Characteristics of acute congestive heart failure with normal ejection fraction and less elevated B-type natriuretic peptide

Abstract

Background: Heterogeneity in B-type natriuretic peptide (BNP) levels, especially among individuals with acute heart failure with normal left ventricular ejection fraction (HFNEF), can cause confusion in interpreting results. We investigated the characteristics of cases of acute HFNEF with only modestly elevated BNP.

Methods: One hundred forty-two patients with acute or acute exacerbation of chronic HFNEF were divided into two groups by BNP level: BNP < 100 pg/ml (NB group, n = 45) and BNP > or = 100 pg/ml (B group, n = 97). We compared clinical findings, echocardiography results, and neurohormonal factors between these two groups.

Results: In the NB group, a history of open-heart surgery (OHS) was more frequent (71% vs. 22%, p < 0.0001) and hypertension was less frequent (p = 0.0005). Left atrial diameter (LAd) was higher (p = 0.0026), while interventricular septal thickness, posterior wall thickness, relative wall thickness, left ventricular mass index were lower (p = 0.0005, p = 0.0225, p = 0.0114, p = 0.0051, respectively) in the NB group. In patients with HFNEF, a history of OHS remained an independent predictor of BNP level (< 100 pg/ml) after adjustment for hypertension, age, LAd, and interventricular septal thickness (odds ratio 3.6, p = 0.0252).

Conclusion: We found associations between acute HFNEF with less elevated BNP and a history of OHS. In a patient suspected of HFNEF, a history of OHS is considered diagnostic evidence of presence of diastolic heart failure when plasma levels of BNP are less elevated.

Figure 1

Comparison of level of B-type natriuretic peptide (BNP) in B group between with and without a history of open-heart surgery (OHS). Patients who had a history of OHS had a significantly lower BNP level. The boxes represent the 25th, 50th(median), and 75th percentiles, and the whiskers indicate the 10th and 90th percentiles.

Figure 2

Comparison of left atrial diameters (LAd) between B group and NB group. Patients in the NB group who had a history of open-heart surgery had marked left atrial enlargement. The boxes represent the 25th, 50th (median), and 75th percentiles, and the whiskers indicate the 10th and 90th percentiles.