Patent Foramen Ovale Closure Versus Medical Therapy for Cryptogenic Ischemic Stroke

A Narrative and Critical Review of Randomized-Controlled Clinical Trials on Patent Foramen Ovale Closure for Reducing the Risk of Stroke Recurrence

Patent foramen ovale (PFO) is a common cardiac anatomic variant that has been increasingly found in young (<60 years) cryptogenic stroke patients. Despite initial neutral randomized-controlled clinical trials (RCTs), there have been four recent RCTs providing consistent data in favor of the efficacy and safety of PFO closure compared to medical therapy for secondary stroke prevention. However, taking into consideration the high prevalence of PFO, the low risk of stroke recurrence under medical treatment and the uncommon yet severe adverse events of the intervention, patient selection is crucial for attaining meaningful clinical benefits. Thorough workup to exclude alternative causes of stroke and identification of high-risk PFOs through clinical, neuroimaging and echocardiographic criteria are essential. Cost effectiveness of the procedure cannot be proven for the time being, since there are no robust data on clinical outcome after PFO-associated stroke but only limited anecdotal data suggesting low risk for long-term disability.

Reprint of : Transcatheter closure of patent foramen ovale to prevent stroke recurrence in patients with otherwise unexplained ischaemic stroke: Expert consensus of the French Neurovascular Society and the French Society of Cardiology

BACKGROUND

Unlike previous randomized clinical trials (RCTs), recent trials and meta-analyses have shown that transcatheter closure of patent foramen ovale (PFO) reduces stroke recurrence risk in young and middle-aged adults with an otherwise unexplained PFO-associated ischaemic stroke.

AIM

To produce an expert consensus on the role of transcatheter PFO closure and antithrombotic drugs for secondary stroke prevention in patients with PFO-associated ischaemic stroke.

METHODS

Five neurologists and five cardiologists with extensive experience in the relevant field were nominated by the French Neurovascular Society and the French Society of Cardiology to make recommendations based on evidence from RCTs and meta-analyses.

RESULTS

The experts recommend that any decision concerning treatment of patients with PFO-associated ischaemic stroke should be taken after neurological and cardiological evaluation, bringing together the necessary neurovascular, echocardiography and interventional cardiology expertise. Transcatheter PFO closure is recommended in patients fulfilling all the following criteria: age 16-60 years; recent (≤6 months) ischaemic stroke; PFO associated with atrial septal aneurysm (>10mm) or with a right-to-left shunt>20 microbubbles or with a diameter≥2mm; PFO felt to be the most likely cause of stroke after thorough aetiological evaluation by a stroke specialist. Long-term oral anticoagulation may be considered in the event of contraindication to or patient refusal of PFO closure, in the absence of a high bleeding risk. After PFO closure, dual anti-platelet therapy with aspirin (75mg/day) and clopidogrel (75mg/day) is recommended for 3 months, followed by monotherapy with aspirin or clopidogrel for≥5 years.

CONCLUSIONS

Although a big step forward that will benefit many patients has been taken with recent trials, many questions remain unanswered. Pending results from further studies, decision-making regarding management of patients with PFO-associated ischaemic stroke should be based on a close coordination between neurologists/stroke specialists and cardiologists.

Impact of contrast-enhanced transcranial Doppler ultrasound diagnosis for young adult with cryptogenic stroke: A protocol of systematic review

BACKGROUND

This study aims to assess the impact of contrast-enhanced transcranial Doppler ultrasound (cTCD) diagnosis for young adult with cryptogenic stroke (CS).

METHODS

This study will analyze data from case-controlled studies investigating the impact of cTCD diagnosis for young adult with CS. A comprehensive literature search will be performed from PUBMED, EMBASE, Cochrane Library, Web of Science, Cumulative Index to Nursing and Allied Health Literature, Chinese Biomedical Literature Database, China National Knowledge Infrastructure, and Wanfang Data from their inceptions up to the August 1, 2019. All databases will be searched with no language limitations. Two researchers will independently carry out study selection, data collection, and study quality assessment. Any discrepancies between two researchers will be solved by a third researcher. We will apply RevMan 5.3 software and Stata 12.0 software for statistical analysis.

RESULTS

Outcomes consist of sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio for determination of cTCD diagnosis for young adult with CS.

CONCLUSION

The results of this study may summarize up-to-date evidence of cTCD diagnosis for young adult with CS.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42019145641.

Transcatheter closure of patent foramen ovale to prevent stroke recurrence in patients with otherwise unexplained ischaemic stroke: Expert consensus of the French Neurovascular Society and the French Society of Cardiology

BACKGROUND

Unlike previous randomized clinical trials (RCTs), recent trials and meta-analyses have shown that transcatheter closure of patent foramen ovale (PFO) reduces stroke recurrence risk in young and middle-aged adults with an otherwise unexplained PFO-associated ischaemic stroke.

AIM

To produce an expert consensus on the role of transcatheter PFO closure and antithrombotic drugs for secondary stroke prevention in patients with PFO-associated ischaemic stroke.

