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Background: This study was conducted to evaluate the impact of functional and anatomic complete revascularization on long-term clinical outcomes after coronary artery bypass grafting (CABG)., Methods: Of 2034 patients who underwent primary isolated CABG between 2006 and 2017, 1162 patients who underwent off-pump CABG for 3-vessel disease and for whom data on functional and anatomic completeness of revascularization were available on the basis of preoperative myocardial single photon emission computed tomography and early postoperative graft angiography were enrolled. The median follow-up duration was 82.4 months (interquartile range, 50.8-122.4 months). Univariate and multivariate analyses were performed to evaluate the impact of the functional and anatomic completeness of revascularization on long-term survival., Results: Of 1162 patients, anatomic complete revascularization was achieved in 1014 patients (87.3%), whereas functional complete revascularization was achieved in 1077 patients (92.7%). Early mortality occurred in 7 patients. Late death occurred in 322 of 1155 early survivors. The 5- and 10-year overall survival rates were 84.3% and 66.7%, respectively. Univariate analyses demonstrated that functional completeness of revascularization was a statistically significant risk factor (P = .038), whereas anatomic completeness was not (P = .859). The multivariate analysis showed that functional completeness of revascularization (hazard ratio, 1.54; 95% CI, 1.08-2.22; P = .019) and age, underweight status, diabetes mellitus, chronic kidney disease, chronic obstructive pulmonary disease, and left ventricular dysfunction were significant factors associated with long-term survival., Conclusions: Functional rather than anatomic completeness of revascularization has a significant impact on the long-term survival in patients who undergo CABG., (Copyright © 2023 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Background: This study presents a new extraction fraction (EF) model based on physiological measures of invasive coronary flow reserve (CFR) and fractional flow reserve (FFR) in patients with suspected coronary artery disease (CAD) and normal index microcirculatory resistance (IMR). To ascertain the clinical relevance of the new EFs, flow measurements using the newly patient-determined EFs were compared to flow measurements using traditional animal-determined EFs., Methods: 39 patients were retrospectively selected that included a total of 91 vascular territories with invasive coronary angiography physiological measures. [N-13]-ammonia dynamic rest/adenosine-stress PET imaging was conducted in all patients and absolute myocardial flow was estimated using four published compartmental models. The extraction fraction during hyperemic flow was iteratively estimated by maximizing the agreement between invasive CFR and FFR with the non-invasive analogs myocardial flow reserve (MFR) and relative flow reserve (RFR) at similar physiological states, respectively., Results: Using the new patient-determined EFs, agreement between CFR vs MFR for Model 1 and 2 was moderate and poor for Model 3 and 4. All models showed moderate agreement for FFR vs RFR. When using published models of animal-determined EFs, agreement between CFR vs MFR remained moderate for Model 1 and 2, and poor for Model 3 and 4. Similarly, all models showed moderate agreement for FFR vs RFR using animal-determined EF values. None of the observed differences were statistically significant., Conclusions: Flow measurements using extraction fraction correction for [N-13]-ammonia based on calibration to invasive intracoronary angiography physiological measures in patients with CAD were not discordant from those reported in the literature. Either patient-determined or traditional animal-determined EF correction, when used with the appropriate flow model, yields moderate agreement with invasive measurements of coronary flow reserve and fractional flow reserve., (© 2021. American Society of Nuclear Cardiology.)

Objective: Vascular calcification is known to be associated with cardiovascular risk factors. Recently, F-NaF PET has been reported to be effective for detecting early and active vascular calcification. In this study, correlations between F-NaF PET/computed tomography (CT) findings and cardiovascular risk factors were investigated in patients with suspected coronary artery disease., Patients and Methods: Forty patients with suspected coronary artery disease underwent F-NaF PET/CT. The maximum and overall burden of calcifying activity, and the overall burden of calcium deposition in the descending thoracic aorta (DTA) were measured on F-NaF PET/CT and they were compared with cardiovascular risk factors, particularly, with those related to metabolic syndrome., Results: The maximum and overall burden of calcifying activity in DTA measured on F-NaF PET were significantly correlated with diabetes mellitus (P = 0.030 and 0.049, respectively) and serum HbA1c level (ρ = 0.433 and 0.344, respectively). In contrast, the overall burden of calcium deposition measured on CT was significantly correlated with hypertension (P < 0.001). The overall burden of calcium deposition was also significantly correlated with metabolic syndrome (P = 0.002) and 10-year cardiovascular disease risk score (P = 0.004) CONCLUSION: F-NaF uptake is closely related to diabetes mellitus, whereas aortic calcification on CT is closely related to hypertension. Although F-NaF uptake in DTA can be a potential prognostic factor, aortic calcification on CT is a more significant prognostic factor for overall cardiovascular risk than F-NaF uptake.

