Effectiveness of adherence to lipid lowering therapy on LDL-cholesterol in patients with very high cardiovascular risk: A real-world evidence study in primary care

Abstract

Background and aimsDespite management guidelines advocating statin/ezetimibe use in very high cardiovascular risk (CV) conditions, adherence to this therapy is still suboptimal and LDL-C target attainment unsatisfactory. We aimed to investigate the level of adherence to statin/ezetimibe and LDL-C target achievement rates in an unselected very high CV risk population in primary care setting in Italy. MethodsWe performed a retrospective population-based study using the Health Search IMS Health Longitudinal Patient Database (HSD), including adult patients at very high CV risk, newly treated with statin, ezetimibe or their combination, with 3 and 6 months of follow-up. ResultsAlthough the large majority of patients had previous major CV events (99.9%), only 61% and 55.14% resulted adherent (Proportion of Days Covered, PDC≥80%) after 3 and 6 months, respectively. High adherence entailed almost a three times higher probability to reach the therapeutic LDL-C target (3 months: OR = 2.26 [95% [CI]: 1.88 to 2.72]; 6-months: OR = 2.74 [95% CI: 2.27 to 3.31]). The odds to treat to LDL-C target was greater for simvastatin-ezetimibe fixed combination, simvastatin, atorvastatin and rosuvastatin, in decreasing order. Finally, poor adherence was slightly more prevalent among patients treated with less effective statins, and at both low and maximal dosage regimens. ConclusionsThis population-based study showed that adherence to statin therapy is poor even among patients who have already experienced a CV event. Failure to achieve recommended LDL-C levels appears imputable to the use of moderate doses and low to standard efficacy statins.