Early drop in systolic blood pressure and worsening renal function in acute heart failure: renal results of Pre-RELAX-AHF.

Aims: We aimed to determine the relation between baseline systolic blood pressure (SBP), change in SBP, and worsening renal function (WRF) in acute heart failure (AHF) patients enrolled in the Pre-RELAX-AHF trial.
Methods and Results: The Pre-RELAX-AHF study enrolled 234 patients within 16 h of admission (median 7 h) for AHF and randomized them to relaxin given intravenous (i.v.) for 48 h or placebo. Blood pressure was measured at baseline, at 3, 6, 9, 12, 24, 36, and 48 h and at 3, 4, and 5 days after enrolment. Worsening renal function was defined as a serum creatinine increase of ≥0.3 mg/dL by Day 5. Worsening renal function was found in 68 of the 225 evaluable patients (30%). Patients with WRF were older (73.5 ± 9.4 vs. 69.1 ± 10.6 years; P= 0.003), had a higher baseline SBP (147.3 ± 19.9 vs. 140.8 ± 16.7 mmHg; P= 0.01), and had a greater early drop in SBP (37.9 ± 16.0 vs. 31.4 ± 12.2 mmHg; P= 0.004). In a multivariable model, higher age, higher baseline creatinine, and a greater early drop in SBP, but not baseline SBP, remained independent predictors of WRF. Furthermore, WRF was associated with a higher Day 60 (P= 0.01), and Day 180 (P= 0.003) mortality.
Conclusions: Worsening renal function in hospitalized AHF patients is related to a poor clinical outcome and is predicted by a greater early drop in SBP. Trial registration clinicaltrials.gov identifier NCT00520806.