Prognostic impact of outpatient loop diuretic reduction patterns in patients with chronic heart failure.

Background: The relationship between patterns of outpatient oral loop diuretic (LD) dose reduction and prognosis in patients with heart failure (HF) remains unclear. Methods: We evaluated 679 patients with HF-prescribed LDs at baseline between September 2015 and August 2019. Dose reduction was defined as a change to a lower LD dose than the previous outpatient dose. Dose intensification was defined as a change to a higher LD dose than the previous outpatient dose. Patients were classified into no-reduction (no LD dose reduction during follow-up) and reduction groups (categorized into successive-reduction [≥2 successive LD dose reductions without intervening LD dose intensification] and single-reduction [LD dose reduction without successive dose reduction] groups). The primary outcomes were all-cause death, HF hospitalization (HFH), and the composite of cardiovascular death (CVD) or HFH. Results: Within a median follow-up of 53.7 (range, 2.6-99.1) months, 156 deaths were recorded: 121 (29 %), 31 (15 %), and three (4 %) patients in the no-reduction (n = 411), single-reduction (n = 195), and successive-reduction (n = 73) groups, respectively. After adjusting for cofounders, the reduction group had a lower risk of primary outcomes than the no reduction group (all-cause death: hazard ratio (HR) = 0.65, 95 % confidence interval (CI) = 0.44-0.96; CVD or HFH: HR=0.69, 95 %CI=0.52-0.93; HFH: HR=0.69, 95 % CI=0.52-0.93). The successive-reduction group had a lower risk of the composite of CVD or HFH (HR=0.26, 95 % CI: 0.10-0.67) and HFH (HR=0.34, 95 % CI=0.13-0.86) than the single-reduction group. Conclusions: Outpatient LD dose reduction patterns can be indicators of good prognosis in HF patients.