From Prehabilitation to Rehabilitation (Prehab2Rehab): Digitally Supported Short-Term Prehabilitation Prior to Cardiac Surgery

Prehab2Rehab is a prospective single-arm feasibility study evaluating the implementation of a multimodal, digitally supported prehabilitation program for adults awaiting elective cardiac surgery. During the routine preoperative waiting period, participants receive individualized education, psychosocial support, nutritional counselling, home-based physical activity guidance, and digital self-management support. The study aims to determine the feasibility, acceptability, usability, and safety of integrating this multidisciplinary prehabilitation pathway into routine clinical care. Exploratory outcomes include functional capacity, psychological well-being, nutritional status, digital engagement, and selected perioperative clinical outcomes to inform the design of future confirmatory trials.

Inclusion Criteria: \- Age ≥ 18 years * Classification as New York Heart Association (NYHA) functional class I-II * Low surgical risk profile, defined as a EuroSCORE between 0 and 3 * Scheduled for one of the following elective cardiac surgical procedures: * Open-heart valve surgery * Coronary artery bypass grafting (CABG) * Combined valve surgery and CABG * Surgical closure of an atrial septal defect (ASD) * Primary residence in Vienna to ensure the feasibility of in-person assessments and supervised sessions * Sufficient German language proficiency to participate in assessments and educational components * Adequate digital literacy to engage with the digital support tools used in the intervention * Clinical and physical assessment confirming that participation in exercise training is medically safe Exclusion Criteria: * Emergency, urgent, or otherwise non-elective cardiac surgery * Highly complex or specialized surgical procedures (e.g., aortic aneurysm repair, cardiac tumor resections) * Interventional cardiac procedures (e.g., transcatheter aortic valve implantation \[TAVI\], MitraClip interventions) * Neuromotor or physical impairments that might prevent adherence to the study protocol or informed participation * Contraindications to spiroergometry according to current guidelines: Absolute contraindications: * Acute coronary syndrome * Symptomatic cardiac arrhythmias and/or hemodynamic instability * Decompensated heart failure * Acute pulmonary embolism * Acute endocarditis, myocarditis, or pericarditis * Febrile infections * Acute deep vein thrombosis of the lower extremities Relative contraindications: * Left main coronary artery stenosis * Electrolyte imbalances * Arterial hypertension (\>160 mmHg systolic) * Tachyarrhythmias * Hypertrophic obstructive cardiomyopathy (HOCM) * High-grade atrioventricular block * Anemia * Physical or psychological impairments