Long-term mortality of patients with acute myocardial infarction in the United States and Canada: comparison of patients enrolled in Global Utilization of Streptokinase and t-PA for Occluded Coronary Arteries (GUSTO)-I.

Abstract

BACKGROUND:

In a previous substudy of the GUSTO-I trial, we observed better functional and quality-of-life outcomes among patients in the United States (US patients) compared with patients in Canada. Rates of invasive therapy were significantly higher in the United States and were associated with a small mortality benefit (0.4%, adjusted P=0.02). We sought to determine whether Canadian-US differences in practice patterns in GUSTO-I had an impact on 5-year mortality.

METHODS AND RESULTS:

Mortality data for 23,105 US and 2898 Canadian patients enrolled in GUSTO-I were obtained from national mortality databases. Median follow-up was 5.46 years in the US and 5.33 years in the Canadian cohort. Five-year mortality rate was 19.6% among US and 21.4% among Canadian patients (P=0.02). After baseline adjustment, enrollment in Canada was associated with a higher hazard of death (1.17; 95% confidence interval, 1.07 to 1.28, P=0.001). Revascularization rates during the index hospitalization in the United States were almost 3 times those in Canada: 30.5% versus 11.4% for angioplasty and 13.1% versus 4.0% for bypass surgery (P<0.01 for both). After accounting for revascularization status as a time-dependent covariate, country was no longer a significant predictor of long-term mortality. These results were confirmed in a propensity-matched analysis.

CONCLUSIONS:

Our results suggest, for the first time, that the more conservative pattern of care with regard to early revascularization in Canada for ST-segment elevation acute myocardial infarction may have a detrimental effect on long-term survival. Our results have important policy implications for cardiac care in countries and healthcare systems wherein use of invasive procedures is similarly conservative.

• Authors: Padma Kaul, Paul W Armstrong, Wei-Ching Chang, C David Naylor, Christopher B Granger, Kerry L Lee, Eric D Peterson, Robert M Califf, Eric J Topol, Daniel B Mark
• Journal: Circulation (Circulation) Vol. 110 Issue 13 Pg. 1754-60 (Sep 28 2004) ISSN: 1524-4539 [Electronic] United States
• PMID: 15381645 (Publication Type: Clinical Trial, Comparative Study, Journal Article, Multicenter Study, Randomized Controlled Trial, Research Support, Non-U.S. Gov't)

Chemical References

• Anticoagulants
• Fibrinolytic Agents
• Heparin
• Streptokinase
• Tissue Plasminogen Activator

Topics

• Aged
• Angioplasty (statistics & numerical data)
• Anticoagulants (administration & dosage, therapeutic use)
• Canada (epidemiology)
• Case Management
• Cohort Studies
• Comorbidity
• Coronary Artery Bypass (statistics & numerical data)
• Drug Therapy, Combination
• Female
• Fibrinolytic Agents (administration & dosage, therapeutic use)
• Follow-Up Studies
• Heparin (administration & dosage, therapeutic use)
• Humans
• Injections, Intravenous
• Injections, Subcutaneous
• Male
• Middle Aged
• Myocardial Infarction (drug therapy, mortality, surgery, therapy)
• Myocardial Revascularization (methods, statistics & numerical data)
• Practice Patterns, Physicians'
• Proportional Hazards Models
• Streptokinase (therapeutic use)
• Survival Analysis
• Thrombolytic Therapy (statistics & numerical data)
• Tissue Plasminogen Activator (therapeutic use)
• Treatment Outcome
• United States (epidemiology)