Patent foramen ovale (PFO) and cryptogenic stroke

Abstract

To cite this article: Anzola GP, Giusti del Giardino L, Piras MP. Patent foramen ovale (PFO) and cryptogenic stroke. J Thromb Haemost 2010; 8: 1675-7.Julius Cohnheim, a German pathologist, is credited, in 1877, as the first to hypothesize that the failed closure after birth of the foramen ovale (the interatrial opening that allows the oxygenated blood from the placenta to bypass the non-functioning pulmonary circulation and enter the fetal systemic circulation) might underlie the spreading of venous emboli to the brain. However, although commonly accepted as a possible cause of stroke, paradoxical embolism was believed to merely represent a medical curiosity up until the end of the 1980s when, due to the advancement of echocardiography, it was recognized that the patency of the foramen ovale (PFO) was two to three times more frequent in patients with strokes of otherwise unknown cause (i.e. cryptogenic) than in healthy controls or in patients with stroke of known etiology [1]. The echocardiographic demonstration, in single case reports, of thrombi trapped across the foramen provided the evidence that emboli of venous origin may be able to bypass the pulmonary filter and enter the systemic circulation across the PFO, and so represent a risk factor for stroke [2].Recent meta-analyses of case-control studies have confirmed that the likelihood of cryptogenic stroke patients with a PFO is about three times that of controls [1,3,4] (Table 1). More recently, Alsheik et al. applied the Bayes theorem to the available data to ascertain the probability of PFO being incidental in a patient with cryptogenic stroke. They came to the conclusion that PFO may represent an incidental finding in 33-48% of cryptogenic strokes when in isolation, but only in 11% when associated with bulging of the interatrial wall (so called atrial septal aneurism -ASA). These figures drop to 20% and 9%, respectively, in patients less than 55 years old [5].Similarly, a prospective study conducted in France on the risk of recurrence in young patients with cryptogenic stroke [6] showed that, compared with patents with no atrial septal abnormalities, the PFO-ASA association conveyed a 4-fold risk of relapse (hazard ratio 4.17, 95% CI 1.47-11.84).That PFO may enhance the risk of getting brain emboli has been further elegantly shown by a recent prospective study that identified, by logistic regression analysis, PFO was found to be an independent predictor of silent brain infarction with an OR of 34.9 (95% CI 31-394.3, P = 0.004) [7].The difficulty in identifying those with truly cryptogenic stroke amongst aged patients (due to the frequent cooccurrence of vascular risk factors) probably explains why PFO was only marginally associated with stroke in patients aged over 55 years in older studies [1]. Recent evidence, however, strongly suggests that PFO is over-represented in cryptogenic strokes irrespective of the age of occurrence [4]. To mitigate the perception that PFO is a dangerous mate, two population-based studies both failed to identify PFO as an ind...

A comparison of contrast transthoracic echocardiography and contrast transcranial Doppler in cryptogenic stroke patients with patent foramen ovale

“…Patent foramen ovale (PFO) arises when children older than 3 years do not have their foramen ovale closed. Approximately 10%–35% of adults have a PFO in the general population, but the frequency is even higher in cryptogenic stroke (CS) patients (Anzola, Giusti Del Giardino, & Piras, ; Belvis et al, ; Katsanos et al, ; Souteyrand et al, ; Yue, Zhai, & Wei, ). Since the PFO shunt is too small, PFO had long been considered a nonserious clinical presentation (Hara et al, ; Zhao, Cheng, Zhang, Li, & Wang, ).…”

“…In recent years, however, increasing studies have shown that PFO patients have a higher morbidity of stroke, migraines, and other relevant diseases than normal population. Hence, more attention has been paid in particular to the relationship between PFO and CS (Anzola et al, ; Handke et al, ; Thaler & Wahl, ).…”

Supranational (international) guidelines for management of the heart structural anomalies

“…Значимо возрастает клиническая значимость АМПП при ООО, сети Киари, удлиненном ЕК [52,104,105]. Данные о взаимосвязи АМПП и ПМК многочисленны, но неоднозначны [101,106,107,108,109,110,111].…”

“…Изолированное ООО встречается реже, чем в сочетании с АМПП [104]. В 70 % случаев ООО сочетается с ЕК [150] и в 83 % -с сетью Киари [120].…”

Management of patients with patent foramen ovale and cryptogenic stroke: A collaborative, multidisciplinary, position paper

“…Observational studies have identified several anatomic and clinical factors associated with PFO that may increase the likelihood that PFO is the cause of the primary or recurrent stroke (Fig. —bottom).…”