Estimated cumulative LDL-C exposure and risk of recurrent cardiovascular events after acute coronary syndrome.

BACKGROUND AND AIMS: Lipid-lowering therapy is essential for secondary prevention in patients with acute coronary syndrome (ACS). Although cumulative LDL-C exposure is a major determinant of cardiovascular risk, its assessment is often impractical due to the lack of longitudinal lipid data. Estimated cumulative LDL-C exposure (eCLE), defined as the product of age and a single LDL-C measurement, has been proposed as a simple surrogate. This study evaluated the clinical utility of eCLE after ACS. METHODS: The HIJ-PROPER trial enrolled 1734 patients with ACS. eCLE was calculated from age and the LDL-C measured at the index event. Among these, 1721 patients with available data were stratified by the median value (8643 mg/dL-years). The primary endpoint was a composite of all-cause death, non-fatal myocardial infarction, non-fatal stroke, unstable angina, and ischemia-driven revascularization. RESULTS: During the entire follow-up period, the endpoint occurred in 339 patients (39.4%) in the high eCLE group and in 260 patients (30.2%) in the low eCLE group. High eCLE was associated with a significantly higher risk of events compared with low eCLE (hazard ratio, 1.37; 95% confidence interval, 1.17-1.61; p < 0.001). This association remained statistically significant after multivariable adjustment, and higher eCLE was associated with an increased risk across quartiles (P for trend = 0.042), with the strongest association at the 8000 mg/dL-years threshold. CONCLUSIONS: Although eCLE does not improve discrimination beyond age and LDL-C entered separately, it is a simple and practical metric that may be useful for risk stratification of cardiovascular events after ACS.