The prognostic effect of cardiac rehabilitation in the era of acute revascularisation and statin therapy: A systematic review and meta-analysis of randomized and non-randomized studies - The Cardiac Rehabilitation Outcome Study (CROS)

Abstract

Background The prognostic effect of multi-component cardiac rehabilitation (CR) in the modern era of statins and acute revascularisation remains controversial. Focusing on actual clinical practice, the aim was to evaluate the effect of CR on total mortality and other clinical endpoints after an acute coronary event. Design Structured review and meta-analysis. Methods Randomised controlled trials (RCTs), retrospective controlled cohort studies (rCCSs) and prospective controlled cohort studies (pCCSs) evaluating patients after acute coronary syndrome (ACS), coronary artery bypass grafting (CABG) or mixed populations with coronary artery disease (CAD) were included, provided the index event was in 1995 or later. Results Out of n = 18,534 abstracts, 25 studies were identified for final evaluation (RCT: n = 1; pCCS: n = 7; rCCS: n = 17), including n = 219,702 patients (after ACS: n = 46,338; after CABG: n = 14,583; mixed populations: n = 158,781; mean follow-up: 40 months). Heterogeneity in design, biometrical assessment of results and potential confounders was evident. CCSs evaluating ACS patients showed a significantly reduced mortality for CR participants (pCCS: hazard ratio (HR) 0.37, 95% confidence interval (CI) 0.20-0.69; rCCS: HR 0.64, 95% CI 0.49-0.84; odds ratio 0.20, 95% CI 0.08-0.48), but the single RCT fulfilling Cardiac Rehabilitation Outcome Study (CROS) inclusion criteria showed neutral results. CR participation was also associated with reduced mortality after CABG (rCCS: HR 0.62, 95% CI 0.54-0.70) and in mixed CAD populations. Conclusions CR participation after ACS and CABG is associated with reduced mortality even in the modern era of CAD treatment. However, the heterogeneity of study designs and CR programmes highlights the need for defining internationally accepted standards in CR delivery and scientific evaluation.

Keywords: Rehabilitation; acute coronary syndrome; coronary artery disease; coronary bypass grafting; hospital readmission; mortality.

Figure 1.

Study selection flow chart. CINAHL: Cumulative Index to Nursing and Allied Health Literature; LILACS: Literatura Latino-Americana e do Caribe em Ciências da Saúde; CIRRIE: Center for International Rehabilitation Research Information and Exchange; PS: primary selection of extracted studies; FTE: full-text evaluation; SSE: structured study evaluation and quality analysis according to the checklist of methodological issues on non-randomized studies; ICTRP: International Clinical Trials Registry Platform.²⁶

Figure 2.

Analysis of total mortality. Forest plots presenting the evaluation of the endpoint ‘total mortality’. HR: hazard ratio; OR: Odds ratio; MH: Mantel–Haenszel pooling method; CR: cardiac rehabilitation; No CR: no cardiac rehabilitation (control); CI: confidence interval; Events: number of events in the evaluated group; Total: number of patients in the evaluated group; Start (w): start of cardiac rehabilitation after hospital discharge in weeks; Follow-up: follow-up in years.