Effects of cardiac rehabilitation in low-and middle-income countries: A systematic review and meta-analysis of randomised controlled trials

Objectives: To assess the effectiveness of cardiac rehabilitation (CR) in low- and middle-income countries (LMICs), given previous reviews have included scant trials from these settings and the great need there. Methods: Six electronic databases (PubMed, Medline, Embase, CINAHL, Cochrane Library, and APA PsycINFO) were searched frominception-May 2020. Randomised controlled CR (i.e., at least initial assessment and structured exercise; any setting; some Phase II) trials with any clinical outcomes (e.g., mortality and morbidity, functional capacity, risk factor control and psychosocial well-being) or cost, with usual care (UC) control or active comparison (AC), in acute coronary syndrome with or without revascularization or heart failure patients in LMICs were included. With regard to data extraction and data synthesis, two reviewers independently vetted identified citations and extracted data from included trials; Risk of bias was assessed using Cochrane's tool. Certainty of evidence was ascertained based on the Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework. A random-effects model was used to calculate weighted mean differences and 95% confidence intervals (CI). Results: Twenty-six trials (6380 participants; 16.9% female; median follow-up = 3 months) were included. CR meaningfully improved functional capacity (VO2peak vs UC: 5 trials; mean difference [MD] = 3.13 ml/kg/min, 95% CI = 2.61 to 3.65; I-2 = 9.0%); moderate-quality evidence), systolic blood pressure (vs UC: MD = -5.29 mmHg, 95% CI = -8.12 to -2.46; I-2 = 45%; low-quality evidence), low-density lipoprotein cholesterol (vs UC: MD = -16.55 mg/dl, 95% CI = -29.97 to -3.14; I-2 = 74%; very low-quality evidence), body mass index (vs AC: MD = -0.84 kg/m(2), 95% CI = -1.61 to -0.07; moderate-quality evidence; I-2 = 0%), and quality of life (QoL; vs UC; SF-12/36 physical: MD = 6.05, 95% CI = 1.77 to 10.34; I-2 = 93%, low-quality evidence; mental: MD = 5.38, 95% CI= 1.13 to 9.63; I-2= 84%; low-quality evidence), among others. There were no evidence of effects on mortality or morbidity. Qualitative analyses revealed CR was associated with lower percutaneous coronary intervention, myocardial infarction, better cardiovascular function, and biomarkers, as well as return to life roles; there were other non-significant effects. Two studies reported low cost of home-based CR. Conclusions: Lowtomoderate-certainty evidence establishesCRas delivered in LMICs improves functional capacity, risk factor control and QoL. Whilemore high-quality research is needed, we must augment access to CR in these settings. Systematic review registration: PROSPERO (CRD42020185296). (C) 2021 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY license (http:// creativecommons.org/licenses/by/4.0/).