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

Abstract

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, ~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.

Keywords: Database study; Heart failure; Hospitalization; Japan; Left ventricular ejection fraction; Medication use.

Figure 1

Patient flow diagram. HF, heart failure; HFmrEF, HF with mildly reduced ejection fraction (40% to <50% LVEF); HFpEF, HF with preserved ejection fraction (≥50% left ventricular ejection fraction); HFrEF, HF with reduced ejection fraction (<40 LVEF); LVEF, left ventricular ejection fraction.

Figure 2

Probability of re‐hospitalization for HF by LVEF category. *1 month = 30.4 days. HF, heart failure; HFmrEF, HF with mildly reduced ejection fraction (40% to <50% LVEF); HFpEF, HF with preserved ejection fraction (≥50% left ventricular ejection fraction); HFrEF, HF with reduced ejection fraction (<40 LVEF); LVEF, left ventricular ejection fraction.

Figure 3

Probability of all‐cause mortality in post‐discharge patients with HF by LVEF category. *1 month = 30.4 days. HF, heart failure; HFmrEF, HF with mildly reduced ejection fraction (40% to <50% LVEF); HFpEF, HF with preserved ejection fraction (≥50% left ventricular ejection fraction); HFrEF, HF with reduced ejection fraction (<40 LVEF), LVEF, left ventricular ejection fraction.