Ten-year statin adherence in survivors of st-segment elevation myocardial infarction: Insights from the ami-quebec study

Abstract

Background Adherence to statins is often sub-optimal and declines over time. Direct costs incurred by patients are often cited as responsible for inadequate statin adherence. To determine whether patients with ST-segment elevation myocardial infarction (STEMI) who benefit from low or no-cost drug dispensation have optimal long-term adherence to statins, we aimed to evaluate 10-year adherence to statin in a cohort of STEMI survivors. Methods The AMI-QUEBEC Study follows a cohort of STEMI patients hospitalized at 17 hospitals in Quebec, Canada during the year 2003. We obtained 10-year data on lipid lowering therapy (LLT) consumption in STEMI survivors with drug coverage by the Quebec Provincial Health Board (i.e., Régie de l’Assurance Maladie du Québec – RAMQ). Optimal adherence was defined as the proportion of days covered (PDC) of ≥80%. We used multivariate logistic regression to determine factors independently associated with optimal adherence to statins. Results Complete 10-year data on statin dispensation was available for 524 patients. Optimal adherence remained stable over time at 80% and more during the 10-year follow-up period. During the last 5 years, despite being STEMI patients at very high-risk and therefore requiring some LLT therapy, 12% of patients did not use any LLT. Patients between the age of 60 and 80 years had the most optimal PDC. Older age (up to 80 years), living in less socially deprived areas, concomitant use of angiotensin-converting-enzyme inhibi-tors (ACEI) or angiotensin receptor blockers (ARB), and admission to percutaneous coronary interventions (PCI)-hospitals were associated with improved statin adherence. Conclusion Future studies are needed to explore the potential factors associated with concomitant use of ACEI/ARB, and admission to PCI-hospitals that may have optimized statin adherence. As for socially deprived patients (single, widow, single-parent family member, and those who lived alone), they may benefit from more support and encouragement to enhance their long-term statin adherence.