Asymptomatic severe aortic stenosis: challenges in diagnosis and management.

Optimal management for asymptomatic severe aortic stenosis (AS) remains controversial. Considering the increase in elderly patients, improved surgical outcomes and the introduction of transcatheter aortic valve implantation, we must reconsider the optimal management of asymptomatic severe AS. In this article, previous studies regarding the natural history of asymptomatic severe AS were reviewed to obtain a clinical perspective of AS in the growing elderly patient population. The incidence of sudden death in asymptomatic severe AS varies among studies from 0.25% to 1.7% per year, with differences related to study design and patient background. Except for very severe AS, sudden death or AS-related cardiac death without preceding symptoms is uncommon if 'watchful' waiting strategy is possible. Therefore, early operation is reasonable in very severe AS, but it is not recommended for all patients with severe AS. Using exercise tests, plasma levels of natriuretic peptides and other parameters, risk stratification of asymptomatic severe AS is needed to select patients who may have greater benefit following early operation. On the other hand, 'watchful' waiting is not always possible in real world of our practice. Patient education and periodic echocardiography are essential in 'watchful' waiting, which is not simply waiting strategy without careful monitoring. Individualised discussion regarding the indication for early operation is necessary, considering age, clinical background, predicted natural history and operative risk in each patient.