Aortic stenosis (AS) is now the most common indication for valve replacement in Europe and North America, with an ever increasing disease prevalence due to the ageing population (Iung B, Baron G, Butchart EG, Delahaye F, Gohlke-Bärwolf C, Levang AW, Tornos P, Vanoverschelde JL, Vermeer F, Boersma E, Ravaud P, Vahanian A. A prospective survey of patients with valvular heart disease in Europe: the Euro Heart Survey on valvular heart disease. Eur Heart J 2003; 24:1231-1243). The recent introduction of transcatheter aortic valve implantation has renewed interest in the optimal approach to patient management. Decision making in valvular heart disease necessitates a careful evaluation of the risk-to-benefit ratio, considering both the results of intervention and the severity-adjusted risk of adverse outcomes without intervention.