Acute treatment of myocardial infarction in Canada 1999-2002

Background — Therapy for management of acute myocardial infarction (AMI) varies according to patient, prescriber and geographical characteristics.

Objectives — To describe the in-hospital use of reperfusion therapy for ST elevation MI (STEMI) and discharge use of acetylsalicylic acid, beta-blockers, angiotensin-converting enzyme inhibitors (ACEIs) and statins in patients presenting with either STEMI or non-STEMI in Canada from 1999 to 2002.

Methods — Four Canadian registries (FASTRAK II, Canadian Acute Coronary Syndromes, Enhanced Feedback for Effective Cardiac Treatment and Improving Cardiovascular Outcomes in Nova Scotia) were used to identify patients with AMI in Canada and to measure in-hospital reperfusion and medication use. Use rates were compared by age, sex, time period and geographical area, according to available data.

Results — Use rates for reperfusion in STEMI patients ranged from 60% to 70%, primarily representing fibrinolytic therapy. A delay in presentation to hospital after symptom onset represented an impediment to timely therapy, which was particularly pronounced for women and elderly patients. Overall, less than 50% of patients met the door-to-needle target of less than 30 min. Medication use rates at discharge increased from 1999/2000 to 2000/2001 across the different data sources: acetylsalicylic acid, 83% to 88%; beta-blockers, 74% to 89%; ACEIs, 54% to 67%; statins, 41% to 53%; and calcium antagonists, 21% to 32%.

Conclusions — Canadian and provincial rates of use of evidence-based medications for the treatment of AMI have increased over time, although there remains room for improvement. A single, comprehensive data source would supply better insights into the management of AMI in Canada.