Morphometric Features of Patent Foramen Ovale as a Risk Factor of Cerebrovascular Accidents: A Systematic Review and Meta-Analysis

Prevalence and characteristics of patent foramen ovale in a sample of Egyptian population: a computed tomography study

BACKGROUND

The reported prevalence of patent foramen ovale (PFO) in the general population is variable. It ranges between 8.6 and 42% according to the population studied and the imaging technique used. We aim to prospectively assess the prevalence and characteristics of PFO and interatrial septum (IAS) abnormalities as well as the related clinical manifestations in a sample of Egyptian population.

RESULTS

This study comprised 1000 patients who were referred for CT coronary angiography (CTCA). Mean age was 52.5 ± 10.9 years. The prevalence of PFO among the studied population was 16.3%; closed PFO (grade I) 44.2%, open PFO (grade II) 50.9%, and open PFO with jet (grade III) 4.9%. Anatomical high-risk PFO features-defined as the presence of at least 2 or more of the following (diameter ≥ 2 mm, length ≥ 10 mm, septal aneurysm "ASA", or redundant septum)-were found in 51.5% of PFOs' population. Other IAS abnormalities as redundant septum (8.6%), ASA (5.3%), Bachmann's bundle (4.5%), microaneurysm (2.6%), and atrial septal defect (ASD) (0.4%) were detected. There was a lower rate of coexistence of ASA with PFO (p = 0.031). Syncope was significantly higher in patients with PFO compared to those without PFO (6.7% vs. 1.6%, p = 0.001). Stroke, transient ischaemic attacks (TIA), and dizziness were similar in both groups. TIA, dizziness, and syncope were significantly higher in patients with IAS abnormalities including PFO compared to those without IAS abnormalities. Syncope was also significantly higher in PFO with high-risk anatomical features compared to those with non-high-risk PFO population (p = 0.02).

CONCLUSION

The prevalence of PFO in our study was approximately 16.3%, almost half of them showed anatomical high-risk features for stroke. Dizziness, syncope and TIA were significantly higher in patients with IAS abnormalities including PFO.

Unresponsiveness to Chiari Malformation Type I Surgery Can Be Related to the Accompanying Chiari Network

Surgical treatment is indicated for Chiari malformation type 1 (CMI) with tonsillar descent (TD) of >5 mm and other clinical manifestations. However, some patients remain unresponsive to surgery; this is an active topic of discussion. A patient presented to the emergency department with dizziness and an impaired gait. He had a history of hypertension. Magnetic resonance investigations revealed a 9-mm TD and cervical syringomyelia. There was no evidence of interatrial septum pathology on transthoracic echocardiography performed preoperatively. Although his complaints were attributed to CMI and surgery was performed, his symptoms remained persistent. Two years later, when the patient's dizziness increased, a posterior fossa transient ischemic attack (TIA) was suspected. A large patent foramen ovale (PFO) and Chiari network (CN) were also detected on transesophageal echocardiography. His complaints were resolved following PFO closure. Our case suggests that neurosurgeons should be informed about the results of the companionship of a PFO and CN. Before deciding on CMI surgery for patients with only dizziness complaints, a detailed investigation of accompanying cardiac pathologies is paramount to ensure accurate diagnosis and treatment.

Paradoxical Embolic Stroke Following Percutaneous Transluminal Angioplasty in a Hemodialysis Patient

Paradoxical embolism is a medical condition characterized by the migration of an embolus from a venous source into the systemic circulation. This occurs through a specific cardiac abnormality known as a right-to-left shunt, ultimately resulting in the possibility of arterial embolism. Patent foramen ovale (PFO) is the most common cause of intracardiac shunting. We reported a rare case of a 56-year-old man on hemodialysis with PFO and arteriovenous fistula dysfunction who suffered a paradoxical embolic ischemic stroke after percutaneous transluminal angioplasty. This case emphasized the potential risk of paradoxical embolism in hemodialysis patients with vascular access problems. We aimed to highlight the importance of searching for PFO, as it may serve as a possible source of embolism in these patients.

