Short and long-term effects of continuous versus intermittent loop diuretics treatment in acute heart failure with renal dysfunction

Intravenous loop diuretics are still the cornerstone of therapy in acute decompensated heart failure, however, the optimal dosage and administration strategies remain poorly defined particularly in patients with an associated renal dysfunction. This is a single-center, pilot, randomized trial involving patients with acute HF and renal dysfunction. Patients were assigned to receive continuous furosemide infusion (cIV) or bolus injections of furosemide (iIV). Primary end points were the evaluation of urine output volumes, renal function, and b-type natriuretic peptide (BNP) levels during treatment time. Secondary end point included: weight loss, length of hospitalization, differences in plasma electrolytes, need for additional treatment, and evaluation of cardiac events during follow-up period. 57 patients were included in the study. The cIV group showed an increase in urine output (2,505 ± 796 vs 2140 ± 468 ml/day, p < 0.04) and a more significant decrease of BNP levels in respect to the iIV group (679.6 ± 397 vs 949 ± 548 pg/ml, p < 0.04). We observed a significant increase in creatinine levels (1.78 ± 0.5 vs 1.41 ± 0.3 mg/dl, p < 0.01), and a reduction of the estimated glomerular filtration rate in cIV (44.8 ± 6.1 vs 46.7 ± 6.1 ml/min, p < 0.05). We observed a significant difference in eGFR (p = 0.01), creatinine (p = 0.02) and BNP levels (p = 0.03) from baseline to the end of treatment in both groups. A significant increase of in-hospital additional treatment as well as length of hospitalization was observed in cIV. Finally, cIV revealed a higher rate of adverse events during the follow-up period (p < 0.03). cIV appears to provide a more efficient diuresis and BNP level reduction during hospitalization, however, it was associated with increased rate of worsening renal function during hospitalization. cIV also appears related to a longer hospitalization and an increased number of adverse events during follow-up. For all of these reasons, a larger multi-center study is required to determine whether high-dose diuretics are responsible for worsening renal function and to define the best modality of administration.