Background: Central sleep apnea (CSA) is frequent among patients with heart failure (HF) and associated with increased morbidity and mortality. Elevated cardiac filling pressures promote CSA and atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) secretion. We hypothesized that circulating natriuretic peptide concentrations predict CSA.
Methods: Consecutive patients with HF (n = 44) with left ventricular ejection fraction (LVEF) ≤ 35% underwent polysomnography for detection of CSA. CSA was defined as an apnea-hypopnea index ≥ 15 with ≥ 50% central apneic events. The relation of natriuretic peptide concentrations to CSA was evaluated by estimation of ORs and receiver operator characteristics (ROCs).
Results: Twenty-seven subjects (61%) had CSA, with men more frequently affected than women (73% vs 27%; OR, 7.1; P = .01); given that only three women had CSA, further analysis was restricted to men. Subjects with CSA had higher mean ANP (4,336 pg/mL vs 2,510 pg/mL, P = .03) and BNP concentrations (746 pg/mL vs 379 pg/mL, P = .05). ANP and BNP concentrations were significantly related to CSA (OR, 3.7 per 3,000 pg/mL, P = .03 and OR, 1.5 per 200 pg/mL, P = .04, respectively), whereas age, LVEF, and New York Heart Association functional class were not. Concentrations of ANP and BNP were predictive of CSA as ROC demonstrated areas under the curve of 0.75 and 0.73, respectively.
Conclusions: Risk of CSA is related to severity of HF. ANP and BNP concentrations performed similarly for detection of CSA; low concentrations appear associated with low risk for CSA in men.