The Covert Impact of Chiari Network and Eustachian Valves on Stroke: A Scoping Review and Meta-Analysis

BACKGROUND

The role of Chiari network (CN) and Eustachian valves (EVs) in cardioembolic strokes is still unclear. There is inconsistency in the literature regarding clinical approach to these lesions to reduce stroke risk. We aimed to describe clinical presentation, neuroimaging and cardioimaging features, as well as management approaches for CN and EV in stroke context.

REVIEW SUMMARY

A systemic search was carried out using PubMed and Web of Science following PRISMA guidelines, Supplemental Digital Content 1 ( http://links.lww.com/NRL/A123 ). We retrieved 4 case-control studies, 2 cross sectional studies as well 8 case reports, with a total of 883 patients with a mean age of 44.6 years (±13.8). The combined prevalence of EV/CN in stroke-related patent foramen ovale (PFO) patients was 50% (95% CI: 31-68). With isolated prevalence for EV and CN of 43% (95% CI: 25-63), 18% (95% CI: 12-25), respectively. Patients with history of stroke had higher prevalence of EV/CN compared with controls odds ratio=2.45 (95% CI: 1.2-5, P <0.01). All case-control and cross-sectional studies defined EV/CN by transesophageal echocardiography or intracardiac cardiography. In the 8 case reports, 7 cases were diagnosed by transesophageal echocardiography, while only 1 case was diagnosed postmortem.

CONCLUSION

EV/CN are relatively common findings in stroke patients with PFO. While it appears that presence of EV/CN with a PFO increases the risk of cardioembolic stroke, they remain underrecognized. EV/CN should be considered as high-risk PFO features. There is a scarcity of research emphasizing their role in clinical decision making, especially PFO closure and antithrombotic therapy choice.

Heart-Stroke Team: A multidisciplinary assessment of patent foramen ovale-associated stroke

INTRODUCTION

Patent foramen ovale (PFO) closure prevents recurrent ischemic stroke in selected patients with a cryptogenic stroke. Trial results tend to be generalized to daily practice, often extending original trial inclusion criteria. This may result in unnecessary closure without benefit, but with risk of complications. We therefore introduced a standardized and structured evaluation by an interdisciplinary Heart-Stroke Team (HST). Our aim was to investigate the proportion of actual PFO closure of all referred patients with a cryptogenic stroke, after evaluation by the HST.

PATIENTS AND METHODS

We conducted a single-center, retrospective cohort study. Patients with an assumed cryptogenic ischemic stroke or transient ischemic attack (TIA) and a PFO who were referred for PFO closure were analyzed. As part of the HST approach, all patients underwent a standardized work-up, first to demonstrate the ischemic event on neuroimaging, second to evaluate all potential causes of stroke and finally, to assess the possible relation between the PFO and stroke. Outcome was the proportion of patients treated with PFO closure after referral.

RESULTS

A total of 195 patients were included. In 124 patients (64%) PFO closure was advised. Fourty-two (22%) patients had a clear alternative cause of stroke and in 13 (7%) patients the initial stroke diagnosis could not be confirmed.

CONCLUSION

After careful analysis of patients referred for PFO closure a relationship between the PFO and stroke could not be demonstrated in 32% of referrals, and 3% preferred best medical treatment over percutaneous closure. This stresses the need for a complete neurovascular work-up and multidisciplinary assessment.

Uncovering Sex-Specific Epigenetic Regulatory Mechanism Involving H3k9me2 in Neural Inflammation, Damage, and Recovery in the Internal Carotid Artery Occlusion Mouse Model

Cerebral ischemic stroke is one of the foremost global causes of death and disability. Due to inadequate knowledge in its sequential disease mechanisms, therapeutic efforts to mitigate acute ischemia-induced brain injury are limited. Recent studies have implicated epigenetic mechanisms, mostly histone lysine acetylation/deacetylation, in ischemia-induced neural damage and death. However, the role of lysine methylation/demethylation, another prevalent epigenetic mechanism in cerebral ischemia has not undergone comprehensive investigation, except a few recent reports, including those from our research cohort. Considering the impact of sex on post-stroke outcomes, we studied both male and female mice to elucidate molecular details using our recently developed Internal Carotid Artery Occlusion (ICAO) model, which induces mild to moderate cerebral ischemia, primarily affecting the striatum and ventral hippocampus. Here, we demonstrate for the first time that female mice exhibit faster recovery than male mice following ICAO, evaluated through neurological deficit score and motor coordination assessment. Furthermore, our investigation unveiled that dysregulated histone lysine demethylases (KDMs), particularly kdm4b/jmjd2b are responsible for the sex-specific variance in the modulation of inflammatory genes. Building upon our prior reportage blocking KDMs by DMOG (Dimethyloxalylglycine) and thus preventing the attenuation in H3k9me2 reduced the post-ICAO transcript levels of the inflammatory molecules and neural damage, our present study delved into investigating the differential role of H3k9me2 in the regulation of pro-inflammatory genes in female vis-à-vis male mice underlying ICAO-induced neural damage and recovery. Overall, our results reveal the important role of epigenetic mark H3k9me2 in mediating sex-specific sequential events in inflammatory response, elicited post-ICAO.

