Effects of Zolpidem CR on Sleep and Nocturnal Ventilation in Patients with Heart Failure

Study Objective: This study aimed to evaluate the effects of zolpidem CR (controlled release) on sleep and nocturnal ventilation in patients with congestive heart failure, a population at risk for insomnia and poor sleep quality. Methods: Fifteen patients with heart failure (ischemic cardiomyopathy) and ejection fraction <= 45% in NYHA functional class I or II were evaluated with full polysomnography in a placebo-controlled, double-blind, randomized trial. Patients underwent three tests: (1) baseline polysomnography and, after randomization, (2) a new test with zolpidem CR 12.5 mg or placebo, and after 1 week, (3) a new polysomnography, crossing the "medication" used. Results: A 16% increase in total sleep time was found with the use of zolpidem CR and an increase in stage 3 NREM sleep (slow wave sleep). The apnea hypopnea index (AHI) did not change with zolpidem CR even after controlling for supine position; however, a slight but significant decrease was observed in lowest oxygen saturation compared with baseline and placebo conditions (83.60 +/- 5.51; 84.43 +/- 3.80; 80.71 +/- 5.18, P = 0.002). Conclusion: Zolpidem CR improved sleep structure in patients with heart failure, did not change apnea hypopnea index, but slightly decreased lowest oxygen saturation.