Is the difference in outcome between men and women treated by primary percutaneous coronary intervention age dependent? Gender difference in STEMI stratified on age

Abstract

Aim:

Poorer outcomes in women with ST-elevation myocardial infarction (STEMI) are often attributed to gender differences in baseline characteristics. However, these may be age dependent. We examined the importance of gender in separate age groups of patients with STEMI undergoing primary percutaneous coronary intervention (PPCI).

Methods and results:

Data of 6746 consecutive patients with STEMI admitted for PPCI between 1998 and 2008 in our hospital were evaluated. Age was stratified into two groups, <65 years (young group) and ≥65 years (elderly). Endpoints were enzymic infarct size as well as 30-day and 1 year mortality. We studied a total of 4991 (74.0%) men and 1755 (26.0%) women; 40% of women were <65 years and 60% of men were <65 years of age. In the elderly group (≥65 years), women had more frequently diabetes and hypertension while they smoked less frequently than men. Younger women smoked more often than similarly aged men and had more hypertension. At angiography, single-vessel disease and TIMI 3 flow before PPCI was more present in younger women than men, whereas these differences were not found in the older age group. Patient delay before admission was shorter in men at all ages, while women had lower creatine kinase levels. Younger women had a higher mortality after 30 days (HR 2.1, 95% CI 1.3−3.4) and at 1 year (HR 1.7, 95% CI 1.2−2.6), whereas in the older age group women mortality rates were higher at 30 days (HR 1.5, 95% CI 1.1−2.0) but not at 1 year (HR 1.2, 95% CI 0.9−1.5). After multivariate analysis, 1-year mortality remained significantly higher in women at younger age (HR 1.7, 95% CI 1.1−2.5). Patient delay before admission was shorter in men in both age groups. Creatine kinase levels were in both age groups higher in men.

Conclusions:

Differences in mortality between men and women with STEMI treated with PPCI are age dependent. Although young women have less obstructive coronary artery disease and more often TIMI 3 flow before PCI (suggesting a lower risk), survival was worse compared to similarly aged men. Women had a longer patient delay compared to men, but this was not related to gender-specific mortality.