4363Do acetazolamide and spironolactone increase natriuresis in congestive heart failure?

Background: Signs and symptoms of volume overload are the most frequent reason for hospital admission in acute heart failure (AHF). Diuretics are mainstay treatment, but their optimal type and dose regimen remains unclear. A stronger natriuretic response to diuretic therapy might be associated with better clinical outcome. Purpose: To evaluate whether upfront combination therapy with acetazolamide and/or spironolactone in AHF patients at high risk for diuretic resistance increases natriuresis, potentially leading to better decongestion and clinical outcome. Methods: AHF patients (n=34) with clinical signs of volume overload and either hyponatremia (serum sodium <136 mmol/L), worsening renal function (WRF) defined as a >0.3 mg/dL increase in serum creatinine, or a urea/creatinine ratio >50, were randomised through a 2x2 factorial design to: (1) acetazolamide 500 mg + bumetanide 2 mg, administered as intravenous bolus versus bumetanide at twice the patient's daily oral maintenance dose, but without acetazolamide (control group); and (2) oral spironolactone 25 mg versus no mineralocorticoid receptor antagonist (control group).