Atrial septal aneurysm contribution to the risk of cryptogenic stroke in patients with patent foramen ovale: A brief updated systematic review and meta-analysis

Atrial septal aneurysms (ASA) play an important role in cryptogenic stroke (CS) in patients with patent foramen ovale (PFO) but its contribution remains still not fully clarified in current literature. We sought to evaluate the contribution of ASA to the risk of CS in PFO patients based on studies published so far by means of a systematic review and metanalysis. A literature search, based on PubMed, Google Scholar and EMBASE databases, was performed to locate articles, published English language between 2000 and 2021, analysing the relationship between ASA and CS. The final research was conducted in September 2021. A total of 577 articles were retrieved after excluding duplicates. The initial screening excluded 215 articles because they did not meet inclusion criteria, leaving 362 articles to assess for eligibility. Subsequently, after evaluation of the full-text articles, 354 were excluded and 8 investigations met the inclusion criteria. Overall, 822 patients (mean age 48.3 years) were enrolled in the reviewed manuscripts with a prevalence of males of 48.7% and a normal distribution of the classical cardiovascular risk factors. ASA was present in 25.3% (208 subjects) of the patients enrolled, while the association of PFO+ASA was observed in 24.3% (200 subjects) of patients enrolled. PFO Patients with ASA were at higher risk of CS compared to those without (odd ratio: 3.38, 95% CI: 2.72-5.51, p<0.001, I2=4.3%,). The relative funnel plot did not show any evident asymmetry, confirming absence of publication bias. Our updated metanalysis enhances the importance of ASA contribution to stroke in patients with patent foramen ovale, being present in a third of patients with symptomatic PFO to whom it confers an additional odd ratio of 3.38.

Three-dimensional Transesophageal Echocardiography for Transcatheter Patent Foramen Ovale Closure: Standardizing Anatomic Nomenclature and Novel Sizing Concepts

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Terminology for PFO tunnel sizing remains unstandardized.

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Device size selection for transcatheter PFO closure is highly variable.

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Tunnel width measurements may be a better descriptor of PFO size.

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Wire sizing may be a useful technique for assessment of PFO dimensions.

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PFO sizing strategies based on tunnel width need to be better studied.

PFO morphology for evaluation of c-TCD and c-TTE RLS grades

Purpose

The purpose of this study was to observe the morphologic characteristics of patent foramen ovale (PFO) by transesophageal echocardiography (TEE), and to analyze its correlation with right-to-left shunt (RLS) of contrast-transthoracic echocardiography (c-TTE) and contrast-transcranial Doppler ultrasonography (c-TCD).

Methods

124 patients with PFO were divided into four groups according to the morphological characteristics of PFO. RLS grade of each group PFO with c-TTE and c-TCD in resting and Valsalva manoeuvre was measured. Anatomical structures influencing RLS grade were analyzed statistically through multivariate logistic analyses and predictive models.

Results

The 124 cases of PFO were divided into four groups: 55 cases (44.4%) with smooth uniform tubular tunnel (SUT), 21 cases (16.9%) with granule uniform tubular tunnel (GUT), 23 cases (18.5%) of right funnelform, 25 cases (20.2%) of left funnelform. Between group comparisons and multivariate logistic analyses revealed that PFO morphotype and interatrial septum(IAS) mobility were influencing factors of RLS degree. During Valsalva, the probability of c-TCD RLS ≥ 2 for the right funnelform PFO was 13.428 times that of the GUT, one unit increase in IAS mobility increased the probability of c-TCD RLS ≥ 2 by a factor of 2.029, model predicted c-TCD RLS ≥ 2 with 78.1% sensitivity and 94.7% specificity; During Valsalva, the probability of c-TCD RLS ≥ 2 for the SUT PFO was 4.244 times that of the GUT, one unit increase in IAS mobility increased the probability of c-TTE RLS ≥ 2 by a factor of 2.392, model predicted c-TTE RLS ≥ 2 with 80.2% sensitivity and 87.9% specificity.

