Damian Sendler: Exercise-based cardiac rehabilitation programs play a significant role in secondary prevention of coronary artery disease. There is a lack of participation in exercise-based rehabilitation programs in some populations. Yoga has been linked to better cardiovascular health, making it a viable option for cardiac rehab programs. Yoga-based cardiac rehabilitation may reduce cardiovascular risk factors and improve physiological and psychological outcomes in patients with coronary artery disease, according to a review of current randomized controlled trials. A medical database search turned up six randomized controlled studies, and meta-analysis was performed on the data to determine the various outcomes. With yoga’s addition to standard care, cardiac health and quality of life were positively affected. The left ventricular systolic function was also improving. This cohort’s improvement in cardiac risk factors, MACE, and mental health has yet to be proven, but it was not inferior to standard or enhanced care, and the benefits became more pronounced at longer follow-up. Longer-term studies with more patients and a larger sample size will help determine whether yoga-based rehabilitation is beneficial in the long term.
Damian Jacob Sendler: More than a third of people die each year from cardiovascular disease, making it the leading global killer. Approximately 126.5 million people around the world have been diagnosed with coronary artery disease, making it the most common type of heart disease. In the UK, that number rose to 311,519 hospitalizations and 64,132 deaths in 2018. 2
Dr. Sendler: Even though interventional and pharmacological therapies are frequently required, risk factor modification plays a crucial role in secondary prevention in patients who have already experienced a coronary event. In patients with cardiovascular disease, exercise-based cardiac rehabilitation (CR) has been shown to reduce cardiovascular mortality and hospitalization, and improve physiological and psychological well-being. 3 As part of the comprehensive recovery program, physical activity is not undertaken in isolation, but rather is integrated into healthy eating, smoking cessation, medication adherence, and stress management, all of which contribute to a healthier lifestyle. A sedentary lifestyle, obesity, and hypertension are all risk factors for cardiovascular disease that can be reduced by aerobic exercise, which increases myocardial perfusion and decreases myocardial oxygen demand. Patients with ischemic heart disease have access to exercise-based cardiac rehabilitation in 111 countries around the world, and it is recommended as a class 1 treatment in European and American clinical practice guidelines. 4–6 However, a variety of other forms of exercise have been tested in an effort to increase CR uptake, enable tele-based programs, and look at lower-cost options.
Yoga is a form of exercise and weight loss program that incorporates physical postures, breath control, and meditation. It has been shown to improve peak oxygen consumption and quality of life in other rehabilitation programs, such as in pulmonary rehabilitation programs for COPD and heart failure. 7,8 As a preventative strategy for COVID-19.9–11 and other conditions like anxiety and depression as well as chronic pain, it has also been shown to be beneficial in numerous other studies. As yoga is more common in India, a low-cost model could increase accessibility and familiarity, which could lead to greater uptake of the practice in the United States. Certain subgroups like women, the elderly, and those with low income, who are traditionally underrepresented in conventional CR, may benefit from this approach more in countries with higher incomes and more developed rehabilitation programs.
Yoga-based rehabilitation has not yet produced conclusive evidence of its benefits, in part because the studies that have examined it have been heterogeneous, looking at different patient groups, comparators, and outcomes. This lack of uniformity makes determining its appropriateness for clinical practice difficult. A review of current randomized controlled trials was conducted to examine the evidence for yoga-based cardiac rehabilitation and to examine whether it improves physiological and psychological outcomes in patients following acute coronary disease compared to standard care.
To see if yoga had an effect on physiological and biochemical parameters, the RCTs examined a wide range of cardiovascular risk factors.
There was a statistically significant difference in BMI reduction between patients who underwent a yoga-based rehabilitation program and those who underwent standard exercise rehabilitation (p=0.001).
13 He showed statistically significant reductions in heart rate and blood pressure levels in comparison to only pharmacological treatment. 15 Even though Tillin and colleagues did their research outside of India, they found no differences in the physiological cardiovascular risk factors they examined: ambulatory, resting and exertional blood pressures; resting heart rates; BMI; waist-to-hip ratios; percent body fat mass; and peak VO2. 16 Over a period of three months, the intervention group’s ambulatory blood pressure dropped from an average daytime ambulatory systolic pressure of 115 millimeters mercury to 113 millimeters mercury (p=0.5).
Blood glucose levels and lipid profiles have been linked to an increased risk of cardiovascular disease in three separate studies. They found that yoga participants had better glycemic control, but it wasn’t statistically significant. Compared to the control group, there was a statistically significant change from baseline for those with poor glucose control (p=0.008 for fasting blood glucose levels >100 mg/dL and p=0.003 for levels >200 mg/dL), but not for those with good control (p=0.41 and 0.032, respectively). When looking at blood glucose levels, Tillin et al. found no statistically significant difference between the two groups (0.05%, confidence interval [CI] -0.23 to 0.33, p=0.7).
