantitative parameters were assessed on the CT-MPI according to a 17-segment model: LV myocardial thickness at end-systolic (WT ES) and end-diastolic (WT ED) phases, systolic wall thickening (SWT), and wall motion (WM). The associations of the measured parameters with the subjects' demographic characteristics and comorbidities were also analyzed. Septal wall (7.2 mm) and basal-level (7.7 mm) LV myocardium demonstrated significantly higher WT (p < 0.001). SWT was highest in lateral (77.8%, p < 0.014) and apical (78.9%, p = 0.009) myocardium, while lateral (7.7 mm) and basal (6.7 mm) myocardium exhibited the greatest WM (p < 0.001). WT was significantly higher in men and younger (<60 years) subjects (all, p < 0.001). Hypertensive individuals presented with significantly higher SWT (79.9%, p = 0.024). LV WT exhibited statistically significant correlations (all positive, except for age) with age, height, weight, body surface area, body mass index, and systolic blood pressure (all, p < 0.010). The present study provides CT-MPI reference values for LV myocardial WT, SWT, and WM measured on an adult Korean population. Knowledge of such normal reference measurements would be beneficial for the efficient interpretation of CT-MPI examinations in populations of Asian ethnicity. • Reference values for the LV WT and other wall motion parameters obtained on CT-MPI are presented in this article • WT was higher in septal wall and basal-level, and significantly associated with age, height, weight, BMI, and blood pressure • SWT was highest in lateral and apical myocardium, while lateral and basal myocardium exhibited the greatest WM • Knowledge of such normal reference measurements could provide additional beneficial information during CT-MPI interpretations [ABSTRACT FROM AUTHOR]

This study analyzes the accuracy of the Fontan circulation using four-dimensional (4D) flow magnetic resonance imaging (MRI) for a variety of spatial resolution and noise scenarios. Using the results of computational fluid dynamics (CFD) as ground truth, hemodynamics in twelve patient-specific Fontan circulations were simulated as 4D flow MRIs, for voxel sizes of 0.5–3.0 mm and noise levels of 0.1–50 cm/s. In each case, three-dimensional streamline tracers were emitted at 1000 randomly sampled points from the inferior vena cava and superior vena cava planes, and the blood flow distribution from the vena cava to pulmonary arteries was quantified. The error of the flow distribution in 4D flow MRI was obtained by substituting the value obtained from 4D flow MRI into that obtained from CFD. Increasing the voxel size in 4D flow MRI affected the accuracy of the flow distribution estimation. The 4D flow MRI assessment of the flow distribution ratio in Fontan patients (2–4 years old) had the errors of ± 0.057, ± 0.145 and ± 0.210 at the voxel sizes of 1.0 mm, 2.0 mm, and 3.0 mm, respectively. Increasing velocity noise increased the missing fraction of the tracers, increasing the mean error of the flow distribution ratio to 0.490 at the missing fractions above 70%. Using the missing fraction of 20% as a cutoff condition for the dataset, the error ratio in the analysis was confined to ± 0.2. Assessment of the flow distribution using 4D flow MRI is sensitive to spatial resolution and velocity noise levels. [ABSTRACT FROM AUTHOR]

