Acetazolamide and Spironolactone to Increase Natriuresis in Congestive Heart Failure

Study Overview
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Brief Summary
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This study has two primary objectives: To compare combination therapy with acetazolamide and low-dose loop diuretics versus high-dose loop diuretics (standard of care) in patients with acute decompensated heart failure at high risk for diuretic resistance. To demonstrate the safety and efficacy of upfront therapy with spironolactone in addition to loop diuretic therapy in patients with acute decompensated heart failure at high risk for diuretic resistance.

Official Title
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Diamox/Aldactone to Increase the URinary Excretion of Sodium: an Investigational Study in Congestive Heart Failure

Conditions
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Heart Failure

Intervention / Treatment
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* Drug: Combination therapy with acetazolamide and low-dose loop diuretics
* Drug: High-dose loop diuretics
* Drug: Upfront therapy with oral spironolactone


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Older than 18 years and able to give informed consent Clinical diagnosis of acute decompensated heart failure within the previous 8 h At least two clinical signs of congestion (edema, ascites, jugular venous distension, or pulmonary vascular congestion on chest radiography) Maintenance therapy with oral loop diuretics at a dose of at least 1 mg bumetanide (1 mg bumetanide = 40 mg furosemide = 20 mg torsemide) for at least 1 month before hospital admission NT-proBNP >1000 ng/L Left ventricular ejection fraction <50% At least one out of three of the following criteria: Serum sodium <136 mmol/L Serum urea/creatinine ratio >50 (comparable to a BUN/creatinine ratio >25) Admission serum creatinine increased with >0.3 mg/dL compared to previous value within 3 months before admission Exclusion Criteria: History of cardiac transplantation and/or ventricular assist device Concurrent diagnosis of an acute coronary syndrome defined as typical chest pain and/or electrocardiographic changes in addition to a troponin rise >99th percentile Mean arterial blood pressure <65 mmHg, or systolic blood pressure <90 mmHg at the moment of admission Use of intravenous inotropes, vasopressors or nitroprusside at any time point during the study A baseline estimated glomerular filtration rate <15 mL/min/1.73m² according to the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formula at the moment of inclusion Use of renal replacement therapy or ultrafiltration before study inclusion Treatment with acetazolamide within the previous month Treatment with ≥2 mg bumetanide or an equivalent dose during the index hospitalization before randomization Use of diuretics, vasopressin antagonists or mineralocorticoid receptor antagonist not specified by the protocol Exposure to nephrotoxic agents (i.e. contrast dye) anticipated within 3 days

