Diuretic dose is a strong prognostic factor in ambulatory patients awaiting heart transplantation

The prognostic value of 'high dose' loop diuretics in advanced heart failure outpatients is unclear. We aimed to assess the prognosis associated with loop diuretic dose in ambulatory patients awaiting heart transplantation (HT).

All ambulatory patients (n = 700, median age 55 years and 70% men) registered on the French national HT waiting list between 1 January 2013 and 31 December 2019 were included. Patients were divided into 'low dose', 'intermediate dose', and 'high dose' loop diuretics corresponding to furosemide equivalent doses of ≤40, 40-250, and >250 mg, respectively. The primary outcome was a combined criterion of waitlist death and urgent HT. N-terminal pro-B-type natriuretic peptide, creatinine levels, pulmonary capillary wedge pressure, and pulmonary pressures gradually increased with higher diuretic dose. At 12 months, the risk of waitlist death/urgent HT was 7.4%, 19.2%, and 25.6% (P = 0.001) for 'low dose', 'intermediate dose', and 'high dose' patients, respectively. When adjusting for confounders, including natriuretic peptides, hepatic, and renal function, the 'high dose' group was associated with increased waitlist mortality or urgent HT [adjusted hazard ratio (HR) 2.23, 1.33 to 3.73; P = 0.002] and a six-fold higher risk of waitlist death (adjusted HR 6.18, 2.16 to 17.72; P < 0.001) when compared with the 'low dose' group. 'Intermediate doses' were not significantly associated with these two outcomes in adjusted models (P > 0.05).

A 'high dose' of loop diuretics is strongly associated with residual congestion and is a predictor of outcome in patients awaiting HT despite adjustment for classical cardiorenal risk factors. This routine variable may be helpful for risk stratification of pre-HT patients.