Yoga-based Cardiac Rehabilitation: Exploring its Mechanism on Heart Failure through Assessing Endothelial Function, Gene Expression, and Arterial Health (Yog-EndOmics)

Heart Failure (HF) is a complex clinical syndrome with symptoms and signs that result from any structural or functional impairment of ventricular filling or ejection of blood. HF is a devastating, resource-intensive syndrome that necessitates several pharmacotherapies and causes early mortality, disability, impaired functional capacity, and decreased quality of life. The incidence of HF in India is estimated to be between 0.5 and 1.7 cases per 1000 person per year, for a total of 0.49 million to 1.8 million new cases per year. An effective therapeutic approach for HF still remains a challenging unmet need. Despite the successful control of CV risk factors with several strategies including drugs, the prognosis is poor with current standard therapy with 65% mortality rate at 5 years. Cardiac Rehabilitation is the process of restoring desirable levels of Physical by Physiotherapist (Exercise therapy), Social Counseling by Dietitian (Smoking cessation, Nutritional Counseling, lifestyle modifications), and psychological functioning by Psychologists (Stress reduction sessions, Counseling & medications for depression) after the onset of cardiovascular illness. It is an effective intervention for the prevention of cardiovascular events. Yoga is an ancient Indian mind-body medicine that works in all aspects of a person. All the 3 elements which require 3 different disciplines which covered in Cardiac Rehabilitation are carried out by single Yoga Physician. A meta-analysis showed Yoga as an effective mind-body approach to improve exercise tolerance and Quality of Life in HF patients. An effective therapeutic approach for HF still remains a challenging unmet need. Endothelial dysfunction has been proposed as a potential target for new therapy development and research in HF treatment. In the present context, a comprehensive holistic -approach that improves endothelial function may be an effective therapy for HF. Yoga based intervention has been shown to improve exercise tolerance and pumping function of the heart, but there are gaps in the understanding of the mechanism underlying the improvement in the heart failure with Yoga and its effect on endothelial system remains to be determined. The study will investigate whether Yoga based cardiac rehabilitation program will induce any improvement in endothelial system, arterial function, oxidative stress and inflammation and will look at how it may contribute in beneficial modulation of systolic and diastolic function of heart. The study will also help in identifying the novel target molecules for effective therapy for HF

**Applicability:**A well-designed RCT of Yoga-CaRe on endothelial system in heart failure is not available. Further, the precise mechanism underlying the effect of Yoga-CaRe on HF remains to be elucidated. The study will investigate whether endothelial function, expression of endothelial genes and its products are influenced by Yoga, and will look at how it may contribute in beneficial modulation of systolic and diastolic function of the heart; and associated co-morbidities as a result of participation in the CR program. Also determine the effect of Yoga-CaRe program on expression of those genes whose products affect vascular and heart health. The study will help in understanding the underlying mechanism of Yoga (through changes in the endothelial function) on HF and in identifying the target molecules for effective therapy for HF

Objectives

1. To determine if Yoga CaRe may improve endothelial function through enhancement of endothelial-dependent vasodilation after 3 months of Yoga CaRe training.

2. To assess the rapid changes in global gene expression profiles in the peripheral blood mononuclear cells immediately after Yoga CaRe training in patients with systolic HF

3. To determine the effect of three months of Yoga CaRe on endothelial-related genes, DNA methylation, central blood pressure, arterial stiffness, oxidative stress, and inflammatory markers.

4. To find whether Yoga CaRe-induced changes in vascular function and associated genes are associated with outcomes in HF.

**Method of assessment and data collection:**Data will be collected at baseline and post-intervention. The following parameters will be investigated:

i. Functional exercise capacity: Functional exercise capacity in HF patients will be evaluated using a six-minute walk test (6MWT).

ii. Echocardiography: Systolic and diastolic function of the heart will be assessed using echocardiography.

iii. Assessment of Endothelial system:

a. Flow-mediated dilatation (FMD): This is a gold standard parameter for the assessment of endothelial function. The brachial artery diameter (endothelial-dependent and independent dilatation) will be measured using an endothelial function analysis system.

b. Carotid intima-media thickness: This test measures the thickness of the inner two layers of the carotid artery—the intima and media which reflects atherosclerosis and endothelial dysfunction.

c. Biomarkers of endothelial function: Endothelin-1 will be evaluated using the ELISA method. Total nitric oxide concentration (NOx) will be determined by the Griess method.

iv. Gene expression profiling:

a. Real-time qRTPCR will be carried out for examination of expression of genes (eNOS, ET-1, TNF-alpha, NADPH oxidase, MMP, Ang-1, VCAM, ICAM) using blood samples.

v. DNA Methylation analysis

a. DNA methylation analysis will be done using Quantitative analysis based on PCR pyrosequencing.

b. Repetitive element methylation will be estimated by performing DNA methylation analysis of ALU and LINE-1 repeated sequences. Measures of ALU and LINE-1 methylation are commonly used as a surrogate of global methylation.

vi. Assessment of arterial health: Arterial stiffness will be evaluated using ARTSENS® Plus, a validated comprehensive vascular health assessment device.

a. Carotid-to-femoral pulse wave velocity

b. Arterial compliance  (common carotid artery)

c. Peak luminal distension

d. One-point local pulse wave velocity

**vii. Central arterial pressure:**Carotid arterial pressure will be determined using ARTSENS®. The following carotid arterial pressure will be recorded:

a. Carotid systolic pressure

b. Carotid diastolic pressure

c. Carotid pulse pressure

viii. Oxidative stress & inflammatory markers: Oxidized-LDL, total antioxidant capacity, TNF- alpha and HsC-reactive protein will be estimated by the ELISA method.

ix. G****lobal gene expression: will be analyzed using Significance Analysis of Microarrays (SAM) method.