Effects of Rehabilitation in Patients With Stable Chronic Heart Failure

Functional Characterization of Respiratory Muscles and Effects of Rehabilitation in Patients With Stable Chronic Heart Failure

Heart failure (HF) is a major public health problem. This is the first cause of hospitalization and mortality of about 65 years old. This syndrome is characterized by a poor prognosis and a high cost of care. Thus, new strategies for treatment and prevention of the HF are among the major challenges facing health sciences today.

The management of HF requires multimodal approach it involves a combination of non-pharmacological and pharmacological treatment, Besides improvements in pharmacological treatment, supervised exercise programs are recommended for all patients with HF as part of a non-pharmacological management but many questions regarding exercise training in HF patients remain unanswered. Even simple questions such as the best mode of training for these patients are unclear.

The aim of this study

1. First, to characterize the physiological functions involved in the genesis of exercise intolerance and dyspnea especially muscle function (respiratory and skeletal), and cardiopulmonary patients suffering from chronic HF.
2. Second, to study and compare the effects of different rehabilitation programs and prove the superiority of the combination of three training modalities program: aerobic training (AT), resistance training (RT) and inspiratory muscle training (IMT).

These modalities are:

Aerobic Training: It has been proven effective in improving muscle abnormalities on changing the ventricular remodeling, dyspnea, functional capacity, increasing the maximum performance and reducing hospitalization in subjects suffering HF.

Resistance Training: It has been proven effective in improving skeletal muscle metabolism and angiogenesis; increasing capillary density and blood flow to the active skeletal muscles, promoting the synthesis and release of nitric oxide, and decreasing oxidative stress.

Selective Inspiratory Muscle Training: It has been proven effective in improving the strength and endurance of the respiratory muscles and reduction of dyspnea during daily activities.

The Heart failure is the major cause of mortality and morbidity especially in elderly subjects.

The main feature of heart failure is exercise intolerance, which is always associated with fatigue and dyspnea in exercises of low intensity. Harrigton et al in 1997 demonstrated the existence of a dysfunction of skeletal muscles. But it is likely that these changes are not limited to the musculature of the lower limbs but are widespread and may affected the respiratory muscles. Thus, this dysfunction of the respiratory and skeletal muscles associated with dyspnea can contribute to the genesis of fatigue and impaired physical performance in turn reducing the autonomy of individuals.

The guidelines recommend no pharmacologic strategies by specific exercises to relieve symptoms, improve exercise tolerance and quality of life and reduce the rate of hospitalization.

The supervised exercise programs are recommended for all patients who have CHF as part of a non-pharmacological management. Thus, the exercise remains the pioneer of cardiac rehabilitation programs. The effectiveness of the training of the skeletal muscles against resistance (RT) and aerobic training (AT) in the rehabilitation HF has been well documented. However, selective training of respiratory muscles (IMT) is a relatively new technique in the field of the ICC.

In 1995, Mancini et al. were the first to publish a report on the advantage of selective training of respiratory muscles in HF patients.

Another study showed the superiority of a high-intensity training, 60% of maximal inspiratory pressure (PI max) on another 15% of PImax by increasing muscle strength and inspiratory muscle endurance, improved exercise capacity, reduction of dyspnea and quality of life.

While the above studies have investigated the benefits of inspiratory muscle training alone in CF patients, the question to ask is "If the benefit of the inspiratory muscle training was added to that observed with aerobic training for the whole body. "

Laoutaris in 2013 showed that the combination of AT with RT and IMT could result in a significant improvement in peripheral muscle and respiratory function with significant improvement in exercise capacity, dyspnea and quality of life compared to that of the 'single AT. However, this study has several limitations. These limits are:

1. Patients in the combined group suffer longer exercise sessions of 20 minutes compared to patients alone aerobic group. Thus, the difference in the time to exercise between the 2 groups may have influenced the results of the study.
2. Furthermore, the authors compared three different modalities of exercising against a modality which affects so the quality of the study.
3. In addition, the extent to which the resistance training or selective training of respiratory muscles contributed to greater improvements in the combined group was not assessed in this study as this would take several modalities groups different exercises and a control group.

Till now,

1. There are no randomized, controlled, double blinding studies that compares different modalities of exercises to each other and to a control group in patients who have CHF. Moreover,
2. It is not known until now what combination of exercises modalities is the most effective and more secure, and
3. If there are additional benefits by combining multiple training modalities by comparing it with other modalities in patients with stable chronic heart failure (CHF).

In this study, the investigators examined the hypothesis of the efficiency of a combined program of three modalities: aerobics, resistance, and selective respiratory muscle on:

1. Heart and lung function,
2. Heart and lung structure,
3. The function of skeletal and respiratory muscles,
4. Functional capacity,
5. Dyspnea, and quality of life.

The main objectives of this project are defined:

1. To characterize the physiological functions involved in the genesis of exercise intolerance and dyspnea.
2. Comparative study of all therapeutic modalities with a control group and each other.
3. To study muscle function: respiratory and skeletal in HF patients in different training groups.
4. To study the muscular structures: respiratory and skeletal.
5. To study the structure and heart function.
6. See the influence of these three training modalities on functional capacity, dyspnea and quality of life.
7. To state the guidelines for heart failure.

Methodology and research requirements Protocol All subjects must sign an informed consent form. Patients will submit a physical examination, and electrocardiographic measurements by a cardiologist. Approximately 60 patients are divided randomly by investigators who are not involved in the implementation of the project to eight different groups.

Before and after the intervention were evaluated all the tests mentioned above by a physiotherapist who do not know the distribution of patients to different interventions.

Groups All types of training sessions are individualized and are carried in Beirut Cardiac Institute. Patients are exerted for twelve weeks at a rate of three times per week, for one hour. Any missed session will be added to the end of the program, so that the 36 sessions will be realized. All sessions must be supervised at all times by a physiotherapist and a cardiologist.

Group 1 (n = 10): Aerobic training (30mn) Group 2 (n = 10): Inspiratory muscle training (20mn) Group 3 (n = 10): Resistance Training (20mn) Group 4 (n = 10): Aerobic Training (30 min) + Inspiratory muscle training (20mn) Group 5 (n = 10): Aerobic Training (30 min) + Inspiratory muscle training (20minutes) + Resistance training (20 minutes) Group 6 (n = 10) Control

Inclusion Criteria

• Congestive heart failure (CHF) due to ischemic or dilated cardiomyopathy.
• Left ejection fraction ≤ 45%.
• NYHA functional class II and III.
• A patient with a diagnosis of CHF for six months including no admission to the hospital or change in medications over the previous 3 months.
• IMW <70% of predicted

Exclusion criteria

• Pulmonary limitation (forced expiratory volume in 1 s and/or vital capacity of less than 60% of predicted value).
• History of significant cardiac arrhythmia.
• History of myocardial infarction or cardiac surgery (6 months).
• Orthopedic or neurologic disease.
• Non echogenic, Unstable.
• Poorly controlled blood pressure.
• End-Stage HF (on the waiting list for transplantation or LVAD).