The Solution for Central Sleep Apnea May Not Be One
Although central sleep apnea is an independent marker for poor prognosis and death in heart failure, suppressing it could have adverse consequences for some patients.
Fed Pract. 2015 September;32(9):e16
Patients with heart failure (HF) often have central sleep apnea (CSA), breathing interruptions, and hyperventilation, which can be dangerous for a failing heart. In fact, CSA is an independent marker for poor prognosis and death in HF. Thus, suppressing these apneas and hypopneas seemed to be a good idea. However, the results of the SERV-HF (Treatment of Sleep-Disordered Breathing with Predominant Central Sleep Apnea by Adaptive Servo Ventilation in Patients with Heart Failure) trial suggest otherwise. The researchers found adaptive servo-ventilation unexpectedly increased all-cause and cardiovascular mortality.
The researchers followed 1,325 patients for a median of 31 months. Of those, 666 patients were in the adaptive servo-ventilation group; 60% used it for an average of ≥ 3 hours per night during the study period.
Despite effective control of CSA during the therapy, the risk of cardiovascular death rose by 34% in the intervention group—a risk that was sustained throughout the trial. Moreover, the researchers found no beneficial effect on quality of life or symptoms of HF.
Two possible mechanisms may be at work, the researchers say. One is that positive airway pressure therapy (not particularly adaptive servo-ventilation) might have adverse consequences on cardiac function in some patients. Second, they suggest, diminishing the compensatory adaptive respiratory pattern of Cheyne-Stokes respiration may be detrimental in patients with HF.
Source Cowie MR, Woehrle H, Wegscheider K, et al. N Engl J Med. 2015;373(12):1095-1105. doi: 10.1056/NEJMoa1506459.