Urine Sodium-Guided Diuretics Cut Risk in Men but Not Women With Acute Heart Failure

One of the most common treatments in medicine may work very differently in men and women. When patients arrive at the hospital gasping for breath because their heart can no longer keep fluid from flooding their lungs, the first line of defense is almost always a loop diuretic—a drug that forces the kidneys to flush out salt and water. For decades, clinicians have adjusted these drugs largely by intuition and weight charts. Now, a detailed sex-specific analysis of the randomized PUSH-AHF trial, published in Clinical Research in Cardiology, suggests that a strategy built on measuring the sodium actually excreted in urine may substantially reduce the risk of death or rehospitalization in men, while showing no such benefit in women. The finding, if confirmed, could force a rethink of how one of cardiology’s most routine interventions is personalized.

The PUSH-AHF trial, conducted at the University Medical Center Groningen in the Netherlands, enrolled 310 patients hospitalized with acute heart failure and randomly assigned them in equal numbers to either standard of care or natriuresis-guided diuretic therapy. In the standard-of-care arm, patients received loop diuretics twice daily according to a protocol based on their outpatient diuretic use and baseline kidney function. In the guided arm, clinicians measured spot urinary sodium and urine volume at fixed time points—2, 6, 12, 18, 24, and 36 hours after starting treatment. If urinary sodium fell below 70 millimoles per liter or urine output dropped under 150 milliliters per hour while congestion persisted, the diuretic dose was escalated. The idea is elegant: rather than guessing whether the kidneys are responding, the treatment algorithm reads the kidneys’ answer directly.

The trial’s dual primary endpoints were total sodium excretion in the first 24 hours and, separately, the composite of all-cause mortality or heart failure rehospitalization at 180 days. Of the enrolled patients, 172 were men and 138 were women. In the new analysis, led by Hailun Qin, Lara Zonneveld, and Jozine ter Maaten, the researchers stratified outcomes by sex and adjusted for baseline differences including heart rate, heart failure etiology, prior myocardial infarction, and baseline sodium, potassium, and creatinine levels. What emerged was a striking asymmetry between the sexes that the original trial’s overall neutral result had obscured.

For men, the guided strategy appeared to deliver on its promise. Mean total 24-hour natriuresis was significantly greater in men receiving natriuresis-guided therapy than in those on standard care—443 versus 354 millimoles, a statistically significant difference. Men in the guided arm also achieved the highest cumulative natriuresis and diuresis over 72 hours of any group in the trial. More importantly, the clinical consequences followed: men treated with the guided approach had a 49 percent lower risk of the 180-day composite of heart failure rehospitalization or all-cause death, with an adjusted hazard ratio of 0.51. In-hospital mortality among men on standard care reached 12 percent, while no men on guided therapy died during admission. Men on guided therapy also went home sooner, with a median hospital stay of six days compared with eight days on standard care.

For women, the picture was fundamentally different. Mean 24-hour natriuresis was nearly identical between treatment arms—357 versus 336 millimoles—and the guided strategy produced no reduction in the 180-day composite endpoint; the adjusted hazard ratio of 1.40 pointed, if anything, in the opposite direction, though it was not statistically significant. The formal test of interaction between sex and treatment was significant for the long-term outcome, with a p-value of 0.026, meaning the treatment effect genuinely appeared to differ between men and women rather than reflecting a simple difference in sample size. Women in the guided arm also showed a lower 24-hour natriuretic response—the amount of sodium excreted per milligram of diuretic administered—than women on standard care, at 23 versus 52 millimoles of urinary sodium per milligram of bumetanide equivalent.

The renal safety signals added another layer of complexity. Women receiving natriuresis-guided therapy experienced worsening renal function—defined as a rise in serum creatinine of at least 26.5 micromoles per liter—far more often than women on standard care, at 42 versus 14 percent. Their estimated glomerular filtration rate declined significantly over the admission compared with the near-flat trajectory seen in women on standard care, with the steepest drop occurring in the first 24 hours. Yet, crucially, this renal worsening was not associated with worse clinical outcomes at 180 days in either sex, echoing findings from other trials such as CLOROTIC. The authors argue that the safety data overall are reassuring, supporting natriuresis-guided therapy as well tolerated regardless of sex, while acknowledging that the renal changes in women warrant confirmation in larger studies.

