Coronary Plaque Features on CTA Can Identify Patients at Increased Risk of Cardiovascular Events

Objectives: This study sought to assess whether coronary atherosclerosis analysis by coronary computed tomography angiography (CTA) may improve prognostic stratification among patients with diffuse coronary artery disease (CAD) BACKGROUND: Coronary CTA has recently emerged as a promising noninvasive tool for advanced analysis of coronary atherosclerosis.

Methods: The multicenter CAPIRE (Coronary Atherosclerosis in outlier subjects: Protective and novel Individual Risk factors Evaluation) study is part of the GISSI Outlier Project. A prospective cohort of subjects who underwent coronary CTA for suspected CAD was enrolled. Based on risk factor (RF) burden, patients were defined as having a low clinical risk (0 to 1 RF with the exclusion of patients with diabetes mellitus as single RF) or at high clinical risk (3 or more RFs). Patients with 2 RFs were not enrolled in the study. Coronary CTA advanced plaque assessment was performed. Outcome measures were 3 combined endpoints: acute coronary syndrome (ACS), cardiac death + ACS, and cardiac death + ACS + late revascularization.

Results: Among the 544 patients enrolled in the CAPIRE study, in 522 patients, a mean follow-up of 37 ± 10 months was obtained (16 patients were excluded due to 1 < segment involvement score <5 at core lab coronary CTA analysis and 6 patients were lost at follow-up). Higher atherosclerotic burden was found in patients with higher clinical risk, but prevalence of elevated noncalcified plaque volume did not significantly differ between low- versus high-risk patients. Quantitative plaque parameters by coronary CTA were associated with composite endpoints at multivariable analysis when corrected for univariate predictors. Elevated noncalcified plaque volume, expressed as dichotomic variable, was associated with all combined endpoints. Even if the low absolute number of events represents a limitation to the present study, patients with low noncalcified plaque volume had similar risk of cardiac events independently from the presence of multivessel disease, while patients with high noncalcified plaque volume had higher rates of cardiac events.

Conclusions: The CAPIRE study confirmed the prognostic value of atherosclerosis assessment by coronary CTA, demonstrating high noncalcified plaque volume as the most ACS-predictive parameter in patients with extensive CAD. (GISSE Outliers CAPIRE [CAPIRE]; NCT02157662).