Abstract Background We aimed to compare the myocardial ischemic burden assessed using semi-quantitative and quantitative analysis of computed tomography-myocardial perfusion imaging (CT-MPI) with that of single-photon emission computed tomography (SPECT). Methods From 2011 to 2013, 97 patients who underwent CT-MPI and SPECT were evaluated. The extent and severity of perfusion defects were assessed on a 5-point scale using a standard 16-segment model, and were expressed as summed stress score (SSS) and summed difference score (SDS). Receiver operating characteristic (ROC) curves for quantitative parameters were generated for the diagnosis of abnormal perfusion defect (SSS ≥ 4) and presence of ischemia (SDS ≥ 2) on SPECT. Results On CT-MPI, 298 (19.2%) of the 1552 segments showed perfusion abnormalities during stress, whereas perfusion abnormalities were shown in 179 (11.5%) segments on SPECT-MPI. On a per-person basis, there was good agreement, with intraclass correlation coefficients of 0.78 for SSS and 0.72 for SDS. A significant reduction of attenuation in stress and myocardial perfusion reserve index, along with an increase in % defect volume of CT-MPI, were demonstrated as the degree of perfusion defect or ischemia on SPECT increased. On the ROC curves, % defect volume on CT-MPI demonstrated the highest area under the curve: 0.91 for abnormal perfusion defect and 0.89 (all p < 0.001) for the presence of ischemia on SPECT. Conclusions Semi-quantitative analysis of CT-MPI showed good accordance with SPECT. A quantitative approach for CT-MPI, especially % defect volume, may provide additional value in the identification of myocardial perfusion abnormalities. Clinical Trial Registration: https://clinicaltrials.gov/ct2/show/NCT01696006. Highlights • CT-MPI showed good agreement with SPECT by a semi-quantitative approach. • The % defect volume demonstrated excellent accuracy in the detection of perfusion abnormality on SPECT. • The % defect volume may play an additional role to identify myocardial perfusion defect and ischemia. [ABSTRACT FROM AUTHOR]

Background: Invasive fractional flow reserve (FFR) is a standard tool for identifying ischemia-producing coronary stenosis. However, in clinical practice, over 70% of treatment decisions still rely on visual estimation of angiographic stenosis, which has limited accuracy (about 60%-65%) for the prediction of FFR < 0.80. One of the reasons for the visual-functional mismatch is that myocardial ischemia can be affected by the supplied myocardial size, which is not always evident by coronary angiography. The aims of this study were to develop an angiography-based machine learning (ML) algorithm for predicting the supplied myocardial volume for a stenosis, as measured using coronary computed tomography angiography (CCTA), and then to build an angiography-based classifier for the lesions with an FFR < 0.80 versus ≥ 0.80.Methods and Findings: A retrospective study was conducted using data from 1,132 stable and unstable angina patients with 1,132 intermediate lesions who underwent invasive coronary angiography, FFR, and CCTA at the Asan Medical Center, Seoul, Korea, between 1 May 2012 and 30 November 2015. The mean age was 63 ± 10 years, 76% were men, and 72% of the patients presented with stable angina. Of these, 932 patients (assessed before 31 January 2015) constituted the training set for the algorithm, and 200 patients (assessed after 1 February 2015) served as a test cohort to validate its diagnostic performance. Additionally, external validation with 79 patients from two centers (CHA University, Seongnam, Korea, and Ajou University, Suwon, Korea) was conducted. After automatic contour calibration using the caliber of guiding catheter, quantitative coronary angiography was performed using the edge-detection algorithms (CAAS-5, Pie-Medical). Clinical information was provided by the Asan BiomedicaL Research Environment (ABLE) system. The CCTA-based myocardial segmentation (CAMS)-derived myocardial volume supplied by each vessel (right coronary artery [RCA], left anterior descending [LAD], left circumflex [LCX]) and the myocardial volume subtended to a stenotic segment (CAMS-%Vsub) were measured for labeling. The ML for (1) predicting vessel territories (CAMS-%LAD, CAMS-%LCX, and CAMS-%RCA) and CAMS-%Vsub and (2) identifying the lesions with an FFR < 0.80 was constructed. Angiography-based ML, employing a light gradient boosting machine (GBM), showed mean absolute errors (MAEs) of 5.42%, 8.57%, and 4.54% for predicting CAMS-%LAD, CAMS-%LCX, and CAMS-%RCA, respectively. The percent myocardial volumes predicted by ML were used to predict the CAMS-%Vsub. With 5-fold cross validation, the MAEs between ML-predicted percent myocardial volume subtended to a stenotic segment (ML-%Vsub) and CAMS-%Vsub were minimized by the elastic net (6.26% ± 0.55% for LAD, 5.79% ± 0.68% for LCX, and 2.95% ± 0.14% for RCA lesions). Using all attributes (age, sex, involved vessel segment, and angiographic features affecting the myocardial territory and stenosis degree), the ML classifiers (L2 penalized logistic regression, support vector machine, and random forest) predicted an FFR < 0.80 with an accuracy of approximately 80% (area under the curve [AUC] = 0.84-0.87, 95% confidence intervals 0.71-0.94) in the test set, which was greater than that of diameter stenosis (DS) > 53% (66%, AUC = 0.71, 95% confidence intervals 0.65-0.78). The external validation showed 84% accuracy (AUC = 0.89, 95% confidence intervals 0.83-0.95). The retrospective design, single ethnicity, and the lack of clinical outcomes may limit this prediction model's generalized application.Conclusion: We found that angiography-based ML is useful to predict subtended myocardial territories and ischemia-producing lesions by mitigating the visual-functional mismatch between angiographic and FFR. Assessment of clinical utility requires further validation in a large, prospective cohort study. [ABSTRACT FROM AUTHOR]

