The Effect of Cardiac Rehabilitation Exercises Combined with Coenzyme Q10 on Functional Capacity and Ejection Fraction in Patients with Chronic Heart Failure

Cardiovascular problems are the leading cause of disease and mortality worldwide, and heart failure is the third leading cause of death in this context. It is associated with a decrease in ATP and mitochondrial dysfunction in cardiac cells, leading to metabolic pathway disruptions, reduced energy, and negative effects on cardiac contractile function.

Factors Preventing Heart Energy Reduction
Therapeutic factors that can prevent heart energy reduction may play a role in treating and controlling heart failure. The increasing prevalence of heart failure in society is a major healthcare challenge. High blood pressure, coronary artery disease, weakened heart muscles, valvular disease, and arrhythmias increase the likelihood of heart failure.

Prevention of Coronary Artery Disease
There is substantial evidence that prognosis and quality of life for patients with cardiovascular disease can be improved with lifestyle changes and pharmacotherapy. Regular, moderate-intensity exercise is one such measure that can help prevent coronary artery disease, which is supported by the World Health Organization. Increased physical activity leads to improved physical and mental health and reduced mortality.

Impact of Physical Activity on Cardiovascular Events
Cardiopulmonary endurance improves after an exercise regimen, as seen in exercise tests, with a marked reduction in subsequent cardiovascular events, both fatal and non-fatal, independent of risk factors. This finding also applies to patients with chronic heart failure. In line with this, cardiac rehabilitation centers, where heart failure patients engage in exercise under the supervision of skilled physicians and nurses, have been established.

Drugs for Heart Failure Management
There are also medications to control heart failure, such as ACE inhibitors, angiotensin receptor blockers, beta-blockers, diuretics, and digoxin. Despite these drugs reducing disease and mortality, chronic symptoms such as fatigue and exercise intolerance remain a challenge. New treatments aimed at regulating heart energy have gained attention.

Coenzyme Q10
Coenzyme Q10, with a structure similar to vitamin K, may improve endothelial function due to its role in facilitating energy production in the mitochondrial electron transport chain and its anti-inflammatory properties. In heart failure patients, plasma Coenzyme Q10 is an independent predictor of mortality, with lower levels observed in those with advanced heart failure symptoms and reduced ejection fraction. This highlights the importance of Coenzyme Q10 supplementation.

Impact of Coenzyme Q10
Recent studies suggest that heart failure is a state of reduced energy due to the harmful effects of reactive oxygen species and oxidative stress, leading to cellular damage and endothelial dysfunction. It has been proposed that Coenzyme Q10, due to its strong antioxidant effects and minimal drug interactions, can reduce toxic effects and potentially decrease mortality in heart failure patients. However, this is a controversial issue. This study aims to investigate the effect of cardiac rehabilitation exercises combined with Coenzyme Q10 as adjunctive treatment on functional capacity and ejection fraction (left ventricular function) in patients.

Studies
Exercise capacity is a very important factor in diagnosing improvement in cardiovascular patients. It also predicts mortality in heart patients. Regular exercise increases work capacity, with hundreds of studies showing that exercise capacity is higher in active individuals compared to sedentary ones. Improvement in exercise tolerance through an exercise program has numerous benefits, including better capacity to handle daily activities, progress in returning to work, and improved quality of life. Studies show that both individuals with cardiovascular disease and healthy individuals experience better lives with higher exercise capacity. Improvements in exercise capacity through exercise can range from 5% to 25%, but increases of over 50% have also been reported.

Factors Affecting Changes in Exercise Capacity
The extent of change in exercise capacity essentially depends on the individual’s initial fitness level, age, gender, as well as the intensity and frequency of exercise. In fact, exercise increases oxygen release in the myocardium by changing vascular nerve responses, and it is important to note that every increase in exercise capacity leads to a 12% increase in survival.