Conclusions

Studies have shown that the morphological structure of PFO is an influencing factor of RLS, and TEE can observe the specific morphological characteristics of PFO, which can further predict the level of RLS, help predict the occurrence of Cryptogenic stroke (CS). The above provides more evidences and surgical options for Interventional device closure indications.

Current Challenges and Future Directions in Handling Stroke Patients With Patent Foramen Ovale—A Brief Review

The role of patent foramen ovale (PFO) in stroke was debated for decades. Randomized clinical trials (RCTs) have shown fewer recurrent events after PFO closure in patients with cryptogenic stroke (CS). However, in clinical practice, treating stroke patients with coexisting PFO raises some questions. This brief review summarizes current knowledge and challenges in handling stroke patients with PFO and identifies issues for future research. The rationale for PFO closure was initially based on the concept of paradoxical embolism from deep vein thrombosis (DVT). However, RCTs did not consider such details, limiting their impact from a pathophysiological perspective. Only a few studies explored the coexistence of PFO and DVT in CS with varying results. Consequently, the PFO itself might play a role as a prothrombotic structure. Transesophageal echocardiography thus appears most appropriate for PFO detection, while a large shunt size or an associated atrial septum aneurysm qualify for a high-risk PFO. For drug-based treatment alone, studies did not find a definite superiority of oral anticoagulation over antiplatelet therapy. Remarkably, drug-based treatment in addition to PFO closure was not standardized in RCTs. The available literature rarely considers patients with transient ischemic attack (TIA), over 60 years of age, and competing etiologies like atrial fibrillation. In summary, RCTs suggest efficacy for closure of high-risk PFO only in a small subgroup of stroke patients. However, research is also needed to reevaluate the pathophysiological concept of PFO-related stroke and establish strategies for older and TIA patients and those with competing risk factors or low-risk PFO.

Intelligent Prediction of Cryptogenic Stroke Using Patent Foramen Ovale from TEE Imaging Data and Machine Learning Methods

In spite of the popularity of random forests (RF) as an efficient machine learning algorithm, methods for constructing the potential association for between patent foramen ovale (PFO) and cryptogenic stroke (CS) using this technique are still barely. For the vital regional study areas (atrial septum), RF was used to predict CS in patients with PFO using partial clinical data of patients and remotely sensed imaging examination data obtained from Tee imaging. We validated our method on a dataset of 151 consecutive patients with detected PFO at a large grade A hospital in China from November 2018 to December 2020, we obtained an area under the relative operating characteristic curve of 0.816, with 65% specificity at 73% sensitivity. The RF models accurately represented the relationship between the CS and remotely sensed predictor variables. Therein, maximum mobility, large right-to-left shunt during Valsalva maneuver, size of PFO in diastole and systole, and diastolic length of the tunnel present higher predictive value in CS. Our findings suggest that multi-Doppler sensor data by transesophageal echocardiography (TEE)-detected morphologic and functional characteristics of PFO may play important roles in the occurrence of CS. These results indicate that the established random forest model has the potential to predict CS in patients with PFO and great promise for application to clinical practice.

Importance of direct right-to-left shunt as high-risk patent foramen ovale associated with cryptogenic stroke

BACKGROUND

Because transcatheter closure of patent foramen ovale (PFO) has become effective for preventing cryptogenic stroke (CS), it is necessary to determine high-risk PFO associated with CS. This study aimed to clarify the importance of direct right-to-left (RL) shunt through the PFO for identifying high-risk PFO.

METHODS

We analyzed 137 patients with and without CS who were confirmed to have PFO. The timing of RL shunt through the PFO was evaluated by cardiac cycles after right atrium (RA) opacification on saline contrast transesophageal echocardiography. Direct RL shunt was defined as microbubbles crossing the PFO before and at the same time of RA opacification.

