Reclassification of Heart Failure With Preserved Ejection Fraction Following Cardiac Sympathetic Nervous System Activation: a New Cutoff Value of 58%

Abstract A left ventricular ejection fraction (LVEF) of 50% as the cutoff for heart failure (HF) with preserved LVEF is controversial. We previously reported that patients with an LVEF of ≥58% have good prognoses. In this study, 123I-metaiodobenzylguanidine scintigraphy was performed to evaluate cardiac sympathetic nervous system (SNS) activity in 63 HF patients (78.4±9.6 years; males, 49.2%). During the follow-up period (median, 3.0 years), 18 all-cause deaths occurred. The delayed heart/mediastinum (H/M) ratio was significantly higher in the LVEF ≥58% group (n=15) than the LVEF <58% group (n=48) (2.1±0.3 vs. 1.7±0.4, p=0.004), and the all-cause mortality was significantly lower in patients in the former than those in the latter group (log-rank, p=0.04). When these patients were divided into LVEF ≥50% (n=22) and LVEF <50% (n=41) groups; no significant differences were found in the delayed H/M ratio, and the all-cause mortality did not differ between the groups (log-rank, p=0.09).In conclusion, cardiac SNS activity was more elevated in patients with an LVEF of <58% than in those with an LVEF of ≥58%. Furthermore, an LVEF of <58% was significantly associated with all-cause mortality. Thus, an LVEF of 58% is a good candidate for reclassifying HF patients according to cardiac SNS activity.