Research
Two other studies showed that daily consumption of 300 mg of Coenzyme Q10 for two years and 200 mg for four months significantly improved the NYHA functional classification and reduced mortality in the test group compared to the placebo group. Researchers found that after taking Coenzyme Q10, functional capacity and left ventricular contractility increased without side effects, and its combination with exercise had a significant impact on patients. Overall, the results of most studies align with these findings. However, due to the heterogeneity and small size of the studies and the lack of consistency in methods and cardiovascular drugs used, meaningful conclusions and widespread recommendations for Coenzyme Q10 use remain limited.

Mechanism of Coenzyme Q10 Action
Nevertheless, considering the mechanism of action of Coenzyme Q10, its positive effects cannot be overlooked. Coenzyme Q10 acts as a strong antioxidant in cell membranes and lipoproteins and is the only antioxidant synthesized in the body. By preventing lipid peroxidation, it can play an essential role in stabilizing cell membranes and reducing cellular damage. It has been recognized in recent years for its key role in mitochondrial biogenesis, acting as an electron carrier in mitochondria and as an essential cofactor for energy production. Internal synthesis and dietary intake prevent deficiency in healthy individuals. However, levels and the ability to produce Coenzyme Q10 in tissues decrease with age and in the hearts of heart failure patients, so its deficiency exacerbates the condition.

Impact of Oral Coenzyme Q10 Supplementation
Oral Coenzyme Q10 supplementation increases its plasma levels, lipoproteins, and blood vessels. However, it is unclear whether Coenzyme Q10 levels in tissues, particularly in patients, increase. Although this supplement may serve as adjunctive treatment alongside conventional therapies for heart failure patients, its impact on cardiovascular patients requires further investigation. It is suggested that the harmful effects of reactive oxygen species increase in heart failure patients, and Coenzyme Q10, due to its antioxidant activity, can help reduce toxic effects. Plasma Coenzyme Q10 levels are an independent predictor of mortality in heart patients. Moreover, Coenzyme Q10 may play a role in myocardial calcium stability (depending on ion channels) and membrane stability, preventing the loss of metabolites required for ATP synthesis.

Research Trends
Based on the findings from previous studies and the mechanisms discussed, Coenzyme Q10 may act as a strong antioxidant, improving endothelial function without side effects or increasing heart energy production, thus improving functional capacity and ejection fraction.

Improvement in Patients
This improvement was more pronounced in patients who participated in rehabilitation programs combined with Coenzyme Q10 supplementation. Cardiac rehabilitation, particularly when combined with Coenzyme Q10, led to better left ventricular function with increased EF and METs in heart patients.

Our Recommendation
It is recommended that cardiac therapists, based on evidence of safe and effective cardiovascular benefits, encourage patients to engage in simultaneous cardiac rehabilitation and Coenzyme Q10 supplementation.

Research Suggestions
Furthermore, future studies with larger numbers of participants receiving Coenzyme Q10 and exercise over longer periods and at varying doses are needed to better understand the role of exercise and supplements in improving these desired outcomes. This will enable more reliable conclusions regarding the efficacy of Coenzyme Q10 supplementation and exercise in the rehabilitation of heart patients. Finding an appropriate exercise and medication protocol for heart patients is challenging, and perhaps exercise protocols with varying intensity and duration may be suitable for individuals with different ages and disease characteristics.

Solution
Additionally, understanding which cellular and molecular mechanisms are involved in cardiovascular adaptations induced by exercise and supplements will help specialists use drugs or other therapeutic methods to assist heart patients in prevention and treatment.

Source
Esteghli, Samira, Ebrahim, Khosrow, Gholami, Mandana, & Jalalian, Rezita. (2017). The effect of cardiac rehabilitation exercises combined with Coenzyme Q10 on functional capacity and ejection fraction in patients with chronic heart failure. Journal of the Faculty of Medicine, Mashhad University of Medical Sciences, 60(6), 756-766. SID.