Placebo-controlled comparison of candoxatril, an orally active neutral endopeptidase inhibitor, and captopril in patients with chronic heart failure

Aims: To compare the effects on exercise capacity of the neutral endopeptid ase inhibitor candoxatril, and the angiotensin converting enzyme inhibitor captopril, in patients with mild to moderate heart failure. Methods;: In th is multi-centre double-blind placebo controlled study, 60 patients with NYH A Class I-III heart failure were randomised to candoxatril 200 mg b.d. (n = 22), captopril 25-50 mg b.d. (n = 23) or placebo (n = 15). Treadmill exerc ise tests were carried out weekly during a 5-week single-blind placebo run- in phase until a stable baseline was achieved, and repeated at 4 weekly int ervals during the 12-week double-blind treatment phase. Results: Nine patie nts withdrew from the study - four candoxatril and five captopril. The plac ebo-adjusted increase in exercise duration after 12 weeks was 56 s (95% CI, -26 to +137 s; P = 0.12) with candoxatril and 37 s (-43 to +117 s; P = 0.2 9) with captopril. Conclusions: Both candoxatril and captopril were well to lerated and treadmill exercise duration appeared to increase during 12 week s of therapy but this did not achieve statistical significance. This study tentatively suggests that in patients with heart failure, neutral endopepti dase inhibition may provide similar symptomatic benefits to angiotensin con verting enzyme inhibition. (C) 1999 European Society of Cardiology. All rig hts reserved.