Drug prescriptions after acute myocardial infarction: Dosage, compliance, and persistence

Background Although it has been well documented that aspirin, beta-blockers; angiotensin-converting enzyme (ACE) inhibitors, and lipid-lowering drugs are under-prescribed for patients with acute myocardial infarction (Am Heart J 2003; 145:438-44.), few studies have examined dosage and long-term compliance and persistence patterns for the use of these drugs after AMI. Methods Using Quebec administrative data on all elderly (aged greater than or equal to65 years) survivors of hospital admissions for AMI between 1996 and 1998 (n = 14,057), we studied the discharge prescriptions, dosages, patient compliance, and per-. sistence during this period for aspirin, beta-blockers, ACE inhibitors, and lipid-lowering drugs. Results Rates of discharge medications were suboptimal (aspirin 65%, beta-blockers 54%, ACE inhibitors 45%, lipid-lowering drugs 21%). Most patients with prescriptions for aspirin and ACE inhibitors were prescribed dosages equivalent to those administered in clinical trials (99% and 88%, respectively). In contrast, only 20% of patients with beta-blocker prescriptions and 48%a of patients with lipid-lowering drug prescriptions were prescribed clinical trial doses. For patients with discharge prescriptions, 1-year compliance rates were high (aspirin 74%, beta-blockers 74%, ACE inhibitors 70%a, lipid-lowering drugs 84%), as were the 1-year persistence rates (aspirin 71%, beta-blockers 72%, ACE inhibitors 69%, lipid-lowering drugs 80%). Conclusion Although cardiac drugs are under-prescribed to patients with AMI, once prescribed, patients are likely to adhere to these prescriptions, with high rates of compliance and persistence.