Cardiac Rehabilitation in Patients with Implantable Cardioverter-Defibrillators: A Systematic Review and Meta-Analysis of Randomized Controlled Trials and TSA.

Background/Objectives: Cardiac rehabilitation (CR) is known to improve clinical outcomes in cardiovascular disease, yet its benefits in patients with implantable cardioverter-defibrillators (ICD) are not well established. This meta-analysis evaluated the impact of CR on functional capacity and safety in ICD recipients. Methods: A systematic search of PubMed, Scopus, and Cochrane Library was performed to identify randomized controlled trials (RCT) involving adults who underwent ICD implantation and were assigned to either CR or standard care. The primary outcome was the change in peak oxygen uptake (peak VO2) from the baseline to the final follow-up. Random-effects models were applied, and subgroup analyses were conducted based on follow-up duration, supervision type, baseline peak VO2, and ischemic vs. non-ischemic etiology. Results: Seven RCTs involving 1461 participants (784 CR; 677 control) met the inclusion criteria. CR was associated with a significant improvement peak VO2 compared with usual care, expressed as the mean difference (MD) in change from the baseline to the last follow-up (MD 2 mL·kg-1·min-1; 95% CI 1.02-2.81; I2 = 65.7%), with consistent effects across all subgroups. Quality of life improved in the CR group (MD 6.46; 95% CI 2.25-10.67; I2 = 0%). A non-significant trend toward increased 6MWT distance was observed. CR did not increase adverse events, including ICD shocks, hospitalizations, or cardiac deaths. Conclusions: CR safely enhances exercise capacity and quality of life in ICD recipients without increasing arrhythmic events or mortality. Larger standardized trials are warranted to optimize CR delivery in this population.