Long-term cerebrovascular outcomes of patients undergoing percutaneous patent foramen ovale closure in observational studies: a systematic review and meta-analysis

OBJECTIVES

Patent foramen ovale (PFO) closure is recommended for patients who experience a cryptogenic stroke attributable to PFO. Although few randomized control trials (RCTs) have captured long-term effectiveness of PFO closure, observational data has been abundant. This is the first systematic review of observational studies determining incidence of long-term adverse outcomes in adults who underwent transcatheter PFO closure, with comparisons to findings from RCTs.

METHODS

Medline, Cochrane, and Embase databases were searched from inception to October 2023. Only observational studies with ≥4 years of mean or median follow-up were included. A meta-analysis was conducted to calculate the incidence of recurrent stroke after PFO closure.

RESULTS

After reviewing 2,432 records, 13 prospective and 12 retrospective cohort studies were included. Average follow-up lengths ranged from 4 to 12.3 years, and sample sizes from 75 to 1,533 participants. The average age ranged between 43.5-63.0, and 24.0-72.8% patients had an atrial septal aneurysm. The incidence of stroke was 0.34 per 100 person-years (I2 = 67%). This was similar to rates from four RCTs that were used for comparison (0.35 per 100 person-years, I2= 51%). There was a significant improvement in heterogeneity once the study with one of the largest follow-up was removed.

CONCLUSIONS

Real-world PFO closure studies with long-term follow-up report similar outcomes as RCTs which is important considering the exclusion of several important populations from trials. Future observational studies should include more rigorous reporting of follow-up strategies and explore different long-term adverse outcomes.

Congenital heart disease: types, pathophysiology, diagnosis, and treatment options

Congenital heart disease (CHD) is a structural abnormality of the heart and/or great vessels and patients with CHD are at an increased risks of various morbidities throughout their lives and reduced long-term survival. Eventually, CHD may result in various complications including heart failure, arrhythmias, stroke, pneumonia, and sudden death. Unfortunately, the exact etiology and pathophysiology of some CHD remain unclear. Although the quality of life and prognosis of patients with CHD have significantly improved following technological advancement, the influence of CHD is lifelong, especially in patients with complicated CHD. Thus, the management of CHD remains a challenge due to its high prevalence. Finally, there are some disagreements on CHD among international guidelines. In this review, we provide an update of the pathophysiology, diagnosis, and treatment in most common type of CHD, including patent foramen ovale, atrial septal defect, ventricular septal defect, atrioventricular septal defect, patent ductus arteriosus, coarctation of the aorta, transposition of the great arteries, congenitally corrected transposition of the great arteries, coronary anomalies, left and right ventricular outflow tract obstruction, tetralogy of Fallot and Ebstein anomaly. In particular, we focus on what is known and what is unknown in these areas, aiming to improve the current understanding of various types of CHD.

Percutaneous Patent Foramen Ovale Closure: Stroke and Beyond

Over 750,000 individuals suffer from stroke annually in the United States, with 87% of these strokes being ischemic in nature. Roughly 40% of ischemic strokes occur in individuals 60 years of age or under. A quarter of all ischemic strokes have no identifiable cause despite extensive workup and are deemed cryptogenic in nature. Patent Foramen Ovales (PFO) has been postulated in stroke causation by either paradoxical embolization or platelet activation in the tunnel of the defect. The incidence of PFO is reported to be 15-25% in the general population but rises to 40% in patients with cryptogenic stroke. While the initial trials evaluating PFO closures were non-revealing, subsequent long-term follow-ups, as well as recent trials evaluating PFO closures in cryptogenic stroke patients 60 years of age or under, demonstrated the superiority of percutaneous closure compared to medical therapy alone, leading to FDA approval of PFO closure devices. In this review, we review the diagnosis of PFO, postulated stroke mechanisms, literature supporting PFO closure, patient selection for percutaneous closure, procedural considerations, and associated procedural complications.

