Clinical Research Directory

Inclusion Criteria * Age ≥18 years and ≤ 90 years * Prior diagnosis of HF with LVEF \> 40%, documented by echocardiography performed within the 6 months before screening * Patient already treated with an SGLT2 inhibitor for HF for at least 4 weeks at a stable dose, as part of routine clinical care * With an indication to receive spironolactone for HF, as part of routine clinical care (i.e., not an experimental treatment introduced for the purpose of this study), at the guideline-recommended starting dose, i.e., 25 mg once daily * For patients in sinus rhythm, NT-proBNP levels ≥ 300 pg/ml; for patients in atrial fibrillation, NT-proBNP levels ≥ 600 pg/ml at screening * Affiliated with a social security scheme * Physical condition compatible with the performance of study-related investigations, as judged by the investigator * Patient who has provided written informed consent * Willingness to shave the electrode attachment sites if necessary Exclusion Criteria * Estimated glomerular filtration rate \< 30 mL/min/1.73 m² at screening * Serum potassium \> 5 mmol/l at screening * History of severe hyperkalemia (i.e., ≥ 6 mmol/l) * Hypersensitivity to spironolactone * Treatment with an approved MRA (e.g., spironolactone, eplerenone, finerenone) for more than 7 days within the last month prior to screening * LVEF \< 40% or alternative primary cardiac diagnosis explaining symptoms (significant valvular disease requiring intervention, hypertrophic or infiltrative cardiomyopathy, constrictive pericarditis) * Systolic blood pressure \<100 mmHg or symptomatic hypotension within the previous 24 hours * Systolic blood pressure ≥180 mmHg regardless of treatment, at the time of screening * Acute coronary syndrome, stroke, or transient ischemic attack within the 3 months before screening * Major cardiac surgery, coronary revascularization, or valvular repair within 3 months prior to screening * History of obstructive hypertrophic cardiomyopathy, infiltrative cardiomyopathy (including amyloidosis), restrictive, or arrhythmogenic right ventricular cardiomyopathy * Active myocarditis or pericardial causes of heart failure * History of mechanical circulatory support or heart transplantation * Renal replacement therapy within the previous 4 weeks or requirement for renal replacement therapy * Severe liver disease or Addison's disease * Severe comorbidity with life expectancy \< 1 year * Inability to perform exercise testing (including VO2max), as determined by the physician * Any contraindication to cardiac MRI: severe claustrophobia, any device which is known to threaten or pose hazard in all magnetic resonance environments (as defined on //www.mrisafety.com/, patients with implanted biomedical devices (cardiac artefacts): pacemakers, cardiac defibrillators or cardiac resynchronization therapy * Allergy to gadolinium * Pregnancy or breastfeeding * Individuals suffering from skin irritation or non-intact skin at the sensor attachment sites (sternum, chest, left upper arm, and index, middle or ring finger) * Known allergies to adhesives and/or Ag/AgCl electrodes and/or metals and/or plastic * Receiving medication that is contraindicated to excessive light exposure (in order to exclude the possibility of local skin irritation from irradiation by LED-light of PPG) * Individuals under legal protection or guardianship * Inability to understand the study procedures * Patient under State Medical Aid (AME)