Although hemodynamic influence of the subprosthetic tissue, termed as pannus, may contribute to prosthetic aortic valve dysfunction, the relationship between pannus extent and hemodynamics in the prosthetic valve has rarely been reported. We investigated the fluid dynamics of pannus formation using in vitro experiments with particle image velocimetry. Subvalvular pannus formation caused substantial changes in prosthetic valve transvalvular peak velocity, transvalvular pressure gradient (TPG) and opening angle. Maximum flow velocity and corresponding TPG were mostly affected by pannus width. When the pannus width was 25% of the valve diameter, pannus formation elevated TPG to >2.5 times higher than that without pannus formation. Opening dysfunction was observed only for a pannus involvement angle of 360°. Although circumferential pannus with an involvement angle of 360° decreased the opening angle of the valve from approximately 82° to 58°, eccentric pannus with an involvement angle of 180° did not induce valve opening dysfunction. The pannus involvement angle largely influenced the velocity flow field at the aortic sinus and corresponding hemodynamic indices, including wall shear stress, principal shear stress and viscous energy loss distributions. Substantial discrepancy between the velocity-based TPG estimation and direct pressure measurements was observed for prosthetic valve flow with pannus formation. [ABSTRACT FROM AUTHOR]

Background & Aims There are limited data on the association between non-alcoholic fatty liver disease (NAFLD) and subclinical coronary atherosclerosis. This study investigated the influence of NAFLD on subclinical coronary atherosclerosis as detected by coronary computed tomography angiography (CCTA) in an asymptomatic population. Methods A total of 5,121 consecutive asymptomatic individuals with no prior history of coronary artery disease or significant alcohol intake voluntarily underwent abdominal ultrasonography and CCTA as part of a general health examination. Fatty liver was assessed by ultrasonography examination. The fatty liver index and NAFLD fibrosis score were also calculated. Coronary atherosclerotic plaques on CCTA were evaluated. The association between NAFLD and subclinical coronary atherosclerosis was determined by logistic regression analysis. Results Of the study participants, 1,979 (38.6%) had ultrasonography-diagnosed NAFLD. After adjustment for cardiovascular risk factors, there were no statistically significant differences in the adjusted odds ratios of NAFLD for calcified plaque (1.03; 95% CI 0.89–1.20; p =  0.673) and mixed plaque (1.15; 95% CI 0.93–1.42; p =  0.214). However, adjusted odds ratios for any atherosclerotic plaque (1.18; 95% CI 1.03–1.35; p =  0.016) and non-calcified plaque (1.27; 95% CI 1.08–1.48; p =  0.003) were significantly higher in NAFLD. In addition, there was a significant association of fatty liver index ≥30 with non-calcified plaque (1.37; 95% CI 1.14–1.65; p =  0.001) and NAFLD fibrosis score ≥−1.455 with non-calcified plaque (1.20; 95% CI 1.08–1.42; p =  0.030). Conclusions In this large cross-sectional study of asymptomatic individuals undergoing CCTA, NAFLD was consistently associated with non-calcified plaque, suggesting an increased cardiovascular risk. Lay summary In asymptomatic individuals, non-alcoholic fatty liver disease (NAFLD) was an independent risk factor for non-calcified plaque, which has been known as a vulnerable plaque associated with sudden and unexpected cardiac events. Therefore, appropriate medical therapy for NAFLD was required to reduce future cardiac events. [ABSTRACT FROM AUTHOR]

