Abstract 14555: International Comparison of Treatment and Long-Term Outcomes for Acute Myocardial Infarction in the Elderly: Minneapolis/St. Paul, MN, US and Gteborg, Sweden

Abstract

Background: International studies of medical practice provide an opportunity to compare treatment approaches and outcomes. Hospitalized acute myocardial infarction (AMI) patients in Minneapolis/St. Paul, US (MSP) and Göteborg, Sweden (GB) were compared. We hypothesized that treatment and long-term outcomes of AMI patients differed between these developed countries.

Methods: A population-based sample of hospitalized AMI (ICD-9 410) patients aged 75 and older in MSP and GB in 2001-02 was abstracted by trained nurses. Mortality was ascertained from death certificates. Patient characteristics, cardiovascular procedures and in-hospital and discharge medications were compared using sex-specific age-adjusted generalized linear models. Cox proportional hazards regression was used to calculate adjusted hazard ratios (HR). Analyses were weighted by the inverse of the sampling fraction.

Results: In MSP 839 (387 men, 452 women) and in GB 564 (275 men, 289 women) AMI patients were identified. Patient age was similar (men: MSP 83 ± 7, GB 82 ± 5; women: MSP 84 ± 6, GB 84 ± 6) yet MSP patients had more prior cardiovascular comorbidities and coronary procedures (PCI/CABG). Guideline-based medication use was high and differed modestly between MSP and GB. MSP AMI patients were significantly more likely to undergo PCI (men: MSP 33%, GB 7%; women: MSP 30%, GB 6%). Thrombolysis was used more often in GB. After adjustment for baseline characteristics and guideline-based therapies, among women, AMI patients in MSP were significantly more likely to survive (HR 0.77; 95% confidence interval [CI] 0.62-0.97; P=0.03) (Figure); among men, there was no difference in survival (HR 0.93; 95% CI 0.77-01.13; P=0.47).

Conclusion: In MSP and GB, the use of guideline-based therapies was high. However, utilization of PCI was markedly higher in MSP. Long-term survival was significantly higher among MSP women suggesting an invasive approach or subsequent care among elderly women is beneficial.