Evaluation of diuretic efficiency of intravenous furosemide in patients with advanced heart failure in a heart failure clinic

Introduction: Diuretic efficiency (DE) is an independent predictor of all-cause mortality in acute heart failure (HF) at long-term follow-up. The performance of DE in advanced HF and the outpatient scenario is unclear. Methods: Survival function analysis on a retrospective cohort of patients with advanced HF followed at the outpatient clinic of Hospital Universitario San Ignacio (Bogotá, Colombia) between 2017 and 2021. DE was calculated as the average of total diuresis in milliliters divided by the dose of IV furosemide in milligrams for each 6-h session, considering all the sessions in which the patient received levosimendan and IV furosemide. We stratified DE in high or low using the median value of the cohort as the cutoff value. The primary outcome was a composite of all-cause mortality and HF hospitalizations during a 12-month follow-up. Kaplan–Meier curves and log-rank test were used to compare patients with high and low DE. Results: In all, 41 patients (66.5 ± 13.2 years old, 75.6% men) were included in the study, with a median DE of 24.5 mL/mg. In total, 20 patients were categorized as low and 21 as high DE. The composite outcome occurred more often in the high DE group (13 versus 5, log-rank test p = 0.0385); the all-cause mortality rate was 29.2% and was more frequent in the high DE group (11 versus 1, log-rank test p = 0.0026). Conclusion: In patients with advanced HF on intermittent inotropic therapy, a high DE efficiency is associated with a higher risk of mortality or HF hospitalization in a 12-month follow-up period.