Objectives Patients with acute congestive heart failure (HF) regularly undergo urinary catheterisation (UC) at hospital admission. We hypothesised that UC has no clinical benefits with regard to weight loss during inpatient diuretic therapy for acute congestive HF and increases the risk of urinary tract infection (UTI).

Design Retrospective, non-inferiority study.

Setting Geneva University Hospitals’ Department of Medicine, a tertiary centre.

Participants In a cohort of HF patients, those catheterised within 24 hours of diuretic therapy (n=113) were compared with non-catheterised patients (n=346).

Primary and secondary outcome measures The primary endpoint was weight loss 48 hours after starting diuretic therapy. Secondary endpoints were time needed to reach target weight, discontinuation of intravenous diuretics and resolution of respiratory failure. Complications included the time to a first UTI, first hospital readmission and death.

Results A total of 48-hour weight loss was not statistically different between groups and the adjusted difference was below the non-inferiority boundary of 1 kg (0.43 kg (95% CI: −0.03 to 0.88) in favour of UC, p<0.01 for non-inferiority). UC was not associated with time to reaching target weight (adjusted HR 1.0; 95% CI: 0.7 to 1.5), discontinuation of intravenous diuretics (aHR 0.9; 95% CI: 0.7 to 1.2) or resolution of respiratory failure (aHR 1.1; 95% CI: 0.5 to 2.4). UC increased the risk of UTI (aHR 2.5; 95% CI: 1.5 to 4.2) but was not associated with hospital readmission (aHR 1.1; 95% CI: 0.8 to 1.4) or 1-year mortality (aHR 1.4; 95% CI: 1.0 to 2.1).

Conclusion In this retrospective study, with no obvious hourly diuresis-based diuretic adjustment strategy, weight loss without UC was not inferior to weight loss after UC within 24 hours of initiating diuretic treatment. UC had no impact on clinical improvement and increased the risk of UTI. This evidence, therefore, argues against the systematic use of UC during a diuretic therapy for HF.