Cardiac Hemodynamics in Men Versus Women During Acute ST-Segment Elevation Myocardial Infarction

Abstract

Several biologic and clinical factors contribute to the increased 30-day mortality and re-infarction rate in women with ST-segment elevation myocardial infarction (STEMI). Sex differences in cardiac hemodynamic parameters such as pulmonary capillary wedge pressure (PCWP) have not been examined and might play an important role. The objectives of the present study were to examine whether female sex is an independent determinant of PCWP during acute STEMI and whether an elevated PCWP contributes to all-cause 30-day mortality and re-infarction in women. The clinical, angiographic, and hemodynamic features of 470 consecutive patients with STEMI (n= 135 women) undergoing emergency coronary angiography with right-side heart catheterization were evaluated with respect to sex. Women had an elevated PCWP (20 ± 8 vs 16 ± 7 mm Hg, p <0.001) and reduced mixed venous oxygen saturation (67 ± 11% vs 71 ± 9%, p= 0.004). On multivariate analysis, female sex (β= 4.04, 95% confidence interval [CI] 2.04 to 6.04, p <0.001), hypertension (β= 2.07, 95% CI 0.31 to 3.83, p= 0.021), and creatine kinase-estimated infarct size (β= 0.001, 95% CI 0.001 to 0.002, p ≤0.001) were independent predictors of an elevated PCWP. Female sex exerted a minor independent effect on 30-day mortality and re-infarction (odds ratio 2.36, 95% CI 1.25 to 4.46, p= 0.008). However, once PCWP was entered into the mediation model, sex was no longer significant, suggesting that the effect of sex on the post-STEMI outcomes is potentially mediated through PCWP (odds ratio 1.07, 95% CI 1.02 to 1.12, p=0.011). In conclusion, during acute STEMI, women have greater left ventricular filling pressures compared with men, independent of age, hypertension, and infarct size. The biologic explanation for this difference requires additional investigation, although it does not appear to contribute to the increased 30-day mortality and re-infarction rate observed in women.