Nocturnal Hypoxemia, But Not Sleep Apnea, Is Associated With a Poor Prognosis in Patients With Pulmonary Arterial Hypertension

Abstract

Study Subjects The retrospectively enrolled subjects were 151 patients with PAH in the Nice Classification group 1 who were admitted for routine hemodynamic follow-up and were screened for SDB from April 2008 through February 2010 (37 males, 114 females; 44±16 years old). The mean PAP (mPAP) was 46±16 mmHg, and PVR was 12±9 Wood units. Patients with a total sleep time <3 h in the sleep studies were excluded. PAH was defined by right-heart catheterization (RHC) as mPAP ≥25 mmHg with a pulmonary artery wedge pressure (PAWP) <15 mmHg. They were classified, on the basis of the Nice Classification; into idiopathic PAH (IPAH; n=78) and associated PAH (n=73) (52% and 48 %, respectively). There were 6 patients with Eisenmenger syndrome in the associated PAH group. Assessments Serum hemoglobin (Hb) and B-type natriuretic peptide S leep apnea (SA) can cause repeated nocturnal arterial oxygen desaturation, sleep fragmentation, increased sympathetic activity, oxidative stress, inflammation and endothelial dysfunction, negative swings in intrathoracic pressure, and acute increase in pulmonary arterial pressure (PAP). 1-5 Pulmonary vasoconstriction occurs in response to alveolar hypoxia, then increased pulmonary vascular resistance (PVR), contributing to an increase in PAP and resulting in pulmonary vascular remodeling. 6,7 Sleep-disordered breathing (SDB) in patients with pulmonary arterial hypertension (PAH), which comprises not only SA, but also periodic breathing and nocturnal hypoxemia, is common. 8-14 Many studies show that the presence of SA is associated with a poor prognosis in patients with left-sided heart failure, 15,16 but the effect of nocturnal hypoxemia and SA on the outcome of patients with PAH is unknown. The objective of the present study, therefore, was to determine whether nocturnal hypoxemia and/or SA is associated with prognosis in PAH patients.

Impact of obstructive sleep apnea on pulmonary hypertension in patients with chronic obstructive pulmonary disease

“…[39] Most studies have found that OSA-induced PH was mild to moderate, and some studies have challenged the effect of AHI on PH. [11,12,37,40] Few studies have focused on PH in patients with COPD with OSA. The coexistence of OSA may have a synergistic adverse effect on pulmonary hemodynamics leading to right ventricular dysfunction in patients with COPD.…”

Hypoxemia during sleep and overnight rostral fluid shift in pulmonary arterial hypertension: a pilot study

“…In a retrospective study on 151 patients with PAH, Nagaoka et al report that 31 (21%) had hypoxemia during sleep, with an increased mortality rate. 10 Hypoxemia during sleep in PAH may promote hypoxic pulmonary vasoconstriction, enhance PVR and pulmonary vascular remodeling, as observed in pulmonary hypertension due to hypoxia (group 3). 35 Moreover, hypoxemia might trigger inflammation-driven vascular remodeling, with elevated circulating tumor necrosis factor-alpha levels, as observed in chronic thromboembolic pulmonary hypertension.…”

“…1 Sleep-related breathing disorders, including sleep apnea (obstructive and central) and hypoxemia during sleep, are common in PAH. [2][3][4][5][6][7][8][9][10] Previous studies included patients with different etiologies, severities of PAH, and clinical characteristics, and did not use a uniform definition for sleep-related breathing disorders. The reported prevalence of sleep apnea in PAH is therefore variable, from 5 to 89%.…”

“…4,7 The most frequent sleep-related breathing disorder in PAH is hypoxemia during sleep, with a prevalence ranging from 21 to 83%, 2,[5][6][7]9 that has been recently associated with a poorer patients' prognosis. 10 However, the underlying mechanism of sleep-related breathing disorders in PAH remains to be fully clarified. Overnight rostral fluid shift from the legs to the upper part of the body promotes sleep apnea in several fluid retaining states, like sedentary lifestyle, 11 drug-resistant hypertension, 12 chronic heart failure, 13 end-stage renal failure, 14 and chronic venous insufficiency.…”

Significant Clinical Indexes of Exercise-Induced Pulmonary Hypertension in Patients With Connective Tissue Disease

“…PH is a hemodynamic and pathophysiological state involving an elevation in mean pulmonary artery pressure (PAP) ≥25 mmHg at rest on right heart catheterization (RHC). 5,6 Despite RHC being a gold standard to diagnose PH, it is an invasive examination and is difficult to perform in all patients with CTD. Thus, echocardiography at rest is the leading modality for screening PH and is used to estimate the systolic PAP (SPAP) based on tricuspid regurgitation pressure gradient on echocardiography.…”