Younger women have a higher risk of in-hospital mortality due to acute myocardial infarction in Chile

Introduction and objectives: Coronary heart disease is the second cause of death in Chilean women, with higher mortality among women, especially at younger ages. The objective was to analyze in-hospital case-fatality by sex and age in patients with acute myocardial infarction in Chile and to evaluate associated factors.

Methods: From the nationwide hospital admissions database and the GEMI registry (a multicenter registry), we selected all cases of acute myocardial infarction (code: I.21) that occurred between 2001 and 2007 in Chile. We estimated odds ratios for in-hospital case-fatality in women by age (crude and adjusted for clinical characteristics and treatment).

Results: In total, 49,287 cases of acute myocardial infarction were hospitalized, 31.3% of them women; 9278 patients were incorporated in the GEMI registry (27.1% women). In-hospital case-fatality was higher (P<.001) in women than men (national database, 20.4% vs 11.3%; GEMI, 14.2% vs 7.3%, irrespective of age. In-hospital case-fatality risk was higher in women aged<45 years: national odds ratio=2.3 (95% confidence interval, 1.5-3.3) and GEMI, odds ratio=2.7 (1.1-6.8). The estimated risk was lower in women aged 75 or more years in both databases, 1.3 (1.2-2.4) and 1.5 (1.2-1.9), respectively. Younger women less often received statins, odds ratio=0.7 (0.6-0.8); acetylsalicylic acid, odds ratio=0.4 (0.2-0.6); betablockers, odds ratio=0.8 (0.6-0.9), and thrombolytics, odds ratio=0.6 (0.5-0.8). An interaction was found between Killip class and sex. After adjusting for covariates, women aged<55 years with ST-segment elevation myocardial infarction and Killip class I-II, had the highest risk, odds ratio=4.3 (2.1-8.9).

Conclusions: In the context of a Latin American country, women aged<55 years with ST-segment elevation myocardial infarction and Killip class I-II had a higher risk of death. Known risk factors do not completely explain this excess of risk.