Sustained effect of continuous positive airway pressure on baroreflex sensitivity in congestive heart failure patients with obstructive sleep apnea.
ABSTRACT Patients with either heart failure or obstructive sleep apnea have a reduced baroreflex sensitivity for heart rate, a sign of poor prognosis. We previously demonstrated that nocturnal application of continuous positive airway pressure to heart failure patients with obstructive sleep apnea increased baroreflex sensitivity acutely, but it is not known whether these effects persist into wakefulness.
To determine whether treating obstructive sleep apnea in heart failure patients with continuous positive airway pressure improves baroreflex sensitivity during wakefulness.
Spontaneous baroreflex sensitivity was assessed during wakefulness in 33 heart failure patients (left ventricular ejection fraction < or = 45%) with obstructive sleep apnea (apnea-hypopnea index > or = 20). Subsequently, baroreflex sensitivity was reassessed 1 month after patients were randomly allocated to nocturnal continuous positive airway pressure treatment or no treatment (control).
Compared with the 14 control patients, the 19 continuous positive airway pressure-treated patients experienced a greater increase in baroreflex sensitivity [median, (25%, 75%)] [from 5.4 (2.2, 8.3) to 7.9 (4.4, 9.4) ms/mmHg; P = 0.01] and left ventricular ejection fraction (P < 0.001). In addition, daytime systolic blood pressure and heart rate decreased more in the continuous positive airway pressure group (from 122 +/- 15 to 113 +/- 12 mmHg; P = 0.02, and from 66 +/- 8 to 62 +/- 8 bpm; P < 0.001, respectively) than in the control group.
Treatment of coexisting obstructive sleep apnea by continuous positive airway pressure in heart failure patients improves baroreflex sensitivity during wakefulness in addition to improving left ventricular ejection fraction and lowering blood pressure and heart rate. These data indicate that the improved autonomic regulation of heart rate in heart failure patients treated for obstructive sleep apnea during sleep persists into wakefulness.
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ABSTRACT: -Heart failure with reduced ejection fraction (HFrEF) and obstructive sleep apnea (OSA), two states of increased metabolic demand and sympathetic nervous system activation, often co-exist. Continuous Positive Airway Pressure (CPAP), which alleviates OSA, can improve ventricular function. It is unknown whether this is due to altered oxidative metabolism or pre-synaptic sympathetic nerve (SN) function. We hypothesized that short-term (6-8 weeks) CPAP in patients with OSA and HFrEF would improve myocardial SN function and energetics.Circulation 07/2014; · 14.95 Impact Factor
- Arquivos Brasileiros de Cardiologia 12/2008; 93(1):3-70. · 1.12 Impact Factor
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ABSTRACT: Background The therapeutic and economic benefits of continuous positive airway pressure (CPAP) for moderate to severe obstructive sleep apnoea (OSA) syndrome have been established in middle-aged people; however, the benefits in older people are unknown. This trial was designed to address this evidence gap. Methods This 12-month, multicentre, randomised trial enrolled patients across 14 National Health Service sleep centres in the UK. Consecutive patients aged 65 years or older with newly diagnosed OSA syndrome were eligible to join the trial. Patients were randomly assigned (1:1) into parallel groups to receive either CPAP with best supportive care (BSC) or BSC alone for 12 months. Randomisation was done by the Medical Research Council Clinical Trials Unit with computer-generated randomisation. The main investigator at each centre was masked to the trial randomisation. Coprimary endpoints were Epworth sleepiness score (ESS) at 3 months and cost-effectiveness over the 12-month trial period. Secondary outcomes were subjective sleepiness at 12 months, plus objective sleepiness, quality of life, mood, functionality, nocturia, mobility, accidents, cognitive function, and cardiovascular risk factors and events at 3 months and 12 months. The analysis was by intention to treat. This study is registered as an International Standard Randomised Controlled Trial, number ISRCTN90464927. Findings Between Feb 24, 2010, and May 30, 2012, 278 patients were randomly assigned to the trial, of whom 231 (83%) completed the trial. 140 patients were allocated to and received CPAP plus BSC and 138 were allocated to and received BSC only. CPAP reduced ESS by 2·1 points (95% CI −3·0 to −1·3; p<0·0001) at 3 months for 124 (89%) of 140 patients compared with 124 (90%) of 138 patients given BSC, and by 2·0 points (−2·8 to −1·2; p<0·0001) at 12 months for 116 patients compared with 122 patients given BSC. The effect was greater in patients with higher CPAP usage or higher baseline ESS. Quality-adjusted life-years were similar between the groups (treatment effect 0·01 (95% CI −0·03 to 0·04; p=0·787) and health-care costs were marginally reduced with CPAP (−£35, −390 to 321; p=0·847). CPAP improved objective sleepiness (p=0·024), mobility (p=0·029), total cholesterol (p=0·048), and LDL cholesterol (p=0·042) at 3 months, but these were not sustained at 12 months. Measures of mood, functionality, nocturia, accidents, cognitive function, and cardiovascular events remained unchanged. Systolic blood pressure fell in the BSC group. 37 serious adverse events occurred in the CPAP group, and 22 in BSC group; all were independently classified as being unrelated to the trial and no significant harm was attributed to CPAP use. Interpretation In older people with OSA syndrome, CPAP reduces sleepiness and is marginally more cost effective over 12 months than is BSC alone. On the basis of these results, we recommend that CPAP treatment should be offered routinely to older patients with OSA syndrome. Funding National Institute of Health Research (NIHR) Health Technology Assessment, NIHR Respiratory Biomedical Research Unit at the Royal Brompton and Harefield NHS Foundation Trust and Imperial College London.The Lancet Respiratory Medicine. 10/2014;