The Role of Echocardiography in the Assessment of the Interatrial Septum and Patent Foramen Ovale as an Emboligenic Source

A comunicação do septo atrial (CIA) representa, aproximadamente, de 6%-10% dos defeitos cardíacos congênitos, com incidência de 1 em 1.500 nascidos vivos.1 Forame oval patente (FOP) é mais comum e está presente em mais de 20%-25% dos adultos.2 Síndromes clínicas associadas a CIA e FOP são variáveis, com implicações abrangendo a medicina pediátrica e adulta, neurologia e cirurgia.

O interesse adicional na anatomia do septo interatrial (SIA) aumentou substancialmente nas últimas duas décadas, com evolução simultânea dos procedimentos percutâneos envolvendo cardiopatia estrutural do lado esquerdo e procedimentos eletrofisiológicos. Idealmente, essas intervenções baseadas em cateter requerem rota direta para o átrio esquerdo (AE) através do SIA, necessitando completo entendimento de sua anatomia. Atualmente, tecnologias de imagem sofisticadas e não invasivas como ecocardiografia transesofágica bidimensional (ETE 2D) e tridimensional (ETE 3D), ressonância cardíaca (RMC) e tomografia computadorizada (TC) passaram por um extraordinário desenvolvimento tecnológico, fornecendo detalhes anatômicos das estruturas cardíacas visualizadas em formato 2D e 3D e são essenciais para diagnóstico e tratamento de pacientes com doenças cardíacas.

A avaliação da anatomia e anormalidades do SIA, portanto, requer abordagem padronizada e sistemática, integrando modalidades diagnósticas e fornecendo avaliação adequada e uniforme para terapias cirúrgicas e transcateter.

Association of Shunt Size and Long-Term Clinical Outcomes in Patients with Cryptogenic Ischemic Stroke and Patent Foramen Ovale on Medical Management

INTRODUCTION

Patent foramen ovale (PFO) is a potential source of cardiac embolism in cryptogenic ischemic stroke, but it may also be incidental. Right-to-left shunt (RLS) size may predict PFO-related stroke, but results have been controversial. In this cohort study of medically-managed PFO patients with cryptogenic stroke, we aimed to investigate the association of shunt size with recurrent stroke, mortality, newly detected atrial fibrillation (AF), and to identify predictors of recurrent stroke.

METHODS

Patients with cryptogenic stroke who screened positive for a RLS using a transcranial Doppler bubble study were included. Patients who underwent PFO closure were excluded. Subjects were divided into two groups: small (Spencer Grade 1, 2, or 3; n = 135) and large (Spencer Grade 4 or 5; n = 99) shunts. The primary outcome was risk of recurrent stroke, and the secondary outcomes were all-cause mortality and newly detected AF.

RESULTS

The study cohort included 234 cryptogenic stroke patients with medically-managed PFO. The mean age was 50.5 years, and 31.2% were female. The median period of follow-up was 348 (IQR 147-1096) days. The rate of recurrent ischemic stroke was higher in patients with large shunts than in those with small shunts (8.1% vs. 2.2%, p = 0.036). Multivariate analyses revealed that a large shunt was significantly associated with an increased risk of recurrent ischemic stroke [aOR 4.09 (95% CI 1.04-16.0), p = 0.043].

CONCLUSIONS

In our cohort of cryptogenic stroke patients with medically managed PFOs, those with large shunts were at a higher risk of recurrent stroke events, independently of RoPE score and left atrium diameter.

Histology of Cerebral Clots in Cryptogenic Stroke Varies According to the Presence of a Patent Foramen Ovale

Although a pathophysiological impact remains difficult to prove in individual patient care, a patent foramen ovale (PFO) is currently considered of high relevance for secondary prophylaxis in selected patients with cryptogenic ischemic stroke. By quantification of histological clot composition, we aimed to enhance pathophysiological understanding of PFO attributable ischemic strokes. Retrospectively, we evaluated all cerebral clots retrieved by mechanical thrombectomy for acute ischemic stroke treatment between 2011 and 2021 at our comprehensive stroke care center. Inclusion criteria applied were cryptogenic stroke, age (≤60 years), and PFO status according to transesophageal echocardiography, resulting in a study population of 58 patients. Relative clot composition was calculated using orbit image analysis to define the ratio of main histologic components (fibrin/platelets (F/P), red blood cell count (RBC), leukocytes). Cryptogenic stroke patients with PFO (PFO+, n = 20) displayed a significantly higher percentage of RBC (0.57 ± 0.17; p = 0.002) and lower percentage of F/P (0.38 ± 0.15; p = 0.003) compared to patients without PFO (PFO–, n = 38) (RBC: 0.41 ± 0.21; F/P: 0.52 ± 0.20). In conclusion, histologic clot composition in cryptogenic stroke varies depending on the presence of a PFO. Our findings histologically support the concept that a PFO may be of pathophysiological relevance in cryptogenic ischemic stroke.

