Residual cardiovascular risk in patients who received lipid-lowering treatment in a real-life setting: retrospective study

INTRODUCTION: The objective of this study was twofold: 1) to assess the residual cardiovascular (CV) risk among patients treated with statins according to guidelines and at the recommended dosages; and 2) to assess the difference, if any, in the frequency of CV events when patients were treated with other lipid-lowering agents alongside statins. METHODS: A retrospective observational study including one local health unit was conducted. Administrative databases were linked to laboratory test database in order to collect cholesterol values at baseline. Patients were included if they had filled at least one prescription for statins between January 1, 2009 and December 31, 2011; patients’ records were considered for a 12-month time span. RESULTS: A total of 27,330 patients treated with statins were included (50% male, mean age 68.0±11.5 years). Among them, 770 were treated with statins according to guidelines and at the recommended dosages and had a low density lipoprotein-cholesterol value below the therapeutic target. Nevertheless, the risk of myocardial infarction or stroke remained: incidence rates were 1.3±1.0 per patient per year for moderate CV risk, 4.1±2.6 for high risk, and 12.5±11.0 for very high risk. This incremental risk was confirmed further using the Cox model, by correcting for age, sex, use of antiplatelet and/or antihypertensive therapy, and adherence to treatment. As a second analysis, we compared, after a propensity score matching, patients extracted from the overall sample who were treated with fibrates. Based on the Cox model, patients on fibrates had a risk for myocardial infarction or stroke lower than patients on statins. CONCLUSION: Among patients treated with statins according to guidelines and at the recommended dosages, a residual CV risk was observed. We concluded that intervention for managing residual CV risk during statin therapy should be implemented.