The simple answer is that aortic valve replacement is indicated whenever symptoms related to the aortic stenosis develop. The classic triad of symptoms is dyspnea on exertion (from heart failure), angina on exertion and syncope on exertion.

Aortic valve replacement is also indicated if the left ventricular systolic function starts to decline from the pressure overload caused by the aortic stenosis.

The clinical significance of a patient with aortic stenosis exhibiting symptoms cannot be underemphasized, as the onset of symptoms is accompanied by a dramatic increase in mortality. According to one large series, if aortic valve replacement is not performed, patients presenting with dyspnea have a mean life expectancy of 2 years, with syncope 3 years and with angina an average of 5 years.