Abstract 69: Defining Futility in Transcatheter Aortic Valve Replacement

Abstract

Background: Transcatheter aortic valve replacement (TAVR) has emerged as a less invasive option for valve replacement for patients with severe aortic stenosis. Although it has been recommended that TAVR 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 and risk model development. Accordingly, we sought to evaluate potential definitions of a poor outcome after TAVR that combine both mortality and quality of life (QoL) components. Methods: Using data from 463 patients who underwent TAVR as part of the PARTNER Trial, we evaluated 6M mortality and QoL outcomes using the Kansas City Cardiomyopathy Questionnaire (KCCQ) to explore 5 potential definitions (DEFs) of a poor outcome. We then examined the strengths and weaknesses of each potential definition by examining the relationship between baseline and 6M KCCQ scores for each patient. Results: We considered 5 alternative definitions for a poor outcome (Table). DEFs #1 and #2 were not optimal as they preferentially identified patients at the high end of baseline KCCQ values as having a poor outcome--many of whom were likely to have undergone TAVR primary for its mortality benefit. DEF #3 incorporates a threshold for the KCCQ score, thereby implying that a patient should achieve a certain level of functional capacity after a successful TAVR. However, it ignores patients with high pre-TAVR KCCQ scores whose health status declines after treatment. We argue that DEFs #4 and #5 best reflect a failure to achieve the therapeutic goals of TAVR, which are a combination of improved quality and extended quantity of life, and we prefer DEF #4 for its simplicity. Conclusion: Using empiric 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 QoL measures into a single composite endpoint. Using this definition, patients at low risk for this poor outcome can be preferentially selected for TAVR and those at high risk can be given appropriate expectations of functional recovery after TAVR.