Optimizing spironolactone dosing for initial treatment success in acute decompensated heart failure: a comparative efficacy study

Patients with decompensated heart failure frequently present with multi-organ dysfunction upon hospital admission, and there is a clear relationship between the number of organs involved and mortality. The priority in managing patients hospitalized for heart failure is improving the clinical picture of congestion. However, effective decongestion is often difficult to achieve, and a considerable number of patients are discharged from the hospital with persistent congestion and a consequent increased risk of death and rehospitalization for heart failure. Diuretics have been used as decongestive therapy; among them, spironolactone has emerged as an important treatment option for heart failure since the 1990s due to its ability to attenuate neurohormonal signals, which play a central role in the progression of heart failure, and to reverse remodeling.

This is a retrospective cohort study (between 2018 to 2024), the sample consisted of patients with acute decompensated heart failure that were admitted to the emergency department . They received either 25mg (low dose), 50mg (intermediate dose) or 100 mg (high dose) of spironolactone, we evaluated clinical congestion score at baseline, 72 hours and 120 hours after.

Inclusion criteria: Age ≥ 18 years, new onset descompensated heart failure, non severe valvulopaties and LVEF < 50 % with E/E' > 14 at admission, ischemic cardiopathy.

Exclusion criteria: Cardiomyopathies, Hyperkalemia, hiponatremia, previous spironolactone use.

The primary outcome was to evaluate the variation in the clinical score, secondary outcomes were to assess the change in glomerular filtration rate and the adverse effects experienced.

All data was processed using SPSS Statistic.

Baseline patient characteristics and scores were similar across all groups (all p > 0.05). At 72 hours, intermediate and high doses of spironolactone produced significantly greater reductions in congestion score versus the low dose (mean differences: 0.725 [p = 0.001] and 0.476 [p = 0.007]). At 120 hours, these differences persisted: low vs intermediate (0.461, p = 0.032), low vs high (0.921, p = 0.000), and intermediate vs high (0.461, p = 0.032) were all significant, favoring higher doses. Intermediate doses consistently maintained higher glomerular filtration rates than low doses (p < 0.001), and also outperformed high doses at some time points, suggesting intermediate dosing optimizes renal function without more adverse events. In intermediate dose group there were risk of hyperkalemia was lower that in high dose group In multivariate analysis were no differences in gender and type of furosemide adminstration.

Intermediate doses of spironolactone appear to be just as effective as high doses, but more safer with regard to the ocurrence of adverse effects.

Baseline patient characteristics