Objectives: The majority of patients with myocardial infarction (MI) and hypercholesterolaemia does not achieve guideline recommended low-density lipoprotein cholesterol (LDL) levels. Suboptimal dosages of statins explain this dilemma in most patients.
Design and setting: We evaluated the relationship between statin treatment quality (optimal: LDL<115 mg/dl, suboptimal: LDL>/=115 mg/dl, no statin therapy despite hypercholesterolaemia) and the subsequent incidence of coronary events (coronary death, nonfatal MI, bypass surgery) over a 30 months follow-up in a large cohort of post MI patients with hypercholesterolaemia (n=2045). Analysis was performed in a nested case-control manner comparing 173 cases with a coronary event and 346 matched controls.
Results: Patients who developed a coronary event were treated optimally in 11.0%, suboptimally in 43.4% (p<0.05 vs. optimal treatment) and were untreated in 45.7% (p<0.001 vs. optimal treatment). Respective numbers in event-free patients were 21.4%, 47.7%, and 30.9%. After adjustment for most potential confounders, including all cardiovascular risk factors and medication, the relative risk of future non-fatal MI and coronary death associated with a suboptimal statin treatment was 2.02 (95% CI 1.04 to 4.18) compared to optimal statin treatment. Moreover, the statin equivalent dose in optimally treated individuals was significantly higher than in suboptimally treated individuals (0.85+/-0.03 vs. 0.78+/-0.02, p<0.05).
Conclusion: In this community-based study, a lipid lowering therapy with statins into the recommended target range of LDL levels may be associated with decreased cardiovascular risk compared to a statin therapy without titrating the LDL level below 115 mg/dl. Thus, the quality of statin treatment was identified as an independent predictor of coronary events in post MI patients.