Aims: Identification of invasive and radionuclide imaging markers of coronary plaque vulnerability by a single, widely available non-invasive technique may provide the opportunity to identify vulnerable plaques and vulnerable patients in broad populations. Our aim was to assess whether radiomic analysis outperforms conventional assessment of coronary computed tomography angiography (CTA) images to identify invasive and radionuclide imaging markers of plaque vulnerability., Methods and Results: We prospectively included patients who underwent coronary CTA, sodium-fluoride positron emission tomography (NaF18-PET), intravascular ultrasound (IVUS), and optical coherence tomography (OCT). We assessed seven conventional plaque features and calculated 935 radiomic parameters from CTA images. In total, 44 plaques of 25 patients were analysed. The best radiomic parameters significantly outperformed the best conventional CT parameters to identify attenuated plaque by IVUS [fractal box counting dimension of high attenuation voxels vs. non-calcified plaque volume, area under the curve (AUC): 0.72, confidence interval (CI): 0.65-0.78 vs. 0.59, CI: 0.57-0.62; P < 0.001], thin-cap fibroatheroma by OCT (fractal box counting dimension of high attenuation voxels vs. presence of low attenuation voxels, AUC: 0.80, CI: 0.72-0.88 vs. 0.66, CI: 0.58-0.73; P < 0.001), and NaF18-positivity (surface of high attenuation voxels vs. presence of two high-risk features, AUC: 0.87, CI: 0.82-0.91 vs. 0.65, CI: 0.64-0.66; P < 0.001)., Conclusion: Coronary CTA radiomics identified invasive and radionuclide imaging markers of plaque vulnerability with good to excellent diagnostic accuracy, significantly outperforming conventional quantitative and qualitative high-risk plaque features. Coronary CTA radiomics may provide a more accurate tool to identify vulnerable plaques compared with conventional methods. Further larger population studies are warranted., (© The Author(s) 2019. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Aims: To compare the cost-effectiveness of coronary computed tomography angiography (CCTA) vs. myocardial single photon emission computed tomography (SPECT) in patients with stable intermediate risk chest pain., Methods and Results: Non-acute patients with 10-90% pre-test probability of coronary artery disease from three high-volume centres in Korea (n = 965) were randomized 1:1 to CCTA or myocardial SPECT as the initial non-invasive imaging test. Medical costs after randomization, the downstream outcome, including all-cause death, acute coronary syndrome, cerebrovascular accident, repeat revascularization, stent thrombosis, and significant bleeding following the initial test and the quality-adjusted life-years (QALYs) gained by the EuroQoL-5D questionnaire was compared between the two groups. In all, 903 patients underwent the initially randomized study (n = 460 for CCTA, 443 for SPECT). In all, 65 patients underwent invasive coronary angiography (ICA) in the CCTA and 85 in the SPECT group, of which 4 in the CCTA and 30 in the SPECT group demonstrated no stenosis on ICA [6.2% (4/65) vs. 35.3% (30/85), P-value < 0.001]. There was no difference in the downstream clinical events. QALYs gained was higher in the SPECT group (0.938 vs. 0.955, P-value = 0.039) but below the threshold of minimal clinically important difference of 0.08. Overall cost per patient was lower in the CCTA group (USD 4514 vs. 5208, P-value = 0.043), the tendency of which was non-significantly opposite in patients with 60-90% pre-test probability (USD 5807 vs. 5659, P-value = 0.845)., Conclusion: CCTA is associated with fewer subsequent ICA with no difference in downstream outcome. CCTA may be more cost-effective than SPECT in Korean patients with stable, intermediate risk chest pain., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2018. For permissions, please email: journals.permissions@oup.com.)

