Clinical impact of frailty after durable left ventricular assist device implantation

Background Durable left ventricular assist devices (dLVAD) improve prognosis in patients with advanced heart failure. However, even after implantation of dLVAD, some patients have an impaired quality of life and die due to LVAD-related complications. Frailty, often accompanied in patients with chronic heart failure, is well known to be associated with impaired quality of life and increased mortality. Patients who received dLVAD implantation also have a great potential for frailty, due to operative invasion, and organ dysfunction which are associated with advanced heart failure before implantation. However, the clinical implications of frailty after dLVAD implantation have not been fully elucidated. Purpose The aim of this study was to explore the incidence of frailty and evaluate the association between frailty and adverse outcomes, in patients after dLVAD implantation. Methods We used the data of the Japanese Registry for Mechanically Assisted Circulatory Support between June 2010 and December 2023. This is the nationwide registry that includes all consecutive patients who received a ventricular assist device in Japan. Patients who received an extracorporeal LVAD, or used a concurrent right ventricular assist device were excluded from the analysis. Frailty Index (FI) was calculated using 31 items, including comorbidities, laboratory parameters, and scores of cognitive and health-related quality of life. Patients were categorized into three groups based on the FI at three months after dLVAD implantation (FI): a FI of less than 0.210 was classified as not frail, 0.210 < FI < 0.311 as more frail, and FI ≥ 0.311 as the most frail. All outcomes were evaluated from three months after dLVAD. Results A total of 1,457 patients were analyzed. Mean age was 44.1±13.8 years, and 73.4% were male. The median FI was 0.25. Of these, 473 (32.5%) were classified in the not frail group, 649 (44.5%) in the more frail group, and 335 (23.0%) in the most frail group. During the median 3.4-year follow-up period, 229 patients (15.7%) died, 572 patients (39.3%) experienced hemocompatibility event, 157 patients (10.8%) right ventricular failure, 465 patients (31.9%) driveline or pump infection, 240 patients (16.5%) ventricular arrhythmia requiring cardioversion, 376 patients (25.8%) pump malfunction. The severity of frailty was associated with higher mortality (HR 1.97 [95%CI 1.33-2.92] in the more frail group; HR 5.01 [95%CI 3.40-7.39] in the most frail group, with the not frail group as the reference) (Figure and Table). This association is similarly observed for hemocompatibility event and right ventricular failure. After adjusting for variables not included in FI, the associations between severity of frailty and outcomes showed similar trends. Conclusion Frailty was commonly observed in patients after dLVAD implantation. Patients with more severe frailty had worse outcomes, highlighting its value in risk stratification and as a target for improvement.