IMPAIRED LEFT-VENTRICULAR FUNCTION IN CHRONIC AORTIC-VALVE DISEASE - SURVIVAL AND FUNCTION AFTER REPLACEMENT BY BJORK-SHILEY PROSTHESIS

Postoperative survival and left ventricular function were studied in 128 patients who underwent isolated aortic valve replacement by the Bjork-Shiley valve between 1973 and 1977. The average follow-up was 2.1 years. Patients with associated coronary artery disease or mitral valve disease were excluded. Preoperative ejection fraction ranged from 15-84%. Forty-two patients were restudied by cardiac catheterization 9.1 ± 1.1 months (mean ± SEM) after valve replacement. The hospital mortality was 11%. Preoperative type of valve lesion, functional class, cardiothoracic ratio, and ejection fraction (EF) had no significant effect on postoperative survival up to 4 years. After operation, left ventricular mass (LVMI) and peak systolic wall stress (PSWS) fell significantly, while EF and mean normalized systolic ejection rate (MNSER) increased in aortic stenosis and in aortic insufficiency. Neither in aortic stenosis nor in aortic insufficiency was there a significant relation between preoperative ejection fraction and postoperative LVMI, EF, MNSER and PSWS. We attributed this to a marked improvement of left ventricular function in patients with preoperative impaired ventricular function. Six patients with paravalvular leak at restudy had a significantly lower EF and MNSER, and a higher PSWS than patients without leak. Patients without leak had normal EF, MNSER and PSWS when compared with 10 normal persons, but LVMI remained moderately elevated. Postoperative transprosthetic gradient was 11.9 mm Hg (range 0-64 mm Hg). We conclude that impaired cardiac function is completely restored after aortic valve replacement by Bjork-Shiley valve, if valve function is good. Patients with impaired cardiac function preoperatively did not have a poorer prognosis after operation than patients with normal function.