Diuretic dose trajectories in dilated cardiomyopathy: prognostic implications

Background For patients with heart failure, prescription of loop diuretics (LD) and of higher doses are associated with an adverse prognosis. We investigated LD dose trajectories and their associations with outcomes in patients with dilated cardiomyopathy (DCM). Methods Associations between outcomes and both furosemide-equivalent dose (FED) at enrolment and change in FED in the subsequent 24 months were evaluated. According to FED trajectory, patients were classified as (i) dose (FED increase by >= 50% or newly initiated); (ii) dose down arrow (FED decrease by >= 50%); (iii) stable dose (change in FED by < 50%); and (iv) never-users. The primary outcome was all-cause-death/heart transplantation/ventricular-assist-device/heart failure hospitalization. The secondary outcome was all-cause-death/heart transplantation/ventricular-assist-device. Results Of 1,131 patients enrolled, 738 (65%) were prescribed LD at baseline. Baseline FED was independently associated with outcome (HR per 20 mg increase: 1.12 [95% CI 1.04-1.22, p = 0.003]. Of the 908 with information on FED within 24 months from enrolment, 31% were never-users; 29% were dose down arrow; 26% were stable dose and 14% were dose up arrow. In adjusted models, compared to never-users, stable dose had a higher risk of the primary outcome (HR 2.42 [95% CI 1.19-4.93], p = 0.015), while dose up arrow had the worst prognosis (HR 2.76 [95% CI 1.27-6.03], p = 0.011). Results were similar for the secondary outcome. Compared to patients who remained on LD, discontinuation of LD (143, 24%) was associated with an improved outcome (HR 0.43 [95% CI 0.28-0.65], p < 0.001). Conclusions In patients with DCM, LD use and increasing FED are powerful markers of adverse outcomes. Patients who never receive LD have an excellent prognosis. [GRAPHICS] .