Do frailty measures improve prediction of mortality and morbidity following transcatheter aortic valve implantation? An analysis of the UK TAVI registry

Objectives Previous studies indicate frailty to be associated with poor outcomes following transcatheter aortic valve implantation (TAVI), but there is limited evidence from multicentre registries. The aim was to investigate the independent association of frailty with TAVI outcomes, and the prognostic utility of adding frailty into existing clinical prediction models (CPMs). Design The UK TAVI registry incorporated three frailty measures since 2013: CSHA, KATZ and poor mobility. We investigated the associations between these frailty measures with short- and long-term outcomes, using logistic regression to estimate multivariable adjusted odds ratios (ORs), and Cox proportional hazards models to explore long-term survival. We compared the predictive performance of existing TAVI CPMs before and after updating them to include each frailty measure. Setting All patients who underwent a TAVI procedure in England or Wales between 2013 and 2014. Participants 2624 TAVI procedures were analysed in this study. Primary and Secondary Outcomes The primary endpoints in this study were 30-day mortality and long-term survival. The Valve Academic Research Consortium (VARC)-2 composite early safety endpoint was considered as a secondary outcome. Results KATZ<6 (OR 2.10, 95% CI: 1.39, 3.15) and poor mobility (OR 2.15, 95% CI: 1.41, 3.28) predicted 30-day mortality after multivariable adjustment. All frailty measures were associated with increased odds of the Valve Academic Research Consortium (VARC)-2 composite early safety endpoint. We observed a significant increase in the area under the ROC curves by approximately 5% after adding KATZ<6 or poor mobility. Risk stratification agreement was significantly improved by the addition of each frailty measure, with an increase in intra-class correlation coefficient of between 0.15 and 0.31. Conclusion Frailty was associated with worse outcomes following TAVI, and incorporating frailty metrics significantly improved the predictive performance of existing CPMs. Physician-estimated frailty measures could aid TAVI risk stratification, until more objective scales are routinely collected.