Testani, Jeffrey M.

Background: Black patients have higher rates of hospitalization for acute heart failure than other race/ethnic groups. We sought to determine whether diuretic efficiency is associated with racial differences in risk for rehospitalization after acute heart failure. Methods: A post hoc analysis was performed on 721 subjects (age, 68±13 years; 22% black) enrolled in 3 acute heart failure clinical trials: ROSE-AHF (Renal Optimization Strategies Evaluation in Acute Heart Failure), DOSE-AHF (Diuretic Optimization Strategy Evaluation in Acute Decompensated Heart Failure), and CARRESS-HF (Cardiorenal Rescue Study in Acute Decompensated Heart Failure). Repeated-measures ANOVA was used to test for a race×time effect on measures of decongestion. Diuretic efficiency was calculated as net fluid balance per total furosemide equivalents. In a subset of subjects, Cox regression was used to examine the association between race and rehospitalization according to plasma renin activity (PRA). Results: Compared with nonblack patients, black patients were younger and more likely to have nonischemic heart failure. During the first 72 to 96 hours, there was greater fluid loss ( P =0.001), decrease in NT-proBNP (N-terminal pro-B-type natriuretic peptide; P =0.002), and lower levels of PRA ( P <0.0001) in black patients. Diuretic efficiency was higher in black than in nonblack patients (403 [interquartile range, 221–795] versus 325 [interquartile range, 154–698]; P =0.014). However, adjustment for baseline PRA attenuated the association between black race and diuretic efficiency. Over a median follow-up of 68 (interquartile range, 56–177) days, there was an increased risk of all-cause and heart failure–specific rehospitalization in nonblack patients with increasing levels of PRA, while the risk of rehospitalization was relatively constant across levels of PRA in black patients. Conclusions: Higher diuretic efficiency in black patients with acute heart failure may be related to racial differences in activity of the renin-angiotensin-aldosterone system.

Background: Worsening renal function (WRF) in the setting of aggressive diuresis for acute heart failure treatment may reflect renal tubular injury or simply indicate a hemodynamic or functional change in glomerular filtration. Well-validated tubular injury biomarkers, N -acetyl-β- d -glucosaminidase, neutrophil gelatinase-associated lipocalin, and kidney injury molecule 1, are now available that can quantify the degree of renal tubular injury. The ROSE-AHF trial (Renal Optimization Strategies Evaluation–Acute Heart Failure) provides an experimental platform for the study of mechanisms of WRF during aggressive diuresis for acute heart failure because the ROSE-AHF protocol dictated high-dose loop diuretic therapy in all patients. We sought to determine whether tubular injury biomarkers are associated with WRF in the setting of aggressive diuresis and its association with prognosis. Methods: Patients in the multicenter ROSE-AHF trial with baseline and 72-hour urine tubular injury biomarkers were analyzed (n=283). WRF was defined as a ≥20% decrease in glomerular filtration rate estimated with cystatin C. Results: Consistent with protocol-driven aggressive dosing of loop diuretics, participants received a median 560 mg IV furosemide equivalents (interquartile range, 300–815 mg), which induced a urine output of 8425 mL (interquartile range, 6341–10 528 mL) over the 72-hour intervention period. Levels of N -acetyl-β- d -glucosaminidase and kidney injury molecule 1 did not change with aggressive diuresis (both P >0.59), whereas levels of neutrophil gelatinase-associated lipocalin decreased slightly (−8.7 ng/mg; interquartile range, −169 to 35 ng/mg; P <0.001). WRF occurred in 21.2% of the population and was not associated with an increase in any marker of renal tubular injury: neutrophil gelatinase-associated lipocalin ( P =0.21), N -acetyl-β- d -glucosaminidase ( P =0.46), or kidney injury molecule 1 ( P =0.22). Increases in neutrophil gelatinase-associated lipocalin, N -acetyl-β- d -glucosaminidase, and kidney injury molecule 1 were paradoxically associated with improved survival (adjusted hazard ratio, 0.80 per 10 percentile increase; 95% confidence interval, 0.69–0.91; P =0.001). Conclusions: Kidney tubular injury does not appear to have an association with WRF in the context of aggressive diuresis of patients with acute heart failure. These findings reinforce the notion that the small to moderate deteriorations in renal function commonly encountered with aggressive diuresis are dissimilar from traditional causes of acute kidney injury.