The concept of cardiac efficiency is old, but it gains new perspective with the evolution of patients with aortic stenosis (AS) who are candidates for transcatheter aortic valve replacement (TAVR). Cardiac efficiency is expressed as the cardiac power to left ventricular mass ratio. This represents the rate of cardiac work of energy stored in the left ventricle. The greater the viability of the myocardium, the greater the stroke volume delivered. Cardiac power decreases with decreased ejection fraction but may also be reduced in patients with preserved ejection fraction. The application of cardiac efficiency as an adjunct to predicting outcomes for TAVR has not been previously explored.