Why might men and women respond so differently to the same physiological logic? Several hypotheses deserve consideration. One candidate is heart failure phenotype itself: men more commonly present with heart failure with reduced ejection fraction, while women more often have the preserved-ejection-fraction form, which involves different underlying physiology of stiffness and congestion. In the ROSE-AHF trial, decongestion strategies improved urine output in patients with reduced ejection fraction but not in those with preserved ejection fraction. PUSH-AHF could not test this directly, because baseline ejection fraction was missing in about a quarter of patients, making adjustment for phenotype impossible. Pharmacokinetics offer another clue: for the loop diuretic torsemide, women show a 1.5-fold higher drug exposure and one-third lower oral clearance than men, suggesting sex-dependent handling of these drugs that could alter both efficacy and renal tolerance.

The authors are careful to frame these results as exploratory and hypothesis-generating rather than practice-changing. The sex-stratified analysis was conducted post hoc, the trial was single-center and open-label, dietary sodium intake—an important determinant of urinary sodium—was not controlled, and the number of events, particularly among women, was small. It remains possible that the apparent benefit in men partly reflects unusually poor outcomes in the standard-care group, or that chance, residual confounding, and limited statistical power explain the divergence. Notably, the overall risk of death or rehospitalization at 180 days was markedly lower in women than in men regardless of treatment, which may have left less room for a guided strategy to demonstrate benefit.

What the analysis does establish is that the absence of benefit in women should not be read as a reason to withhold natriuresis-guided therapy from them. The authors explicitly state that the observed sex-specific patterns do not support denying the strategy to women; instead, they highlight the need to investigate whether the optimal marker, threshold, dosing approach, or renal tolerance of decongestion differs by sex and heart failure phenotype. Prior evidence already shows that women derive different magnitudes of benefit from other heart failure drugs—appearing to gain more from sacubitril/valsartan and spironolactone, and reaching lowest risk at lower target doses of ACE inhibitors and beta-blockers than men—so a sex-dependent response to decongestion would fit a broader pattern rather than stand alone.

The broader significance of the study lies in what it says about precision medicine’s blind spots. Urinary sodium is increasingly embraced as a real-time biomarker of diuretic effectiveness, and the European Society of Cardiology guidelines already recommend evaluating diuretic response during hospitalization. A meta-analysis of 19 studies has linked higher urinary sodium to greater weight loss, shorter hospital stays, and lower mortality. If the PUSH-AHF findings hold up in adequately powered, multi-center prospective trials, the next generation of decongestion protocols may need sex-specific targets and escalation rules—and clinicians may finally have a data-driven answer to the question of why two patients given the same diuretic can respond so differently. Until then, the trial stands as a vivid reminder that even the oldest tools in cardiology still hold secrets worth measuring, one urine sample at a time.

Subject of Research: Sex-specific effects of natriuresis-guided diuretic therapy in acute heart failure

Article Title: Effects of natriuresis-guided diuretic therapy in men and women with acute heart failure: insights from PUSH-AHF

Article References: Qin, H., Zonneveld, L. E. E. C., Voors, A. A., Beldhuis, I. E., Ravera, A., van Veldhuisen, D. J., Coster, J. E., Nieuwland, W., Krikken, J. A., van der Meer, P., Damman, K., & ter Maaten, J. M. (2026). Effects of natriuresis-guided diuretic therapy in men and women with acute heart failure: insights from PUSH-AHF. Clinical Research in Cardiology. https://doi.org/10.1007/s00392-026-03030-1

Image Credits: AI Generated

DOI: 10.1007/s00392-026-03030-1

Keywords: acute heart failure, natriuresis, diuretic therapy, loop diuretics, urinary sodium, sex differences, PUSH-AHF trial, decongestion, worsening renal function, rehospitalization, precision medicine, cardiology