Comparison of vasopeptidase inhibitor, omapatrilat, and lisinopril on exercise tolerance and morbidity in patients with heart failure: IMPRESS randomised trial

Abstract

We aimed to assess in patients with congestive heart failure whether dual inhibition of neutral endopeptidase and angiotensin-converting enzyme (ACE) with the vasopeptidase inhibitor omapatrilat is better than ACE inhibition alone with lisinopril on functional capacity and clinical outcome. We did a prospective, randomised, double-blind, parallel trial of 573 patients with New York Heart Association (NYHA) class II-IV congestive heart failure, left-ventricular ejection fraction of 40% or less, and receiving an ACE inhibitor. Patients were randomly assigned omapatrilat at a daily target dose of 40 mg (n=289) or lisinopril at a daily target dose of 20 mg (n=284) for 24 weeks. The primary endpoint was improvement in maximum exercise treadmill test (ETT) at week 12. Secondary endpoints included death and comorbid events indicative of worsening heart failure. Week 12 ETT increased similarly in the omapatrilat and lisinopril groups (24 vs 31 s, p=0.45). The two drugs were fairly well tolerated, but there were fewer cardiovascular-system serious adverse events in the omapatrilat group than in the lisinopril group (20 [7%] vs 34 [12%], p=0.04). There was a suggestive trend in favour of omapatrilat on the combined endpoint of death or admission for worsening heart failure (p=0.052; hazard ratio 0.53 [95% CI 0.27-1.02]) and a significant benefit of omapatrilat in the composite of death, admission, or discontinuation of study treatment for worsening heart failure (p=0.035; 0.52 [0.28-0.96]). Omapatrilat improved NYHA class more than lisinopril in patients who had NYHA class III and IV (p=0.035), but not if patients with NYHA class II were included. Our findings suggest that omapatrilat could have some advantages over lisinopril in the treatment of patients with congestive heart failure. Thus use of vasopeptidase inhibitors could constitute a potentially important treatment for further improving the prognosis and well being of patients with this disorder.