Left Ventricular Ejection Fraction (EF) of 55% as Cutoff for Late Transition From Heart Failure (HF) With Preserved EF to HF With Mildly Reduced EF.

BACKGROUND Heart failure (HF) with preserved (HFpEF) left ventricular ejection fraction (LVEF) is a syndrome with complex pathophysiology. Little is known about changes in LVEF that occur over time in HFpEF patients. A fundamental clinical question about HFpEF is whether HFpEF is an early manifestation of HF with reduced LVEF (HFrEF). If so, which patients with HFpEF are likely to show a decline in LVEF to less than 50%? The aim of the present study was to examine longitudinal changes in LVEF in patients with HFpEF. METHODSANDRESULTS Among 279 consecutive HFpEF patients admitted as emergencies, we examined 100 who underwent echocardiography at least 1 year after discharge. EF >50% was used as the definition of HFpEF. During a mean duration from hospitalization to follow-up echocardiography of 31.5 months, 11% of patients had LVEF ≤50% (mildly reduced LVEF), known as mildly reduced (HFmrEF). The utility of LVEF during hospitalization to predict HFmrEF was assessed with receiver-operating characteristic curve analysis. A cutoff value of 55% had sensitivity of 90.9% and specificity of 97.7%. Logistic regression analysis indicated that LVEF ≤55% and ischemic etiology were strong predictors of progression from HFpEF to HFmrEF (odds ratio [OR] 435, 95% confidence interval [CI] 52.65-10,614, P<0.0001 and OR 10.9, 95% CI 2.60-74.80, P=0.0007, respectively). CONCLUSIONS The present study suggests that HFpEF patients with LVEF ≤55% may progress to HFmrEF in the future.