Differences in coronary artery disease by CT angiography between patients developing unstable angina pectoris vs. major adverse cardiac events

Abstract

Objective: CT angiography (CTA) has prognostic value in patients. But it is unknown whether differences in atherosclerosis by CTA predict the development of unstable angina pectoris (UAP) vs. major adverse cardiac events (MACE).

Methods: We followed patients undergoing CTA as part of their acute chest pain work-up. Primary outcome was the development of UAP or MACE (cardiac death, myocardial infarction, revascularization) during a minimum follow-up of 12-months. CTAs were assessed for extent and composition of coronary plaque and stenosis. Ordinal regression with a 3-level outcome (no events, UAP, MACE) was applied.

Results: Among 315 patients, 22 developed UAP and 31 MACE. While UAP patients had higher atherosclerosis burden with respect to all assessed features compared to patients with no events (p ≤ 0.02), only mixed plaque extent was significantly different between UAP and MACE patients (p=0.02). The odds ratio was 4.55 for being in a higher disease-level comparing patients with low extent to those with no mixed plaque, and 3.02 comparing patients with high to those with low. These findings remained after adjustments for potential confounders.

Conclusion: The extent of mixed coronary plaque is different between patients who develop UAP vs. MACE, supporting the hypothesis that it is a more culprit morphology.

Keywords: Computed tomographic angiography; Major adverse cardiac events; Partially calcified plaque; Unstable angina pectoris; Vulnerable plaque.