Background: 18 F-sodium fluoride ( 18 F-NaF) positron-emission tomography has been introduced as a potential noninvasive imaging tool to identify plaques with high-risk characteristics in patients with coronary artery disease. We sought to evaluate the clinical relevance of 18 F-NaF uptake using optical coherence tomography (OCT), intravascular ultrasound (IVUS), and coronary computed tomography angiography in patients with coronary artery disease., Methods and Results: The target population consisted of 51 prospectively enrolled patients (93 stenoses) who underwent 18 F-NaF positron-emission tomography before invasive coronary angiography. 18 F-NaF uptake was compared with IVUS- and OCT-derived plaque characteristics. In the coronary computed tomography angiography subgroup (46 lesions), qualitative lesion characteristics were compared between 18 F-NaF-positive and 18 F-NaF-negative plaques using adverse plaque characteristics. The plaques with 18 F-NaF uptake showed significantly higher plaque burden, more frequent posterior attenuation and positive remodeling in IVUS, and significantly higher maximum lipid arc and more frequent microvessels in OCT (all P <0.05). There were no differences in minimum lumen area and area of calcium between 18 F-NaF-positive and 18 F-NaF-negative lesions. Among 51 lesions with 18 F-NaF-positive uptake, 48 lesions (94.1%) had at least one of high-risk characteristics. The 18 F-NaF tissue-to-background ratio in plaques with high-risk characteristics was significantly higher than in those without (1.09 [95% confidence interval, 0.85-1.34] versus 0.62 [95% confidence interval, 0.42-0.82], P <0.001 for IVUS definition; 0.76 [95% confidence interval, 0.54-0.98] versus 0.42 [95% confidence interval, 0.21-0.62], P =0.014 for OCT definition). Among the 15 lesions that met both IVUS- and OCT-defined criteria for high-risk plaque, 14 (93.3%) showed 18 F-NaF-positive uptake. There was no difference in the prevalence of plaques with any adverse plaque characteristics between 18 F-NaF-positive and 18 F-NaF-negative plaques in the coronary computed tomography angiography subgroup (85.2% versus 78.9%; P =0.583)., Conclusions: This study's results suggest that 18 F-NaF positron-emission tomography can be a useful noninvasive diagnostic tool to identify and localize plaque with high-risk characteristics., Clinical Trial Registration: URL: http://www.clinicaltrials.gov. Unique identifier: NCT02388412., (© 2017 American Heart Association, Inc.)

Objective: We evaluated the relationships between coronary flow reserve (CFR) and relative flow reserve (RFR) measured by N-13 ammonia positron emission tomography (PET) for characterization of epicardial coronary artery disease (CAD)., Methods: Sixty-nine consecutive stable angina patients underwent N-13 ammonia PET, coronary computed tomography angiography (CCTA), and if necessary, invasive coronary angiography (CAG) within 2 weeks. Myocardial blood flow (MBF), CFR, RFR, and coronary vascular resistance of the reference arterial territory (CVR ref ) were measured by N-13 ammonia PET. The presence of significant stenosis (SS) and diffuse atherosclerosis (DA) was evaluated on CCTA and CAG. Functional parameters measured by PET were compared among arteries with and without SS and DA., Results: Arteries with SS and those with DA showed significantly lower stress MBF, as compared to those without. RFR was significantly lower in arteries with SS as compared to those without, while CFR was not. CFR was significantly lower in arteries with DA as compared to those without, while RFR was not. Among arteries without SS, CFR was significantly lower in those with DA as compared to those without. However, among arteries with SS, CFR was similar between those with and without DA. In contrast, RFR was significantly lower in arteries with SS, regardless of the presence of DA. CFR and RFR showed a weak positive correlation (r = 0.269) with discordance in 24 cases (35%). Among the arteries with CFR-RFR discordance, the prevalence of DA was significantly higher in those with low CFR but preserved RFR, as compared to those with preserved CFR but low RFR (75 vs 25%, p = 0.028). CVR ref was significantly higher in arteries with DA, implicating a correlation of DA with underlying microvascular disease., Conclusions: CFR and RFR measured by myocardial perfusion PET could provide a comprehensive information for characterization of epicardial CAD.

