Characteristics and outcomes of heart failure in Japan: A hospital-based administrative database analysis

Aims Epidemiological and outcome studies on patients in Japan with heart failure (HF) categorized by left ventricular ejection fraction (LVEF) are currently limited. The aim of this non-interventional database study was to provide further information on these patients. Methods and results Administrative claims data and electronic medical records from hospitals participating in the Voluntary Hospitals in Japan (VHJ) organization were used. Patients hospitalized with a primary diagnosis of HF between 1 April 2017 and 30 March 2020 were categorized by baseline LVEF on echocardiogram: HF with reduced EF (HFrEF, LVEF <40%); HF with preserved EF (HFpEF, LVEF >= 50%); and HF with mildly reduced EF (HFmrEF, 40% to <50% LVEF). Patients were evaluated for baseline characteristics, pre-admission diagnosis, prescription drugs, length of hospitalization, HF treatment cost, overall cost of hospitalization, and in-hospital prescription. An exploratory analysis compared post-hospitalization mortality and re-hospitalization rates. In total, 10 646 hospitalized patients from 17 VHJ hospitals were enrolled. Of these, 7212 were included in the analysis set and categorized into HFpEF (3183, 44.1%), HFmrEF (1280, 17.7%), and HFrEF (2749, 38.1%) groups based on baseline LVEF. Beta-blocker use increased during hospitalization, with a mean (95% confidence interval [CI]) of 23.3% (22.3-24.3) of patients receiving these agents before admission versus 69.4% (68.3-70.5) at discharge. Administration of diuretics, angiotensin converting enzyme (ACE) inhibitors, and angiotensin II receptor blockers (ARBs) showed a similar trend. Differences in treatments were observed between HF categories at discharge, with a higher proportion (95% CI) of ACE inhibitor use in the HFrEF group (40.6% [38.7-42.4]) versus HFmrEF (27.5% [25.1-30.0]) and HFpEF (20.6% [19.2-22.1]) groups (P < 0.0001), and more ARB use in the HFmrEF and HFpEF groups (32.5% [29.9-35.1] and 31.2% [29.6-32.9], respectively) versus HFrEF (25.1% [23.5-26.8]; P < 0.0001). Mean (standard deviation [SD]) length of hospitalization was 22.2 (23.3) days, and the median (interquartile range) was 17 (11-25) days. Estimated average cost of HF treatment per patient during index hospitalization was 300 090 yen with HFrEF treatment costing the most. Average total healthcare expenditure during hospitalization was 1 225 650 yen per index hospitalization per patient, with HFrEF also the most expensive. During a mean (SD) observation period of 324 (304) days, (similar to)21% of patients in each group required re-hospitalization for HF, and 625 patients (8.7%) died. Conclusions The proportion of patients in each HF category was largely consistent with existing data. Discharge medications indicated high prescription of guideline-directed therapy. This study provides real-world data on patients with HF in Japan that can help inform future clinical decision-making.