METHODS

Five neurologists and five cardiologists with extensive experience in the relevant field were nominated by the French Neurovascular Society and the French Society of Cardiology to make recommendations based on evidence from RCTs and meta-analyses.

RESULTS

The experts recommend that any decision concerning treatment of patients with PFO-associated ischaemic stroke should be taken after neurological and cardiological evaluation, bringing together the necessary neurovascular, echocardiography and interventional cardiology expertise. Transcatheter PFO closure is recommended in patients fulfilling all the following criteria: age 16-60 years; recent (≤6 months) ischaemic stroke; PFO associated with atrial septal aneurysm (>10mm) or with a right-to-left shunt>20 microbubbles or with a diameter≥2mm; PFO felt to be the most likely cause of stroke after thorough aetiological evaluation by a stroke specialist. Long-term oral anticoagulation may be considered in the event of contraindication to or patient refusal of PFO closure, in the absence of a high bleeding risk. After PFO closure, dual anti-platelet therapy with aspirin (75mg/day) and clopidogrel (75mg/day) is recommended for 3 months, followed by monotherapy with aspirin or clopidogrel for≥5 years.

CONCLUSIONS

Although a big step forward that will benefit many patients has been taken with recent trials, many questions remain unanswered. Pending results from further studies, decision-making regarding management of patients with PFO-associated ischaemic stroke should be based on a close coordination between neurologists/stroke specialists and cardiologists.

Management of Patients with Patent Foramen Ovale and Cryptogenic Stroke: An Update

Patent foramen ovale (PFO) is a common benign finding in healthy subjects, but its prevalence is higher in patients with stroke of unclear cause (cryptogenic stroke). PFO is believed to be associated with stroke through paradoxical embolism, and certain clinical and anatomical criteria seem to increase the likelihood of a PFO to be pathological. Recent trials have shown that closure of PFO, especially if associated with an atrial septal aneurysm and/or a large interatrial shunt, may reduce the risk of recurrent stroke as compared to medical treatment. However, it remains challenging to risk stratify patients with suspected PFO-related stroke and to decide if device closure is indicated. We sought to review contemporary evidence and to conclude an evidence-based strategy to prevent recurrence of PFO-related stroke.

Patent foramen ovale and embolic cryptogenic stroke

The paper considers the actual problem of cryptogenic stroke and patent foramen ovale (PFO). It highlights the issues of pathogenesis and role of paradoxical embolism in the development of cerebral circulation disorders. The features of clinical manifestations and neuroimaging pattern of stroke in the presence of PFO are described. Ultrasound diagnostic techniques used to verify a cardiac anomaly are characterized. Approaches to establishing a cause-and-effect relationship between the presence of PFO and the development of stroke are presented. The current possibilities of secondary prevention in this category of patients, in particular the results of studies of percutaneous PFO occlusion, are discussed.

Epidemiology, aetiology, and management of ischaemic stroke in young adults

Epidemiological evidence suggests that the incidence of ischaemic stroke in young adults (18-50 years) has increased substantially. These patients have a long life expectancy after stroke, and the costs of long-term care pose huge challenges to health-care systems. Although the current recommendations for treatment of young and old (>50 years) patients with stroke are similar, the optimal management of young adult patients with stroke is unknown. They are usually not included in trials, and specific subanalyses limited to young adult patients with stroke are usually not done, owing to lower incidence of stroke and lower prevalence of vascular risk factors in young adults. Progress has been made in identifying patients with a considerable risk of stroke occurrence, such as those with patent foramen ovale. Future prevention studies might result in a decrease in the incidence of stroke and its sequelae in young adults. The development of guidelines specifically devoted to the management of stroke in young adults will be an important step in achieving this aim.

Device Closure of Patent Foramen Ovale for Cryptogenic Stroke: Patient Selection and Outcomes According to New Randomized Trials

PURPOSE OF REVIEW

This review summarizes the most recent randomized clinical trials that studied the role of device-mediated patent foramen ovale (PFO) closure in patients after an ischemic stroke presumed to have been caused by a paradoxical embolism.

RECENT FINDINGS

Three major randomized trials published in 2017 studied the strategy of using PFO closure for secondary prevention in patients between the ages of 18 and 60 who presented with an index stroke having characteristics of an embolic mechanism. All patients had a PFO that potentially could have enabled paradoxical embolism and other causes of stroke were excluded by a thorough neurologic and cardiac evaluation. Patients were randomized to PFO closure versus medical therapy alone using a variety of guideline-recommended medications. After multiple years of follow-up, all three trials showed superiority in the device arm versus the medical arm with a relative risk reduction of recurrent stroke from 46 to 100% and an absolute recurrent stroke reduction from 0.49 to 1.32% per year. Complications related to the procedure and the device were infrequent and mostly transient. These results have transformed the care of these patients, lead to FDA approval of two PFO closure devices, and started the process of updating guidelines. Patient selection is critically important since the presence of a PFO may be incidental. Therefore, both a neurologist and a cardiologist, who can also perform this procedure safely and effectively, should complete the initial evaluation and discuss their findings and recommendations with the patient as part of a shared decision-making process. There are remaining questions regarding how these trial results relate to older patients, patients with overt venothrombotic disease, and those with thrombophilia.

