Female Sex Is Inversely and Independently Associated With Marked ST-Segment Elevation. A Study in Patients With ST-Segment Elevation Acute Myocardial Infarction and Early Admission

Abstract

In patients with acute myocardial infarction, a number of variables in the initial ECG are useful prognostic indicators. The presence of ST-segment elevation, however, usually indicates the need for reperfusion therapy. The aims of this study were to investigate sex differences in the ECGs of patients with ST-elevation myocardial infarction (STEMI) and to look for a possible association between sex and marked ST-segment elevation. A prospective observational longitudinal study of consecutive patients (n=1422) who were admitted early for a first STEMI to one of two coronary units was carried out. Initial ECG parameters were analyzed for sex differences. Multivariate analysis was performed to identify variables associated with marked ST-segment elevation (i.e., total ST-segment elevation >11 mm, according to the upper tertile of the frequency distribution). In women (n=336), Q-wave myocardial infarction was observed more often in the initial ECG (19% versus 15.6%; P< .03), the total ST-segment elevation was lower (10+/-6.6 mm versus 11.1+/-7.9 mm; P< .004), and marked ST-segment elevation was less common (26.4% versus 35.5%; P< .005). There was an independent inverse association between female sex and marked ST-segment elevation (odds ratio=0.70; 95% confidence interval, 0.52-0.96; P< .02). In patients with STEMI, female sex was associated with a lower total ST-segment elevation and there was an independent inverse association with marked ST-segment elevation.