REVIVE-HF: study protocol for a randomized controlled trial of immersive virtual reality-augmented aerobic exercise in hospitalized patients with heart failure

Background Heart failure (HF) is characterized by exercise intolerance, which results in poor quality of life. Supervised aerobic exercise is central to cardiac rehabilitation, but tolerance and adherence may be hindered by physical and motivational barriers. Immersive virtual reality (VR) may enhance engagement during exercise. Methods This was a parallel-group randomized controlled trial (1:1, no stratification). Hemodynamically stable adults hospitalized with decompensated HF will complete a single supervised cycle-ergometer session seated in a hospital armchair: five 3-min pedaling blocks with 1-min rests (early termination per safety/symptom criteria). Groups: control (exercise only) vs intervention (same exercise delivered with VZfit on a Meta Quest 2 headset). The primary endpoint was effective exercise time (minutes) = cumulative pedaling time (scheduled rests excluded) to termination due to symptoms or predefined safety thresholds. The secondary endpoints were as follows: block-level hemodynamics (SBP/DBP, HR, RR, SpO₂), the rating of perceived exertion (RPE; modified Borg 0–10), PACES (between-group), and the SUS (VR arm only). The outcome assessors and data analysts will be blinded. Discussion This trial tests whether VR increases exercise tolerance during HF hospitalization and may inform the integration of VR into inpatient cardiac rehabilitation. Trial registration: Brazilian Clinical Trials Registry (ReBEC), RBR-4hrmkzz, registered on March 11, 2022.