Abstract Background The effects of low-dose carperitide on long-term clinical outcomes of patients with acute heart failure (AHF) have not yet been fully elucidated. This study aimed to evaluate the effects of low-dose intravenous carperitide on the long-term clinical outcomes of patients with AHF. Methods In this multicentre, open-label, randomised controlled trial, 247 patients with AHF received low-dose carperitide intravenously with standard treatment or a matching standard treatment for 72 h from November 2014 to March 2021 across nine sites in Japan. The primary endpoint was a composite of all-cause death and heart failure hospitalisation within 2 years. Results The primary endpoint was observed in 36 of 122 patients (29.5%) and 35 of 125 patients (28.0%) in the carperitide group and standard treatment groups, respectively (hazard ratio 1.26; 95% confidence interval (CI) 0.78–2.06, P = 0.827). No significant differences were observed in the secondary endpoints, including cumulative urine volume at 72 h; change in the degree of dyspnoea over 72 h; and changes in brain natriuretic peptide, cystatin C, renin, aldosterone, and catecholamine levels at 72 h post randomisation between the groups. A greater decrease in the estimated glomerular filtration rate was observed in the carperitide group compared with the standard treatment group (inter-group difference -3.9 ml/min/1.73 m2; 95% CI -7.0 to -0.8). Conclusion In patients with AHF, low-dose carperitide did not reduce long-term mortality or hospitalisation events when combined with standard treatment. Because patient enrolment was terminated prematurely, the study was underpowered and inconclusive.
