Macitentan for Heart Failure With Preserved or Mildly Reduced Ejection Fraction and Pulmonary Vascular Disease: Results of the SERENADE Randomized Clinical Trial and Open-Label Extension Study.

BACKGROUND

Despite favorable hemodynamic and neurohormonal effects, endothelin receptor antagonists have not improved outcomes in patients with heart failure (HF), possibly because they cause fluid retention.

METHODS

In this randomized, double-blind, multicenter trial (SERENADE [Macitentan in Heart Failure With Preserved Ejection Fraction and Pulmonary Vascular Disease]), we evaluated the effects of an endothelin receptor antagonist, macitentan, in patients with HF, left ventricular ejection fraction ≥40%, and pulmonary vascular disease. After a 4-week placebo run-in (to ensure clinical stability), followed by a 5-week single-blind macitentan run-in, patients who did not exhibit fluid retention were randomized to macitentan or placebo. The primary end point was change in NT-proBNP (N-terminal pro-B-type natriuretic peptide; baseline to 24 weeks); secondary end points included change in KCCQ (Kansas City Cardiomyopathy Questionnaire) clinical summary score (baseline to 24 weeks) and time to worsening HF by 52 weeks.

RESULTS

Of 230 patients enrolled, 28 were excluded during the placebo run-in, 60 excluded during the macitentan run-in, and 142 were randomized. Macitentan had no effect on change in NT-proBNP (geometric mean ratio [macitentan/placebo], 1.02 [90% CI, 0.88-1.19]; P=0.79) or on secondary end points (placebo-corrected change in KCCQ clinical summary score, -3.5 [90% CI, -8.2 to +1.2]; P=0.22). Worsening HF occurred in 20 (28%) patients assigned to macitentan and 13 (18%) assigned to placebo (hazard ratio, 1.48 [90% CI, 0.83-2.67]; P=0.24). More macitentan-treated patients developed fluid retention (16 [23%] versus 10 [14%]) and cardiac adverse events (33 [46%] versus 22 [31%]) versus placebo.

CONCLUSIONS

Despite a novel enrichment trial design to target pulmonary vascular disease and exclude treatment-related fluid retention in patients with HF and preserved/mildly reduced left ventricular ejection fraction, macitentan neither lowered NT-proBNP nor improved HF outcomes.

REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifiers: NCT03153111 and NCT03714815.