Risk of Perioperative Stroke in Patients with Patent Foramen Ovale: A Systematic Review and Meta-Analysis

BACKGROUND

Patent foramen ovale (PFO) is a common congenital cardiac abnormality. Risk of stroke increases perioperatively; however, the association of PFO with perioperative stroke risk remains unclear. We conducted a systematic review to inform the risk of perioperative stroke in patients with PFO undergoing surgery.

METHODS

EMBASE, MEDLINE, and Cochrane databases were searched from inception to January 2020. We described methods used for establishing PFO and perioperative stroke diagnosis. We conducted meta-analyses to obtain pooled estimates for risk of stroke in patients with and without PFO in different surgical populations.

RESULTS

Ten articles with a total of 20,858,011 patients met the eligibility criteria. Prevalence of PFO ranged from 0.06-1.4% based on ICD code diagnosis and 10.4-40.4% based on echocardiography diagnosis. Perioperative stroke was observed in 0-25% of patients with PFO, and 0-16.7% without PFO. Studies that use echocardiography to diagnose PFO found no association between PFO and perioperative stroke. Studies that used ICD codes, found strong association but were highly heterogenous. PFO was not associated with a risk of perioperative stroke in cardiac and transplant surgeries. While the adjusted odds ratios for stroke were substantial for orthopedic, general, genitourinary, neuro, and thoracic surgeries (with PFO status established based on ICD codes), data heterogeneity and quality of data create significant uncertainty.

CONCLUSION

In conclusion, PFO is likely a risk factor for perioperative stroke in select types of surgeries. However, this is based on a very low-quality evidence. Rigorous, prospective studies are needed to further investigate this relationship.

Percutaneous Patent Foramen Ovale Closure in Patients with Cryptogenic Stroke or Transient Ischemic Attack: A Retrospective Study

Background

Patent foramen ovale (PFO) is associated with cryptogenic stroke (CS). Transcatheter closure of PFO is superior to pharmacotherapy for patients with CS or transient ischemic attack (TIA). More evidence is needed to evaluate the efficacy and safety of PFO closure in Chinese patients.

Methods

This study enrolled ten CS patients and two TIA patients (mean age of 40.8 ± 9.7 y), including seven males (58%) and five females (42%) who underwent PFO closure in our center from January 2017 to July 2019. Baseline data, imaging data, and RoPE (Risk of Paradoxical Embolism) score were collected retrospectively. The preprocedural assessment and percutaneous transcatheter PFO closure were described in detail. The perioperative complications and follow-ups were recorded from all patients.

Results

Among ten patients with CS, eight patients had a RoPE score of >6 and two patients had a RoPE score of 6. MRI confirmed multiple infarcts in seven cases, and infarct involving the cortex in nine cases. Abnormal ECG was found in three patients and abnormal Echo in four patients. Right-to-left shunt (RLS) was detected in all the patients by cTCD or cTTE. To be specific, RLS was observed in nine of the ten TEE-detected patients. No case had PFO complicated with atrial septal aneurysm (ASA). The success rate of PFO closure was 91.6%. No serious perioperative complications were observed. During a mean time of 26.5 ± 8 months (15-41 months) of follow-up, no recurrent cerebral infarction, TIA, or thromboembolism were detected in postoperative patients.

Conclusions

PFO closure is safe and effective in the treatment of Chinese patients with CS or TIA.

Comparison of right-to-left shunt characteristics in cryptogenic embolic ischemic stroke and non-cardioembolic ischemic stroke

BACKGROUND

Patent foramen ovale (PFO) has been considered a potential mechanism of embolic stroke of undetermined origin.

