Increased plasma level of apelin with NYHA grade II and III but not IV.

The change in plasma apelin level in heart failure (HF) patients is controversial. We investigated the change in plasma apelin level in HF patients versus control and non-HF patients. The plasma level of apelin was measured by ELISA and plasma level of B-type natriuretic peptide (BNP) by fluorescence immunoassay. We included 101 patients with HF, 32 patients without HF and 20 controls. The three groups did not differ in general and clinical characteristics. Plasma levels of apelin and BNP were both higher in HF patients than non-HF patients and controls. Plasma levels of apelin and BNP were not correlated. Plasma level of BNP was increased with increasing New York Heart Association grade and apelin level was decreased. Apelin level was lower in HF patients with NYHA grade IV than in controls and non-HF patients. Apelin level had 75% diagnostic value for HF, and BNP level had 96.8% diagnostic value. At a cutoff of 6.44 ng/mL apelin level, sensitivity was 69.3%, and specificity 97.1%. However, the diagnostic of apelin for NYHA II patients was higher than that of BNP (99.6% vs. 96.1%). These results suggested that apelin might be particularly useful in association with BNP in mild HF patients.