Objective: We studied long-term outcomes in severe aortic stenosis and the importance of prosthesis type (mechanical vs biologic) and size, preoperative left ventricular ejection fraction, diastolic function, and left ventricular mass.
Methods: Patients undergoing valve replacement from 1991 to 1993 (n = 399, 45% women) were included. The diastolic function was evaluated by integrating mitral and pulmonary venous flow data with Doppler echocardiography. The patients were classified as having either normal diastolic function to mild diastolic dysfunction or moderate to severe diastolic dysfunction. Left ventricular ejection fraction and the diastolic function category were incorporated together with age, sex, and time since operation into a Poisson regression model with death as the end point. Prosthesis type and size and left ventricular mass were also investigated.
Results: The age (mean +/- SD) was 71 +/- 9 years, and the overall survival after 12 years was 50%. Although markedly reduced during the initial 6-month period, mortality risk subsequently increased more than could be explained by age (hazard ratio of 1-year difference = 1.12, P = .0005). The moderate to severe diastolic dysfunction pattern independently predicted late mortality (hazard ratio = 1.72, P = .0038), whereas left ventricular ejection fraction did not (hazard ratio = 0.99, P = .18). The prognostic importance of moderate to severe diastolic dysfunction did not diminish with time; on the contrary, it tended to increase. Mortality after 12 years was not predicted by left ventricular mass (P = .66), prosthesis type (P = .57), or prosthesis size (P = .58).
Conclusion: This study reveals that moderate to severe diastolic dysfunction in patients with aortic stenosis is an independent predictor of late mortality after valve replacement and that its importance does not decrease with time. Our findings may suggest that moderate to severe diastolic dysfunction implies nonreversible myocardial changes that negatively affect survival.