Impact of frailty on short- and long-term morbidity and mortality after transcatheter aortic valve implantation: risk assessment by Katz Index of activities of daily living

Abstract

Aims: Transcatheter aortic valve implantation (TAVI) represents a less invasive treatment option for elderly patients. Therefore, we aimed to determine the impact of frailty measured by the Katz Index of activities of daily living (ADL) on short- and long-term mortality after TAVI.

Methods and results: Our study included 300 consecutive patients (mean age, 82±5 years) who had undergone TAVI at our institution (158 transapical, 142 transfemoral procedures). At baseline, 144 patients were impaired in at least one ADL and therefore defined as frail (Katz Index <6). Regarding in-hospital outcome, all serious complications except for stage 3 acute kidney injury were equally distributed in both groups, but early mortality was significantly higher in frail persons (5.5% vs. 1.3%, p=0.04 for immediate procedural mortality; 17% vs. 5.8%, p=0.002 for 30-day mortality; and 23% vs. 6.4%, p<0.0001 for procedural mortality). The risk-score-based 30-day mortality estimates (29% vs. 24% for log. EuroSCORE I, 9.5% vs. 7.5% for EuroSCORE II, and 8.8% vs. 5.9% for STS score) reflected neither the observed 30-day mortality in both groups nor the threefold risk elevation in frail patients. In contrast, the Katz Index <6 was identified as a significant independent predictor of long-term all-cause mortality by multivariate analysis (HR 2.67 [95% CI: 1.7-4.3], p<0.0001). During follow-up (median observation period 537 days) 56% of frail vs. 24% of non-frail patients died.

Conclusions: Frailty status measured by the Katz Index represents a powerful predictor of adverse early and late outcome after TAVI, whereas commonly used risk scores lack calibration and discrimination in a TAVI-specific patient cohort. Therefore, we propose the incorporation of this simple and reproducible measure into pre-TAVI risk assessment.