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.