OBJECTIVE

The aim of the present study was to identify the features of the right-to-left shunt (RLS) in patients with undetermined embolic ischemic stroke and compare them with those of patients with non-cardioembolic ischemic stroke.

METHODS

A retrospective study was conducted with 168 patients with stroke and RLS separated into the following two groups: the undetermined embolic stroke group (UES group) and non-cardioembolic stroke group (NCES group). All patients were assessed by transcranial Doppler to evaluate the presence and quantification of microembolic signals (MES) at rest and under Valsalva maneuver.

RESULTS

Of all patients evaluated in the current study, 96 were included in the UES group and 72 in the NCES group. In the UES group, 65 patients had RLS with ≥10 MES (67.7%), which was higher than that observed in the NCES group (51.4%, p=0.038). According to the moment of the cardiac cycle, 75 patients (78.1%) in the UES group had a positive test at rest compared to 42 (58.3%) in the NCES group (p=0.007).

CONCLUSIONS

The current study demonstrated that almost 70% of patients with undetermined embolic stroke and PFO presented a large RLS and more than 75% had RLS at rest. These findings suggest that the size of the shunt should be taken into account when evaluating whether PFO could be a possible mechanism underlying cryptogenic stroke.

Concomitant pulmonary embolism and upper limb ischaemia as a first presentation of a patent foramen ovale

A 78-year-old female patient presented to the emergency department with syncope and dyspnoea. The left arm appeared to be cold and radial pulse was not palpable. A CT scan of the chest and left arm with intravenous contrast displayed bilateral central pulmonary embolisms in combination with a left subclavian artery embolism and an atrial septal aneurysm. Transthoracic echocardiography identified a patent foramen ovale with right-to-left shunting confirming the diagnosis of paradoxical embolism. The patient was treated with anticoagulants. In a patient presenting with a combination of a pulmonary embolism and a peripheral arterial embolism, the clinician should consider a right-to-left shunt with paradoxical embolism. In line with this, when diagnosing a peripheral arterial embolism, a central venous origin should be considered. Furthermore, when diagnosing a pulmonary embolism or other forms of venous thromboembolism, the clinician should be aware of signs of a peripheral arterial embolism.

Prognosis of Cryptogenic Stroke With Patent Foramen Ovale at Older Ages and Implications for Trials: A Population-Based Study and Systematic Review

Importance

Patent foramen ovale (PFO) closure may prevent recurrent stroke after cryptogenic transient ischemic attack (TIA) or stroke (TIA/stroke) in patients aged 60 years or younger. Patent foramen ovale is associated with cryptogenic stroke in the older population, but risk of recurrence is unknown. Data on prognosis of patients receiving medical treatment at older ages (≥60 years) are essential to justify trials of PFO closure.

Objective

To examine the age-specific risk of recurrence in patients with cryptogenic TIA/stroke with PFO.

Design, Setting, and Participants

A prospective study was nested in the population-based Oxford Vascular Study between September 1, 2014, and March 31, 2019, with face-to-face follow-up for 5 years. A total of 416 consecutive patients with a diagnosis of cryptogenic TIA or nondisabling stroke, screened for PFO at a rapid-access TIA/stroke clinic, were included. A systematic review and meta-analysis of cohort studies reporting on ischemic stroke recurrence after cryptogenic TIA/stroke in patients with PFO who were receiving medical therapy alone, or with PFO vs no-PFO was conducted. Sample size calculation for future trials on PFO closure was performed for patients aged 60 years or older.

Exposures

Patent foramen ovale and age as modifiers of risk of recurrent stroke after cryptogenic TIA/stroke in patients receiving only medical therapy.

Main Outcomes and Measures

Risk of ischemic stroke recurrence in patients with cryptogenic TIA/stroke and PFO receiving medical therapy only, and in patients with vs without PFO, stratified by age (<65 vs ≥65 years), as well as sample-size calculation for future trials of PFO closure in patients aged 60 years or older.

