Yoga-Based Cardiac Rehabilitation Offers Mixed Results Post-MI

Patrice Wendling

November 11, 2018

CHICAGO — A yoga-based cardiac rehabilitation program was safe and improved quality of life after a myocardial infarction (MI) but fell short of offering significant clinical gains in a randomized trial from India.

Yoga is becoming more popular all over the world and has the potential to become a low-cost alternative to conventional rehabilitation programs, study author Dorairaj Prabhakaran, MD, DM, Centre for Chronic Disease Control, New Delhi, India, told | Medscape Cardiology.

"In the United States, the minority population, women, and the elderly actually do not take up conventional rehabilitation because they find it difficult, particularly the physical activity component," he said. "So we can introduce some of the gentler poses, meditation, and breathing exercises, which they might find more acceptable."

The study was featured in a late-breaking science session here at the American Heart Association (AHA) 2018 Scientific Sessions.

Investigators at 24 centers in India randomly assigned 3959 patients within 14 days of acute MI to 14 weeks of the Yoga-CaRe intervention or enhanced standard care involving three educational sessions and printed leaflets delivered by a nurse or cardiac care team.

Yoga-CaRe consisted of lifestyle education, three health-rejuvenating exercises, and training in breathing/mediation techniques and 15 yoga postures delivered over 13 weeks by trained yoga instructors, with self-practice at home for the final week.

Three fourths of patients had an ST-segment elevation MI, and almost a third had hypertension or diabetes or were current smokers. Their mean age was 53.4 years.

There was a high standard of contemporary cardiac care in both arms, Prabhakaran noted, with nearly 60% of patients undergoing percutaneous coronary intervention, 98.5% receiving antiplatelets, 84% dual antiplatelet therapy, 93% statins, and about 50% angiotensin-converting enzyme inhibitors/angiotensin receptor blockers.

At 42 months, 6.7% of the Yoga-CaRe group and 7.3% of controls experienced the composite primary endpoint of death, nonfatal MI, nonfatal stroke, and emergency cardiovascular hospitalization. The difference failed to reach statistical significance in an intent-to-treat analysis (hazard ratio [HR], 0.91; 95% confidence interval [CI], 0.72  - 1.15).

The analysis was underpowered to detect differences because less than half the number of estimated events occurred, said Prabhakaran, who also noted that post-MI care improved in India during the study.

In a per-protocol analysis of 1059 patients who completed at least 10 Yoga-CaRe sessions, however, the number of primary endpoint events was nearly halved (HR, 0.54; 95% CI, 0.38 - 0.76; log rank P < .001).

Self-rated quality of life, measured by the mean change in the EQ-5D Visual Analog Scale score at 3 months, significantly favored the Yoga-CaRe group over controls (10.7 vs 9.2; P = .002).

Patients who practiced yoga  were more likely to return to preinfarct daily activities (P < .001) and to achieve up to six health states (P = .04) but were just as likely as controls to stop smoking (P = .11) or to achieve high medication adherence (P = .52).

Was It a Fair Comparator?

Invited discussant Vera Bittner, MD, University of Alabama, Birmingham, said the yoga intervention was well defined but that the enhanced standard care intervention had far fewer contacts with study staff.

"This is something that could have affected the quality of life and also the return to prior activities measure since we know from cardiac rehab settings that encouragement from staff can actually play a big role in these measurements," she said.

There also was no physical activity intervention in the control arm, raising the question of whether the observed group differences are yoga-specific and whether similar results could be achieved with a home-walking program.

As to the generalizability of the results, Bittner said it is unclear whether they would translate to MI populations in other settings or to sicker patients, given the young age of the patients, low proportion of women, and low cardiovascular event rate.

Adherence to the yoga intervention of only 53% further raises the question of whether adherence would be worse outside the clinical trial setting.

Going forward, yoga intervention studies need to compare standard in-center or home-based cardiac rehabilitation, Bittner concluded.

"What we were missing here is a comparison with our traditional evidence-based protocol of cardiac rehab vs yoga," past AHA president Donna Arnett, MSPH, PhD, University of Kentucky College of Public Health, Lexington, told | Medscape Cardiology. "Seeing that comparison would be a great next step in this research."

Cardiac rehabilitation is one of the best evidenced-based programs available for preventing secondary infarctions for people in the post-MI setting but is vastly underused, she observed.

"I think what we need to better understand right now is why we have such a low uptake of cardiac rehab in our population," Arnett said. "Maybe yoga would be less threatening to a population in the post-MI setting than cardiac rehab using traditional methods, but we still need that comparison."

That said, she added, "In low- and middle-income countries, this potentially could be a great solution."

Having demonstrated the safety and feasibility of yoga in the post-MI setting, Prabhakaran said they want to extend the intervention to heart failure. "The heart failure population is growing and a recent study in India showed that 50 percent of patients are dead in five years," he said in an interview.

As to whether yoga could be a low-cost alternative, rather than only an adjunct to standard cardiac rehabilitation, he added, "It can replace it but it would be a leap of faith for a country like the United States, which has years of experience with cardiac rehabilitation."

The trial was funded by the Indian Council for Medical Researh (India) and Medical Research Council (United Kingdom). Prabhakaran, Arnett, and Vittner reported no relevant conflicts of interest.

American Heart Association (AHA) 2018 Scientific Sessions. Abstract 19546. Presented November 10, 2018.

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