Automated Referral to Cardiac Rehabilitation After Coronary Artery Bypass Grafting Is Associated With Modest Improvement in Program Completion

Background: Cardiac rehabilitation (CR) is a guideline-indicated modality for reducing residual cardiovascular risk among patients undergoing coronary artery bypass grafting (CABG) surgery. However, many referred patients do not initiate or complete a CR program; even more patients are never even referred. Methods: All post-CABG patients in Calgary, Alberta, Canada, from January 1, 1996, to March 31, 2016, were included. Data were obtained from the Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease and TotalCardiology Rehabilitation databases. Automated referral to CR at discharge after CABG was instituted on July 1, 2007. We used interrupted time series analysis to evaluate the impact of automated referral on CR referral and completion rates and studied the association of these CR process markers with mortality. Results: A total of 8,118 patients underwent CABG surgery during the study period: 5,103 before automation and 3,015 after automation. Automation increased referral rates from 39.5% to 75.0% (P < 0.001). Automated referral was associated with a 7.2% increase in CR completion in the overall population (33.3% vs 26.1%; P < 0.001). In adjusted models, CR referral alone was not associated with reduced mortality (hazard ratio [HR] 0.84, 95% CI 0.64-1.11), but CR completion was (HR 0.43, 95% CI 0.31-0.61). Conclusion: Automated referral in post-CABG patients resulted in modest improvement in CR program completion. Therefore, even when CR referral is automated to include all eligible patients, additional strategies to support CR program enrollment and completion remain necessary to achieve the desired health benefits.