Prognostic Impact of Nonobstructive Coronary Artery Disease Detected by Coronary Computed Tomographic Angiography

Coronary computed tomographic angiography (CCTA) is a promising technique for ruling out coronary artery disease (CAD) in patients with chest pain. We aimed to investigate the prognostic impact of nonobstructive CAD on CCTA. We retrospectively reviewed patients who underwent CCTA between 2010 and 2016 at our institution. We divided them into 3 groups: (1) patients with no CAD, (2) patients with nonobstructive CAD, and (3) patients with obstructive CAD. We investigated the incidence of the primary outcome (combination of death, nonfatal myocardial infarction, unstable angina, and late revascularization). A total of 989 patients were included: 540 patients had CAD, which was obstructive (≥50% stenosis) in 256 cases. During the follow-up period, 99 events occurred (32 [7%] in patients without CAD, 26 [9%] in patients with nonobstructive CAD, and 41 [16%] in patients with obstructive CAD; P < .001). The presence of nonobstructive and obstructive CAD was an independent predictor of events (HR: 2.33 [1.15-4.69], P < .001; and 4.02 [1.98-8.13], P = .019, respectively) compared with no CAD. Nonobstructive CAD on CCTA is associated with a 2-fold increase in risk of coronary events compared with patients with no CAD.