Inclusion of Functional Status Measures in the Risk Adjustment of 30-Day Mortality After Transcatheter Aortic Valve Replacement. A Report from the STS/ACC TVT Registry ™

Background— Assessment of risk for transcatheter aortic valve replacement (TAVR) is important both for patient selection and provider comparisons. Prior efforts for risk adjustment have focused on in-hospital mortality, which is easily obtainable but can be biased due to early discharge of ill patients. Objective— To develop and validate a risk adjustment model for 30-day mortality that accounted for both standard clinical factors as well as pre-procedural health status and frailty. Methods— Using data from patients who underwent TAVR as part of the STS/ACC TVT Registry (6/2013–5/2016), we developed and internally validated a hierarchical logistic regression model to estimate risk of 30-day mortality after TAVR based only on pre-procedural factors and access site. The model included factors from the original TVT in-hospital mortality model but added Kansas City Cardiomyopathy Questionnaire (KCCQ; health status) and gait speed (5-m walk test). Results— Among 21,661 TAVR patients at 188 sites, 1,025 (4.7%) died within 30 days. Independent predictors of 30-day death included older age, low body weight, worse renal function, peripheral artery disease, home oxygen, prior myocardial infarction, left main disease, tricuspid regurgitation, nonfemoral access, worse baseline health status, and being unable to walk. The predicted 30-day mortality risk ranged from 1.1% (lowest decile of risk) to 13.8% (highest decile of risk). The model was able to stratify risk based on patient factors with good discrimination (c=0.71 derivation, 0.70 split-sample validation) and excellent calibration, both overall and in key patient subgroups. Conclusion— We developed a clinical risk model for 30-day death after TAVR that included clinical data as well as health status and frailty. This model will facilitate tracking outcomes over time as TAVR expands to lower risk patients and to less experienced sites as well as to allow for an objective comparison of short-term mortality rates across centers.