[Closure of the patent foramen ovale (PFO) in cryptogenic stroke]

Autopsy studies and echocardiographic investigations have shown that around 20-25% of the healthy population have a patent foramen ovale (PFO). In patients younger than 55 years the risk of a cryptogenic stroke is increased in the presence of a PFO. The first three randomized studies could not demonstrate superiority of an interventional closure of a PFO compared to antithrombotic treatment in patients with cryptogenic stroke. The results of three recently published studies and the extension of an earlier study showed a superiority of an interventional closure of a PFO compared to stroke prevention with antiplatelet therapy in patients aged 18-60 years after a cryptogenic stroke; however, PFO closure was not superior to oral anticoagulation but anticoagulation is associated with an increased risk of bleeding. The implantation of a PFO occluder can be associated with transient atrial fibrillation in some patients. The collaboration of neurologists and cardiologists is essential in order to select patients who are most likely to benefit from a PFO closure.

Cryptogenic stroke and patent foramen ovale (abridged and translated version)

Interventional patent foramen ovale (PFO) closure should be performed in patients aged 16 to 60 years (after extensive neurological and cardiological diagnostic work-up) with a history of cryptogenic ischaemic stroke and patent foramen ovale, with moderate or extensive right-to-left shunt. In patients with cryptogenic ischaemic stroke and patent foramen ovale, who reject a PFO closure, there is no evidence of superiority of oral anticoagulation over antiplatelet therapy. Therefore, secondary prevention should be performed with aspirin or clopidogrel. Atrial fibrillation, pericardial tamponade, and pulmonary embolism are reported complications during and after implantation of an occluder. However, these events are so rare that they should not influence the recommendation for implantation. This article is an abridged and translated version of the guideline published in Nervenarzt: Diener, HC., für die Deutsche Gesellschaft für Neurologie (DGN), Grau, A.J. et al. Nervenarzt (2018) 89: 1143. 10.1007/s00115-018-0609-y.

Cryptogenic stroke - How to make sense of a non-diagnostic entity

Secondary preventive strategies in ischaemic stroke depend on the underlying aetiology. However, approximately one-third of ischaemic strokes remain unexplained, or 'cryptogenic'. There is a wide range of possible underlying causes in cryptogenic stroke, and the best approach to secondary prevention of these may differ. To date, though, the widely accepted and uniform secondary preventive strategy in this group consists of modification of vascular risk factors, and of treatment with a combination of antiplatelet therapy and antihypertensive and lipid-lowering medication. Among the potential causes for cryptogenic stroke are occult atrial fibrillation, patent foramen ovale, atrial cardiopathy, aortic arch atheroma and hypercoagulable states. While it is possible to diagnose these conditions, in individual patients there is often uncertainty over whether they have a directly causative role, are markers of disease, or are innocent bystanders. Similarly, even if the cause is found, the best secondary preventive strategies remain uncertain, which questions the benefit of extensive investigations in a clinical setting. More recently, the concept of "embolic stroke of unknown source (ESUS)" has been introduced, in the hope that anticoagulation may offer better secondary prevention than antiplatelet therapy, but trials so far have been negative. At present, there is little justification for introducing extensive new investigative strategies into the management of patients with cryptogenic stroke. Investigations should be targeted at identifying those high-risk conditions which lead to a change in management. Further investigations need to be tailored individually, according to clinical circumstances. This should include identifying patients for participation in clinical trials, as the significance and best management of many of the potential causes for cryptogenic stroke require further research.

Patent Foramen Ovale: Story Closed?

The optimal treatment strategy for secondary prevention in patients with cryptogenic stroke and patent foramen ovale (PFO) has been a matter of controversy for decades. After three randomized trials failed to show a benefit of closure with an excess of complications in the interventional arm, two large recent trials suggest a benefit with regard of preventing further ischemic strokes. With this discrepancy in results it is important to discuss recent trials in detail and evolve an informed clinical approach for daily practice.

Closure of Patent Foramen Ovale and Cryptogenic Stroke: Unresolved Issues

PURPOSE OF REVIEW

This review summarises the results of randomised trials comparing closure of patent foramen ovale (PFO) with antithrombotic therapy in patients with cryptogenic stroke.

RECENT FINDINGS

Initially, three randomised trials failed to show superiority of PFO closure over antithrombotic therapy in patients with cryptogenic stroke. Three recently performed trials and the prolongation of an earlier trial provided evidence that PFO closure in patients with cryptogenic stroke and an age range of 18-60 years is superior to stroke prevention with antiplatelet therapy. PFO closure was not superior to anticoagulation. Anticoagulation, however, has a higher long-term bleeding risk. PFO closure could result in atrial fibrillation (AF) in a small number of patients. In most patients, AF was transient in duration. Optimal patient selection requires future research. In patients with cryptogenic stroke aged &lt; 60 years, PFO closure is superior to antiplatelet therapy in the prevention of recurrent stroke.