Natriuretic Response to Acetazolamide in Patients With Acute Heart Failure and Volume Overload

BACKGROUND Acetazolamide facilitates decongestion in acute decompensated heart failure (ADHF). OBJECTIVES This study sought to investigate the effect of acetazolamide on natriuresis in ADHF and its relationship with outcomes. METHODS Patients from the ADVOR (Acetazolamide in Decompensated Heart Failure with Volume Overload) trial with complete data on urine output and urine sodium concentration (UNa) were analyzed. Predictors of natriuresis and its relationship with the main trial endpoints were evaluated. RESULTS This analysis included 462 of 519 patients (89%) from the ADVOR trial. During 2 days after randomization, UNa was 92 ± 25 mmol/L on average, and total natriuresis was 425 ± 234 mmol. Allocation to acetazolamide strongly and independently predicted natriuresis with a 16 mmol/L (19%) increase in UNa and 115 mmol (32%) greater total natriuresis. Higher systolic blood pressure, better renal function, higher serum sodium levels, and male sex also independently predicted both a higher UNa and greater total natriuresis. A stronger natriuretic response was associated with faster and more complete relief of signs of volume overload, and this effect was already significant on the first morning of assessment (P = 0.022). A significant interaction was observed between the effect of allocation to acetazolamide and UNa on decongestion (P = 0.007). Stronger natriuresis with better decongestion translated into a shorter hospital stay (P < 0.001). After multivariable adjustments, every 10 mmol/L UNa increase was independently associated with a lower risk of all-cause death or heart failure readmission (HR: 0.92; 95% CI: 0.85-0.99). CONCLUSIONS Increased natriuresis is strongly related to successful decongestion with acetazolamide in ADHF. UNa may be an attractive measure of effective decongestion for future trials. (Acetazolamide in Decompensated Heart Failure with Volume Overload ADVOR; NCT03505788).