Liberal fluid intake versus fluid restriction in chronic heart failure: a randomized clinical trial

Fluid restriction is frequently recommended to patients with chronic heart failure, but randomized clinical trials assessing the effects of fluid restriction remain scarce. In this multicenter open-label trial, outpatients with chronic heart failure were randomized to receiving advice for liberal fluid intake versus receiving advice for fluid restriction, up to 1,500 ml per day of fluid intake. The primary outcome of the trial was health status after 3 months, as assessed by the Kansas City Cardiomyopathy Questionnaire Overall Summary Score (KCCQ-OSS). Secondary outcomes included thirst distress and safety events. Among 504 randomized patients (67.3% male), the KCCQ-OSS after 3 months was 74.0 in the liberal fluid intake group versus 72.2 in the fluid restriction group, with a mean difference after adjustment for baseline scores of 2.17 (95% confidence interval −0.06 to 4.39; P = 0.06), indicating that the primary outcome was not met. Thirst distress was higher in the fluid restriction group and no differences were observed for safety events between the two groups. These findings question the benefit of fluid restriction in chronic heart failure. ClinicalTrials.gov registration: NCT04551729.