Objective: Phase analysis using gated myocardial perfusion single-photon emission computed tomography (GMPS) is a tool used to assess left ventricular (LV) dyssynchrony. We attempted to investigate the role of LV dyssynchrony assessed by GMPS using phase analysis for the late LV function after coronary artery bypass graft surgery (CABG) in patients with patent grafts., Methods: A total of 45 patients who received off-pump CABG with patent graft 1 year after CABG and preserved perfusion reserve were enrolled retrospectively. All patients underwent GMPS before and 3 months and 1 year after CABG. Using the Emory Cardiac Toolbox, both phase histogram bandwidth (PBW) and phase SD derived by phase analysis were used for the analysis, in addition to the conventional perfusion parameters. For the evaluation of LV function, transthoracic echocardiography was also performed., Results: All of the patients showed perfusion improvement (paired t-test, P<0.05) after CABG. Nonetheless, 30 of 45 patients showed LV dyssynchrony 3 months after CABG. One year after CABG, however, 25 out of 45 patients showed reverse remodeling. Among those patients with reverse remodeling, 19 patients had shown LV 3 months after CABG. Using stepwise logistic regression with forward selection, PBW 3 months after CABG could predict reverse remodeling 1 year after CABG (odds ratio 1.03, P<0.05). Using receiver operating characteristic analysis, PBW 3 months after CABG had the largest area under the curve to detect reverse remodeling 1 year after CABG with a cut-off value of 82 (sensitivity 0.95, specificity 0.56, P<0.001)., Conclusion: Postoperative LV dyssynchrony assessed by GMPS using phase analysis may reflect late reverse remodeling and potential of further functional improvement in patients with patent grafts and preserved perfusion reserve after CABG.

Background: Recent evidence suggests that the diagnostic accuracy of myocardial perfusion imaging is improved by quantifying stress myocardial blood flow (MBF) in absolute terms. We evaluated a comprehensive quantitative (13)N-ammonia positron emission tomography ((13)NH3-PET) diagnostic panel, including stress MBF, coronary flow reserve (CFR), and relative flow reserve (RFR) in conjunction with relative perfusion defect (PD) assessments to better detect functionally significant coronary artery stenosis., Methods and Results: A total of 130 patients (307 vessels) with coronary artery disease underwent both (13)NH3-PET and invasive coronary angiography with fractional flow reserve (FFR) measurement. Diagnostic accuracy, optimal cut points, and discrimination indices of respective (13)NH3-PET quantitative measures were compared, with FFR as standard reference. The capacity to discern disease with stepwise addition of stress MBF, CFR, and RFR to qualitatively assessed relative PD was also gauged, using the category-free net reclassification index. All quantitative measures showed significant correlation with FFR (PET-derived CFR, r=0.388; stress MBF, r=0.496; and RFR, r=0.780; all P<0.001). Optimal respective cut points for FFR ≤0.8 and ≤0.75 were 1.99 and 1.84 mL/min per g for stress MBF and 2.12 and 2.00 for PET-derived CFR. Discrimination indices of quantitative measures that correlated with FFR ≤0.8 were all significantly higher than that of relative PD (area under the curve: 0.626, 0.730, 0.806, and 0.897 for relative PD, CFR, stress MBF, and RFR, respectively; overall comparison P<0.001). The capacity for functionally significant coronary stenosis was incrementally improved by the successive addition of CFR (net reclassification index=0.629), stress MBF (net reclassification index=0.950), and RFR (net reclassification index=1.253; all P<0.001) to relative PD., Conclusions: Integrating quantitative (13)NH3-PET measures with qualitative myocardial perfusion assessment provides superior diagnostic accuracy and improves the capacity to detect functionally significant coronary artery stenosis., Clinical Trial Registration: URL: http://www.clinicaltrials.gov. Unique identifiers: NCT01621438 and NCT01366404., (© 2016 American Heart Association, Inc.)

