Long-Term Prognostic Value of Coronary Computed Tomography Angiography in an Asymptomatic Elderly Population

Abstract

Background The prognostic value of coronary computed tomographic angiography (CCTA) for evaluating coronary artery disease in asymptomatic older adults is controversial. We investigated the prognostic value of CCTA in community-dwelling elderly Koreans. Methods and Results Participants (n=470; mean age: 75.1±7.3 years) who underwent CCTA were enrolled from KLoSHA (Korean Longitudinal Study on Health and Aging), a community-based prospective cohort. Using CCTA, coronary artery disease was classified as normal, nonobstructive, or obstructive according to the presence of 0%, <50%, or ≥50% stenosis, respectively. Coronary artery calcium scores were investigated together with Framingham risk score, atherosclerotic cardiovascular disease score, and individual risk factors. Major adverse cardiac events (MACE) were defined as a composite of cardiac event-related death or nonfatal myocardial infarction. During a median follow-up of 8.2 years (interquartile range: 7.7-10.1 years), MACE occurred in 24 participants (5.1%). Compared with the normal group, participants in the obstructive group showed higher incidence of MACE (hazard ratio: 5.65; 95% CI, 1.22-26.16; P=0.027), whereas there were no significant differences in MACE between the normal and nonobstructive groups. The 8-year event-free survival rates were 98.1±1.1%, 94.9±1.6%, and 81.7±4.8% in the normal, nonobstructive, and obstructive groups, respectively. Compared with the Framingham risk score and coronary artery calcium score model, CCTA improved risk prediction by C-index (from 0.698 to 0.749) and category-free net reclassification index (0.478; P=0.022). Conclusions CCTA showed better long-term prognostic value for MACE than coronary artery calcium score in this asymptomatic older population.

Keywords: Asian; elderly; major adverse cardiac outcome; prognosis; subclinical atherosclerosis.

Figure 1

Kaplan–Meier curves for cardiac event‐free survival based on coronary computed tomographic angiography (CCTA) findings among asymptomatic older adults. Event‐free survival curves according to (A) the severity of coronary artery disease (CAD), (B) the number of diseased vessels, (C) segment involvement score (SIS), (D) segment stenosis score (SSS), and (E) modified Duke score. LM, left main; VD, vessel disease.