Hydrochlorothiazide for Hypertrophic cardiomyopathy | Hypertrophic obstructive cardiomyopathy

Inclusion criteria

• {"criterion_text":"- Diagnosis of HCM consistent with the current Guidelines of the European Society of Cardiology and American College of Cardiology Foundation/American Heart Association: presence of increased left ventricular wall thickness (≥15mm or ≥13mm with positive family history of HCM) in any myocardial segment that is not explained solely by loading conditions"}
• {"criterion_text":"- SAM-associated LVOTO, defined as peak LVOT pressure gradient ≥ 30mmHg at rest assessed 30 to 60 minutes after standardized meal intake"}
• {"criterion_text":"- Fasting office blood pressure ≥ 135/85 mmHg (either systolic or diastolic BP increased), measured as standardized office blood pressure after at least six hours of fasting"}
• {"criterion_text":"- Treatment with cardioselective betablocker in maximally tolerated dose or intolerance/contraindication to betablocker"}
• {"criterion_text":"- Age ≥ 18 years"}
• {"criterion_text":"- Female participants are eligible to participate if they are not pregnant or breastfeeding, and at least 1 of the following conditions applies: o\tis not a women of childbearing potential (WOCBP) or o\tis a WOCBP and using a contraceptive method that is highly effective (failure rate <1% per year) during the intervention period"}
• {"criterion_text":"- No additional contraceptive measures are required to be used for male participants"}
• {"criterion_text":"- Willingness and ability to provide signed written informed consent form (ICF) in accordance with regulatory, local, and institutional guidelines."}

Exclusion criteria

• {"criterion_text":"- Known infiltrative or storage disorder causing cardiac hypertrophy that mimics HCM, such as amyloidosis, Fabry disease, Noonan syndrome, or other HCM-phenocopies."}
• {"criterion_text":"- Initiation or change in myosin-inhibitor therapy 52 weeks prior to randomization or planned initiation during the active study period"}
• {"criterion_text":"- Known allergy to HCT or valsartan or their constituents, or to medications with a similar chemical structure"}
• {"criterion_text":"- Any other contraindication for treatment with either HCT or valsartan, including: •\teGFR <30mL/min and/or serum creatinine >1.8mg/100mL •\tacute glomerulonephritis •\tsevere hepatic zirrhosis or failure, hepatic precoma/coma •\tsystolic blood pressure <90mmHg •\theart rate <50bpm •\tsodium <130mmol/L •\ttotal calcium >2.65mmol/L •\tgout •\tsecond and third trimester of pregnancy"}
• {"criterion_text":"- Women who are breastfeeding or pregnant"}
• {"criterion_text":"- Any other serious condition that in the opinion of the investigator could prevent participation in the study."}
• {"criterion_text":"- Completed a study with an investigational device or drug <30 days or 5 half-lives to screening."}
• {"criterion_text":"- Enrolled in another study and receiving any investigational treatment (device or drug)."}
• {"criterion_text":"- Current treatment or treatment within 2 weeks prior to randomization with either a thiazide diuretic or an angiotensin receptor blocker"}
• {"criterion_text":"- Change in antihypertensive therapy within 2 weeks prior to randomization and up to the day of randomization."}
• {"criterion_text":"- Concomitant use of Aliskiren in patients with diabetes mellitus or renal disease (estimated glomerular filtration rate [eGFR] <60mL/min)."}
• {"criterion_text":"- Invasive septal reduction therapy (surgical myectomy or percutaneous alcohol septal ablation) within 6 months prior to screening or planned invasive septal reduction therapy during the study."}

Primary endpoints

• {"endpoint_text":"- Difference in absolute change of peak LVOT gradient at rest from before to after the treatment period between the two interventions","definition_or_measurement_approach":"Difference in absolute change of peak LVOT gradient at rest from before to after the treatment period between the two interventions"}

Secondary endpoints

• {"endpoint_text":"- Difference of absolute changes between the two intervention groups of Peak LVOT gradient after Valsalva-Maneuver","definition_or_measurement_approach":"Difference of absolute changes between the two intervention groups of Peak LVOT gradient after Valsalva-Maneuver"}
• {"endpoint_text":"- Difference of absolute changes between the two intervention groups of left ventricular systolic pressure calculated from brachial blood pressure and LVOT gradient","definition_or_measurement_approach":"Left ventricular systolic pressure calculated from brachial blood pressure and LVOT gradient; comparison of absolute changes between groups"}
• {"endpoint_text":"- Difference of absolute changes between the two intervention groups of Kansas City Cardiomyopathy Questionnaire (KCCQ-23 Score)","definition_or_measurement_approach":"Difference of absolute changes in KCCQ-23 Score between intervention groups"}
• {"endpoint_text":"- Difference of absolute changes between the two intervention groups of EQ5D5L score","definition_or_measurement_approach":"Difference of absolute changes in EQ-5D-5L score between intervention groups"}
• {"endpoint_text":"- Difference of absolute changes between the two intervention groups of NT-proBNP","definition_or_measurement_approach":"Difference of absolute changes in NT-proBNP between intervention groups"}
• {"endpoint_text":"- Difference of absolute changes between the two intervention groups of High-sensitive Troponin T/I","definition_or_measurement_approach":"Difference of absolute changes in high-sensitive Troponin T/I between intervention groups"}
• {"endpoint_text":"- Difference of absolute changes between the two intervention groups of Interleukin-6","definition_or_measurement_approach":"Difference of absolute changes in Interleukin-6 between intervention groups"}
• {"endpoint_text":"- Difference of absolute changes between the two intervention groups of pVO2 during CPET (CPET sub-study)","definition_or_measurement_approach":"Difference of absolute changes in peak VO2 (pVO2) during cardiopulmonary exercise testing (CPET) between intervention groups"}
• {"endpoint_text":"- Difference of absolute changes between the two intervention groups of mean systolic postprandial office blood pressure","definition_or_measurement_approach":"Difference of absolute changes in mean systolic postprandial office blood pressure between intervention groups"}
• {"endpoint_text":"- Difference of absolute changes between the two intervention groups of mean diastolic postprandial office blood pressure","definition_or_measurement_approach":"Difference of absolute changes in mean diastolic postprandial office blood pressure between intervention groups"}
• {"endpoint_text":"- Number of serious adverse events (SAEs)","definition_or_measurement_approach":"Count of serious adverse events (SAEs)"}
• {"endpoint_text":"- Difference of absolute changes between the two intervention groups of NYHA class","definition_or_measurement_approach":"Difference of absolute changes in NYHA class between intervention groups"}

Austria

Earliest CTIS Part Ii Submission Date

22-10-2025

Latest Decision Or Authorization Date

29-12-2025

Processing Time Days

68

Number Of Sites

5

Number Of Participants

40

Primary sponsor

Full Name

Medical University Of Graz

Organisation Type

Educational Institution

Country Of Registered Address

Austria

Third parties

• {"country":"","full_name":"Austrian Society of Cardiology","duties_or_roles":"Source of monetary support","organisation_type":""}