Aim: Early and intensive low-density lipoprotein (LDL-C)-lowering therapy plays important roles in secondary prevention of acute coronary syndrome (ACS), but the treatment period for further clinical benefit remains undefined. This single-center, retrospective study explored LDL-C trajectory after ACS and its associations with subsequent cardiovascular events (CVE).
Methods: In 831 patients with ACS, we evaluated LDL-C reduction during the first 2 months post-ACS as an index of early intervention and the area over the curve for LDL-C using 70 mg/dl as the threshold in the next 6 months (AOC-70) as a persistent intensity index. Patients were followed for a median of 3.0 (1.1-5.2) years for CVE, defined as the composite of cardiovascular death, non-fatal myocardial infarction, angina pectoris requiring revascularization, cerebral infarction, and coronary bypass grafting.
Results: LDL-C decreased from baseline to 2 months post-ACS (107±38 mg/dl to 78±25 mg/dl, p＜0.001) through high-intensity statin prescription (91.8%), while achieving rates of LDL-C ＜70 mg/dl at 2 months remained only 40.2% with no significant changes thereafter. During the follow-up period, CVE occurred in 200 patients. LDL-C reduction during the first 2 months and AOC-70 in the next 6 months were both associated with subsequent CVE risk (sub-HR [hazard ratio] [95% confidence interval]: 1.48 [1.16-1.89] and 1.22 [1.05-1.44]). Furthermore, early intervention followed by persistently intensive LDL-C-lowering therapy resulted in further CVE risk reduction.
Conclusions: The present study observed that achieving early and intensive LDL-C reduction within the first two months after ACS and maintaining it for the next six months suppressed subsequent CVE risk, suggesting the importance of early, intensive, and persistent LDL-C-lowering therapy in the secondary prevention of ACS.
Keywords: Acute coronary syndrome; Early intervention; High-intensity statins; Intensive LDL-C-lowering therapy; Residual risk.