How to define a poor outcome after transcatheter aortic valve replacement: conceptual framework and empirical observations from the placement of aortic transcatheter valve (PARTNER) trial.

BACKGROUND: Transcatheter aortic valve replacement (TAVR) has emerged as a less invasive option for valve replacement of patients with severe aortic stenosis. Although it has been recommended that TAVR should not be offered to patients who will not improve functionally or derive meaningful survival benefit from the procedure, no guidance exists on how best to identify such patients. The first step in this process is to define a poor outcome that can then be used as a foundation for subsequent case identification. We sought to evaluate potential definitions of a poor outcome after TAVR that combine both mortality and quality of life components.

METHODS AND RESULTS: Using data from 463 patients who underwent TAVR as part of the Placement of AoRTic TraNscathetER Valve (PARTNER) trial, we evaluated 6-month mortality and quality of life outcomes using the Kansas City Cardiomyopathy Questionnaire to explore potential definitions of a poor outcome. We then compared the strengths and weaknesses of each potential definition by examining the relationship between baseline and 6-month Kansas City Cardiomyopathy Questionnaire scores for each patient. Based on these analyses, we argue that the most appropriate definition of a poor outcome after TAVR is (1) death, (2) Kansas City Cardiomyopathy Questionnaire overall summary score <45, or (3) Kansas City Cardiomyopathy Questionnaire decrease of ≥10 points, which best reflects a failure to achieve the therapeutic goals of TAVR.

CONCLUSIONS: Using empirical data on a large number of patients enrolled in the PARTNER trial, we propose a definition for poor outcome after TAVR that combines both mortality and quality of life measures into a single composite end point. Use of this end point (or other similar end points) in future studies can facilitate development of predictive models that may be useful to identify patients who are poor candidates for TAVR and to provide such patients and their families with appropriate expectations of functional recovery after TAVR.