Relation of gender to infarct size in patients with ST-segment elevation myocardial infarction undergoing primary angioplasty

Previous reports have shown that female gender is associated with impaired outcomes among patients with ST-segment elevation myocardial infarction (STEMI) treated by thrombolysis, mainly owing to a worst risk profile (more diabetes, more advanced age, and higher Killip class at presentation) compared to men. Still contrasting are data on the effect of gender on the outcome in patients with STEMI undergoing primary angioplasty. In particular, it is still unclear whether a larger infarct size might contribute to the explanation of the worse outcome in women. Therefore, the aim of the present study was to investigate gender-related differences in infarct size as evaluated by myocardial scintigraphy in a large cohort of patients with STEMI undergoing primary percutaneous coronary intervention. We included 830 patients with STEMI undergoing primary percutaneous coronary intervention. The infarct size was evaluated at 30 days using technetium-99m-sestamibi. A logistic regression analysis was performed to determine the relation between gender and infarct size (as percentage of patients above the median) after correction for baseline confounding factors. We also evaluated the presence of a potential age-gender interaction. A total of 183 patients (20.8%) were women. Female gender was associated with more advanced age and a greater prevalence of hypertension; previous infarction and smoking were more frequently observed in men. Female gender was associated with a smaller infarct size (p <0.001) that was confirmed after correction for baseline confounding factors (adjusted odds ratio 0.48, 95% confidence interval 0.33-0.7, p <0.001). No age-gender interaction was observed (p = 0.13). In conclusion, the results of the present study have shown that despite the presence of high-risk features at presentation, female gender was associated with a smaller infarct size than that in men, without any interaction between age and gender.