Ten-Year Statin Adherence in Survivors of ST-Segment Elevation Myocardial Infarction

Background          Adherence to statins is often sub-optimal and declines over time. Direct costs incurred by patients are frequently cited as responsible for inadequate statin adherence. To determine whether survivors of 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 the ten-year adherence to statin of these patients. Methods          The AMI-QUEBEC Study follows a cohort of STEMI survivors hospitalized at 17 hospitals in Quebec, Canada during the year 2003. We obtained their 10-year data on lipid lowering therapy (LLT) consumption. Optimal adherence was defined as the proportion of days covered 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 five years, 12% of patients did not use any LLT. Older age, living in less socially deprived areas, concomitant use of angiotensin-converting-enzyme inhibitors (ACEI) or angiotensin receptor blockers (ARB), and admission to hospitals with percutaneous coronary interventions facilities (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. Socially deprived patients may benefit from more support and encouragement to enhance their long-term statin adherence.