Background: Improvements in myocardial perfusion and thickening were compared in coronary artery bypass grafting patients who received saphenous vein (SV) Y-composite grafts versus those who received right internal thoracic artery ([R]ITA) Y-composite grafts., Methods: Of the 224 patients enrolled in a randomized clinical trial, 116 patients (SV group, n = 65; RITA group, n = 51) in whom myocardial single-photon-emission computed tomography was performed preoperatively, and at 3 months and 1 year postoperatively, were retrospectively studied. A 20-segment model was adopted, and a total of 792 ischemic myocardial segments (SV group, n = 443; RITA group, n = 349) were analyzed. The reversibility score (rest minus stress perfusion value) as an indicator of ischemic myocardium, and Z-values for segmental myocardial thickening, were calculated., Results: Compared with preoperative values, both myocardial perfusion and segmental myocardial thickening had improved significantly at 3 months and 1 year postoperatively (reversibility scores [mean ± SD] were, respectively: 13.5 ± 8.0 vs 5.8 ± 6.2 and 5.1 ± 6.2, P < .001; Z-values were -1.13 ± 1.53 vs -0.62 ± 1.40 and -0.67 ± 1.35, P < .001). Mixed-effect model analyses showed no differences in improvements in myocardial perfusion and segmental myocardial thickening between the 2 groups 1 year after revascularization. Separate analysis demonstrated less improvement of myocardial perfusion in the right coronary artery territory of the RITA group than the SV group, with marginal significance (P = .056)., Conclusions: Improvements in myocardial perfusion and segmental myocardial thickening were similar between the 2 groups at 1 year after revascularization. The SV, versus the right ITA, composite graft may be more beneficial in perfusion improvement of the right coronary artery territory., (Copyright © 2015 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.)

Different angiographic patterns and restenosis rate may affect diagnostic value of single-photon emission computed tomography (SPECT) in the era of drug-eluting stents (DES). We aimed to determine the ability of myocardial SPECT to detect in-stent restenosis (ISR) in patients treated with DES compared to that of patients treated with bare metal stent (BMS). We evaluated 228 consecutive patients who underwent 6 months follow-up SPECT and coronary angiography (CAG) after stent implantation. In 228 patients, 354 vessels were treated with stent implantation (BMS, n = 105; DES, n = 249) and 65 (18.4%) vessels showed ISR (angiographic % diameter stenosis ≥ 50%) at the 6-month follow-up CAG. In patients with BMS-ISR (n = 37), restenosis was primarily diffuse (70.3%), whereas patients with DES-ISR (n = 28) exhibited more focal restenosis (53.6%, p = 0.028). The sensitivity and specificity of myocardial SPECT did not differ significantly between patients with BMS and those with DES (BMS vs. DES: sensitivity 56.8 vs. 39.3%, p = 0.163; specificity 72.1 vs. 76.5%, p = 0.460). Evaluation of 71 false positive and 33 false negative lesions showed that the most common cause of false-positive results in SPECT was the perfusion decrease which improved but not disappeared compared with the baseline (46 among 71 vascular territories). Despite different patterns of restenosis and ISR rates, the diagnostic value of SPECT did not differ between BMS and DES. Further study looking at ISR in larger number of patients and using other protocol such as Fleming-Harrington Redistribution Wash-in Washout may give additional information.

