Evaluation of the influence of cardiac resynchronization therapy on sleep apnea syndrome

Introduction Many studies have shown a high prevalence of sleep apnea syndrome (SAS), whether obstructive sleep apnea (OSA) or central sleep apnea (CSA) in heart failure patients (HF). Very few data exit about HF patients with cardiac resynchronization therapy (CRT). Purpose In this study, we will determine the prevalence of SAS in this population and study the influence of CRT about SAS. Methods A prospective open-label, single-center, non-interventional, cohort-type study was conducted at Reims University Hospital between 1st January and 31st August 2016. All patients implanted with CRT device without known SAS were included. Screening polysomnography was performed before and 6 months after implantation. Primary endpoint was the incidence of SAS and secondary endpoint was the evaluation of the impact of CRT on SAS. Results During the study period, 31 patients were implanted with a CRT device: 10 were already known having SAS and 5 did not give their consent. At M0, 100% of the 16 included patients were diagnosed having SAS, with 69% severe OSAS. All were treated by CPAP according to guidelines. At 6 months, after 48 h CPAP washout, no independent significant influence of CRT on the Apnea-Hypopnea Index (AHI) was demonstrated (37 ± 19 vs 60 ± 12, P  = 0.0625). An improvement in HF parameters was observed (NYHA class (−1, P  = 0.0195), QRS width (−26 ms, P  = 0.0002) and LVEF (+9.5%, P  = 0.0039)). At 6 months, the CRT response rate was high with significant NYHA class and LVEF improvement in 79 and 57% patients respectively. Conclusion SAS (especially OSA) is frequent in HF patients eligible for CRT and mostly under-diagnosed. The lack of improvement of the AHI by the CRT alone and the existence of a specific treatment of the OSAS improving morbi-mortality, maintaining a very good response rate to the CRT invite to screen this population.