Why is the In-Hospital Case-Fatality Rate of Acute Myocardial Infarction Higher in Women?

Abstract

Purpose - To assess the influence of age, disease severity at admission and therapeutic interventions on the higher in-hospital case-fatality rate of acute myocardial infarction (MI) in women. Methods - A retrospective cohort study involving a total of 388 acute MI patients (50 deaths). The following variables were treated as possible explanatory factors for the association between gender and case-fatality rate of acute MI: age (<60 vs ≥ 60 years), duration of symptoms, Killip class, type of infarction (Q wave vs non-Q wave), comorbidities, previous history of stroke and specific therapeutic interventions for acute MI (aspirin, beta-blocking drugs, and thrombolytic agents). Logistic regression models were used to assess the influence of potential confounders on the association between gender and in-hospital death. Results -The in-hospital case-fatality rate of acute MI was higher in women (19.5% vs 9.4%) than in men (odds ratio (OR) = 2.34; 95% CI= 1.12-4.47). Although women were significantly older than men (p<0.01), the association between gender and death was reduced only by 15 percent after adjusting for age (OR=1.99; 95% CI= 1.07-3.67). This association became weaker after taking into account disease severity at admission (OR=1.84; 95% CI= 0.90-3.74) and therapeutic interventions for acute MI (OR=1.50; 95% CI= 0.67-3.38). Conclusion - Differences in age cannot fully explain the higher case-fatality rate in women than in men with acute MI. Severity of disease at admission and differences in therapeutic interventions might play an important role in the higher case-fatality rate of acute MI among women.