Exercise training for chronic heart failure (ExTraMATCH II): Protocol for an individual participant data meta-analysis

'Background': Patients with chronic heart failure (HF) experience a marked reduction in their exercise capacity, health-related quality of life, and life expectancy. Despite substantive evidence supporting exercise training in HF, uncertainties remain in the interpretation and understanding of this evidence base. Clinicians and healthcare providers seek definitive estimates of impact on mortality, hospitalisation and health-related quality of life, and which HF patient subgroups are likely to most benefit. The original Exercise Training Meta-Analysis for Chronic Heart Failure (ExTraMATCH) individual participant data (IPD) meta-analysis conducted in 2004 will be updated by the current collaboration (ExTraMATCH II), to investigate the effects of exercise training in HF. 'Methods': Randomised controlled trials have been identified from the updated 2014 Cochrane systematic review and the original ExTraMATCH IPD meta-analysis with exercise training of 3 weeks' duration or more compared with a non-exercise control and a minimum follow-up of 6 months. Particular outcomes of interest aremortality, hospitalisation and health-related quality of life plus key baseline patient demographic and clinical data. Original IPD will be requested from the authors of all eligible trials; we will check original data and compile a master dataset. IPD meta-analyses will be conducted using a one-step approach where the IPD from all studies are modelled simultaneously whilst accounting for the clustering of participants with studies. 'Discussion': The information from ExTraMATCH II will help inform future national and international clinical and policy decision-making on the use of exercise-based interventions in HF and improve the quality, design and reporting of future trials in this field.