The effects of continuous positive airway pressure on plasma brain natriuretic peptide concentrations in patients presenting with acute cardiogenic pulmonary edema with preserved left ventricular systolic function

Sleep Disorder and Heart Failure with Preserved Ejection Fraction

It is generally considered that obstructive sleep apnea is a potential cause of heart failure (HF), and insomnia and central sleep apnea are results of HF. However, the number of reports describing the bidirectional relationship between sleep disorder and HF has increased. Sleep disorder may contribute to left ventricular diastolic dysfunction via left atrial overload, left ventricular remodeling, pulmonary hypertension, and atrial fibrillation, which lead to HF with preserved left ventricular ejection fraction. Overnight rostral fluid shift and lung congestion may lead to airflow obstruction in the upper pharynx and stimulate pulmonary irritant receptors, which induce hyperventilation and sleep disorder.

Beneficial Effects of Positive Airway Pressure Therapy for Sleep-Disordered Breathing in Heart Failure Patients With Preserved Left Ventricular Ejection Fraction

BACKGROUND

Right-heart dysfunction is associated with poor prognosis in heart failure with preserved left ventricular ejection fraction (HFpEF). It remains unclear whether sleep-disordered breathing (SDB) treatment using positive airway pressure (PAP) improves right-heart and pulmonary function and exercise capacity and reduces mortality rates of HFpEF patients.

HYPOTHESIS

PAP may improve right-heart and pulmonary function, exercise capacity and prognosis in HFpEF patients with SDB.

METHODS

One hundred nine consecutive patients with HFpEF (left ventricular ejection fraction >50%) and moderate to severe SDB (apnea-hypopnea index ≥15/h) treated with medications were divided into 2 groups: 31 patients with PAP (PAP group) and 78 patients without PAP (non-PAP group). Right ventricular fractional area change (RV-FAC), tricuspid valve regurgitation pressure gradient (TR-PG), tricuspid valve E/E', forced expiratory volume in 1 second/forced vital capacity (FEV1 /FVC), percentage of vital capacity, and peak VO2 were determined before and 6 months later, and all-cause mortality was followed up for 916 days.

RESULTS

All parameters improved in the PAP group (RV-FAC, 36.0% -46.5%; TR-PG, 31.1 mm Hg-22.4 mm Hg; tricuspid valve E/E', 7.8-5.1; FEV1 /FVC, 83.9%-89.8%; percentage of vital capacity, 83.5%-89.9%; and peak VO2 , 16.6 mL/kg/min-19.6 mL/kg/min; P <0.05, respectively) but not in the non-PAP group. Importantly, all-cause mortality was significantly lower in the PAP group than in the non-PAP group (0% vs 12.8%; log-rank P = 0.014).

CONCLUSIONS

Positive airway pressure improves right-heart and pulmonary function and exercise capacity and may reduce all-cause mortality in patients with HFpEF and SDB.

Impact of continuous positive airway pressure treatment on left ventricular ejection fraction in patients with obstructive sleep apnea: a meta-analysis of randomized controlled trials

BACKGROUND

It has been known for a long time that obstructive sleep apnea (OSA) is associated with a decreased left ventricular ejection fraction (LVEF). Continuous positive airway pressure (CPAP) is the gold standard treatment for OSA; however, it is unknown whether or not CPAP treatment will improve the LVEF. The aim of the current study was to assess whether or not CPAP treatment improves the LVEF. A meta-analysis was conducted to determine the effect of CPAP treatment on the LVEF among patients with OSA.

METHODS

A literature search of PubMed, the Web of Science, and Cochrane Collaboration's database were utilized to identify eligible reports for this trial. Ten randomized controlled trails were examined and the meta-analysis was performed using STATA 11.

RESULTS

A significant improvement in the LVEF was observed after CPAP treatment (weighted mean difference(WMD) = 3.59, 95% CI = 1.74-5.44; P<0.001). Subgroup analysis revealed that patients with OSA and heart failure had a significant improvement in the LVEF after CPAP treatment (WMD = 5.18, 95% CI = 3.27-7.08; P<0.001); however, the LVEF of patients with OSA only increased 1.11% and there was no statistical significance (WMD = 1.11, 95% CI = -1.13-3.35; P = 0.331). Furthermore, based on univariate meta-regression analysis, only the baseline AHI had a statistically significant correlation with the LVEF.

CONCLUSIONS

Our meta-analysis supports the notion that CPAP may improve the LVEF among patients with OSA.

Left Ventricular Systolic and Diastolic Function in Obstructive Sleep Apnea

Background—

Previous studies in obstructive sleep apnea (OSA) were limited by study cohorts with comorbidities that confound assessment of left ventricular (LV) systolic and diastolic function. We comprehensively evaluated LV function using 2-dimensional echocardiography (2DE), tissue Doppler imaging (TDI), and 3-dimensional echocardiography (3DE) in subjects moderate-severe OSA, who were compared with disease (patients with hypertension, no OSA) and healthy control subjects.

Methods and Results—

A total of 120 subjects (n=40 each of matched OSA, hypertension and healthy cohorts) underwent echocardiographic examination for the assessment of septal and posterior wall thickness, LV mass index, LV volumes and ejection fraction, mitral valve inflow indices (E, A), mitral annular velocity (S, E′), and left atrial volume index (LAVI). OSA subjects were treated with continuous positive airway pressure (mean duration of 26 weeks), after which the echocardiographic parameters were reassessed. Posterior wall thickness and LV mass index were significantly higher in OSA and hypertensive groups compared with healthy. Systolic S velocity was reduced in OSA and hypertensive compared with healthy control subjects ( P <0.05). Diastolic function (E/A, IVRT, and E/E′) was impaired in both OSA and hypertensive groups. On 3DE, mean LAVI was significantly greater in OSA and hypertensive compared with healthy. In OSA patients, continuous positive airway pressure therapy resulted in reduction of the posterior wall thickness ( P =0.02) and improvement in LV ejection fraction ( P <0.05), systolic S velocity ( P <0.05), and diastolic LV impairment parameters.

Conclusions—

Moderate to severe OSA causes structural and functional changes in LV function and are comparable to that seen in hypertension. These abnormalities significantly improve after CPAP therapy.