Sustaining cardiac rehabilitation delivery throughout COVID-19 lock-down: results from the SCRAM telerehabilitation randomized controlled trial (Preprint)

Abstract

Accessibility barriers contribute to low participation in center-based cardiac rehabilitation. We developed an innovative, comprehensive, dual-phase telerehabilitation program to address this gap (Smartphone Cardiac Rehabilitation Assisted Self-Management; SCRAM).

To determine the effectiveness of SCRAM for increasing maximal aerobic exercise capacity (VO2max).

A multi-center, parallel two-arm randomized controlled trial recruited clinically stable adults (aged 18+ years) with diagnosed coronary heart disease at three hospitals in Victoria, Australia (Melbourne, Geelong, Bendigo) from 2018-2021. Participants were randomized (1:1), stratified by sex and study site, to receive SCRAM plus usual cardiovascular care (intervention), or usual cardiovascular care alone (control). SCRAM intervention provided 24 weeks of remote exercise supervision, coaching, and behavior change support via smartphone. Usual cardiovascular care included standard medical care and advice to seek a referral to centre-based cardiac rehabilitation (CR), which was heavily impacted during the COVID-19 pandemic. Due to the nature of the treatments, participants were not blinded to allocation; primary outcome assessors and biostatisticians were blinded. The primary outcome was VO2max at 24 weeks, analyzed on the principle of intention-to-treat, using linear regression adjusted for baseline and stratification factors on multiple imputed data.

Recruitment and data collection were heavily impacted by COVID-19, although SCRAM delivery was sustained throughout. Of 220 required participants, only 123 (56%) were recruited and randomized (intervention n=63, control n=60); 45% had missing VO2max at 24 weeks—largely due to enforced COVID-19 restrictions. VO2max at 24 weeks favored SCRAM, but this was not statistically significant (mean difference=1.61 ml/kg/min; 95% CI [-1.38, 4.61], P=.28). Among secondary outcomes, patients receiving SCRAM had lower diastolic blood pressure at 24 weeks (mean difference=-5.54 mmHg; 95% CI [-10.01, -1.06]).

SCRAM was resilient to COVID-19-related disruptions to CR delivery but, while findings were inconclusive, it did not lead to a clinically important difference in VO2max. Further research is needed to conclusively assess treatment effects and understand how virtual CR delivery models can be translated into routine practice.

Australian New Zealand Clinical Trials Registry (ACTRN): 12618001458224