Objectives: To validate a method for performing myocardial segmentation based on coronary anatomy using coronary CT angiography (CCTA).Methods: Coronary artery-based myocardial segmentation (CAMS) was developed for use with CCTA. To validate and compare this method with the conventional American Heart Association (AHA) classification, a single coronary occlusion model was prepared and validated using six pigs. The unstained occluded coronary territories of the specimens and corresponding arterial territories from CAMS and AHA segmentations were compared using slice-by-slice matching and 100 virtual myocardial columns.Results: CAMS more precisely predicted ischaemic area than the AHA method, as indicated by 95% versus 76% (p < 0.001) of the percentage of matched columns (defined as percentage of matched columns of segmentation method divided by number of unstained columns in the specimen). According to the subgroup analyses, CAMS demonstrated a higher percentage of matched columns than the AHA method in the left anterior descending artery (100% vs. 77%; p < 0.001) and mid- (99% vs. 83%; p = 0.046) and apical-level territories of the left ventricle (90% vs. 52%; p = 0.011).Conclusions: CAMS is a feasible method for identifying the corresponding myocardial territories of the coronary arteries using CCTA.Key Points: • CAMS is a feasible method for identifying corresponding coronary territory using CTA • CAMS is more accurate in predicting coronary territory than the AHA method • The AHA method may underestimate the ischaemic territory of LAD stenosis. [ABSTRACT FROM AUTHOR]

Background There are limited data regarding the influence of glycemic status on the risk of subclinical coronary atherosclerosis on coronary computed tomographic angiography (CCTA) in asymptomatic individuals. Methods We analyzed 6434 asymptomatic individuals who underwent CCTA. The degree and extent of subclinical coronary atherosclerosis were assessed by CCTA, and ≥ 50% diameter stenosis was defined as significant. Of study participants, 2197 (34.1%), 3122 (48.5%), and 1115 (17.3%) were categorized as normal, prediabetic and diabetic individuals, respectively. Results Compared with normal individuals, there were no statistically differences in the adjusted odds ratios of prediabetic individuals for significant coronary artery stenosis (0.98, 95% confidence interval [CI] 0.80–1.22, p = 0.888), any plaque (0.96, 95% CI 0.86–1.07, p = 0.483), calcified plaque (0.90, 95% CI 0.79–1.01, p = 0.080), non-calcified plaque (1.02, 95% CI 0.88–1.17, p = 0.803), and mixed plaque (1.00, 95% CI 0.82–1.22, p = 0.983). However, adjusted odds ratios for significant coronary artery stenosis (1.71, 95% CI 1.34–2.19, p < 0.001), any plaque (1.45, 95% CI 1.26–1.68, p < 0.001), calcified plaque (1.35, 95% CI 1.15–1.57, p < 0.001), non-calcified plaque (1.33, 95% CI 1.11–1.59, p = 0.002), and mixed plaque (1.64, 95% CI 1.30–2.07, p < 0.001) of diabetic individuals were significantly higher than those of the normal individuals. Conclusion In asymptomatic individuals, diabetic individuals had a higher risk for subclinical coronary atherosclerosis, but prediabetic individuals were not associated with an increased risk of subclinical coronary atherosclerosis. [ABSTRACT FROM AUTHOR]

