This is a prospective study, blinded for the evaluator, randomized (1:1) to receive standard management alone or combined with a training program (aerobic combined with strength exercises) that will be carried out in a single center. After randomization, patients will be clinically evaluated. The primary endpoint (peakVO2) will be assessed by cardiopulmonary exercise testing combined with echocardiography (echo-CPET) at 12 weeks. Ambulatory patients with heart failure and cardiorenal syndrome and functional class NYHA II-III will be enrolled. A sample size estimation [alfa: 0.05, power: 80%, a 20% loss rate, and at least a delta change of mean peakVO2: +2,4 mL/kg/min (SD±2)] of 26 patients (13 per arm) would be necessary to test our hypothesis.

Heart failure (HF) is a highly prevalent clinical entity that predominantly affects elderly people with comorbidities. Among these, chronic kidney disease is particularly frequent, complicating disease management and worsening prognosis. Supervised training programs in patients with HF have improved functional capacity and reduced hospitalizations. However, the evidence is scarce regarding the effects of a supervised training program on patients with HF and cardiorenal syndrome. This work aims to evaluate the effect of a supervised exercise program for 12 weeks in patients with HF and cardiorenal syndrome on peak oxygen consumption (peakVO2).

This is a prospective study, blinded for the evaluator, randomized (1:1) to receive standard management alone or combined with a training program (aerobic combined with strength exercises) that will be carried out in a single center. After randomization, patients will be clinically evaluated. The primary endpoint (peakVO2) will be assessed by cardiopulmonary exercise testing combined with echocardiography (echo-CPET) at 12 weeks. Ambulatory patients with heart failure and cardiorenal syndrome and functional class NYHA II-III will be enrolled. A sample size estimation [alfa: 0.05, power: 80%, a 20% loss rate, and at least a delta change of mean peakVO2: +2,4 mL/kg/min (SD±2)] of 26 patients (13 per arm) would be necessary to test our hypothesis.

Inclusion Criteria:

• Patients diagnosed with heart failure according to 2021 ESC guidelines for Heart Failure.
• Evidence of cardiorenal syndrome, defined as coexistent very high risk chronic kidney disease (CKD) (estimated glomerular filtration rate [eGFR] <30 ml/min/1.73m2 or eGFR 30 to 44 ml/min/1.73m2 and Urine Albumin-Creatinine Ratio [uACR] >30 mg/g) or rapidly progressive CKD (loss of >5 ml/min/1.73m2 in one year).
• Stable symptomatic heart failure patients (New York Heart Association functional class II-III/IV) during the last month.
• Age ≥ 18 years old.
• Willing to provide written informed consent.

Exclusion Criteria:

• Inability to perform a valid baseline cardiopulmonary exercise test.
• Significant primary severe valve disease that is considered the main symptom driver.
• Effort angina or signs of ischemia during CPET.
• Primary cardiomyopathies.
• Cardiac transplantation.
• Any other comorbidity with a life expectancy of less than one year.

Blinded only for the evaluator of primary and secondary endpoints.