LAUSR

BACKGROUND In hospitalized heart failure patients, a poor diuretic response (DR) during the first days of hospital admission is associated with worse outcomes. However, it remains unknown whether DR in the first hours has similar prognostic value. Moreover, data on the sequential change in DR during hospital admission are lacking. METHODS AND RESULTS DR (urine output per 40-mg furosemide-equivalent diuretics dose) was measured from 0 to 6 hours (DR6), 6 to 48 hours (DR6-48), and 0 to 48 hours (DR48) of the patient's emergency department (ED) arrival in 1551 patients with acute heart failure (AHF; mean age 78 years, 56% male, and 48% de novo patients with heart failure). Patients with a poor DR within the first 6 hours were older age, had worse renal function, and were already on diuretic treatment before admission. DR6 was only weakly correlated with DR6-48 (Spearman's rho = 0.273; P < .001). DR6, DR6-48, and DR48 were all significantly associated with 60-day mortality independent of other prognostic factors. DR6 and DR48 showed comparable prognostic ability. However, the model combining DR6 with DR6-48 significantly exceeded both DR6 (net reclassification improvement 0.249; P = .032) and DR48 (net reclassification improvement 0.287; P = 0.025) with regard to 60-day mortality prediction. CONCLUSIONS DR measured within the first 6 hours of ED arrival and DR measured during the first 48 hours in patients with AHF have similar prognostic value, although they were moderately correlated. Changes in DR over time provide additional prognostic information.