Abstract 12530: Cardiac Resynchronization Therapy Affects Sleep Apnea and Quality of Sleep in Patients With Chronic Heart Failure
Background: Patients with chronic heart failure(CHF)often have sleep-related breathing disorders that contribute to exacerbation of CHF. Biventricular stimulation (CRT) not only improves mechanical heart performance but likely affects other aspects of CHF pathophysiology. The central type of sleep apnea, especially Cheyne-Stokes respiration, is found predominantly in individuals with CHF. Sleep apnea can exacerbate CHF, while CHF influences the pathophysiology of sleep-related breathing disorders. The aim of the study was to assess the influence of CRT on subjective and objective sleep features. Material and methods: Fifty consecutive patients (aged 67.4±9.5; 43 men - 86% ) with CHF (54.0 % with ischaemic background and 46.0 % of non-ischaemic etiology) in stable for at least 3 months NYHA class III - IV despite optimized pharmacotherapy, left ventricular ejection fraction (LVEF) < 35% and wide QRS complex (≥ 120 ms) were appraised before and 12-16 weeks after CRT introduction clinically (including 6-minute walk test - 6-MWT), echocardiographically and in polisomnography. The apnea-hypopnea index (AHI) and apnea indexes (AI) of central, obstructive and mixed types were calculated. The sleep quality was assessed with the Pittsburg Sleep Quality Index (PSQI), daytime sleepiness with the Epworth Sleepiness Scale (ESS).
Results: Three months after introduction of CRT: LVEF increased (26.2 % ± 6.5 vs 30.6 % ± 8.6; p<0.0001), so did 6-MWT distance (285.1 m ± 99.5 vs 361.0 m ± 93.7; p=0.0002), left ventricular end-systolic and end-diastolic diameters decreased (61.3 mm ± 10.0 vs 57.9 mm ± 9.7; p=0.0002 and 72.0 mm ± 9.6 vs 68.8 mm ± 9.0; p=0.0003 respectively), also left ventricular end-systolic volume decreased (167.4 ml ± 73.2 vs 148.4 ± 63.2;p=0.0122). Our study confirms the positive effect of CRT on central sleep apnea. Although we did not record the change of AHI (33.3 ± 16.1 vs 28.6 ± 17.8; p=0,09), the central AI decreased significantly (8.1 ± 11.6 vs 4.2 ± 7.6; p=0.0018). Central AI drop was followed by improvement in sleep quality assessed with PSQI (8.72 ± 3.74 vs 6.38 ± 2.94; p=0.0008).
Conclusions: Cardiac resynchronization therapy decreases central sleep apnea and improves quality of sleep in patients with chronic heart failure.
- © 2012 by American Heart Association, Inc.