Mode of Death Among Japanese Adults With Heart Failure With Preserved, Midrange, and Reduced Ejection Fraction

IMPORTANCE: Despite intensive treatment, hospitalized patients with acute decompensated heart failure (ADHF) have a substantial risk of postdischarge mortality. Limited data are available on the possible differences in the incidence and mechanisms of death among patients with heart failure with reduced ejection fraction (HFrEF), heart failure with midrange ejection fraction (HFmrEF), and heart failure with preserved ejection fraction (HFpEF). OBJECTIVES: To examine the incidences and mode of postdischarge mortality among patients with ADHF and to compare the risk profile among patients with HFrEF, HFmrEF, and HFpEF. DESIGN, SETTING, AND PARTICIPANTS: This prospective cohort study of 4056 patients hospitalized for ADHF analyzed data from 3717 patients who were discharged from October 1, 2014, to March 31, 2016. Data analysis was performed from April 1 to August 31, 2019. EXPOSURES: Death among patients with ADHF after hospital discharge. MAIN OUTCOMES AND MEASURES: All-cause death and cause of postdischarge mortality after the index hospitalization by left ventricular ejection fraction (LVEF) subgroup. RESULTS: A total of 3717 patients (mean [SD] age, 77.7 [12.0] years; 2049 [55.1%] male) were included in the study. The mean (SD) LVEF at baseline was 46.4% (16.2%). Among 3717 enrolled patients, 1383 (37.2%) were categorized as having HFrEF (LVEF, <40%), 703 (18.9%) as having HFmrEF (LVEF, 40%-49%), and 1631 (43.9%) as having HFpEF (LVEF, ≥50%). The incidence and causes of death were evaluated after discharge from the index hospitalization. The median follow-up period was 470 days (interquartile range, 357-649 days), and the 1-year follow-up rate was 96%. During follow-up, all-cause death occurred in 848 patients (22.8%; HFrEF group: 298 [21.5%; 95% CI, 19.5%-23.8%]; HFmrEF group: 158 [22.5%; 95% CI, 19.5%-25.7%]; and HRpEF group: 392 [24.0%; 95% CI, 22.0%-26.2%]; P = .26), cardiovascular deaths occurred in 523 patients (14.1%; HFrEF group: 203 [14.7%; 95% CI, 12.9%-16.6%]; HFmrEF group: 97 [13.8%; 95% CI, 11.4%-16.5%]; and HFpEF group: 223 [13.7%; 95% CI, 12.1%-15.4%]; P = .71), and sudden cardiac death occurred in 98 patients (2.6%; HFrEF group: 44 [3.2%; 95% CI, 2.4%-4.2%]; HFmrEF group: 14 [2.0%; 95% CI, 1.2%-3.3%]; and HFpEF group: 40 [2.5%; 95% CI, 1.8%-3.3%]; P = .23). The risks of causes of death were similar among the subtypes. CONCLUSIONS AND RELEVANCE: The mode of death was similar among the heart failure subtypes. Given the nonnegligible incidence of sudden cardiac death in patients with HFpEF found in this study, further studies appear to be warranted to identify a high-risk subset in this population.