Background To characterize gender differences in recovery of ventricular function and survival after aortic valve replacement (AVR), baseline characteristics related to outcome were analyzed in 1012 consecutive patients (329 women and 683 men) undergoing AVR in 1983 through 1990.Methods and Results Seventy-seven percent of patients had aortic stenosis (AS), 11% insufficiency (AI), and 12% mixed AS/AI; 42% underwent concomitant coronary artery bypass. Women as a group had a greater mean age (P<.0001), had AS more frequently than AI or AS/AI (P<.01), had coronary disease less frequently (P<.01), and had a higher preoperative left ventricular ejection fraction (EF) (P<.0001), although preoperative New York Heart Association (NYHA) functional class was similar (P=NS) compared with men. Male sex (P<.0001), advanced age (P<.0003), AI rather than AS (P<.01), and greater extent of coronary disease (P<.04) were independently associated with lower preoperative EF. Women with coronary disease were as likely as men (P=NS) to undergo concomitant coronary bypass, and completeness of revascularization did not differ (P=NS) by gender. Observed survival probabilities after AVR (expressed as 30-day/5-year) were.97/.81 overall,.94/.77 for women, and.98/.83 for men (P<.02). Cox model analysis showed advanced age, decreased preoperative EF, greater extent of coronary disease, requirement for annular enlargement, smaller prosthetic valve size, and advanced NYHA class (all P<.04) but neither female sex nor smaller body surface area (both P=NS) as multivariate risk factors for overall mortality. In 664 patients (66%), postoperative EF was measured a mean 1.4 years after AVR. In patients with preoperative EF <=45% (n=167), the change in EF after AVR was greater (P<.02) in women (from 33+-8% to 48+-15%, P<.001) than in men (from 32+-9% to 42+-15%, P<.001). By multivariate regression analysis, female sex (P<.02) and lesser extent of coronary disease (P<.05) were independent predictors of early improvement in EF. Improvement in EF conveyed an independent subsequent survival benefit to both women (P<.03) and men (P<.001), and the magnitude of benefit did not differ (P=.4) between the two groups.Conclusions These data suggest that gender-related factors importantly influence the adaptive and recovery response of the left ventricle to pressure and volume overload. However, gender differences in LV adaptation do not influence survival after AVR. (Circulation. 1994;90(part 2):II-183-II-189.)