The prevalence and importance of frailty in cardiac resynchronization therapy patients

FUNDING ACKNOWLEDGEMENTS: Type of funding sources: Public grant(s) – EU funding. Main funding source(s): Nemzeti Kardiovaszkuláris Laboratórium RRF-2.3.1-21-2022-00003. BACKGROUND: Frailty, characterized by loss of homeostatic reserves and increased vulnerability to physiological decompensation, results from an aggregation of insults across multiple organ systems. Frailty can be quantified by counting the number of ‘health deficits’ across a range of domains. AIMS: We assessed the frequency of, and outcomes related to frailty in patients with heart failure and reduced ejection fraction who previously underwent cardiac resynchronization therapy (CRT) implantation. METHODS: We used a cumulative deficits approach to construct a 30-item frailty index (FI) and applied it to identify frail patients enrolled in our CRT registry. The 30 items were derived from medical history, other patient characteristics and laboratory results, covering a range of body systems. In keeping with previous studies, patients with FI ≤0.210 were classified as non-frail and those with higher scores were divided into two categories using score increments of 0.100. Our primary endpoint was all-cause mortality. RESULTS: Among 1004 included patients, 75 (7%) were considered Non-frail, while 271 (27%) and 658 (66%) participants were categorized as Frail in groups 1- and 2. Patients in Frail group 2 were older, had a less favorable renal function, and generally had more comorbidities (i.e. atrial fibrillation, hypertension, ischemic cardiovascular disease) than patients categorized in the Non-frail or Frail group 1. During the median follow-up time of 4.4 (2.3-6.9) years, 17 (22%) patients in the Non-frail group, 103 (38%) in Frail group 1, and 479 (73%) in the Frail group 2 reached the primary endpoint. Non-frail patient group showed the most beneficial survival with a 70% (HR 0.31; 95% CI: 0.23-0.41; p<0.001) lower all-cause mortality risk compared to Frail group 2. Adjusting for relevant covariates, NYHA class, creatinine, and TAPSE were identified as independent predictors for all-cause mortality. CONCLUSION: Based on our results, CRT candidates are exceedingly vulnerable with a high prevalence of frailty. The calculated frailty index was associated with the primary outcome of death from any cause. FI proved to be prevalent in individual risk stratification and can predict the outcome. [Figure: see text] [Figure: see text]