Abstract 15352: Plasma Levels of BNP are Lower in Patients With Heart failure With Preserved EF (HFpEF) as Compared With Those With Reduced EF (HFrEF)

Abstract

Introduction: Heart failure with preserved ejection fraction (HFpEF) is increasing in prevalence and causes substantial morbidity, mortality, and resource utilization in the aging population. The plasma level of B-type natriuretic peptide (BNP) is used as a marker of HF with reduced EF (HFrEF). However, the role of BNP in HFpEF is not well known. The purpose of the present study was to compare the levels of BNP together with the echocardiographic findings between HFpEF and HFrEF. Methods: The study subjects consisted of 1574 patients with HF and early diastolic flow velocity (E)/velocity of early diastolic mitral annular motion (e′) or E/e′≥15 (as a measure of elevated left atrial pressure) (574 men and 1000 women, mean age 78.8±10.7) admitted at our hospital. They were divided into 1238 patients with HFpEF (373 men and 865 women, mean age 79.7±10.2) [left ventricular (LV) EF≥50% and E/e′≥15] and 336 patients with HFrEF (201 men and 135 women, mean age 75.4±11.8) (LVEF<50%). Echocardiographic parameters, age, gender, and BNP were examined. Results: The levels of BNP were lower [107(47, 225) pg/ml vs. 296(121, 626) pg/ml, P<0.001] in the HFpEF group than in the HFrEF group. The frequencies of female gender, age, EF, LV posterior wall thickness were higher (all P<0.001, respectively) and LV mass, LV end-diastolic diameter (LVDd), LV end-systolic diameter (LVDs) and left atrial diameter (LAD) were lower (all P<0.001, respectively) in the HFpEF group than in the HFrEF group. A multiple regression analysis revealed EF (t=-17.0), age (t=11.2), E/e′ (t=10.5), LAD (t=9.0), LV mass (t=7.9), and LVDd (t=-5.3) were independent predictors (all P<0.001, respectively) for the BNP level (P<0.001, R2=0.40) in this order. Conclusions: HFpEF was associated with lower levels of BNP and smaller heart and was more prevalent in the elders and women as compared with HFrEF. Predictors for the levels of BNP were EF, age, and E/e′ in this order. These findings imply that the plasma levels of BNP reflect LVEF more than LV diastolic function (E/e′) and thus are lower in the HFpEF group than in the HFrEF group. These findings suggest that the role of BNP in HF may be different between HFpEF and HFrEF.