In Reply We thank the authors for their insightful comments regarding our substudy of the Prospective Multicenter Imaging Study for Evaluation of Chest Pain (PROMISE) trial.1 The authors have made several important points, and we would like to provide the data and rationale to support our analyses and conclusions.
We appreciate the intricacies of the data obtained from a coronary computed tomography angiography (CTA) evaluation. The authors correctly note that the prognostic information gained from a coronary CTA is not only from the presence or absence of obstructive coronary disease but also based on the plaque location and morphology. A separate substudy of the PROMISE trial examined the risk stratification of patients using high-risk coronary plaque detection.2 In that analysis, the authors found that, among patients in the PROMISE trial, the presence of high-risk plaque conferred an independent risk of a major adverse cardiovascular event beyond that of cardiovascular risk factors and obstructive coronary artery disease. However, importantly, there was no significant difference in age between patients with or without high-risk plaque identified by coronary CTA (61.0 years vs 60.4 years; P = .07). When patients were stratified by age less than vs greater than the median, the study showed that the predictive value of high-risk plaque presence was stronger in younger patients (adjusted hazard ratio [HR], 2.33; 95% CI, 1.20-4.51) than in older patients (adjusted hazard ratio, 1.36; 95% CI, 0.77-2.39). This aligns with our study where CTA better stratified risk for cardiovascular death or myocardial infarction among patients younger than 65 years.