Objectives: To validate 4D flow MRI in a flow phantom using a flowmeter and computational fluid dynamics (CFD) as reference.Methods: Validation of 4D flow MRI was performed using flow phantoms with 75 % and 90 % stenosis. The effect of spatial resolution on flow rate, peak velocity and flow patterns was investigated in coronal and axial scans. The accuracy of flow rate with 4D flow MRI was evaluated using a flowmeter as reference, and the peak velocity and flow patterns obtained were compared with CFD analysis results.Results: 4D flow MRI accurately measured the flow rate in proximal and distal regions of the stenosis (percent error ≤3.6 % in axial scanning with 1.6-mm resolution). The peak velocity of 4D flow MRI was underestimated by more than 22.8 %, especially from the second half of the stenosis. With 1-mm isotropic resolution, the maximum thickness of the recirculating flow region was estimated within a 1-mm difference, but the turbulent velocity fluctuations mostly disappeared in the post-stenotic region.Conclusion: 4D flow MRI accurately measures the flow rates in the proximal and distal regions of a stenosis in axial scan but has limitations in its estimation of peak velocity and turbulent characteristics.Key Points: • 4D flow MRI accurately measures the flow rate in axial scan. • The peak velocity was underestimated by 4D flow MRI. •4D flow MRI demonstrates the principal pattern of post-stenotic flow. [ABSTRACT FROM AUTHOR]

Quantifying turbulence velocity fluctuation is important because it indicates the fluid energy dissipation of the blood flow, which is closely related to the pressure drop along the blood vessel. This study aims to evaluate the effects of scan parameters and the target vessel size of 4D phase-contrast (PC)-MRI on quantification of turbulent kinetic energy (TKE). Comprehensive 4D PC-MRI measurements with various velocity-encoding (VENC), echo time (TE), and voxel size values were carried out to estimate TKE distribution in stenotic flow. The total TKE (TKE sum ), maximum TKE (TKE max ), and background noise level (TKE noise ) were compared for each scan parameter. The feasibility of TKE estimation in small vessels was also investigated. Results show that the optimum VENC for stenotic flow with a peak velocity of 125 cm/s was 70 cm/s. Higher VENC values overestimated the TKE sum by up to six-fold due to increased TKE noise , whereas lower VENC values (30 cm/s) underestimated it by 57.1%. TE and voxel size did not significantly influence the TKE sum and TKE noise , although the TKE max significantly increased as the voxel size increased. TKE quantification in small-sized vessels (3–5-mm diameter) was feasible unless high-velocity turbulence caused severe phase dispersion in the reference image. [ABSTRACT FROM AUTHOR]

Purpose To investigate the details of the flow structure of a plug-like jet that had a vortex ring in pulsatile stenotic phantoms using 4D flow MRI. Method Pulsatile Newtonian flows in two stenotic phantoms with 50% and 75% reductions in area were scanned by 4D flow MRI. Blood analog working fluid was circulated via the stenotic phantom using a pulsatile pump at a constant pulsating frequency of 1 Hz. The velocity and vorticity fields of the plug-like jet with a vortex ring were quantitatively analyzed in the spatial and temporal domains. Results Pulsatile stenotic flow showed a plug-like jet at the specific stenotic degree of 50% in our pulsatile waveform design. This plug-like jet was found at the decelerating period in the post-stenotic region of 26.4 mm (1.2 D). It revealed a vortex ring structure with vorticity strength in the range of ± 100 s − 1 . Conclusion We observed a plug-like jet with a vortex ring in pulsatile stenotic flow by in vitro visualization using 4D flow MRI. In this plug-like jet, the local fastest flow region occurred at the post-systole phase in the post-stenotic region, which was distinguishable from a typical stenotic jet flow at systole phase. [ABSTRACT FROM AUTHOR]