Participants’ lipid profiles were examined by Raghuram et al, Tillin et al, and Sharma et al. At three months, neither Tillin et al. nor Sharma et al. found a statistically significant difference in triglycerides, total cholesterol, HDL or LDL. There was a statistically significant reduction in total triglycerides (p=0.03), total HDL (p=0.001) and total VLDL after one year of treatment. There was no significant difference in total cholesterol or total LDL between the groups, but there was a significant reduction in the yoga group compared to the control group in patients with a high baseline LDL (100 mg/dL). There was no subgroup analysis in Tillin and Sharma. Figures 5–7 show a non-statistically significant trend favoring the yoga group in risk management for cardiovascular disease. According to Raghuram et al., the baseline mean triglyceride, total cholesterol, and fasting blood sugar levels were all higher in the Indian cohort than in the UK cohort.
Clinical patient-reported measures and measurements of LVEF and diastolic function on echocardiogram have been used to examine changes in cardiac function.
Damian Jacob Markiewicz Sendler: Three studies looked at clinical measures of improvement in cardiac function. Sharma et al used the Duke Activity Status Index (DASI) and derived metabolic equivalents from these self-administered functional scores to determine patient-perceived improvement in cardiac function and found that those who underwent the yoga-based program had significantly better scores at three months than a control group (p0.001). Additionally, in the group that practiced Yoga-CaRe, Prabhakaran et al. discovered a slight improvement in self-reported return to pre-infarct activity (88.3 vs. 87.0; p=0.039). There was no difference between groups in the subjective assessment of cardiac function using the International Physical Activity Questionnaire administered by Tillin et al (p=0.8).
After a 12-week yoga program, patients with acute MI had their heart rate variability compared to standard care, which did not include an exercise-based rehabilitation program, which was published by Christa et al in 2019.
17 It was discovered that adding yoga interventions to standard medical therapy improved parasympathetic activity and overall cardiac autonomic tone in patients.
LVEF was examined in two separate studies following yoga-based rehab. With no difference between groups, Raghuram and coworkers found that CABG resulted in significant improvement in LV systolic function. After a year of yoga rehab, patients with less than 53% functional capacity had a greater improvement than those who did not. Ejection fraction improved from 47.5% to 53% in the yoga group, whereas the control group only improved from 49.5% to 49% (p=0.02). Because patients with an EF below 30% were excluded from the study, it is impossible to say whether a low aerobic exercise program would be even more beneficial for those with more severe LV dysfunction. According to Sharma et al, there was no difference in LV function between the groups (this may be due to the short follow-up period of only three months), but Raghuram et al found a difference after six months. There was no statistically significant difference found in meta-analysis (Figure 8). There was no statistically significant difference between the yoga and control groups in the improvement of left ventricular diastolic function (p=0.04).
Only one randomized controlled trial has looked at the reduction in MACE following a yoga-based intervention, and that was conducted by Prabhakaran et al. Personalized yoga exercises, breathing control techniques, meditation, and relaxation exercises were all part of the Yoga-CaRe program that was implemented in multiple Indian centers. In addition to three sessions of educational advice, the improved standard of care program did not routinely offer an exercise program.
Major adverse cardiovascular event (MACE) was defined as death from any cause, MI, CVA or emergency cardiovascular hospitalization without death. After making a mid-trial change to MACE criteria to include emergency cardiovascular hospitalizations in order to achieve higher event rates, the study was still underpowered to detect a 20% reduction in MACE.
They screened 6737 patients and enrolled 3959 between August 2014 and March 2018, and the patients were well matched at baseline. MACE occurred in 6.7% of Yoga-CaRe and 7.4% of standard enhanced care patients, with an incidence of 0.9 (95 percent confidence interval 0.71–1.15).
A reduction in cardiovascular hospitalization was seen in the Yoga-CaRe group, but this was underpowered. There was no statistical difference in total MACE. In terms of MACE risk, those who had previously had coronary artery disease (0.49) and did not have diabetes (0.65; 95 percent CI 0.47–0.91) were statistically more likely to benefit from Yoga-CaRe.
Many studies have found yoga to have a positive effect on both cardiovascular and psychological health.
11,18 Patient-reported scores for psychological health were evaluated in four RCTs. Both the Cardiac Depression Scale (CDS) and the Hamilton Anxiety Rating Scale (HAM-A) showed a significant decrease in scoring, both with p 0.001. Yoga-base-adjusted CaRe’s mean (EQ-5D-5L) was 1.50 (95 percent CI 0.53–2.48; P=0.002), whereas Prabhakhan et al. found their OQL questionnaire (EQ-5D-5L) results in favor of the yoga group at 12 weeks, with 77 points versus 75.7. In the yoga group, self-reported depression, anxiety, and stress levels improved, but this difference was not statistically significant when compared to the control group. Only the increase in the patient’s overall positive affectivity following the intervention (PANAS p=0.02) was statistically significantly better with yoga than the control group in this study. While the QOL questionnaire (EQ-5D-3L) and perceived stress score scale were not significantly different between groups, Tillin et al. found no difference in their findings.
