Sex-based differences in clinical practice and outcomes for Japanese patients with acute myocardial infarction undergoing primary percutaneous coronary intervention.
BACKGROUND
 Limited data are available for sex-based differences in Japanese patients with acute myocardial infarction (AMI) undergoing primary percutaneous coronary intervention (PCI).


METHODS AND RESULTS
 The study patients comprised 1,197 women and 3,182 men who underwent primary PCI for AMI in 2005-2007. Compared with the men, the women were significantly older, and had significantly longer onset-to-balloon time and lower rate of follow-up coronary angiography. In-hospital mortality was higher among women than men (8.7% vs. 4.9%, P<0.001). Although the cumulative incidence of all-cause death at 3 years was also higher for women (17.7% vs. 10.7%, P<0.001), the adjusted risk for all-cause death was comparable [hazard ratio (HR, women vs. men)=0.94, 95% confidence interval (CI): 0.71-1.24, P=0.66]. The incidence (12.1% vs. 12.4%, P=0.77) and the adjusted risk (HR=0.99, 95% CI 0.78-1.24, P=0.92) for any clinically-driven coronary revascularization were both comparable. However, regarding any non-clinically-driven coronary revascularization, the incidence (19.6% vs. 27.8%, P<0.001) and the adjusted risk (HR=0.79, 95% CI 0.65-0.95, P=0.012) were both lower in women relative to men.


CONCLUSIONS
 In current Japanese clinical practice for AMI, onset-to-balloon time was significantly longer in women than in men. Female sex was associated with lower follow-up coronary angiography rate and lower incidence of any non-clinically-driven coronary revascularization, whereas the incidence of any clinically-driven coronary revascularization was comparable between the sexes. 