Relation of left ventricular ejection fraction and clinical features or co-morbidities to outcomes among patients hospitalized for acute heart failure syndromes.

The aim of this study was to evaluate the heterogeneity of the association of a preserved or reduced ejection fraction (EF) with the increased risk of outcomes among patients with acute heart failure syndromes. Of the 4,842 patients enrolled in the Acute Decompensated Heart Failure Syndromes (ATTEND) registry in Japan, 4,720 patients were evaluated to investigate the association of EF and clinical features or co-morbidities with all-cause mortality after admission. The median follow-up period after admission was 519 (388 to 781) days. The all-cause mortality rate did not differ between the reduced EF and preserved EF groups (24.9% and 24.5%, respectively). To evaluate the heterogeneity of the influence of a preserved or reduced EF on all-cause mortality, subgroup analyses were performed. As a result, there were significant interactions in the association of a preserved or reduced EF with all-cause mortality when the patients were stratified by an ischemic cause, a hypertensive cause, previous hospitalization for heart failure, diabetes mellitus, and anemia. The influence of a nonischemic cause, a hypertensive cause, or new-onset heart failure on the risk of all-cause mortality was significantly greater in patients with preserved EF than in those with reduced EF. In contrast, the influence of diabetes mellitus or anemia on the risk of all-cause mortality was significantly greater in patients with reduced EF than in those with preserved EF. In conclusion, the present analysis demonstrated that the association of a preserved or reduced EF with the clinical outcome differs markedly in relation to the clinical features or co-morbidities of these patients.