Search

Background Mismatches between the severity of coronary stenosis and the presence of ischemia by invasive fractional flow reserve (FFR) are frequently reported. Purpose To investigate whether plaque characteristics as evaluated with coronary computed tomography angiography (CCTA) may explain this discordance in nonobstructive versus obstructive coronary artery disease (CAD). Methods From the CREDENCE trial, 612 patients with suspected CAD at 13 sites (64±10 years, 70% men) underwent CCTA with semi-automated whole heart quantification and invasive coronary angiography with 3-vessel FFR measurements. Obstructive CAD was visually defined as ≥50% stenosis. The primary endpoint of coronary vessel-specific ischemia was defined as FFR ≤0.80. Generalized estimating equations were calculated to evaluate the effect of plaque characteristics on coronary vessel-specific ischemia. Interactions were tested by obstructive CAD, adjusted for age. Results Among 1,686 vessels, ischemia was present in 436 (26%) vessels. In both nonobstructive and obstructive CAD, the majority of plaque characteristics were associated with coronary vessel-specific ischemia (p≤0.005, Figure 1). In nonobstructive CAD, odds for ischemia were significantly higher for total percent atheroma volume (PAV, p Conclusion Our findings reveal that ischemia by FFR is documented in the setting of both nonobstructive and obstructive CAD on CCTA. Detection of atherosclerotic plaque characteristics associated with ischemia can potentially improve diagnostic certainty and guide management of symptomatic patients with nonobstructive CAD. Figure 1. Odds ratios for ischemia. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): National Institutes of Health - National Heart, Lung, and Blood Institute

Background Evolving evidence suggests unique sex-specific mechanisms underlying coronary artery disease (CAD). However, it remains unknown if certain coronary atherosclerotic features confer a higher risk for ischemia in women versus men. Purpose To determine the association between coronary atherosclerotic features on coronary computed tomography angiography (CCTA) and ischemia by invasive fractional flow reserve (FFR) in women versus men. Methods Secondary analysis of the CREDENCE trial, including patients referred for nonemergent invasive coronary angiography (ICA). All patients underwent CCTA with semi-automatic quantification of coronary atherosclerosis, as well as ICA with FFR interrogation of all major epicardial arteries ≥2 mm. Generalized estimating equations were calculated to assess the association between coronary atherosclerotic features and invasive vessel-specific ischemia (FFR ≤0.80). Sex interactions were tested, adjusted for age. Results From 612 patients (mean age 64±10 years, 30% women) with 1,686 analyzed vessels, a total of 436 (26%) vessels were ischemic. Women were significantly older than men (p30% stenosis (p=0.030), noncalcified PAV Conclusion Our results support a prominent influence of coronary atherosclerotic features that uniquely impact ischemic risk among women more so than men. These data support the role of CCTA for providing valuable information to guide management of symptomatic women. Figure 1. Ischemic risk in women vs. men Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): National Institutes of Health - National Heart, Lung, and Blood Institute

Background Atherosclerotic plaques in the left circumflex artery (LCx) are associated with a lower risk of future events than plaques in the right coronary artery (RCA) and left anterior descending artery (LAD). High risk plaque subtypes including necrotic core and fibrofatty plaque can be evaluated on computed coronary tomography angiography (CCTA) by Hounsfield Unit (HU) density. To date, little is known regarding differences in high risk plaque composition between major epicardial vessels. Purpose The aim of this analysis was to compare plaque extent and composition between the three coronary arteries. Methods This is a secondary analysis of baseline scans from the PARADIGM study which enrolled consecutive patients with suspected coronary artery disease undergoing serial CCTA at a scan interval of ≥2 years. Plaque quantification by composition was performed in the three coronary arteries based on fixed HU thresholds: high risk subtypes consisting of necrotic core ( Results From 1,271 patients (mean age 60.3±9.3 years; 57% men; median ASCVD score 9.3%), 3,813 vessels were analyzed. The prevalence of any plaque was lowest in the LCx, as was the prevalence of high risk plaque (Figure; P Conclusion Prevalence of any plaque as well as high risk plaque subtypes was significantly higher in the LAD and RCA than in the LCx. Also, high risk plaque subtypes made up significantly the lowest proportion in the LCx, whereas calcified plaque made up the largest proportion in the LCx. These data support a different atherogenic milieu contributing to the variable risk patterns between the epicardial coronary arteries. Figure 1. Prevalence of (high risk) plaque Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): This work was supported by the Leading Foreign Research Institute Recruitment Program through the National Research Foundation (NRF) of Korea funded by the Ministry of Science and ICT (MSIT) (Grant no. 2012027176).