Age-specific gender differences in in-hospital mortality by type of acute myocardial infarction.

Younger women hospitalized with an acute myocardial infarction (MI) have a poorer prognosis than men. Whether this is true for patients with acute ST-segment elevation MI (STEMI) and non-STEMI (NSTEMI) is not extensively studied. Using the MarketScan 2004 to 2007 Commercial and Medicare supplemental admission databases, we assessed gender differences in in-hospital mortality according to age in 91,088 patients (35,899 with STEMI, 55,189 with NSTEMI) who were 18 to 89 years old and had acute MI as their primary diagnosis. Patients with STEMI had significantly higher in-hospital mortality than those with NSTEMI (4.35% vs 3.53%, p <0.0001). Compared to men women were older, had higher co-morbidity scores, and were less likely to undergo revascularization during hospitalization in the STEMI and NSTEMI populations. In patients with STEMI the unadjusted women-to-men odds ratio for in-hospital mortality was 2.29 (95% confidence interval 1.48 to 3.55) for the 18- to 49-year age group, 1.68 (1.28 to 2.21) for 50 to 59, 1.48 (1.17 to 1.88) for 60 to 69, 1.28 (1.06 to 1.57) for 70 to 79, and 1.01 (0.83 to 1.23) for 80 to 89. Corresponding unadjusted odds ratios were 1.51 (0.87 to 2.61), 1.46 (1.11 to 1.92), 1.29 (1.04 to 1.61), 0.83 (0.70 to 0.99) and 0.82 (0.70 to 0.94) for patients with NSTEMI. After adjustment for potential confounding factors, excess risk for in-hospital mortality in younger women versus their men counterparts (<60 years old) persisted in STEMI. In patients with NSTEMI the difference between younger women and younger men was not statistically significant; however, older women (≥70 years old) had better survival than men. In conclusion, higher risk of in-hospital mortality in younger women compared to younger men is more evident in patients with STEMI.