[Sleep apnea syndrome in heart failure. Effect of continuous positive airway pressure].

INTRODUCTION: Sleep disordered breathing and heart failure are common disorders that are frequently associated in the same patients which may bring on serious consequences.

OBJECTIVE: To determine the prevalence of sleep apnea syndrome (SAS) in patients with controlled heart failure and the associated prevalence of arrhythmia. In addition, we to aim to evaluate the effectiveness of continuous positive airway pressure (CPAP) treatment for OSAS on left ventricular ejection fraction (EF).

MATERIAL AND METHODS: We prospectively studied 60 patients (50 men, 10 women) with heart failure due to systolic dysfunction (left ventricular EF < 45%). All subjects were classified according the NYHA functional scale and received a specific questionnaire, as well as a home respiratory polygraphy and EKG Holter. A subject was considered to have SAS if their IAH > 15, and, according to standard recommendation, patients with IAH > 30 were treated with CPAP. After 3 months of treatment, the questionnaire, respiratory polygraphy and EKG Holter were repeated.

RESULTS: Age was 69.3 +/- 10.4 years and the BMI was 28.5 +/- 4.74 kg/m2. Of the total sample, 55% (33 cases) were habitual snorers. The Epworth scale scores were 7.83 +/- 4.8. The EF was 36.3 +/- 7.4%, and 36 patients were NYHA class II, 23 were class III, and one patient was class IV. A total of 38 patients had SAS (63%): 14 (36%) had central sleep apnea and 24 (64%) had obstructive sleep apnea. EF revealed no significant differences between the SAS and non-SAS groups (36.42 +/- 7.6 vs. 35.81 +/- 6.6%, respectively). The SAS group presented a higher prevalence of bradicardia than the non-SAS group (24 % vs. 9%). After CPAP treatment, there was a significant improvement in EF (9%), in cases of obstructive sleep apnea, but no significant improvement was observed in patients with central sleep apnea.

CONCLUSIONS: The prevalence of SAS in patients with heart failure due to systolic dysfunction is very high. CPAP treatment improved the EF in patients with obstructive sleep apnea.