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Factorial Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Acetazolamide/low-dose loop diuretics, upfront spironolactone<br>2x2 factorial design: This group is the experimental group for both study interventions (acetazolamide and upfront spironolactone). See interventions for more details. | Drug: Combination therapy with acetazolamide and low-dose loop diuretics<br>* Patients receive 500 mg of intravenous acetazolamide immediately after randomization, with 250 mg intravenous acetazolamide administered on each consecutive day in the morning for as long as the patient is considered volume overloaded by his/her treating cardiologist. Patients receive 2 mg of intravenous bumetanide immediately after randomization, with 1 mg intravenous bumetanide administered on each consecutive day in the morning for as long as the patient is considered volume overloaded by his/her treating cardiologist. If diuresis <1,5 L while the patient is still considered volume overloaded by his/her treating cardiologist, the dose of acetazolamide is maintained at 500 mg and the dose of bumetanide is maintained at 2mg. In case of therapy-refractory congestion, treatment is at the discretion of the treating physician, but addition of chlorthalidone 50 mg PO is recommended by the investigators as a first-line option.<br>* Other names: Burinex/Bumex (loop diuretics);Drug: Upfront therapy with oral spironolactone<br>* Patients randomized to this group receive oral spironolactone (25mg) immediately after randomization and in the morning of each subsequent day unless the serum potassium level is >5 mmol/L. Note: Investigators and treating physicians are blinded to treatment allocation for this arm, but no matching placebo is provided, so patients are not.<br>* Other names: Aldactone;|
| Experimental: High-dose loop diuretics, upfront spironolactone<br>2x2 factorial design: This group is the experimental group for the study intervention with upfront spironolactone. This group receives high-dose loop diuretics as an active comparator to the study intervention with acetazolamide. See interventions for more details. | Drug: High-dose loop diuretics<br>* Patients receive the double of their daily maintenance dose of oral loop diuretics converted to mg bumetanide as an intravenous bolus after randomization. Patients continue to receive this dose daily on the next 3 days divided between two administrations with at least a 6 h interval for as long as they are considered volume overloaded by the treating cardiologist. If diuresis <1,5 L while the patient is still considered volume overloaded by the treating cardiologist, the dose of bumetanide is doubled. In case of therapy-refractory congestion, treatment is at the discretion of the treating physician, but addition of chlorthalidone 50 mg PO is recommended by the investigators as a first-line option.<br>* Other names: Burinex/Bumex;Drug: Upfront therapy with oral spironolactone<br>* Patients randomized to this group receive oral spironolactone (25mg) immediately after randomization and in the morning of each subsequent day unless the serum potassium level is >5 mmol/L. Note: Investigators and treating physicians are blinded to treatment allocation for this arm, but no matching placebo is provided, so patients are not.<br>* Other names: Aldactone;|
| Experimental: Acetazolamide/low-dose loop diuretics, no spironolactone<br>2x2 factorial design: This group is the experimental group for the study intervention with acetazolamide. This group receives no intervention with regards to the spironolactone arm. See interventions for more details. | Drug: Combination therapy with acetazolamide and low-dose loop diuretics<br>* Patients receive 500 mg of intravenous acetazolamide immediately after randomization, with 250 mg intravenous acetazolamide administered on each consecutive day in the morning for as long as the patient is considered volume overloaded by his/her treating cardiologist. Patients receive 2 mg of intravenous bumetanide immediately after randomization, with 1 mg intravenous bumetanide administered on each consecutive day in the morning for as long as the patient is considered volume overloaded by his/her treating cardiologist. If diuresis <1,5 L while the patient is still considered volume overloaded by his/her treating cardiologist, the dose of acetazolamide is maintained at 500 mg and the dose of bumetanide is maintained at 2mg. In case of therapy-refractory congestion, treatment is at the discretion of the treating physician, but addition of chlorthalidone 50 mg PO is recommended by the investigators as a first-line option.<br>* Other names: Burinex/Bumex (loop diuretics);|
| Active Comparator: High-dose loop diuretics, no spironolactone<br>2x2 factorial design: This group receives high-dose loop diuretics as an active comparator to the study intervention with acetazolamide. This group receives no intervention with regards to the spironolactone arm. See interventions for more details. | Drug: High-dose loop diuretics<br>* Patients receive the double of their daily maintenance dose of oral loop diuretics converted to mg bumetanide as an intravenous bolus after randomization. Patients continue to receive this dose daily on the next 3 days divided between two administrations with at least a 6 h interval for as long as they are considered volume overloaded by the treating cardiologist. If diuresis <1,5 L while the patient is still considered volume overloaded by the treating cardiologist, the dose of bumetanide is doubled. In case of therapy-refractory congestion, treatment is at the discretion of the treating physician, but addition of chlorthalidone 50 mg PO is recommended by the investigators as a first-line option.<br>* Other names: Burinex/Bumex;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Acetazolamide Arm: Natriuresis 24 h | For the acetazolamide arm of the study, the primary end-point is total natriuresis after 24 h (mmol). To assess this, urine is collected for 24 h after the first administration of diuretics according to the study protocol and natriuresis is calculated as the total amount of diuresis (L) multiplied by the urinary sodium concentration (mmol/L). Subsequently, patients receiving acetazolamide and low-dose loop diuretics (both the groups with and without upfront spironolactone together) are compared to patients not receiving acetazolamide but high-dose loop diuretics instead (both the groups with or without upfront spironolactone together) | 24h | 
| Spironolactone Arm: Incidence of Hypo- (Serum Potassium <3.5 mmol/L) or Hyperkalemia (Serum Potassium >5.0 mmol/L) | For the spironolactone arm of the study, the primary end-point is the incidence of either hypo- (serum potassium <3.5 mmol/L) or hyperkalemia (serum potassium >5.0 mmol/L) at any of 3 morning blood samples at consecutive days after randomization. Patients receiving upfront spironolactone (both the group receiving acetazolamide+low dose loop diuretics and the group receiving high-dose loop diuretic therapy) are compared with them receiving no spironolactone (both the group receiving acetazolamide+low dose loop diuretics and the group receiving high-dose loop diuretic therapy). | 72h | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| NT-proBNP Change After 72 h | Relative NT-proBNP change (%) after 72 h compared to baseline. | 72h | 
| Number of Participants With Worsening Renal Function | Worsening renal function is defined as a rise in serum creatine >0.3 mg/dL or a >20% decrease in estimated glomerular filtration rate by the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formula compared to baseline at any time point before 72 h. Serum creatinine values are assessed at three consecutive mornings after study inclusion. | 72h | 
| Persistent Renal Impairment | Persistent renal impairment is defined as a persistently elevated serum creatine >0.3mg/dL or >20% decrease in estimated glomerular filtration rate by the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formula, above the baseline value of the patient and will be assessed on a scheduled follow-up appointment 4 weeks after hospital discharge. | 4 weeks after hospital discharge | 
| Peak Plasma Aldosterone Concentration After 72 h | At three consecutive mornings after study inclusion, blood samples will be taken to assess plasma aldosterone levels. The highest value will constitute the peak plasma aldosterone concentration (ng/L). | 72h | 
| Peak Plasma Renin Activity After 72 h | At three consecutive mornings after study inclusion, blood samples will be taken to assess plasma renin activity. The highest value will constitute the peak plasma renin activity (ng/mL/h). | 72h | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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acetazolamide, bumetanide, cardio-renal syndrome, diuretics, heart failure, natriuresis, spironolactone