Introduction: Patients with a history of myocardial infarction (MI) are at very high risk of subsequent cardiovascular events. This study evaluated the association of treatment intensity and adherence to lipid-lowering therapies (LLT) with major adverse cardiovascular events (MACE) among post-MI patients in Germany.
Methods: We carried out a retrospective cohort study using German health claims data (2010-2015). We included patients ≥ 18 years, with a history of MI and who started an LLT (statin and/or ezetimibe), between 2011 and 2013. The follow-up period started 1 year after the second LLT prescription and continued until MACE, all-cause death or December 31, 2015, whichever occurred first. Treatment intensity was classified based on expected low-density lipoprotein cholesterol reduction; adherence was measured by the proportion of days covered using prescription data. A combined adherence-adjusted intensity variable was created by multiplying intensity and adherence. We used Cox proportional hazards models to control for age, sex, Charlson Comorbidity Index and other cardiovascular risk factors at baseline.
Results: A total of 14,944 patients were included. Mean age was 66.7 (SD = 13.0) years; 68.7% of patients were men. Each 10% increase in treatment intensity, adherence, or adherence-adjusted intensity was associated with a decrease in the risk of MACE of 17% (HR = 0.83, 95% CI 0.79-0.87), 5% (HR = 0.95, 95% CI 0.94-0.97), and 14% (HR = 0.86, 95% CI 0.83-0.90), respectively.
Conclusions: Higher treatment intensity and/or adherence of LLT was associated with significantly lower risk of MACE in post-MI patients. Strategies to tailor intensity to patient profiles and improve adherence could reduce the risk of cardiovascular events.
Keywords: Cardiovascular disease; Lipid-lowering therapy; Myocardial infarction; Statins; Treatment adherence; Treatment intensity.