Asymptomatic severe aortic stenosis: always surgical treatment? The opinion of the surgeon

Prophylactic valve replacement in asymptomatic patients with severe aortic stenosis is controversial. Most authors consider that patients could be managed without surgery until symptoms develop. The incidence of sudden death in patients without symptoms is low, < 1%/year and valve replacement is complicated by an operative mortality up to 5 and 1-2% of incidence of valve-related major events. Early surgical approach is suggested by several observations. The first one is the unpredictable risk of myocardial fibrosis after long standing left ventricular hypertrophy and pressure overload, with associated systolic and diastolic dysfunction. Left ventricular impairment can persist after valve replacement influencing exercise capacity and survival in selected patients. On the other hand, major improvement in myocardial protection techniques, intraoperative monitoring with transesophageal echocardiography, prosthetic design (stentless, supra-annular), all have reduced in-hospital mortality and morbidity. More precise recommendations can be made according to an improved characterization of the patients from fast to slow evolution, according to age, type of aortic stenosis, degree of calcification, changes in transaortic gradients over time, tolerance to exercise test and response of aortic valve area to dobutamine. In patients with high risk of progression (severely calcified valve, Doppler velocity > 4 m/s, rapidly increasing with time), indirect evidence of myocardial fibrosis (excessive left ventricular hypertrophy, systolic or diastolic dysfunction), and need of myocardial revascularization, an early surgical approach should be considered.