Comparison of omapatrilat and enalapril in patients with chronic heart failure: the Omapatrilat Versus Enalapril Randomized Trial of Utility in Reducing Events (OVERTURE).
BACKGROUND
Combined inhibition of the angiotensin-converting enzyme (ACE) and neutral endopeptidase (NEP) may produce greater benefits in heart failure than ACE inhibition alone.


RESULTS
We randomly assigned 5770 patients with New York Heart Association class II to IV heart failure to double-blind treatment with either the ACE inhibitor enalapril (10 mg BID, n=2884) or to the ACE-NEP inhibitor omapatrilat (40 mg once daily, n=2886) for a mean of 14.5 months. The primary end point-the combined risk of death or hospitalization for heart failure requiring intravenous treatment--was used prospectively to test both a superiority and noninferiority hypothesis (based on the effect of enalapril in the Studies of Left Ventricular Dysfunction [SOLVD] Treatment Trial). A primary end point was achieved in 973 patients in the enalapril group and in 914 patients in the omapatrilat group (hazard ratio 0.94; 95% CI: 0.86 to 1.03, P=0.187)--a result that fulfilled prespecified criteria for noninferiority but not for superiority. The omapatrilat group also had a 9% lower risk of cardiovascular death or hospitalization (P=0.024) and a 6% lower risk of death (P=0.339). Post hoc analysis of the primary end point with the definition used in the SOLVD Treatment Trial (which included all hospitalizations for heart failure) showed an 11% lower risk in patients treated with omapatrilat (nominal P=0.012).


CONCLUSIONS
Omapatrilat reduces the risk of death and hospitalization in chronic heart failure but was not more effective than ACE inhibition alone in reducing the risk of a primary clinical event. Between-group differences in favor of omapatrilat observed in secondary and post hoc analyses warrant further study.
Packer
Milton
M
Division of Circulatory Physiology, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA. mp65@Columbia.edu
Califf
Robert M
RM
Konstam
Marvin A
MA
Krum
Henry
H
McMurray
John J
JJ
Rouleau
Jean-Lucien
JL
Swedberg
Karl
K
D000806:Angiotensin-Converting Enzyme Inhibitors / Q000009:adverse effects / Q000627:therapeutic use*; D002908:Chronic Disease; D018572:Disease-Free Survival; D004311:Double-Blind Method; D004656:Enalapril / Q000009:adverse effects / Q000627:therapeutic use*; D023381:Endpoint Determination; D005260:Female; D006333:Heart Failure / Q000188:drug therapy* / Q000401:mortality; D006801:Humans; D008297:Male; D008875:Middle Aged; D015260:Neprilysin / Q000037:antagonists & inhibitors*; D011480:Protease Inhibitors / Q000009:adverse effects / Q000627:therapeutic use*; D011725:Pyridines / Q000009:adverse effects / Q000627:therapeutic use*; D013841:Thiazepines / Q000009:adverse effects / Q000627:therapeutic use*
D000806:Angiotensin-Converting Enzyme Inhibitors; D011480:Protease Inhibitors; D011725:Pyridines; D013841:Thiazepines; C106266:omapatrilat; D004656:Enalapril; D015260:Neprilysin