Background: Although the measurement of turbulence kinetic energy (TKE) by using magnetic resonance imaging (MRI) has been introduced as an alternative index for quantifying energy loss through the cardiac valve, experimental verification and clinical application of this parameter are still required. Objectives: The goal of this study is to verify MRI measurements of TKE by using a phantom stenosis with particle image velocimetry (PIV) as the reference standard. In addition, the feasibility of measuring TKE with MRI is explored. Methods: MRI measurements of TKE through a phantom stenosis was performed by using clinical 3T MRI scanner. The MRI measurements were verified experimentally by using PIV as the reference standard. In vivo application of MRI-driven TKE was explored in seven patients with aortic valve disease and one healthy volunteer. Transvalvular gradients measured by MRI and echocardiography were compared. Results: MRI and PIV measurements of TKE are consistent for turbulent flow (0.666 < R2 < 0.738) with a mean difference of −11.13 J/m3 (SD = 4.34 J/m3). Results of MRI and PIV measurements differ by 2.76 ± 0.82 cm/s (velocity) and −11.13 ± 4.34 J/m3 (TKE) for turbulent flow (Re > 400). The turbulence pressure drop correlates strongly with total TKE (R2 = 0.986). However, in vivo measurements of TKE are not consistent with the transvalvular pressure gradient estimated by echocardiography. Conclusions: These results suggest that TKE measurement via MRI may provide a potential benefit as an energy-loss index to characterize blood flow through the aortic valve. However, further clinical studies are necessary to reach definitive conclusions regarding this technique. [ABSTRACT FROM AUTHOR]

Background Elevated serum gamma-glutamyltransferase (GGT) has been demonstrated to be associated with coronary artery calcification (CAC). CAC progression is an important marker of atherosclerosis and correlates with future cardiovascular risk. However, there is a lack of research that directly examines the association between serum GGT and CAC progression. The aim of this study was to elucidate the association between serum GGT activity and CAC progression. Methods We enrolled 1246 asymptomatic participants who underwent repeated CAC score measurement during routine health examinations. To eliminate the dependence of the inter scan variability on the baseline CAC scores, square root-transformed CAC scores were used to analyze CAC progression. In addition, the annualized rate of change in CAC scores was computed. Results Serum GGT activities were significantly higher in “progressors” than “nonprogressors”. The prevalence of progression increased with the GGT tertile (11.9%, 20.1% and 27.9% in the 1st, 2nd, and 3rd GGT tertiles, respectively; p < 0.001). In the multivariate logistic regression analysis, the odds ratio (95% confidence interval) for CAC score progression was 1.85 (1.14–3.00) in the highest GGT tertile group. By multivariate linear regression analysis, baseline serum GGT activity demonstrated a positive association with the annualized change in CAC score (β = 0.002; p = 0.006) after adjusting for cardiovascular risk factors. Conclusion Elevated serum GGT levels are independently associated with CAC progression. Serum GGT levels may be a potential biomarker of future coronary atherosclerosis and prognosis. [ABSTRACT FROM AUTHOR]

Background: The usefulness of the 2013 ACC/AHA guidelines for the management of blood cholesterol in the Asian population remains controversial. In this study, we investigated whether eligibility for statin therapy determined by the 2013 ACC/AHA guidelines is better aligned with the presence of subclinical coronary atherosclerosis detected by CCTA (coronary computed tomography angiography) compared to the previously recommended 2004 NCEP ATP III guidelines. Methods: We collected the data from 5,837 asymptomatic subjects who underwent CCTA using MDCT during routine health examinations. Based on risk factor assessment and lipid data, we determined guideline-based eligibility for statin therapy according to the 2013 ACC/AHA and 2004 NCEP ATP III guidelines. We defined the presence and severity of subclinical coronary atherosclerosis detected in CCTA according to the presence of significant coronary artery stenosis (defined as >50% stenosis), plaques, and the degree of coronary calcification. Results: As compared to the 2004 ATP III guidelines, a significantly higher proportion of subjects with significant coronary stenosis (61.8% vs. 33.8%), plaques (52.3% vs. 24.7%), and higher CACS (CACS >100, 63.6% vs. 26.5%) was assigned to statin therapy using the 2013 ACC/AHA guidelines (P < .001 for all variables). The area under the curves of the pooled cohort equation of the new guidelines in detecting significant stenosis, plaques, and higher CACS were significantly higher than those of the Framingham risk calculator. Conclusions: Compared to the previous ATP III guidelines, the 2013 ACC/AHA guidelines were more sensitive in identifying subjects with subclinical coronary atherosclerosis detected by CCTA in an Asian population. [ABSTRACT FROM AUTHOR]

