Safety and Efficacy of Exercise Training in Patients With an Implantable Cardioverter-Defibrillator: A Meta-Analysis

Objectives In this study, the authors performed a meta-analysis of currently available comparative prospective studies to assess the efficacy and safety of exercise training in heart failure (HF) patients with implantable cardioverter-defibrillators (ICD). Background ICDs have been shown to improve survival in patients with HF. However, many patients with ICDs experience fear of shocks and avoid physical activity. Few data exist for efficacy and safety of exercise training in HF patients with ICDs. Methods Prospective parallel arm trials with control and exercise training groups that evaluated the efficacy of exercise training in patients with ICDs were included in the meta-analysis. Outcomes of interest were difference in the change in cardiorespiratory fitness (CRF) (ml/kg/min) between exercise and control group and the likelihood of ICD shocks among exercise training compared with that among control participants on follow-up. Results We included study level data from 6 trials (5 randomized controlled trials and 1 nonrandomized controlled trial). In the pooled analysis, ICD patients undergoing exercise training had significant improvement in CRF (weighted mean difference: 1.98 ml/kg/min; 95% confidence interval [CI]: 0.58 to 3.38). The likelihood of ICD shocks on follow-up was also significantly lower among exercise training than among control participants (pooled odds ratio: 0.47; 95% CI: 0.24 to 0.91). Conclusions Among patients with HF and ICD implantation, exercise training was associated with significant improvement in CRF and lower likelihood of ICD shocks.