Relative prognostic value of baseline Q wave and time from symptom onset among men and women with ST-elevation myocardial infarction undergoing percutaneous coronary intervention.

Q waves have been shown to be a stronger prognostic marker than time from symptom onset to percutaneous coronary intervention (PCI) in ST-segment elevation myocardial infarction. We examined whether the relative importance of these 2 measurements is modulated by patient gender. Q waves in the area of ST-segment elevation on baseline electrocardiogram were evaluated at a central core laboratory in 4,530 patients with ST-segment elevation myocardial infarction (3,468 men and 1,062 women) without previous infarction and who underwent PCI in the Assessment of Pexelizumab in Acute Myocardial Infarction (APEX-AMI) trial. Women were older and had higher rates of diabetes, hypertension, Killip class >I, and lower creatinine clearance compared to men. Time from symptom onset to PCI >3 hours was associated with a trend toward worse 90-day mortality (adjusted hazard ratio 1.5, 95% confidence interval 0.9 to 2.2) in men but not in women (0.8, 0.5 to 1.4). In contrast, presence of Q waves on baseline electrocardiogram was associated with significantly higher 90-day mortality in men (adjusted hazard ratio 1.7, 95% confidence interval 1.0 to 2.7) and women (2.3, 1.2 to 4.2). In conclusion, in this gender-specific analysis, baseline Q wave was found be a better marker of risk of 90-day mortality than time from symptom onset to PCI, overall, and especially in women.