Traditional vs extended hybrid cardiac rehabilitation based on the continuous care model for patients who have undergone coronary artery bypass surgery in a middle-income country: A randomized controlled trial

Objective: To compare traditional (1-month supervised) vs hybrid cardiac rehabilitation (CR; usual care) with an additional 3 months offered remotely based on the continuous care model (intervention) in patients who have undergone coronary artery bypass graft (CABG). Design: Randomized controlled trial, with blinded outcome assessment. Setting: A major heart center in a middle-income country. Participants: Of 107 eligible patients who were referred to CR during the period of study, 82.2% (N=88) were enrolled (target sample size). Participants were randomly assigned 1:1 (concealed; 44 per parallel arm). There was 92.0% retention. Interventions: After CR, participants were given a mobile application and communicated biweekly with the nurse from months 1-4 to control risk factors. Main outcome measures: Quality of life (QOL, Short Form-36, primary outcome); functional capacity (treadmill test); and the Depression, Anxiety and Stress Scale were evaluated pre-CR, after 1 month, and 3 months after CR (end of intervention), as well as rehospitalization. Results: The analysis of variance interaction effects for the physical and mental component summary scores of QOL were <.001, favoring intervention (per protocol); there were also significant increases from pre-CR to 1 month, and from 1 month to the final assessment in the intervention arm (P<.001), with change in the control arm only to 1 month. The effect sizes were 0.115 and 0.248, respectively. Similarly, the interaction effect for functional capacity was significant (P<.001), with a clinically significant 1.5 metabolic equivalent of task increase in the intervention arm. There were trends for group effects for the psychosocial indicators, with paired t tests revealing significant increases in each at both assessment points in the intervention arm. At 4 months, there were 4 (10.3%) rehospitalizations in the control arm and none in intervention (P=.049). Intended theoretical mechanisms were also affected by the intervention. Conclusions: Extending CR in this accessible manner, rendering it more comprehensive, was effective in improving outcomes.The authors thank the Vice-Chancellor for Research and Technology of the Tarbiat Modares University for approving and supporting this work (No. IR.MODARES.REC.1397.183). We would like to thank the staff of Farshchian Heart Center for their collaboration with this work