Evaluation of the Effects of Sauna Therapy on Congestion and Loop Diuretic Use in Patients With Heart Failure With Reduced or Moderately Reduced Ejection Fraction

This study aims to evaluate the effect of sauna therapy on congestion levels during cardiac rehabilitation in patients with heart failure who have an impaired or moderately impaired ejection fraction, compared to standard cardiac rehabilitation care. To investigate this, patients with reduced cardiac function who are hospitalized as part of a cardiac rehabilitation program will be included. These patients will be randomly assigned to two groups: standard cardiac rehabilitation program (control group) and sauna group (intervention group). The study will also assess whether this approach could allow for a reduction in the dose of diuretics, which are commonly used to remove excess fluid, thereby helping to avoid certain side effects. The expected benefits include a reduction in symptoms such as shortness of breath and swelling, improvements in quality of life and physical fitness, and enhanced blood vessel function.

Inclusion Criteria: * Age ≥ 18 years. * Heart failure with ejection fraction \ 400 pg/ml or BNP \> 100 pg/ml. * Estimated glomerular filtration rate (eGFR) ≥ 20 ml/min/1.73 m². * Patient scheduled for a hospital-based cardiac rehabilitation program for a minimum of 3 weeks. * Person who has undergone a preliminary clinical examination suitable for clinical research. * Person affiliated with a social security system or a beneficiary of such a system. * Person who has received complete information about the organization of the clinical research and has signed informed consent. Exclusion Criteria: * Person presenting a contraindication to sauna therapy (for example, intolerance to heat). * Serum sodium \< 130 mmol/L. * Serum potassium \> 5.5 mmol/L. * Active infection, liver disease, or peripheral vascular disease. * Acute coronary syndrome or recent stroke (\