The Impact of Clinical and Biochemical Frailty on Outcomes following Transcatheter Aortic Valve Replacement

BACKGROUND: Frailty results from declining reserve and function and is a modifiable cardiovascular risk-factor. Despite this, there is limited evidence surrounding its role in lower-risk TAVR cohorts. OBJECTIVES: This study aimed to evaluate frailty among contemporary TAVR patients, delineate the impact of biochemical and clinical frailty, and understand its additive value to existing risk-prediction tools. METHODS: Analysis of a multicenter Australian registry. Biochemical frailty (BF) was defined as serum albumin <35 g/L and clinical frailty (CF) as a Rockwood Clinical Frailty Scale ≥5. Patients meeting BF or CF criteria were categorized as frail. RESULTS: Of the 2,661 patients, the median age 82 (IQR: 77-86), 60% male, and median STS 3.3 (2-5.2), 920 patients (35%) were considered frail. A total of 171 (19%) of frail patients fulfilled both BF and CF criteria. The frail group was older (83 vs 81, P < 0.001), more females (43% vs 38%; P = 0.016) with higher STS scores (4 vs 3, P < 0.001). Kaplan-Meier analysis showed a stepwise increase in 12-month mortality with increasing frailty (no frailty 4% vs BF or CF 7% vs BF + CF 16%, Log-rank P < 0.001). In Cox proportional hazards regression BF or CF (adjusted HR: 1.6; 95% CI: 1.0-2.4; P = 0.033) and BF + CF (adjusted HR: 3.3; 95% CI: 1.9-5.6; P < 0.001) independently predicted 12-month mortality. Addition of frailty to STS Score improved mortality prediction (area under the receiver-operating characteristic curve: 0.608 vs 0.664; DeLong's P = 0.021), with Shapley analysis demonstrating significant contribution from frailty. CONCLUSIONS: Frailty is common with significant implications in TAVR. Patients with biochemical and clinical frailty criteria are highest risk. Development of strategies to address frailty is critical.