Transcatheter aortic valve replacement in low-risk patients: superiority or shifting goalposts and statistical...

Transcatheter aortic valve replacement (TAVR) has been compared to surgical aortic valve replacement (SAVR) in two different industry-sponsored trials (Edwards Lifesciences-the SAPIEN 3 system; Medtronic-the CoreValve, EvolutR, and EvolutPRO) in patients with low risk for surgical aortic valve replacement. In the balloon-expandable SAPIEN 3 system, requirements for both non-inferiority (P < 0.001) and superiority (P < 0.001) were met for the primary outcome which was a composite of death from any cause, stroke, or re-hospitalization. In the self-expanding EVOLUT valve study, the requirement for the non-inferiority of TAVR was met for a composite of death and stroke. In both studies, the mean age of patients was 74, and extrapolation of these results to a younger low-risk population cannot be recommended. Moreover, unblinded adjudication of end points, the large numbers of concomitant procedures in the SAVR group, using a composite end point as the primary outcome and the use of estimated rather than actual figures remain some of the important concerns of these studies.