Prognostic Implications of Nonobstructive Coronary Plaques in Patients With Non–ST-Segment Elevation Myocardial Infarction: A Multidetector Computed Tomography Study

Abstract

We sought to determine whether the amount of noncalcified plaque (NCP) in nonobstructive coronary lesions as detected by multidetector computed tomography (MDCT) was a predictor of future coronary events. Patients presenting with non–ST-segment elevation myocardial infarction (NSTEMI) frequently have multiple coronary plaques, which may be detected with MDCT. We included 312 consecutive patients presenting with NSTEMI, who underwent 64-slice MDCT coronary angiography and coronary artery calcium scoring before invasive coronary angiography. All patients were treated according to current guidelines based on an invasive treatment approach. Quantitative measurements of plaque composition and volume were performed by MDCT in all nonobstructive coronary lesions. The endpoint was cardiac death, acute coronary syndrome, or symptom-driven revascularization. After a median follow-up of 16 months, 23 patients had suffered a cardiac event. Age, male sex, and diabetes mellitus were all associated with an increasing amount of NCP. In a multivariate regression analysis for events, the total amount of NCP in nonobstructive lesions was independently associated with an increased hazard ratio (1.18/100-mm3 plaque volume increase, p = 0.01). Contrary to this, neither Agatston score nor the amount of calcium in nonobstructive lesions was associated with an increased risk. Multidetector computed tomography plaque imaging identified patients at increased risk of recurrent coronary events after NSTEMI by measuring the total amount of NCP in nonobstructive lesions. The amount of calcified plaque was not associated with an increased risk.