Trial event rate assumption and noninferiority margin in comparative trials of aortic valve replacement.

This letter evaluates whether overestimation of control event rates and the use of absolute noninferiority margins influenced conclusions of randomized trials comparing transcatheter and surgical aortic valve replacement. By reanalyzing published noninferiority trials using observed event rates and corresponding relative margins, we assessed the robustness of trial conclusions to alternative margin specifications. Our findings inform interpretation of noninferiority evidence underlying contemporary clinical decision-making in aortic valve replacement.