Prognosis of anatomic coronary artery disease without myocardial ischemia: Coronary computed tomography angiography detects high-risk patients even in cases of negative single-photon emission computed tomography findings

Abstract

BackgroundWhile coronary computed tomography angiography (CCTA) provides comprehensive anatomic evaluation of coronary artery disease (CAD) with prognostic implications, clinically, the focus is usually placed on presence or absence of functionally significant CAD. Herein, we aimed to suggest a new risk stratification strategy using CCTA in patients with anatomic CAD but without myocardial ischemia on single-photon emission computed tomography (SPECT). MethodsConsecutive patients (n=798) with CAD on CCTA who underwent SPECT for evaluation of myocardial ischemia were retrospectively evaluated. The primary outcome was the occurrence of adverse cardiac events, including cardiac death, nonfatal myocardial infarction, unstable angina, and late revascularization. ResultsOf the enrolled patients, 542 (68%) showed no perfusion defect (PD) on SPECT. During the follow-up (median, 22.6 months), adverse cardiac events occurred in 23 patients without PD (4.6%). Presence of plaque in ≥4 coronary segments, plaque in the left main or proximal left anterior descending coronary artery, and partially calcified plaque presence were independent predictors of adverse events. When we defined the CCTA score based on these 3 predictors (0–3 points), the annualized event rates increased with increasing CCTA scores. Patients with a CCTA score of 3 were associated with a 23-fold risk increase (adjusted HR 23.18; p=0.003) and showed unfavorable event-free survival, comparable to those with PD on SPECT (p=0.191). ConclusionAnatomic CAD patients without evidence of myocardial ischemia on SPECT but with high-risk characteristics on CCTA showed unfavorable outcomes, comparable to those with PD. CCTA allows further risk stratification even in patients with negative SPECT findings.