• Cycle-consistent adversarial denoising for unsupervised cardiac CT data. • Wavelet-based preprocessing to disentangle noise components from images. • Effective noise reduction of 4% extreme-low-dose CT images without creating artifacts. • Extensive evaluation of denoised image quality on a data set of 149 patients. [Display omitted] In electrocardiography (ECG) gated cardiac CT angiography (CCTA), multiple images covering the entire cardiac cycle are taken continuously, so reduction of the accumulated radiation dose could be an important issue for patient safety. Although ECG-gated dose modulation (so-called ECG pulsing) is used to acquire many phases of CT images at a low dose, the reduction of the radiation dose introduces noise into the image reconstruction. To address this, we developed a high performance unsupervised deep learning method using noise disentanglement that can effectively learn the noise patterns even from extreme low dose CT images. For noise disentanglement, we use a wavelet transform to extract the high-frequency signals that contain the most noise. Since matched low-dose and high-dose cardiac CT data are impossible to obtain in practice, our neural network was trained in an unsupervised manner using cycleGAN for the extracted high frequency signals from the low-dose and unpaired high-dose CT images. Once the network is trained, denoised images are obtained by subtracting the estimated noise components from the input images. Image quality evaluation of the denoised images from only 4% dose CT images was performed by experienced radiologists for several anatomical structures. Visual grading analysis was conducted according to the sharpness level, noise level, and structural visibility. Also, the signal-to-noise ratio was calculated. The evaluation results showed that the quality of the images produced by the proposed method is much improved compared to low-dose CT images and to the baseline cycleGAN results. The proposed noise-disentangled cycleGAN with wavelet transform effectively removed noise from extreme low-dose CT images compared to the existing baseline algorithms. It can be an important denoising platform for low-dose CT. [ABSTRACT FROM AUTHOR]

Computed tomographic coronary angiography (CTCA) has prognostic value for early major adverse cardiac events (MACEs) after liver transplantation. However, the association between CTCA and long-term MACEs in liver transplant (LT) recipients remains unknown. We evaluated the association between CTCA and long-term MACEs within 5 years after living donor liver transplantation (LDLT). A total of 628 LDLT recipients who underwent CTCA were analyzed between 2010 and 2012. MACEs were investigated within 5 years after LDLT. The factors associated with long-term MACEs in transplant recipients were evaluated. Only 48 (7.6%) patients developed MACEs. In the Fine and Gray competing risk regression, a coronary artery calcium score (CACS) of >400 combined with obstructive coronary artery disease (CAD) (subdistribution hazard ratio: 5.01, 95% confidence interval: 2.37–10.58, p < 0.001), age (1.05, 1.01–1.10, p = 0.018), diabetes mellitus (2.43, 1.37–4.29, p = 0.002), dyslipidemia (2.45, 1.23–4.70, p = 0.023), and creatinine (1.19, 1.08–1.30, p < 0.001) were independently associated with long-term MACEs. CACS (>400) combined with obstructive CAD may be associated with MACEs within 5 years after LDLT, suggesting the importance of preoperative noninvasive CTCA in LT recipients. The evaluation of coronary artery stenosis on CTCA combined with CACS may have a prognostic value for long-term MACEs in LT recipients. [ABSTRACT FROM AUTHOR]