Risk factors and prognostic value of daytime Cheyne–Stokes respiration in chronic heart failure patients

BackgroundSleep-related Cheyne–Stokes (CS) respiration is a known phenomenon in chronic heart failure (CHF). We aimed to study the prevalence, clinical correlates, risk factors and prognostic relevance of daytime CS, as well as its relation with neurohormonal derangement.MethodsOne hundred forty seven CHF patients with left ventricular systolic dysfunction (age: 64 ± 12 years, ejection fraction, EF, 31 ± 8%, mean ± SD) underwent morning polygraphic recording, in addition to comprehensive clinical and neurohormonal evaluation.ResultsDaytime CS was detected in 87 patients (59%), and associated with worse NYHA class (2.6 ± 0.7 vs 2.2 ± 0.8, P < 0.05), lower EF (29 ± 8 vs 33 ± 8%, P < 0.05), peak oxygen consumption (11.3 ± 8.3 vs 13.4 ± 4 mL/min/kg, P < 0.05), resting carbon dioxide level (33.1 ± 4.2 vs 37.9 ± 3.8 mm Hg, P < 0.001), higher norepinephrine [588 (395–939) vs (331–681) ng/L, median (interquartile range) P < 0.01] and natriuretic peptides [ANP: 136 (57–230) vs 66 (18–103); BNP: 284 (99–510) vs 64 (21–202); NT-proBNP: 2575 (814–3320) vs 448 (147–1599) ng/L, all: P < 0.001]. At univariate analysis, CS risk factors were age, EF, carbon dioxide, creatinine, norepinephrine, natriuretic peptides, whereas age and NT-proBNP level were the only multivariate predictors. On a 33-month follow-up, CS resulted among univariate predictors of cardiac death, NT-proBNP emerging as the only variable at multivariate analysis.ConclusionsDaytime CS is frequent in CHF and is correlated with clinical severity, neurohormonal derangement, particularly of NT-proBNP, and long-term prognosis.