Relationship between sleep-disordered breathing and plasma brain natriuretic peptide in chronic heart failure

Abstract

Background: Sleep-disordered breathing (SDB) is a poor prognostic indicator in patients with congestive heart failure (CHF). Plasma brain natriuretic peptide (BNP) levels correlate with severity of CHF and are an important prognostic predictor in CHF patients. Accordingly, we assessed the relationship between plasma BNP and SDB severity in patients with CHF. Methods: Forty-two patients with stable CHF and left ventricular ejection fraction (LVEF) <40% (30 men, mean age 63 ± 11 years) underwent overnights sleep study with use of pulse-oxymetry, and were evaluated 4% oxygen desaturation index (ODI), a number of episodes of oxygen concentration reduction 4% from baseline per hour. In all patients, hemodynamic parameters and plasma BNP levels were measured during cardiac catheterization. Result: Twenty-three patients had SDB when we defined SDB as 4%ODI > 5, and mean 4%ODI was 13.3 per hour. Patients with and without SDB did not differ with respect to pulmonary capillary wedge pressure (13 ± 9 versus 11 ± 7 mmHg) and LVEF (31 ± 7 versus 33 ± 10 %). Plasma BNP levels were significantly higher in SDB group (480 ± 337 versus 207 ± 218 pg/ml), and well correlated with 4%ODI (r = 0.517, P = 0.0004). Conclusions: Plasma BNP levels are significantly elevated in CHF patients with SDB and closely correlated with 4%ODI. Our findings suggest that plasma BNP may be a biochemical marker of central sleep apnea in CHF patients.