Purpose: Ischaemic myocardial dysfunction shows different time courses of functional recovery according to the pathophysiological characteristics of the dysfunction. In this study, we investigated the time course of functional recovery according to the preoperative reversibility of perfusion impairment on myocardial single-photon emission computed tomography (SPECT) after revascularisation surgery., Methods: Forty-eight patients (42 men and 6 women; mean age 59+/-9 years) who underwent revascularisation surgery were included in the study. 201Tl rest/dipyridamole stress (99m)Tc-sestamibi gated SPECT was performed 10+/-8 days before (preoperative), 105+/-13 days after (early follow-up) and 497+/-66 days after (late follow-up) surgery. Using a 20-segment model, segmental perfusion and thickening were quantified with automatic software. As an indicator of the reversibility of perfusion impairment, a reversibility score (RevS) was defined as a measure of rest minus stress perfusion values. Segmental dysfunction and functional recovery were defined from quantified thickening values. Function-recovered segments were divided into early recovery and late recovery groups, and preoperative perfusion status was compared in these groups. Function-recovered segments were also re-classified into high-RevS and low-RevS groups according to the preoperative RevS, and the time courses of functional recovery were investigated in each group., Results: A total of 502 segments were included in the analysis and 263 were finally classified as function-recovered segments. Of these, 172 were in the early recovery and 91 in the late recovery group. In terms of preoperative perfusion status, RevS was 8.9+/-10.8 in the early recovery group and 5.4+/-11.0 in the late recovery group (P=0.01). When all 502 segments were classified by RevS, no difference in the proportion of final function recovery was observed between the high-RevS and the low-RevS group (54% vs 51%). However, the proportion of early recovery was higher in the high-RevS group (73%) than in the low-RevS group (57%) (P=0.01)., Conclusion: Ischaemic dysfunctional myocardium with reversible perfusion impairment tends to recover function earlier after revascularisation surgery than myocardium with a persistent decrease in perfusion.

Myocardial viability can be defined as functional improvement of dysfunctional myocardium after revascularization. The purpose of this study was to define the optimal criteria for definition of regional functional improvement after coronary artery bypass graft (CABG) surgery on quantitative gated single-photon emission tomography (SPET). Thirty-two patients (26 men, 6 women; age 56 +/- 13 years) with coronary artery disease (three-vessel disease, 17; two-vessel disease, 15; previous history of myocardial infarction, 9) and severe left ventricular dysfunction (LVEF < or = 35%) underwent CABG. Rest thallium-201/dipyridamole stress technetium-99m methoxyisobutylisonitrile gated myocardial SPET was performed before and 3 months after CABG. Global LV functional improvement was defined as either an improvement in LVEF of 10% ( n = 15) or an improvement in LVEF of 5% combined with a decrease in end-systolic volume of 10 ml ( n = 2) after CABG on quantitative gated SPET. Postoperative regional wall thickening improvement (DeltaRWT), regional wall motion improvement (DeltaRWM) and regional resting (DeltaRP) and stress perfusion improvement (DeltaRstrP) were used to determine global functional improvement by ROC curve analysis, and the optimal criteria for definition of viable regional dysfunctional myocardium were defined on the ROC curves. Correlations were verified by determining the number of improved myocardial regions and LVEF improvement. LVEF was improved from 25% +/- 6% to 34% +/- 11% after CABG. A total of 229 segments were dysfunctional (wall motion < or = 2 mm, thickening < or = 20%) before CABG. On ROC curve analysis using global functional improvement as an indicator of viability, the areas under the ROC curves (AUCs) of DeltaRWT and DeltaRWM were 0.717 and 0.620, respectively. The AUC of DeltaRWT was significantly larger than that of DeltaRWM ( P = 0.009) and the optimal cut-off value of DeltaRWT was 15%. The AUCs of DeltaRP and DeltaRstrP were not significant. The correlation coefficients between summed DeltaRWT and DeltaRWM and LVEF improvement were 0.591 and 0.472, respectively. The number of segments with a DeltaRWT of more than 15% correlated with LVEF improvement (rho = 0.533 by Spearman rank correlation). Regional wall thickening improvement showed the best correlation with global LV functional improvement after CABG. The most reliable regional criterion of myocardial viability was improvement in regional wall thickening by > or = 15% on quantitative gated SPET.

