Cardiac rehabilitation (CR) started 2 weeks after sternotomy for a cardiac procedure was noninferior to usual care, in which CR starts 6 weeks after the procedure, with a greater improvement in 6-minute walk test outcomes, a randomized study suggests.
There was no difference in adverse events between groups, although the researchers pointed out that the study was not powered specifically for safety outcomes.
“Cardiac surgical techniques have evolved significantly over the last 60 years, leading to improved survival and shorter hospital stays,” Gordon McGregor, PhD, University of Warwick, Coventry, England, told this news organization. “However, sternal precautions and rehabilitation guidelines have not changed accordingly. There has never been a guideline based on empirical evidence to support rehabilitation professionals working with cardiac surgery patients after median sternotomy.”
“By adopting a progressive individualized approach,” he added, “cardiac surgery sternotomy patients can start cardiac rehabilitation up to 4 weeks earlier than current guidance, and thus potentially complete their recovery sooner.”
Results of the Early Initiation of Poststernotomy Cardiac Rehabilitation Exercise Training study were published online in JAMA Cardiology.
In the study, Dr. McGregor and colleagues randomly assigned 158 patients (mean age, 63 years; 84% men) to 8 weeks of 1-hour, twice-weekly supervised CR exercise training starting 2 weeks (early) or 6 weeks (usual care) after sternotomy.
The primary outcome was change in the 6-minute walk test distance from baseline to 10 or 14 weeks after sternotomy, respectively, and 12 months after randomization.
For usual care, training followed British standards: a warm-up with light cardiovascular and mobility exercises; continuous moderate-intensity cardiovascular exercise; a cooldown; functional exercises using resistance machines and free weights; and upper-body exercises designed to prevent sternal and leg wound pain and complications.
There are no specific outpatient CR exercise guidelines for early CR, so study participants followed an individualized exercise program for the first 2-3 weeks after surgery, starting with light mobility and moderate-intensity cardiovascular training when they could do those exercises with minimal discomfort. They then progressed to current British standards, as per usual care.
Forty patients were lost to follow-up, largely because of the pandemic; about half the participants in each group were included in the primary analysis.
Early CR was not inferior to usual care, the authors wrote. The mean change in 6-minute walk distance from baseline to completion of CR was 28 meters greater in the early group than in the usual-care group, and was achieved 4 weeks earlier in the recovery timeline.
Secondary outcomes (functional fitness and quality of life) improved in both groups and between-group differences were not statistically significant, indicating the noninferiority of early CR, the authors noted.
Safety not proven
There were more adverse events in the early group than in the usual-care group (58 vs. 46) and more serious adverse events (18 vs. 14), but fewer deaths (1 vs. 2).
Although there was no between-group difference in the likelihood of having an adverse or serious adverse event, Dr. McGregor acknowledged that the study was “not powered specifically for safety outcomes.” He added that “there is the potential to run a very large multination definitive superiority [randomized, controlled trial] with safety as the primary outcome; however, a very large sample would be required.”
Meanwhile, he said, “we can say with some degree of certainty that early CR was likely as safe as usual-care CR. In the United Kingdom, we work closely with the British Association for Cardiovascular Prevention and Rehabilitation and the Association of Chartered Physiotherapists in Cardiovascular Rehabilitation, who will incorporate our findings in their guidelines and training courses.”