Effects of serelaxin on the outcome of patients with or without substantial peripheral edema: A subgroup analysis from the RELAX-AHF trial.

Background: Acute heart failure (AHF) is a heterogeneous disorder, with most of the patients presenting with breathlessness along with varying degrees of peripheral edema. The presence of peripheral edema suggests that volume overload is the cause of decompensation leading to AHF, whereas breathlessness in the absence of edema may reflect a "vascular phenotype." This analysis investigated the characteristics, therapeutic response, and outcome of patients with AHF, with and without overt peripheral edema in the RELAX-AHF trial.

Methods: Physician-assessed edema scores at baseline were used to categorize the population into those with no/mild edema (score 0 or 1+) and moderate/severe edema (score 2+ or 3+). The effect of serelaxin vs placebo was assessed within each subgroup.

Results: Patients with moderate/severe edema (n = 583; 50.5%) were more likely to have severe dyspnea, orthopnea (>30°), rales (≥1/3), and elevated jugular venous pressure (>6 cm) than the patients with little or no peripheral edema (n=571; 49.5%). The relative benefits of serelaxin in terms of reduction in breathlessness, lower diuretic requirements, decreased length of initial hospital stay and days in intensive care unit/cardiac care unit, and improved prognosis (180-day cardiovascular and all-cause mortality) were generally similar for patients with or without peripheral edema. However, because patients with moderate/severe peripheral edema had worse outcomes, the absolute benefit was generally greater than in patients with no/mild edema.

Conclusions: Overall, patients with AHF and moderate/severe peripheral edema have a worse prognosis but appear to receive similar relative benefit and perhaps greater absolute benefit from serelaxin administration.