Parabolas of medication use and discontinuation after myocardial infarction--are we closing the treatment gap?
OBJECTIVE
Little is known on the use of evidence-based medications in patients with acute myocardial infarction (AMI) across all ages. We undertook this study to describe the patterns of prescription and discontinuation of anti-platelet agents, beta-blockers, angiotensin converting enzyme (ACE) inhibitors and/or angiotensin receptor blockers (ARBs) and statins in all patients post-AMI.


METHODS
Using population-based administrative databases, patients with an AMI between 1999 and 2004 (21 494 men and 13 241 women) were identified. Rates of prescriptions after discharge and time to discontinuation of the study drugs were computed for various age groups.


RESULTS
The proportion of patients prescribed a study drug increased throughout the study period. In 2003-2004, 90% of patients were prescribed an anti-platelet agent, 77% a beta-blocker, 72% a statin and 70% an ACE inhibitor and/or an ARB within 30 days of discharge from their AMI. However, the rates of discontinuation increased significantly during follow-up and, in men, reached 27% by 2 years and 42% by 5 years for beta-blockers. The rates of discontinuation of all four study drugs had a parabolic shape with the youngest and oldest patients having the highest rates.


CONCLUSIONS
The use of evidence-based drugs for patients after AMI is increasing. However, efforts aimed at closing the treatment gap may be mitigated by high rates of discontinuation, especially in patients at the extremes of the age spectrum.
Hudson
Marie
M
Division of Clinical Epidemiology, the Research Institute of the McGill University Health Center, 687 Pine Avenue west, Building V, Montreal, Québec, Canada. marie.hudson@mcgill.ca
Richard
Hugues
H
Pilote
Louise
L
D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D047228:Angiotensin II Type 1 Receptor Blockers / Q000627:therapeutic use; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000627:therapeutic use; D001241:Aspirin / Q000627:therapeutic use; D016208:Databases, Factual; D019317:Evidence-Based Medicine; D005260:Female; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000188:drug therapy*; D010351:Patient Discharge / Q000706:statistics & numerical data; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use; D010818:Practice Patterns, Physicians' / Q000706:statistics & numerical data*
D000319:Adrenergic beta-Antagonists; D047228:Angiotensin II Type 1 Receptor Blockers; D000806:Angiotensin-Converting Enzyme Inhibitors; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D010975:Platelet Aggregation Inhibitors; D001241:Aspirin