The benefits of early valve replacement in asymptomatic patients with severe aortic stenosis

Abstract

The prevalence of aortic valve stenosis increases with age, and often the diagnosis is made by echocardiography before symptoms develop. To address the controversies in management of asymptomatic patients with severe aortic stenosis, we assessed the early and late outcomes of aortic valve replacement in these patients. We analyzed data of 622 patients, aged 72 +/- 11 years, with isolated asymptomatic severe aortic stenosis. Patients were identified with a peak systolic velocity of greater than 4 m/s by transthoracic echocardiography and monitored for the development of symptoms and need for aortic valve replacement. After the initial diagnosis, 166 (27%) patients who were initially asymptomatic experienced the development of chest pain, shortness of breath, or syncope and had aortic valve replacement at Mayo Clinic. Another 97 (16%) patients had aortic valve replacement in the absence of symptoms. Symptomatic patients were more likely to undergo coronary bypass grafting (P < .01) and have diabetes, hypercholesterolemia, and a lower ejection fraction (P < .05 for each). Operative mortality was 2% for symptomatic patients and 1% for asymptomatic patients (P = .43). The survival of the 263 patients who underwent aortic valve replacement was not significantly different from an age- and sex-matched population (P = .99); 10-year survival was 64% (95% confidence interval [CI] 57%-72%) for symptomatic patients and 64% (95% CI 54%-75%) for asymptomatic patients (P = .92). At 3 years after diagnosis of severe aortic stenosis, 52% (95% CI 48%-56%) of 622 patients had had symptoms develop, undergone aortic valve replacement, or died. Among the entire cohort, older age at diagnosis (hazard ratio [HR] 1.1 per year, P < .001), diabetes (HR 1.7, P < .001), decreased ejection fraction (HR 1.1 per 1% downward arrow, P = .01), symptoms (HR 2.13, P < .001), and absence of aortic valve replacement (HR 3.53, P < .001) were identified as independent risk factors for mortality. Among patients with severe aortic stenosis who underwent aortic valve replacement, early and late outcomes were similarly good in patients who had symptoms before the operation compared with those who were asymptomatic. It is important to note that among patients with asymptomatic severe aortic stenosis, the omission of surgical treatment was the most important risk factor for late mortality.