Comparison of the Effect of Two Types of Physical Exercises in Patients With Heart Failure With Preserved Ejection Fraction

Comparison of the Effect of Two Types of Physical Exercise on the Improvement of Exercise Capacity, Diastolic Function, Endothelial Function, and Arterial Stiffness in Patients With Heart Failure With Preserved Ejection Fraction (ExIC-FEp Study)

Background: Heart failure (HF) is a chronic disease with a very important and increasingly severe social and health impact with a prevalence of 6.8% in Spain. HF with preserved ejection fraction (HFpEF) represents approximately 50% of all patients with HF. In the absence of pharmacological treatments that have succeeded in reducing mortality or morbidity in this pathology, it is recommended that interventions be directed at prevention, symptomatic treatment of HF and treatment of comorbidities to avoid exacerbations, thus physical exercise is recognized as an important adjunct in the treatment of HF and is recommended by the guidelines of the American College of Cardiology (ACC)/American Heart Association (AHA) and the European Society of Cardiology (ESC). Currently, aerobic exercise is the most studied physical exercise in this population, but in recent years high-intensity interval training (HIIT) and the combination of aerobic exercise with strength training (combined exercise) have emerged.

Objectives: The overall objective of this study is to compare the effectiveness of combined training and HIIT on exercise capacity, diastolic function, endothelial function, and arterial stiffness in patients with HFpEF. The specific objectives of this study are: a) to compare the effectiveness of combined training and HIIT on quality of life in patients with HFpEF and b) to analyze the cost-effectiveness of combined training and HIIT versus conventional treatment in patients with HFpEF.

Methodology: The ExIC-FEp study will be a single-blind randomized clinical trial with 3 arms (combined exercise, HIIT and a control group), conducted at the Health and Social Research Center of the University of Castilla-La Mancha, to analyze two types of supervised physical exercise in patients with HFpEF for 6 months. Patients with HFpEF will be randomly assigned (1:1:1) to the combined exercise, HIIT or control group. All participants will be examined, at baseline (prior to randomization), at three months (mid-intervention) and at six months (at the end of the intervention). Participants will undergo physical examination, echocardiography, maximal cardiopulmonary stress test, and measurement of endothelial function and arterial stiffness. In addition, sociodemographic variables, quality of life, physical activity, adherence to the Mediterranean diet, strength, spirometry and blood sampling will be measured.

Expected scientific contributions: this randomized clinical trial will represent a a significant advance in the scientific evidence available on the efficacy of physical exercise in the treatment of HFpEF, through: (a) transfer of the results to physicians, nurses and patients; (b) dissemination of results through scientific articles, doctoral theses and participation in congresses; (c) press releases and press conferences with the aim of disseminating the research results to the population; (d) dissemination through social networks to improve the social impact; and (e) design and content development of a web page.

Inclusion Criteria:

1. Heart Failure with preserved ejection fraction picture (diagnosis according to ESC 2021 criteria)

   1. Signs and symptoms of Heart Failure
   2. A left ventricular ejection fraction of ≥50%.
   3. Objective evidence of cardiac structural and/or functional abnormalities consistent with the presence of left ventricular diastolic dysfunction/elevated left ventricular filling pressures, including elevated natriuretic peptides.

2. Sedentary men and women (structured exercise <2 x 30 min/week).

3. Age ≥40 years

4. Written informed consent

5. Clinically stable for 6 weeks

6. Optimal medical treatment for ≥6 weeks

Exclusion Criteria:

1. Non-cardiac causes of heart failure symptoms:

   • Significant valvular or coronary artery disease - Uncontrolled hypertension or arrhythmias.
   • Primary cardiomyopathies

2. Significant pulmonary disease (FEV1<50% predicted, GOLD III-IV)

3. Inability to exercise or conditions that may interfere with exercise intervention.

4. Myocardial infarction in the last 3 months

5. Signs of ischaemia during maximal cardiopulmonary exercise test.

6. Comorbidity that may influence one-year prognosis 7. Participation in another clinical trial.