4.15 Elevated B-Type Natriuretic Peptide Indicates Increased End-Diastolic Pressure in Patients with Mild-Moderate Heart Failure and Systolic Dysfunction: The AREA-IN-CHF Study

Introduction: Although B-type natriuretic peptide (BNP) is a marker of severity of LV dysfunction, it is only modestly related to echocardiographic indices of LV filling. Little is known on its relation with left atrial volume (LAV), and echocardiographically-estimated LV end-diastolic pressure (LVEDP).

Methods: The AREA-IN-CHF (AntiRemodeling Effect of Aldosterone receptors blockade with canrenone IN mild Chronic Heart Failure) is a prospective, randomized, double blind study on antialdosterone treatment in patients with Class 2 NYHA chronic heart failure (CHF) and ejection fraction <45%. Among 505 participants who underwent Doppler-echocardiography, we evaluated 277 subjects without valvular of rhythm abnormalities (mean age 62.4±9.7 yrs, 45 women), with available BNP. LAV was calculated using biplanes orthogonal dimensions by the ellipsoidal model. As recommended, BNP was considered increased when > 100pg/mL. LVEDP was computed from pulmonary and mitral A wave duration, applying an invasively-validated equation.

Results: BNP correlated positively to age (r=0.25), LV mass (r=0.21), LAV (r=0.36), LVEDP (r=0.41) and negatively to ejection fraction (r=−0.36) and mitral E deceleration time (r=−0.22) (p for all LVEDP, lower ejection fraction and relative wall thickness, and shorter mitral E deceleration time. In binary logistic regression, presence of increased BNP was predicted by LAV (OR= 1.02/ml; 95%CI=1.01−1.05; pLVEDP (OR= 1.07/mmHg; 95%CI=1.02−1.13; p<0,05).

Conclusions: In a cohort of 277 patients in NYHA class 2 CHF without valvular of rhythm abnormalities, increased BNP is frequent (40.4%) and associated with dilated LA and elevated LVEDP, independently of LV geometry and function.