Abstract Background Congestion in acute heart failure (AHF) is treated with furosemide, mainly in continuous infusion (furosemide continuous, FC) or iv boluses, and combination of different diuretics. Randomized controlled trials (RCTs) only compared the efficacy and safety of some diuretic strategies with discordant results. Purpose To provide a comprehensive synthesis of the effects of diuretic regimens in AHF. Methods The PubMed, EMBASE, SCOPUS and Cochrane databases were searched for phase III RCTs until July 31st, 2023, evaluating diuretics without any other intervention in patients admitted for AHF, with randomization within 48 hours, no run-in period and/or need of clinical stabilization. The arms assigned to iv boluses or undefined schemas of furosemide/loop diuretic (LD) were grouped together as "furosemide bolus" (FB). The endpoints were weight loss over 24 hours (WL), worsening renal function (WRF), total urine output (tUO) and net urine output (nUO) over 24 hours, hypokalemia (hypoK), and hyponatremia (hypoNa). Heterogeneity was estimated by Thompsons’ I2 statistics, and odds ratios (OR) with 95% confidence intervals were calculated by means of a random-effects model with inverse variance weighting. A leave-one-out analysis, an analysis limited to studies with specified mode of furosemide/LD administration, and an analysis of measures of congestion/decongestion were also carried out. Results Twenty-five RCTs were selected, for a total of 7,095 patients with mean age 69.2±11.1 years and mean LVEF 38.1±12.7%. In subjects treated with furosemide/LD, the mean furosemide equivalent dose was 154.7±53.0 mg/24 hours. Heterogeneity was moderate-to-high (37.3%-66.0% across the study endpoints). FC, FB plus tolvaptan, FB plus sodium-glucose cotransporter inhibitor (SGLT2i), and FB plus thiazide were associated with greater WL than FB (Figure 1A). The combination of FB and thiazide or SGLT2i also portended higher odds of WRF than FB alone, as did the combination of FB and acetazolamide (Figure 1B). tUO was greater with FC (OR 2.77 [1.98-3.88]), FB plus tolvaptan (OR 1.69 [1.22-2.35]), and FB plus SGLT2i (OR 1.95 [1.16-3.28]) than with FB, and nUO was greater with FC (OR 1.50 [1.06-2.13]) and FB plus tolvaptan (OR 1.76 [1.06-2.92]) than with FB. Compared with FB, hypoK was more frequent with FB and thiazide (OR 1.68 [1.29-2.19]), while there was a trend for less hypoK events with FB plus tolvaptan (OR 0.86 [0.69-1.08]). No differences in hypoNa rates were found. Sensitivity analyses were consistent with the main one. Thirteen (52%) and 14 (56%) studies had published information about symptoms and signs of congestion, respectively, and 6 (24%) adopted pre-specified scoring systems. Conclusions FC and most combination diuretic regimens have greater efficacy than FB in promoting WL and diuresis, but at the cost of WRF and hyoK, especially when thiazide is used. Congestion has inconsistently been evaluated in RCTs of diuretic therapy in AHF.