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.

Methods and results: 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.