Results

Among the 153 Oxford Vascular Study patients with PFO (mean [SD] age, 66.7 [13.7] years; 80 [52.3%] men), recurrent ischemic stroke risk (2.05 per 100 patient-years) was similar to the pooled estimate from a systematic review of 23 other studies (9 trials and 14 observational studies) (2.00 per 100 patient-years; 95% CI, 1.55-2.58). However, there was heterogeneity between studies (P < .001 for heterogeneity), owing mainly to risk increasing with mean cohort age (meta-regression: R2 = 0.31; P = .003). In the pooled analysis of 4 studies including patients with or without PFO, increased risk of stroke recurrence with PFO was seen only at age 65 years or older (odds ratio, 2.5; 95% CI, 1.4-4.2; P = .001 for difference; P = .39 for heterogeneity). The pooled ischemic stroke risk was 3.27 per 100 patient-years (95% CI, 2.59-4.13) in 4 cohorts with mean age 60 years or older. Assuming the more conservative 2.0 per 100 patient-years ischemic stroke risk in the PFO nonclosure arms of future trials in patients aged 60 years or older, projected sample sizes were 1080 per arm for 80% power to detect a 33% relative risk reduction.

Conclusions and Relevance

The findings of this study suggest that age is a determinant of risk of ischemic stroke after cryptogenic TIA/stroke in patients with PFO, such that trials of PFO closure at older ages are justified; however, projected sample sizes are large.

Cardiac and Echocardiographic Markers in Cryptogenic Stroke with Incidental Patent Foramen Ovale

OBJECTIVE

Some cardiac abnormalities could be a substrate for potential embolic source in cryptogenic stroke (CS). We evaluated whether cardiac and echocardiographic markers were associated with CS in patients with incidental patent foramen ovale (PFO) as defined using the Risk of Paradoxical Embolism (RoPE) score.

MATERIALS AND METHODS

Among 677 patients enrolled in a multicenter observational CS registry, 300 patients (44%) had PFOs detected by transesophageal echocardiography. They were classified into probable PFO-related stroke (RoPE score>6, n = 32) and stroke with incidental PFO (RoPE score≤6, n = 268) groups, and clinical characteristics, laboratory findings, cardiac and echocardiographic markers (i.e. brain natriuretic peptide, left atrial [LA] diameter, ejection fraction, early transmitral flow velocity/early diastolic tissue Doppler imaging velocity [E/e'], LA appendage flow velocity, spontaneous echo contrast, atrial septal aneurysm, substantial PFO, and aortic arch plaques), stroke recurrence, and excellent outcome (modified Rankin scale score <2) at discharge were compared. Risk factors for low RoPE scores were determined using multiple logistic regression analysis.

RESULTS

Higher brain natriuretic peptide levels (p = 0.032), LA enlargement (p < 0.001), higher E/e' (p = 0.001), lower LA appendage flow velocity (p < 0.001), non-substantial PFO (p = 0.021), and aortic arch plaques (p = 0.002) were associated with the low RoPE score group. Patients with high RoPE scores had excellent outcomes (58% versus 78%, p = 0.035). LA enlargement (age- and sex-adjusted odds ratio, 1.15; 95 % confidence interval, 1.00-1.32; p = 0.039) was an independent predictor of low RoPE scores.

CONCLUSIONS

Abnormal cardiac substrate could be associated with CS occurrence in a subset of patients with PFO. Patients with CS who had incidental PFO may be at risk of cardioembolism.

Wide-ranging clinical spectrum of paradoxical embolism

The purpose of this review is to raise the index of suspicion for paradoxical embolism among generalists. The review is based solely on anecdotal reports compiled from EMBASE, MEDLINE, Googlescholar and Pubmed. Search terms were 'paradoxical embolism', 'pulmonary embolism' and 'pulmonary arteriovenous malformations'. What emerged was that right-to-left paradoxical embolism could occur with or without concurrent pulmonary embolism, and also with and without proof of the presence of an 'embolus-in-transit'. Potential sites of single or multiple systemic involvement included the central nervous system, the coronary circulation, renal arterial circulation, splenic circulation, the mesenteric circulation and the limbs. In many cases, the deep veins of the lower limbs were the source of thromboembolism. In other cases, thrombi originated from an atrial septal aneurysm, from a central venous line, from a haemodialysis-related arterio-venous shunt, from a popliteal vein aneurysm, internal jugular vein, superior vena cava, from a pulmonary arteriovenous malformation, from tricuspid valve endocarditis (with and without pulmonary embolism) and from the right atrium, respectively. Stroke was by far the commonest systemic manifestation of paradoxical embolism. Some strokes were attributable to pulmonary arteriovenous malformations with or without coexistence of intracardiac shunts. Clinicians should have a high index of suspicion for paradoxical embolism because of its time-sensitive dimension when it occurs in the context of involvement of the intracranial circulation, coronary circulation, mesenteric circulation, and peripheral limb circulation.