Prabhakhan et alresearch .’s was the only one to compare the health habits of different groups and found no difference between the high rates of medication adherence and the cessation of tobacco use. Both the educational sessions in both programs and the patient selection cohort likely had an impact on this result. Patients who were not likely to complete the rehabilitation program were excluded from the study. Once participants were enrolled in the study, there was no difference in their adherence to the exercise program based on their age or gender.
Damien Sendler: Less aerobic activity is required in yoga-based cardiac rehabilitation programs in Europe than in traditional exercise-based rehabilitation programs. Cardiovascular rehabilitation’s fundamental principles are upheld by yoga-rehab, however: a structured exercise program that improves functional capacity in a safe environment while promoting healthy behaviors in order to lower the risk of cardiovascular disease. According to previous studies, the practice of yoga lowers blood pressure, heart rate variability, abdominal obesity, insulin resistance and hyperlipidemia, all of which are risk factors for heart disease and other types of cardiovascular disease. 18 Yoga was found to have the greatest impact on lowering 10-year cardiovascular risk when compared to other lifestyle changes (16.7 percent ). 19
After examining the results of six randomized controlled trials (RCTs) examining the effects of yoga on cardiac rehabilitation in patients with coronary artery disease, no clear benefits of yoga can be discerned, due to the evidence’s current limitations, which make interpretation difficult.
Damian Sendler
Weight loss was observed in one study, but no significant difference was found in any of the other cardiac risk factors examined. Because meta-analysis favors yoga, it’s possible that the small sample size in that study is to blame. Biochemical risk factors did not differ significantly between studies with 3-month follow-up, but Raghuram et al found reductions in HDL and VLDL at one year. However, a meta-analysis found yoga to be beneficial in reducing triglycerides, total cholesterol, and LDL, albeit with varying baselines and patient populations. Most of the studies, except for Tillin et al., reported an improvement in cardiac function. After a year, the echocardiogram showed an improvement, but only in those who had a lower baseline function. At one year, the ejection fraction had increased by six percent. Despite the fact that many accreditation services now recommend reporting ejection fraction as a range rather than an exact number, the measurement cannot be said to be reliable. When it came to the primary outcome and subgroup analysis, only one study examined whether yoga had any impact on MACE. A meta-analysis of studies examining psychological health found that patients in the yoga groups had a 50 percent improvement in their stress levels.
As a result of the diverse populations studied, a small number of studies yielded different results. Some studies only included those with LV systolic dysfunction, while others included patients with normal function. Some studies focused on men only, while others examined a variety of ethnic groups with varying baseline characteristics. Some studies had a 3-month follow-up period, while others had a 1-year follow-up period. Many of the 1-year studies found that the 3-month follow-up period was too short to see a difference in outcomes. Furthermore, the sample sizes of the majority of the studies make it difficult to draw firm conclusions. With nearly 4,000 participants, Prabhakhan et alstudy .’s was the largest to date. It was necessary to include additional MACE events midway through the trial because this was still an underpowered study, and it reflects the difficulty in recruiting enough patients to find statistical significance.
Several different outcomes have been examined in these studies, but it is difficult to determine the validity of results without some degree of standardized repetition. The majority of studies were conducted in India, making it difficult to generalize the findings to other populations; this is reflected in the differences between Raghuram et al and Tillin et al in baseline characteristics. The yoga group’s loss to follow-up was significantly higher than the normal cardiac rehab group’s in the only study conducted in the UK (37.5 percent vs 12.5 percent , respectively). An unwillingness to continue attending yoga classes was documented in the study’s small sample size (40 participants at the outset). According to the research, women and the elderly, two underrepresented groups in traditional rehab, have not increased their participation. Prabhakhan et al. found a lack of interest in recruiting women and the elderly, and men made up the majority of participants in all of the studies they looked at.
Damian Jacob Sendler
Cardiovascular rehabilitation in low- and middle-income countries has been hindered by a lack of resources, affordability, and patient and physician participation in rehabilitation programs..
As a result of the reduced equipment and location of classes as well as the fact that yoga is already widely practiced in Asia, the costs associated with a yoga-based program are significantly lower than conventional cardiac rehabilitation.
In general, studies show that including yoga in cardiac rehabilitation programs improves patients’ subjective perceptions of health and their overall well-being. A trend was also seen in those who had previously had an impaired left ventricular systolic function. This cohort’s improvement in cardiac risk factors, MACE, and mental health has yet to be proven, but it was not inferior to standard or enhanced care, and the benefits became more pronounced at longer follow-up.
In spite of the fact that it has not been proven to be superior, yoga-based cardiac rehabilitation may be a suitable alternative rehab, particularly in communities where engagement is likely to be better and where patients are therefore more likely to persist beyond the initial program. As a low-cost alternative, it could be considered when the MDT recruitment process is difficult or when the patient’s geographic location prevents them from accessing treatment options.
Other areas of cardiac rehabilitation, such as the treatment of heart failure, may reap the benefits of improved autonomic function as well. Longer-term studies with more patients and a larger sample size will help determine whether yoga-based rehabilitation is beneficial in the long term.