Aims To compare the cost-effectiveness of coronary computed tomography angiography (CCTA) vs. myocardial single photon emission computed tomography (SPECT) in patients with stable intermediate risk chest pain. Methods and results Non-acute patients with 10–90% pre-test probability of coronary artery disease from three high-volume centres in Korea (n  = 965) were randomized 1:1 to CCTA or myocardial SPECT as the initial non-invasive imaging test. Medical costs after randomization, the downstream outcome, including all-cause death, acute coronary syndrome, cerebrovascular accident, repeat revascularization, stent thrombosis, and significant bleeding following the initial test and the quality-adjusted life-years (QALYs) gained by the EuroQoL-5D questionnaire was compared between the two groups. In all, 903 patients underwent the initially randomized study (n  = 460 for CCTA, 443 for SPECT). In all, 65 patients underwent invasive coronary angiography (ICA) in the CCTA and 85 in the SPECT group, of which 4 in the CCTA and 30 in the SPECT group demonstrated no stenosis on ICA [6.2% (4/65) vs. 35.3% (30/85), P -value < 0.001]. There was no difference in the downstream clinical events. QALYs gained was higher in the SPECT group (0.938 vs. 0.955, P -value = 0.039) but below the threshold of minimal clinically important difference of 0.08. Overall cost per patient was lower in the CCTA group (USD 4514 vs. 5208, P -value = 0.043), the tendency of which was non-significantly opposite in patients with 60–90% pre-test probability (USD 5807 vs. 5659, P -value = 0.845). Conclusion CCTA is associated with fewer subsequent ICA with no difference in downstream outcome. CCTA may be more cost-effective than SPECT in Korean patients with stable, intermediate risk chest pain. [ABSTRACT FROM AUTHOR]

Objectives The authors sought to compare the diagnostic performance of fractional flow reserve (FFR), instantaneous wave-free ratio (iFR), and resting distal coronary artery pressure/aortic pressure (Pd/Pa) using 13 N-ammonia positron emission tomography (PET). Background The diagnostic performance of invasive physiological indices was reported to be different according to the reference to define the presence of myocardial ischemia. Methods A total of 115 consecutive patients with left anterior descending artery stenosis who underwent both 13 N-ammonia PET and invasive physiological measurement were included. Optimal cutoff values and diagnostic performance of FFR, iFR, and resting Pd/Pa were assessed using PET-derived coronary flow reserve (CFR) and relative flow reserve (RFR) as references. To compare discrimination and reclassification ability, each index was compared with integrated discrimination improvement (IDI) and category-free net reclassification index (NRI). Results All invasive physiological indices correlated with CFR and RFR (all p values <0.001). The overall diagnostic accuracies of FFR, iFR, and resting Pd/Pa were not different for CFR <2.0 (FFR 69.6%, iFR 73.9%, and resting Pd/Pa 70.4%) and RFR <0.75 (FFR 73.9%, iFR 71.3%, and resting Pd/Pa 74.8%). Discrimination and reclassification abilities of invasive physiological indices were comparable for CFR. For RFR, FFR showed better discrimination and reclassification ability than resting indices (IDI = 0.170 and category-free NRI = 0.971 for iFR; IDI = 0.183 and category-free NRI = 1.058 for resting Pd/Pa; all p values <0.001). Conclusions The diagnostic performance of invasive physiological indices showed no differences in the prediction of myocardial ischemia defined by CFR. Using RFR as a reference, FFR showed a better discrimination and reclassification ability than resting indices. [ABSTRACT FROM AUTHOR]

Aims This study was conducted to investigate the incremental prognostic value of sequential use of single-photon emission computed tomography (SPECT) and coronary computed tomography angiography (CCTA) in patients with suspected coronary artery disease (CAD). Methods and results A total of 1295 patients with suspected CAD who underwent both CCTA and SPECT within 90 days was retrospectively reviewed in three cardiac centres. Cardiovascular events including cardiac death, non-fatal myocardial infarction, unstable angina, and late (> 90 days of imaging tests) revascularization were assessed. During the mean follow-up period of 795 ± 566 days (median, 735 days), there were 109 events (8.4%). Perfusion defect on SPECT and significant stenosis (≥50%) on CCTA were independent predictors for events. Sequential use of both imaging tests significantly improved prediction of the cardiovascular events. The incremental prognostic value of SPECT was significant in patients with stenosis of <90% but not in patients with stenosis of ≥90% on CCTA. Similarly, the incremental prognostic value of CCTA was significant in patients with the summed stress score (SSS) <4 but not in patients with SSS ≥4 on SPECT. Conclusions Sequential use of SPECT and CCTA showed an incremental prognostic value in patients with suspected CAD. However, additional benefits were not significant when CCTA revealed stenosis of ≥90% or SPECT revealed SSS ≥4. These results suggest an effective risk stratification strategy for sequential use of SPECT and CCTA, and maximizing the benefits in these patients. [ABSTRACT FROM PUBLISHER]