Search

Background Cardiac resynchronization therapy (CRT) has been shown to improve cardiac function and reduce Cheyne-Stokes respiration but has not been evaluated in patients with obstructive sleep apnea (OSA). In this pilot study, we investigated the impact of both CRT and CRT plus increased rate pacing in heart failure ( ie , congestive heart failure [CHF]) patients with OSA. We hypothesized that through increased cardiac output CRT/pacing would reduce obstructive events and daytime symptoms of sleepiness. Methods Full polysomnograms were performed on CHF patients who were scheduled for CRT, and those patients with an apnea-hypopnea index (AHI) of > 5 events per hour were approached about study enrollment. Patients had a pre-CRT implant baseline echocardiogram and an echocardiogram a mean (± SEM) duration of 6.6 ± 1.4 months post-CRT implant; polysomnography; and responded to the Minnesota Living with Heart Failure questionnaire, the Epworth sleepiness scale, and the Functional Outcomes of Sleep Questionnaire. An additional third polysomnography was performed combining CRT with a pacing rate of 15 beats/min above the baseline sleeping heart rate within 1 week of the second polysomnography. Assessments for the change in cardiac output during the polysomnography were performed using circulation time to pulse oximeter as a surrogate. Results Twenty-four patients were screened, and 13 patients (mean age, 68.6 years; body mass index, 28.7 kg/m 2 ) had evidence of OSA. The mean AHI decreased from 40.9 ± 6.4 to 29.5 ± 5.9 events per hour with CRT (p = 0.04). The mean baseline ejection fraction was 22 ± 1.7% and increased post-CRT to 33.6 ± 2.0% (p r = 0.89; p Conclusions CRT improved cardiac function and reduced the AHI. Reduced circulatory delay likely stabilized ventilatory control systems and may represent a new therapeutic target in OSA.

Although the treatment of obstructive sleep apnea (OSA) with positive airway pressure (PAP) has been shown to be effective, nightly adherence to treatment remains poor. The objective of this study was to examine the degree to which various levels of PAP therapy adherence normalized verbal memory function after 3 months of therapy in patients with OSA who were memory-impaired prior to the initiation of PAP therapy.Participants were administered neuropsychological testing prior to the initiation of PAP treatment and at a 3-month follow-up visit. Fifty-eight memory-impaired participants were categorized into the following three groups based on 3 months of adherence to PAP therapy: (1) poor users (n = 14), participants who averaged2 h of PAP use per night; (2) moderate users (n = 25), participants who averaged 2 to 6 h of PAP use per night; and (3) optimal users (n = 19), participants who averaged6 h of PAP use per night.Logistic regression analyses revealed that the odds of optimal users exhibiting normalization of memory function following 3 months of PAP therapy were 7.9 times (p = 0.01) the odds of poor users exhibiting normalization of memory abilities. Overall, 21% of poor users, 44% of moderate users, and 68% of optimal users exhibited memory performance in the clinically normal range following 3 months of PAP use (chi(2) = 7.27; p = 0.03).These preliminary findings indicate that impaired verbal memory performance in patients with OSA may be reversible with optimal levels of PAP treatment. OSA patients exhibiting verbal memory impairments may experience a clinically meaningful benefit in their memory abilities when they use PAP for at least 6 h per night.

To compare adherence and clinical outcomes between flexible positive airway pressure (PAP) [C-Flex; Respironics; Murraysville, PA] and standard PAP therapy (ie, continuous positive airway pressure [CPAP]).A controlled clinical trial of CPAP therapy vs therapy using the C-Flex device in participants with moderate-to-severe obstructive sleep apnea. Participants were recruited from and followed up through an academic sleep disorders center.Eighty-nine participants were recruited into the study after they had undergone complete in-laboratory polysomnography and before initiating therapy. Participants received either therapy with CPAP (n = 41) or with the C-Flex device (n = 48), depending on the available treatment at the time of recruitment, with those recruited earlier receiving CPAP therapy and those recruited later receiving therapy with the C-Flex device. Follow-up assessments were conducted at 3 months.The groups were similar demographically. The mean (+/- SD) treatment adherence over the 3-month follow-up period was higher in the C-Flex group compared to the CPAP group (weeks 2 to 4, 4.2 +/- 2.4 vs 3.5 +/- 2.8, respectively; weeks 9 to 12, 4.8 +/- 2.4 vs 3.1 +/- 2.8, respectively). Clinical outcomes and attitudes toward treatment (self-efficacy) were also measured. Change in subjective sleepiness and functional outcomes associated with sleep did not improve more in one group over the other. Self-efficacy showed a trend toward being higher at the follow-up in those patients who had been treated with the C-Flex device compared to CPAP treatment.Therapy with the C-Flex device may improve overall adherence over 3 months compared to standard therapy with CPAP. Clinical outcomes do not improve consistently, but C-Flex users may be more confident about their ability to adhere to treatment. Randomized clinical trials are needed to replicate these findings.

Cardiac resynchronization therapy (CRT) has been shown to improve cardiac function and reduce Cheyne-Stokes respiration but has not been evaluated in patients with obstructive sleep apnea (OSA). In this pilot study, we investigated the impact of both CRT and CRT plus increased rate pacing in heart failure (ie, congestive heart failure [CHF]) patients with OSA. We hypothesized that through increased cardiac output CRT/pacing would reduce obstructive events and daytime symptoms of sleepiness.Full polysomnograms were performed on CHF patients who were scheduled for CRT, and those patients with an apnea-hypopnea index (AHI) of5 events per hour were approached about study enrollment. Patients had a pre-CRT implant baseline echocardiogram and an echocardiogram a mean (+/- SEM) duration of 6.6 +/- 1.4 months post-CRT implant; polysomnography; and responded to the Minnesota Living with Heart Failure questionnaire, the Epworth sleepiness scale, and the Functional Outcomes of Sleep Questionnaire. An additional third polysomnography was performed combining CRT with a pacing rate of 15 beats/min above the baseline sleeping heart rate within 1 week of the second polysomnography. Assessments for the change in cardiac output during the polysomnography were performed using circulation time to pulse oximeter as a surrogate.Twenty-four patients were screened, and 13 patients (mean age, 68.6 years; body mass index, 28.7 kg/m(2)) had evidence of OSA. The mean AHI decreased from 40.9 +/- 6.4 to 29.5 +/- 5.9 events per hour with CRT (p = 0.04). The mean baseline ejection fraction was 22 +/- 1.7% and increased post-CRT to 33.6 +/- 2.0% (p0.05). The reduction in AHI with CRT closely correlated with a decrease in circulation time (r = 0.89; p0.001) with CRT. Increased rate pacing made no additional impact on the AHI or circulation time. CRT had a limited impact on sleep architecture or daytime symptom scores.CRT improved cardiac function and reduced the AHI. Reduced circulatory delay likely stabilized ventilatory control systems and may represent a new therapeutic target in OSA.