[Associated factors for sleep apnea in heart failure]

Genesis of sleep apnoea syndrome (SAS) in chronic heart failure (CHF) is not well known. The aim of our study was to find associated factors to SAS in heart failure (HF) and to look for differences between central sleep apnea (CSA) and obstructive sleep apnea (OSA).

We realised a cross-sectional and retrospective study. Thirty patients with stable heart failure under medical optimal therapy were included. Polygraphy, echocardiography and cardiopulmonary exercise were systematically performed.

Men were predominant (80%) in the group. Mean age, left ventricular ejection fraction (LVEF) were respectively 64.1±13.8years and 40±9.8%. SAS was present in 60% of patients (33.3% were classified as central sleep apnoea [CSA] and 26.7% as obstructive sleep apnoea [OSA]). Body mass index, blood pressure and left ventricular pressures estimated by the E/Ea ratio were significantly higher in the group with SAS (P<0.05) compared to the non SAS group. New York Heart Association class was significantly higher (P=0.04) and the predicted peak VO(2) was significantly lower in CSA patients compared to OSA patients.

High left ventricular pressures estimated by the E/Ea are significantly associated with SAS in heart failure. CSA patients tend to have a worse functional state than OSA patients.