Sex-Related Differences in In-Hospital Mortality in Japanese ST-Elevation Acute Myocardial Infarction Patients Presenting to Hospital in the 24 Hours After Symptom Onset　― Results From K-ACTIVE ―

Background: Despite the drastic advances in clinical care for patients with acute ST-elevation myocardial infarction (STEMI), female STEMI patients have higher in-hospital mortality rates than male patients. This study assessed the influence of sex on in-hospital mortality in STEMI patients in Kanagawa Prefecture, Japan. Methods and Results: From October 2015 to June 2018, 2,491 consecutive STEMI patients (23.9% female) who presented to hospital in the 24 h after symptom onset were analyzed. The female patients were 9 years older and less frequently had diabetes, smoking and prior MI than male patients. Pre-hospital managements, including prehospital 12-lead electrocardiography, and symptom-to-door time were similar between the sexes. A door-to-device time ≤90 min was achieved in 61.3% of female cases and in 65.0% of male cases (P=0.13). Reperfusion therapy was provided to 94.6% of female and 97.6% of male patients (P<0.001). In-hospital mortality rate was not significantly different between female and male patients (6.6% vs. 7.8%, P=0.37). On multivariate logistic regression analysis, female sex itself was not associated with in-hospital mortality (OR, 1.52; 95% CI: 0.67–3.47, P=0.32). Conclusions: There was no sex discrepancy in the in-hospital mortality of STEMI patients in this study. Guideline-based treatment, such as advanced pre-hospital management and a high use of reperfusion therapy might have attenuated the sex-related differences in the in-hospital mortality.