Patent Foramen Ovale and Cryptogenic Stroke: A Matter of Age?

Abstract

A patent foramen ovale (PFO) enables a right-to-left shunt in about a quarter of the population. The marked association between cryptogenic stroke and PFO supports the hypothesis that paradoxical embolism could be a relevant cause of stroke. Although this association has been described in several studies for patients <55 years of age, only limited data are available on the role of PFO in older patients. Recent studies, however, have also shown a significant association between cryptogenic stroke and PFO in patients >55 years of age. The relationship is especially marked in the presence of atrial septum aneurysm (ASA). This finding is in accordance with previous reports indicating that PFO and concomitant ASA is a high-risk feature. Factors promoting paradoxical embolism, such as deep vein thrombosis (DVT) and elevated right-heart pressure, are more frequently encountered in older than in younger patients. Independent of age, contrast-enhanced transthoracic and transesophageal echocardiography are the methods of choice for the detection and imaging of PFO and atrial septal aneurysm. Transcranial Doppler can be used as a screening method in patients with cryptogenic stroke to detect a right-to-left shunt. Proof of DVT strongly supports the suspicion of paradoxical embolism and should lead to oral anticoagulation. If paradoxical embolism is suspected without proof of DVT, both drug therapy with aspirin or warfarin and percutaneous closure of the PFO are available as therapeutic options. Recent studies have shown that percutaneous closure can be performed safely and with a low rate of recurrence both in older and younger patients. Thus far, however, there is no clear-cut evidence of superiority for either therapeutic strategy.

Percutaneous closure of the patent foramen ovale: A cardiological perspective

“…(27)(28)(29)(30) Although this association with stroke has been more convincingly established in patients younger than 55 years of age, recent studies have also demonstrated significant associations in older patients. (13,28,31,32) In addition, a recent publication illustrated that the co-existence of a PFO with atrial septal aneurysm play an important pathogenic role in the severity of white matter lesions in these patients (odds ratio 2.4; 95% CI: 1.11-5.17) compared to stroke patients without septal abnormalities (p = 0.026).…”

Patent Foramen Ovale and Stroke: Should PFOs Be Closed in Otherwise Cryptogenic Stroke?

“…Transesophageal echocardiography (TEE) is generally considered the reference standard for diagnosis of PFO, using two-dimensional B-mode echocardiography, or color Doppler [10]. A contrast agent, usually saline agitated with air to produce microbubbles is also used, allowing direct visualization of the PFO and atrial septum, and quantification of shunting both at rest and during Valsalva maneuver.…”

“…Transthoracic echocardiography may also be used to detect PFO, particularly in conjunction with injected contrast and Valsalva maneuver, but earlier studies reported relative sensitivities for detection of PFO of only 30% to 50%. However, more recent studies with improved technology have reported sensitivities of 90% or more [10,12]. Finally, transcranial Doppler may also be used to detect evidence of right-to-left shunting via a PFO, by detecting the embolic signals of microbubbles in the middle cerebral artery after a contrast injection with or without Valsalva maneuver.…”

Percutaneous Patent Foramen Ovale Closure versus Medical Therapy in Cryptogenic Stroke: An Update Meta-Analysis of Randomized Controlled Trials

“…The cause of stroke without identifiable aetiology in PFO patients might be paradoxical thromboembolism [3]. Epidemiologic study has found a significant association between PFO and cryptogenic stroke both in the younger and older patients [3] [4]. It was reported that the incidence of stroke recurrence in PFO patients after medical therapy within a four-year follow-up period was approximately 25% [5].…”