Patent foramen ovale closure in the management of cryptogenic stroke: a review of current literature and guideline statements

OBJECTIVE

The management recommendations for patent foramen ovale (PFO) closure in cryptogenic stroke are rapidly evolving. The data has expanded recently with four major trials demonstrating superiority of percutaneous device closure over medical management in preventing cryptogenic stroke recurrence. This paper aims to review the current literature for referring physicians who may encounter patients with patent foramen ovale before referring these patients to stroke specialists and/or interventional cardiologists.

METHOD

For this Narrative review, we conducted a broad literature search with expert selection of relevant data. Our search included a review of the currently available trials, guideline statements, position papers, cost-effectiveness of device closure data, as well as the impact of device closure on quality of life.

RESULTS

Most European societies are now in favor of evaluating all patients aged 60 years or younger with recent cryptogenic stroke in the setting of a PFO after careful consideration of the patient's echocardiographic and clinical risk factors. On the other hand, American societies, except for the American Academy of Neurology, have not yet passed official updated recommendations.

CONCLUSION

PFO closure can be considered for the prevention of recurrent cryptogenic stroke in patients aged ≤60 years after a thorough evaluation and discussion about benefits and potential risks (including but not limited to atrial fibrillation) of the procedure. Accumulating evidence supports prognostic, quality of life, and economic benefit from percutaneous PFO closure with newer generation closure devices in the right subset of patients.

HIGHLIGHTS

Data from 4 major trials (RESPECT, CLOSE, DEFENSE-PFO, REDUCE) demonstrates the superiority of PFO closure over medical management alone in preventing cryptogenic stroke recurrence. Trials investigated mostly patients ≤60 years old, and therefore results may not be generalizable to the entire population. Further randomized trials evaluating the safety and efficacy of PFO closure in patients older than 60 years are warranted.Atrial fibrillation is one of the most common "occult" causes of cryptogenic stroke and should be excluded by ambulatory electrocardiographic monitoring. It is important to also rule out other causes of stroke, including hypercoagulable states, atherosclerotic lesions, other cardioembolic sources, and arterial dissection.Complications of PFO procedure include new-onset AF, development of scar tissue, risk of aortic root dilation and subsequent erosions, and potential thrombi formation on the device.PFO closure with medical therapy is more cost-effective than medical therapy alone.Patients who underwent PFO closure had lower rates of depression, anxiety, and stress compared to those who did undergo closure.Development of the RoPE score has helped clinicians identify patients with cryptogenic stroke and PFO who might be a candidate for PFO closure. A score of 7, 8, and 9-10 corresponds to a causal risk of 72%, 84%, and 88%, respectively, and defines a subset of patients who may benefit from PFO closure.Current guidelines recommend determining the need for PFO closure on a case-by-case basis, depending on risk factors, in patients age 60 or less with recent cryptogenic stroke in the setting of PFO.

Atrial Fibrillation Following Patent Foramen Ovale Closure: Systematic Review and Meta-Analysis of Observational Studies and Clinical Trials

[Figure: see text].

New-onset atrial fibrillation following percutaneous closure of patent foramen ovale: a systematic review and meta-analysis

PURPOSE

A patent foramen ovale (PFO), present in up to 25% of adults, is an embryologic remnant which allows for right to left shunting and has been implicated in cryptogenic stroke (Neill and Lin, Methodist Debakey Cardiovasc J. 13(3):152-159, 2017; Bass 2015). The current standard of care for selected patients with PFO and cryptogenic stroke is transcatheter closure, but the risk of post-closure, new-onset atrial fibrillation (AF) is unknown (Vaidya et al., Cardiovasc Diagn Ther. 8(6):739-753, 2018; Kjeld et al., Acta Radiol Open. 7(9):2058460118793922, 2018; Staubach et al., Catheter Cardiovasc Interv. 74(6):889-95, 2009). This systematic review and meta-analysis synthesized evidence on AF development post transcatheter PFO closure and predictors of AF development, and assessed existing knowledge gaps.

