Patent Foramen Ovale Closure in Obstructive Sleep Apnea Improves Blood Pressure and Cardiovascular Function

Abstract

O bstructive sleep apnea (OSA) is characterized by intermittent hypoxemia and associated with increased prevalence of vascular dysfunction and arterial hypertension, but the underlying mechanisms are incompletely understood.1 In OSA, apneas are related to excessive throat muscle relaxation with consequent inspiratory efforts against the closed glottis, finally resulting in the patient's arousal associated with sympathetic activation and hyperventilation. The hyperventilation, in turn, contributes to the next apnea by reducing the arterial partial pressure of CO 2 toward the apnea threshold. In this scenario, arterial oxygen desaturation plays a pivotal role by narrowing the gap between the eupneic and apneic CO 2 pressure level, thereby rendering the CO 2 -controlled breathing regulation more unstable and, thus, prone to periodic breathing. 2In patients with OSA, the presence of patent foramen ovale (PFO) is associated with a marked increase in the frequency and severity of nocturnal oxygen desaturations.3 This could be related, at least in part, to right to left shunting across a PFO, as evidenced by invasive hemodynamic measurements in healthy humans, demonstrating that during the onset of simulated OSA, the right atrial pressure exceeds left atrial pressure in response to the steep decline in intrathoracic pressure. 4 Improvement of arterial oxygen saturation by PFO closure may prevent this problem.We recently reported preliminary findings showing that PFO closure in patients with newly diagnosed OSA was associated with a reduction of nocturnal apnea-hypopnea events and oxygen desaturations and decreased pulmonary artery pressure.5 Moreover, circumstantial evidence shows that intermittent hypoxia is associated with systemic endothelial dysfunction and arterial hypertension. 6,7 In line with these observations, systemic endothelial function is impaired in OSA patients without any traditional cardiovascular risk factors.8 Systemic endothelial dysfunction precedes the development of arteriosclerosis and contributes to the pathogenesis of arterial hypertension.9 Accordingly, the prevalence of arterial Abstract-Obstructive sleep apnea (OSA) is a frequent syndrome characterized by intermittent hypoxemia and increased prevalence of arterial hypertension and cardiovascular morbidity. In OSA, the presence of patent foramen ovale (PFO) is associated with increased number of apneas and more severe oxygen desaturation. We hypothesized that PFO closure improves sleep-disordered breathing and, in turn, has favorable effects on vascular function and arterial blood pressure. In 40 consecutive patients with newly diagnosed OSA, we searched for PFO. After initial cardiovascular assessment, the 14 patients with PFO underwent initial device closure and the 26 without PFO served as control group. Conventional treatment for OSA was postponed for 3 months in both groups, and polysomnographic and cardiovascular examinations were repeated at the end of the follow-up period. PFO closure significantly improved the apnea-hypopnea index ...

Cardiovascular magnetic resonance assessment of acute cardiovascular effects of voluntary apnoea in elite divers

“…Patent foramen ovale has been demonstrated to have a higher prevalence in patients with obstructive sleep aponoea compared to healthy controls, and is suspected to inrease nocturnal oxygen desaturation in these patients [ 42 ] and to enhance other pathologic conditions associated with OSA [ 43 ]. In both scuba and apnoea divers knowledge about the implications of a patent foramen ovale regarding incidence and severity of decompression sickness is scarce [ 44 ], especially because it is unkown if recurrent decompression sickness is a result of a patent foramen ovale, the inabiliy to adopt a more conservative diving style, or both [ 45 ].…”

Sleep apnoea and pulmonary hypertension in high-altitude dwellers: more than an association?

“…Searching for the presence of a PFO by transoesophageal echocardiography, which is possible under field conditions, could have been not only of mechanistic but also of therapeutic importance in this high-altitude population living under remote conditions, among which classical treatment of sleep-disordered breathing with continuous positive airway pressure (CPAP) therapy might not be possible for technical reasons. Indeed, in analogy to recent observations in patients with sleep apnoea syndrome at low altitude [3], it appears possible that PFO closure may attenuate pulmonary (and systemic) hypertension and improve sleep-disordered breathing in Kyrgyz high-altitude dwellers.…”

Patent foramen ovale and atrial fibrillation as causes of cryptogenic stroke: is treatment with surgery superior to device closure and anticoagulation? A review of the literature

“…A recent retrospective longitudinal multicenter study of 199 patients, “DysrhythmiAs in patieNts with congenitAl heaRt diseAse” (DaNaRA), demonstrated that patients with congenital heart disease, particularly patients with complex defects, develop AF at a young age and progress frequently from paroxysmal AF to (long-standing) persistent/permanent AF ( 91 ). Sixteen patients (8%) experienced a cerebrovascular event 14 ( 2 – 33 ) years before the first documented AF. The total incidence of TIA/stroke in the population was 13%.…”

“…The Paradoxical Emboli from Large Veins in Ischemic Stroke (PELVIS) study confirmed that patients with cryptogenic stroke have an increased prevalence (20%) of pelvic deep venous thrombosis ( 8 ). Cryptogenic stroke also seems to be associated with vigorous or strenuous exercise, decompression illness, sneezing, coughing, obstructive sleep apnea, and even migraine ( 9 – 17 ).…”