Characteristics Of Patients With Pulmonary Hypertension And Sleep-disordered Breathing

Objects:Sleep-disordered breathing(SDB)like OS A(obstructive sleep apnea)are causes and complications of pulmonary hypertension.SDB could cause many cardiovascular diseases and link to poor prognosis of patients.There are controversies about reasonable diagnosis and treatment of SDB in patients of pulmonary hypertension.This study is to investigate the incidence and the clinical characteristics of SDB inpatients with pulmonary hypertension,to observe the treatment effect in patients with OSA and severe pulmonary hypertension and to explore reasonable therapy of this disease.Methods:Between December 2014 and December 2017,a total of 154 patients with pulmonary hypertension were prospectively examined using a sleep apnea monitoring system after undergoing right cardiac catheterization at our institution.Results of common clinical examine and demographic parameters of right cardiac catheterization,cardiopulmonary exercise test,six-minute walking distance were recorded and analyzed to compare differences between patients with and without OSA or nocturnal oxygen desaturation.19 patient with OSA and severe pulmonary hypertension accepted re-examination in median time of 3.27 months,to compare the difference between before and after treatment.The correlation analysis and linear-regression analysis were done to evaluate relationship between OSA,AHI,nocturnal oxygen desaturation,time of nocturnal oxygen desaturation and cardiac index,concentration of NT-proBNP and six-minute walking distance.Results:Among 154 participants,68(44.16%)patients are diagnosed with long-term nocturnal hypoxia,45(29.22%)with OSA and mean AHI is 15.92/h.There are 10 OSA in 20 CTEPH patients and 28 OSA in 32 pulmonary hypertension due to lung disease and/or hypoxia patients.There are 2 OSA,2 OSA and 3 OSA in pulmonary hypertension due to connective tissue disease,pulmonary hypertension due to congenital heart disease and pulmonary hypertension due to other reasons patients separately.OSA is prevalent in patients with chronic thromboembolic pulmonary hypertension(CTEPH)and pulmonary hypertension due to lung disease and/or hypoxia;this difference in prevalence is significant.Patients with OSA were older,predominantly male and presented a higher body mass index.Patients with OSA had lower arterial partial pressure of oxygen,longer nocturnal hypoxia time,higher concentration of NT-proBNP,lower PeakV02(corrected by weight),and a lower cardiac index than patients without OSA,Patients with nocturnal long-term hypoxia had older age,lower arterial partial pressure and saturation of oxygen,shorter 6-minute walking distance and lower PeakVO2(corrected by weight)than patients without nocturnal long-term hypoxia.OSA and higher AHI are not risk factors of higher concentration of NT-proBNP and shorter 6-minute walking distance.Time of nocturnal hypoxia is a risk factor of shorter 6-minute walking distance and lower peak V02.The longer time of nocturnal hypoxia is,the shorter 6-minute walking distance and lower peak V02 are.After accepted treatment,14 severe pulmonary hypertension patients with mild OSA got lower diastolic blood pressure,longer 6-minute walking distance,higher VE/VCO2 while this result are not sure in severe pulmonary hypertension patients with moderate or severe OSA.Conclusions:Nocturnal hypoxia and OSA are prevalent among patients with pulmonary hypertension.Old age,high body mass index and male gender are risk factors of OSA in patients with pulmonary hypertension.Nocturnal oxygen desaturation is a risk factor of shorter six-minute walking distance and lower peakVO2.Therapy of pulmonary vasodilators and CPAP could improve concentration of NT-proBNP and six-minute walking distance in mild OSA with severe pulmonary hypertension,but cannot be seen in patients with moderate or severe OSA.Above all,sleep apnea monitoring should be examined in patients of pulmonary hypertension to know whether sleep apnea and nocturnal hypoxia exists.Reasonable diagnosis and therapy of severe pulmonary with OSA should be further investigated.