Statin therapy in individuals with intermediate cardiovascular risk

Abstract

Background: As intermediate cardiovascular risk group accounts for a large part of the total population, determining appropriate cholesterol target in this population is critical. Herein, we investigated the optimal low-density lipoprotein cholesterol (LDL-C) level in individuals with intermediate cardiovascular risk after statin therapy.

Methods: This was a nationwide observational and validation cohort study (median duration of follow-up: 7.5 and 8.7 years, respectively), using data from the Korean National Health Insurance Service and a tertiary hospital database. Among individuals who underwent regular health examinations, those with ≥2 cardiovascular risk factors except diabetes mellitus, LDL-C 100-189 mg/dL, and newly used statins were enrolled. Of the 358,694 screened people, 57,594 met the inclusion criteria, of whom 27,793 were finally analyzed. The study population was stratified according to post-treatment LDL-C levels as follows: <100, 100-119, 120-139, and ≥ 140 mg/dL. The primary outcome variable was composite cardiovascular events (myocardial infarction, coronary revascularization, and ischemic stroke). From the patients screened of Severance Hospital cohort, 1859 meeting inclusion criteria were used for validation.

Results: The rates of composite events ranged from 7.74 to 9.10 (mean 8.38)/1000 person-years in the three lower LDL-C groups. Adjusted hazard ratios (aHRs) ranged from 0.78 to 0.95 in the three groups with lower LDL-C, and a lower event risk was more evident in the groups that achieved LDL-C levels <120 mg/dL (p = 0.001-0.009). The total mortality risk did not differ between groups. In the validation cohort, the mean rate of composite events was 10.83/1000 person-years. aHRs ranged from 0.52 to 0.78 in the groups with lower LDL-C, and a lower risk was more obvious in patients who achieved LDL-C levels <100 mg/dL (p = 0.006-0.03).

Conclusions: Individuals with intermediate cardiovascular risk who achieved LDL-C levels <120 mg/dL after statin therapy had lower event risk. This result provides clinically useful evidence on target LDL-C levels in this population.

Keywords: Atherosclerosis; Coronary artery disease; Evidence-based medicine; Lipid metabolism; Outcome assessment, health care.