Preoperative left ventricular wall stress, ejection fraction, and aortic valve gradient as prognostic indicators in aortic valve stenosis

Abstract

Patients with aortic valve stenosis (AS) and left ventricular (LV) dysfunction may dramatically improve after aortic valve replacement, but operative risk is high. In an earlier study, all patients with low preoperative wall stress and low ejection fraction, or with low aortic valve gradient, died or had persistent heart failure after operation. Because wall stress is difficult to calculate, we reassessed its effect and the effect of other preoperative characteristics on outcome in 66 consecutive catheterization patients with predominant aortic stenosis referred for valve replacement. Despite ejection fraction that was inordinately low compared with afterloading wall stress in nine patients, seven patients improved with surgery. All three patients with ejection fraction < 20% improved after surgery. Two of three patients with mean aortic valve gradients of < 30 mm Hg improved. Mortality was 33% in patients with mean gradient < 30 mm Hg and 19% with mean gradient < 50 mm Hg. In the 54 patients with calculated aortic valve areas of ≤ 0.8 cm², 1 (2%) had continuing heart failure, while 6 of 12 (50%, P < .01) patients with aortic valve areas of 0.9–1.2 cm² had continued symptoms of or died of heart failure. Patients who died or failed to improve after operation were older (71 ± 9 years) than those who improved (65 ± 9 years, P = .02). We conclude that wall stress calculations do not predict which patients with aortic stenosis will benefit from aortic valve replacement and that poor left ventricular function and low mean aortic valve gradient do not absolutely preclude operation. On the other hand, low gradient, non‐critical valve area, and advanced age are all relative contraindications to aortic valve replacement in aortic stenosis.