Title: Serelaxin, recombinant human relaxin-2, for treatment of acute heart failure (RELAX-AHF): a randomised, placebo-controlled trial

Teerlink JR, Cotter G, et al.


What You Need to Know:

Treatment with serelaxin, a recombinant human relaxin-2 vasoactive peptide hormone, resulted in dyspnea relief and other clinical improvements but had no effect on hospital readmission, according to findings from the ARELAX-AHF trial.

Trial Design:

  • RELAX-AHF was an international, double-blind, placebo-controlled trial that included patients admitted to the hospital for acute heart failure
  • All patients had dyspnea, congestion on chest radiograph, increase BNP or N-terminal prohormone of BNP, mild-to-moderate renal insufficiency, and systolic BP >125mmHg
  • Patients were randomized (1:1) to standard care + 48-hour IV infusion of placebo (n=580) or serelaxin 30mcg/kg daily (n=581) within 16 hours of presentation
  • Primary endpoints: change from baseline in the visual analogue scale area under the curve (VAS AUC) to Day 5, proportion of patients with moderate or marked dyspnea improvement (Likert scale) during the first 24 hours

Key Outcomes:

  • Serelaxin improved VAS AUC primary dyspnea endpoint (448mmxh, 95% CI: 120–775; P=0.007) vs. placebo
  • No significant effect on Likert scale endpoint (26% vs. 27%; P=0.70)
  • No significant effects for secondary endpoints of cardiovascular death or readmission for heart failure or renal failure (placebo 75 events [13.0%] vs. serelaxin 76 events [13.2%]; hazard ratio [HR] 1.02, 95% CI: 0.74–1.41; P=0.89)
  • No significant effect on days alive out of the hospital up to Day 60 (placebo 47.7 days vs. serelaxin 48.3 days; P=0.37)
  • Significant reduction 180-day mortality (placebo 65 deaths vs. serelaxin 42 deaths; HR 0.63, 95% CI: 0.42–0.93; P=0.019)
  • Serelaxin was well tolerated and safe