Cardiovascular event rates and trajectories of LDL-cholesterol levels and lipid-lowering therapy in patients with atherosclerotic cardiovascular disease: A population-based cohort study.

BACKGROUND

An understanding of cardiovascular event rates and low-density lipoprotein cholesterol (LDL-C) levels and trajectories in patients with atherosclerotic cardiovascular disease is needed to evaluate treatment goals and adherence to guidelines.

METHODS

We conducted a population-based cohort study in the North and Central Denmark Regions. Patients with prevalent atherosclerotic cardiovascular disease (myocardial infarction, non-hemorrhagic stroke, or peripheral artery disease) during 2006-2009 were identified. All patients received lipid-lowering therapy (statins or ezetimibe) and had LDL-C levels ≥1.8 mmol/L at baseline (January 1, 2010). We followed patients for 6 years until a primary composite outcome of cardiovascular death, myocardial infarction, non-hemorrhagic stroke, hospitalization for unstable angina, or coronary revascularization. Additionally, we characterized changes in LDL-C levels and use of statins during follow-up.

RESULTS

The study included 10,772 patients (median age 69.2 years, 60.4% male). The overall event rate for the primary outcome was 62.7 (95% confidence interval: 59.2-66.2) per 1000 person-years. This event rate was higher among men than among women and increased with age and baseline LDL-C levels. Approximately 25% of patients with LDL-C measurements during follow-up achieved LDL-C levels below 1.8 mmol/L. Of the approximately two-thirds of patients using statins at the end of follow-up, nearly all patients (97%) received high-intensity therapy.

CONCLUSIONS

In this population of patients with atherosclerotic cardiovascular disease, we found high cardiovascular event rates, which increased with baseline LDL-C levels. Although most patients were on high-intensity statin therapy at end of follow-up, only one-quarter reached the guideline-recommended target LDL-C level ≤ 1.8 mmol/L.