Frailty as a Prognostic Indicator in Lung Transplantation: A Comprehensive Analysis

Introduction: Frailty is a complex pathobiological process characterized by diminished physiological reserve and increased vulnerability to stressors, which has been associated with unfavorable outcomes before and after lung transplantation. Methods: We undertook an extensive narrative review, encompassing a thorough exploration of original papers, observational studies, case reports, and meta-analyses published between 1990 and July 2023, in various databases, including PubMed, Embase, Cochrane Library, Wiley Online Library databases, and Google Scholar. The search terms [frailty] AND [lung transplant] were utilized. Additionally, the reference lists of retrieved articles were examined. Inclusion criteria comprised studies written in English and involving human subjects. The identified studies were categorized into pre-transplant and post-transplant populations, and the measurement tools used to assess frailty were analyzed, along with the clinical implications reported in the studies. Results: From 1 January 1990 to 1 July 2023, a total of 10 studies on frailty and lung transplantation were identified through online sources and bibliographic searches, involving a total of 2759 patients. Among these studies, six focused on the pre-transplant population, while four examined the post-transplant population. The Fried Frailty Phenotype (FFP) and the Short Physical Performance Battery (SPPB) were the most employed tools for measuring frailty. A table presents additional frailty assessment instruments and the clinical implications described in the studies. Conclusions: Frailty is prevalent both in patients with end-stage respiratory diseases awaiting lung transplantation and in postoperative lung transplant recipients. Most transplant centers recognize the value of assessing frailty in the evaluation of potential candidates for lung transplantation. Frailty has been shown to impact mortality on the waitlist and in the post-transplant period. However, the most effective methods for measuring frailty in lung transplant candidates and recipients have yet to be determined. Strategies to reverse frailty are available and show promising results on outcomes.