Use of a mobile-assisted telehealth regimen to increase exercise (MATRIX) in transplant candidates – A home-based prehabilitation pilot and feasibility trial

ABSTRACT Introduction. Physical fitness assessed by the liver frailty index (LFI) and 6-minute walk test (6MWT) informs the prognosis of liver transplant (LT) candidates although there is limited data on its reversibility following a prehabilitation. On a home-based exercise trial, we aimed to improve LFI and 6MWT and to investigate trial feasibility and intervention adherence. Methods. LT candidates with cirrhosis wore a personal activity tracker (PAT) and used EL-FIT (Exercise & Liver FITness app) for 14 weeks, including a 2-week technology acclimation run-in. The 12-week intervention consisted of EL-FIT plus PAT and 15-/30-min weekly calls with a physical activity coach aiming to complete ≥2 video-training sessions/week, or ≥500 step/day baseline increase for ≥8 weeks. We defined feasibility as ≥66% of subjects engaging in the intervention phase and adherence as ≥50% subjects meeting training endpoint. Results. 31 patients (61±7 years, 71% female, MELD 17±5, ∼33% frail) consented and 21 (68%) started the intervention. In the 15 subjects who completed the study, LFI improved from 3.84±0.71 to 3.47±0.90 (p=0.03) and 6MWT from 318±73 to 358±64 m (p=0.005). Attrition reasons included death (n=4) and surgery (n=2). There was 57% adherence, better for videos than for walking, although daily steps significantly increased (3508 vs. baseline:1260) during best performance week. One adverse event was attributed to the intervention. Discussion. Our clinical trial meaningfully improved LFI by 0.4 and 6MWT by 41 m and met feasibility/adherence goals. In-training daily step increase supported physical self-efficacy and intervention uptake, but maintenance remained a challenge despite counseling.