METHODS

Randomized controlled trials and observational studies were selected according to the inclusion criteria of adults that underwent a transcatheter PFO closure without a history of AF. Studies were retrieved from electronic databases from inception until February 2019. A Freeman-Tukey arcsine transformation was performed for meta-analysis of AF incidence rate.

RESULTS

From 765 studies, 45 were included in quantitative data synthesis. Study sample sizes ranged between 20 and 1887 individuals, and average patient age between 37 to 67 years across studies. The overall incidence rate was 0.013 person-years, and 0.014 person-years for the within 6 months follow-up subgroup. There was no consistency in reported predictors of AF development.

CONCLUSIONS

The incidence of AF post-PFO closure was low across studies, with a high level of between-study heterogeneity. Until a concerted effort is made to improve accurate AF diagnosis, it will be difficult to gauge the association between transcatheter PFO closure and incidence of AF.

Advances and ongoing controversies in PFO closure and cryptogenic stroke

Approximately one-third of strokes are cryptogenic in origin. These patients have a higher prevalence of patent foramen ovale (PFO) compared to individuals with stroke of known origin. It has been proposed that some cryptogenic strokes (CSs) can be caused by paradoxical embolism across a PFO. PFOs can be treated medically with antithrombotic agents and percutaneously with occluder devices. Large randomized clinical trials have found transcatheter PFO closure to be superior to medical treatment for the prevention of recurrent stroke in young patients with CS. However, the superiority of PFO closure over medical treatment in unselected populations has not been demonstrated. In this chapter, we review the evidence supporting PFO closure and the selection of patients for such intervention.

Closure of the patent foramen ovale in patients with embolic stroke of undetermined source: A clinical expert opinion and consensus statement for the Asian-Pacific region

Recently published long-term data from randomized controlled trials have provided evidence for the prevention of recurrent embolic stroke of undetermined source by percutaneous closure of the patent foramen ovale. However, most data were obtained from Caucasian populations and evidence on patent foramen ovale closure in Asian-Pacific patients is limited. The relative paucity in clinical data from this population, as well as the fact that Asian-Pacific patients may have higher bleeding risks than Caucasians, complicates clinical decision-making. This document, resulting from a consensus meeting of Asian-Pacific clinical experts, states the consensus among these experts about how to treat Asian-Pacific patients who had an embolic stroke of undetermined source and have a patent foramen ovale, based on currently available evidence and expert opinions. In addition, uncertainties and the need for clinical data regarding patent foramen ovale closure for prevention of recurrent embolic stroke of undetermined source in general, and specifically for Asian-Pacific patients, are identified.

Patent Foramen Ovale in Cryptogenic Ischemic Stroke: Direct Cause, Risk Factor, or Incidental Finding?

Patent foramen ovale (PFO) has been associated with cryptogenic stroke. There is conflicting data and it remains uncertain whether PFO is the direct cause, a risk factor or an incidental finding. Potential stroke mechanisms include paradoxical embolism from a venous clot which traverses the PFO, in situ clot formation within the PFO, and atrial arrhythmias due to electrical signaling disruption. Main risk factors linked with PFO-attributable strokes are young age, PFO size, right-to-left shunt degree, PFO morphology, presence of atrial septal aneurysm, intrinsic coagulation-anticoagulation systems imbalance, and co-existence of other atrial abnormalities, such as right atrial septal pouch, Eustachian valve and Chiari's network. These may act independently or synergistically, multiplying the risk of embolic events. The RoPE score, a scale that includes factors such as young age, cortical infarct location and absence of traditional stroke risk factors, is associated with the probability of a PFO being pathogenic and stroke recurrence risk after the index stroke. Multiple investigators have attempted to correlate other PFO features with the risk of PFO-related stroke, but further investigation is needed before any robust conclusions are reached. PFO presence in young patients with cryptogenic stroke should be considered as etiologically suspect. Caution should be exercised in interpreting the relevance of other PFO features.

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.

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.