Remnant Cholesterol Predicts Risk of Cardiovascular Events in Patients With Myocardial Infarction With Nonobstructive Coronary Arteries

Background Remnant cholesterol (RC) has been reported to promote atherosclerotic cardiovascular disease. Yet little is known regarding the RC-related residual risk in patients with myocardial infarction (MI) with nonobstructive coronary arteries. Methods and Results A total of 1179 patients with MI with nonobstructive coronary arteries were enrolled and divided according to median level of RC calculated as non-high-density lipoprotein cholesterol minus low-density lipoprotein cholesterol. The primary end point was a composite of major adverse cardiovascular events (MACEs), including all-cause death, nonfatal MI, stroke, revascularization, and hospitalization for unstable angina or heart failure. Kaplan-Meier, Cox regression, and receiver-operating characteristic analyses were used. Patients with higher median level of RC had a significantly higher incidence of MACEs (16.9% versus 11.5%; P=0.009) over the median follow-up of 41.7 months. High RC levels were significantly associated with an increased risk of MACEs after adjustment for multiple clinically relevant variables (per 1 SD increase, hazard ratio, 0.61; 95% CI, 1.12-2.31; P=0.009). Elevated RC also contributed to residual risk beyond conventional lipid parameters. Moreover, RC had an area under the curve of 0.61 for MACE prediction. When adding RC to the Thrombolysis in Myocardial Infarction risk score, the combined model yielded a significant improvement in discrimination for MACEs. Conclusions Elevated RC was closely associated with poor outcomes after MI with nonobstructive coronary arteries independent of traditional risk factors, indicating the utility of RC for risk stratification and a rationale for targeted RC-lowering trials in patients with MI with nonobstructive coronary arteries.