A study of the efficacy and safety of irbesartan in combination with conventional therapy, including ACE inhibitors, in heart failure

Because heart failure therapy with angiotensin-converting enzyme (ACE) inhibitors may not be optimal, owing to persistent levels of angiotensin II occurring through incomplete blockade and alternate pathways, the benefit of adding irbesartan, an angiotensin receptor antagonist, to conventional therapy, including ACE inhibitors, was examined. In this multicentre, randomised, double-blind, placebo-controlled study, 109 patients with heart failure (New York Heart Association functional class II and III) and left ventricular ejection fraction (LVEF) ≤ 40% received stable doses of ACE inhibitors and diuretics before and throughout the study. Irbesartan was titrated as tolerated to 150 mg once daily in all patients. Exercise tolerance time (ETT), LVEF and clinical status were assessed at baseline and after 12 weeks. Compared with placebo, irbesartan in combination with conventional therapy, including ACE inhibitors, produced favourable trends in ETT and LVEF and was well tolerated in patients with mild to moderate heart failure.