Elevated Remnant Cholesterol Reclassifies Risk of Ischemic Heart Disease and Myocardial Infarction.

Abstract

Elevated remnant cholesterol causes ischemic heart disease. We tested the hypothesis that the inclusion of elevated remnant cholesterol will lead to appropriate reclassification of individuals who later experience myocardial infarction and ischemic heart disease. For >10 years we followed up 41,928 white Danish individuals from the Copenhagen General Population Study without a history of ischemic cardiovascular disease, diabetes, and statin use. Using predefined cut points for elevated remnant cholesterol, we calculated net reclassification index (NRI) from below to above 5%, 7.5%, and/or 10% 10-year occurrence of myocardial infarction and ischemic heart disease defined as a composite of death from ischemic heart disease, myocardial infarction, and coronary revascularization. For individuals with remnant cholesterol levels ≥95th percentile (≥1.6 mmol/L, 61 mg/dL), 23% (P < 0.001) of myocardial infarction and 21% (P < 0.001) of ischemic heart disease were reclassified correctly from below to above 5% for 10-year occurrence when remnant cholesterol levels were added to models based on conventional risk factors, whereas no events were reclassified incorrectly. Consequently, the addition of remnant cholesterol levels yielded NRI of 10% (95% CI: 1%-20%) for myocardial infarction and 5% (95% CI: -3% to 13%) for ischemic heart disease. Correspondingly, when reclassifications were combined from below to above 5%, 7.5%, and 10% risk of events, 42% (P < 0.001) of individuals with myocardial infarction and 41% (P < 0.001) with ischemic heart disease were reclassified appropriately, leading to NRI of respectively 20% (95% CI: 9%-31%) and 11% (95% CI: 2%-21%). Elevated remnant cholesterol levels considerably improve myocardial infarction and ischemic heart disease risk prediction.