Functional evaluation after aortic valve replacement.
Preoperative and sequential postoperative bicycle exercise tests were compared with clinical and catheterization data in assessment of the functional outcome of uncomplicated aortic valve replacement (AVR) in 33 patients. The operation was done because of aortic stenosis (AS) in 14 patients and aortic regurgitation (AR) in 19. Both groups of patients showed improved NYHA functional class and peak achieved workload after AVR, but the results in these respects did not correlate. Nor did the regression in left ventricular (LV) hypertrophy and dilatation after AVR that was seen in both patient groups correlate with the changes measured in exercise tolerance. Preoperative exercise capacity was not predictive of the postoperative performance. In the AR patients, however, preoperative ability to raise the systolic blood pressure during exercise appeared to predict which patients were likely to show enhanced resting LV systolic pump function after AVR. It is concluded that objective tests of exercise tolerance alone permit reliable evaluation of the functional outcome of uncomplicated AVR. Indices of resting LV performance, though helpful in observation of the changes resulting from removal of the untoward LV burden after AVR, are likely to be less useful for evaluating changes in the LV exercise reserve. The response of the systolic blood pressure to exercise may be an additional predictive factor for postoperative resting LV performance in patients with AR.