Abstract P27: Effect of Age on Sex Difference in In-Hospital Mortality by Type of Myocardial Infarction: Results from the MarketScan Database

Abstract

Background: Studies have shown consistently that younger women hospitalized with a myocardial infarction (MI) have poorer prognosis than men. It remains unclear whether this relationship is true for both ST-elevation MI (STEMI) and non-ST-elevation MI (NSTEMI) patients. Methods: Using the MarketScan 2004-2007 in-patient admission database, we assessed the sex difference in in-hospital mortality according to age among 87,962 (STEMI: 34,720; NSTEMI: 53,242) patients who were 18 to 89 years of age with an initial episode of MI as the primary diagnosis. The interaction between age (18-49, 50-59, 60-69, 70-79 and 80-89 yrs) and sex was examined by multivariable logistic regression for STEMI, NSTEMI and the combined population before and after adjusting for other risk factors. Results: STEMI patients had significantly higher in-hospital mortality than NSTEMI patients (4.40% vs. 3.57%, p<0.0001). Women had older mean age than men at admission for the STEMI (65.5 vs. 59.5 yrs), NSTEMI (69.0 vs. 64.5 yrs) and the combined population (67.9 vs. 62.4 yrs). Women had higher comorbidity scores, and were less likely to undergo revascularization during hospitalization in all three populations. In both STEMI and the combined population, younger women had higher in-hospital mortality compared to men of similar age, and the mortality difference between women and men decreased with aging, with women having better outcomes after 80 years of age in the combined population. After adjustment for potential confounding factors, the excess risk in in-hospital mortality for younger women compared with men persisted. In NSTEMI patients, the difference between younger women and younger men was not statistically significant, however, older women (age ≥70) had better outcomes than men (see Table). Conclusions: Higher risk of in-hospital mortality in younger women is confined to STEMI, but not NSTEMI, patients. Management of younger women with STEMI may require more use of intensive care. Table Odds Ratios (Women vs. Men) of In-hospital Mortality by Type of Myocardial Infarction Variable Combined population STEMI NSTEMI Before adjustment After adjustment Before adjustment After adjustment Before adjustment After adjustment 18-49 yrs 1.822 (1.29, 2.56) 1.648 (1.15, 2.36) 2.285 (1.48, 3.54) 1.960 (1.23, 3.11) 1.480 (0.86, 2.56) 1.254 (0.71, 2.22) 50-59 yrs 1.531 (1.26, 1.86) 1.446 (1.18, 1.78) 1.699 (1.29, 2.23) 1.531 (1.14, 2.06) 1.451 (1.10, 1.91) 1.284 (0.96, 1.72) 60-69 yrs 1.339 (1.14, 1.57) 1.262 (1.06, 1.50) 1.481 (1.17, 1.88) 1.310 (1.01, 1.70) 1.301 (1.04, 1.62) 1.241 (0.98, 1.57) 70-79 yrs 1.019 (0.89, 1.16) 0.970 (0.84, 1.12) 1.306 (1.07, 1.59) 1.253 (1.01, 1.56) 0.848 (0.71, 1.01) 0.817 (0.68, 0.99) 80-89 yrs 0.888 (0.79, 0.99) 0.887 (0.78, 1.01) 0.988 (0.81, 1.20) 0.956 (0.77, 1.19) 0.823 (0.71, 0.95) 0.820 (0.73, 0.99) P value for interaction <0.0001 <0.0001 0.0010 0.0234 0.0002 0.0073