Risk stratification in asymptomatic severe aortic stenosis: a critical appraisal. 
Aortic stenosis is one of the most common forms of acquired valvular heart disease.  The development of symptoms, namely syncope, angina, or heart failure, in patients with severe aortic stenosis predicts a high likelihood of mortality.  Aortic valve replacement is the current standard of care.  In truly asymptomatic patients, the risk of sudden death is perceived to be low; therefore many advocate conservative management of these patients until symptoms develop.  Emerging data suggest that certain markers may identify subsets of asymptomatic patients who are at a high risk of cardiac events.  This review critically appraises the growing plethora of adverse prognostic markers that have been identified and evaluates how these parameters may influence clinical practice and potentially identify patients in whom early surgical intervention is warranted.