RESULTS

Cardiac cycles of microbubbles crossing the PFO were shorter in patients with CS than in those without CS (2.0 ± 2.2 vs .5 ± 1.1, p < 0.01). Direct RL shunt was more frequently observed in patients with CS than in those without CS (77% vs 29%, p < 0.01), with a sensitivity of 79% and a specificity of 71% for the association with CS. Multivariate analysis revealed that direct RL shunt was related to atrial septal aneurysm and low-angle PFO. Regarding functional features of PFO, the detection rate of CS was 50% for large RL shunt alone, and was increased to 83% when direct RL shunt was added.

CONCLUSION

Direct RL shunt was associated with CS and had the incremental value in detecting PFO associated with CS for large RL shunt. The timing of RL shunt can be valuable for identifying high-risk PFO.

Patent Foramen Ovale Channel Morphometric Characteristics Associated with Cryptogenic Stroke: The MorPFO Score

BACKGROUND

It is still disputable whether the specific morphologic properties of patent foramen ovale (PFO) may contribute to the occurrence of stroke. The aim of this study was to evaluate the differences in the morphometric and functional features of the PFO channel in patients with cryptogenic stroke and those without stroke.

METHODS

PFO channel morphology in 106 consecutive patients with cryptogenic stroke and 93 control patients without stroke with diagnosed PFO (by transesophageal echocardiography) was analyzed using transesophageal echocardiography. A validation cohort was established that consisted of 31 patients with cryptogenic stroke and 30 without stroke.

RESULTS

Multivariable regression logistic analyses indicated PFO channel length change (odds ratio [OR], 2.50; 95% confidence interval [CI], 1.75-3.55; P < .001), PFO length/height ratio during the Valsalva maneuver (OR, 0.75; 95% CI, 0.60-0.95; P = .015), septum primum thickness (OR, 0.34; 95% CI, 0.14-0.80; P = .013), septum secundum height (OR, 0.91; 95% CI, 0.84-0.98; P = .013), the presence of an atrial septal aneurysm (OR, 3.38; 95% CI, 1.27-8.97; P = .014), and large shunt (OR, 2.49; 95% CI, 1.13-5.46; P = .022) as PFO-related stroke factors. The Morphologic Stroke Factors of PFO (MorPFO) score was developed, in which six factors were included: PFO channel length reduction (≥21%; 7 points), short septum secundum (<8.6 mm; 5 points), thin septum primum (<1.6 mm; 3 points), large right-to-left shunt (3 points), low PFO channel length/height ratio during the Valsalva maneuver (≤2.1; 2 points), and atrial septal aneurysm presence (1 point). Patients with scores of 0 to 7 points have low-risk PFO channels, those with scores of 8 to 11 points have intermediate-risk PFO channels, and those with scores of 12 to 21 points have high-risk PFO channels. External validation showed good MorPFO score performance (C index = 0.90).

CONCLUSIONS

Transesophageal echocardiography can be used to differentiate pathogenic from incidental PFO channels on the basis of their morphologic characteristics. The MorPFO score may help identify high-stroke-risk PFO channels.

Patent Foramen Ovale-A Not So Innocuous Septal Atrial Defect in Adults

Patent foramen ovale (PFO) is a common congenital atrial septal defect with an incidence of 15–35% in the adult population. The development of the interatrial septum is a process that begins in the fourth gestational week and is completed only after birth. During intrauterine life, the foramen ovale allows the passage of highly oxygenated blood from the right to the left atrium and into the systemic arteries, thus bypassing the pulmonary circulation. In 75% of the general population, the foramen ovale closes after birth, and only an oval depression, called fossa ovalis, remains on the right side of the interatrial septum. Patent foramen ovale can be associated with various clinically important conditions, including migraine and stroke, or decompression illness in divers. The aim of this review is to summarize the PFO developmental and anatomical features and to discuss the clinical risks associated with this atrial septal defect in adults.

Impact of Patent Foramen Ovale Anatomic Features on Right-to-Left Shunt in Patients with Cryptogenic Stroke

The purpose of this study was to investigate the impact of the morphologic characteristics of patent foramen ovale (PFO) on right-to-left shunt (RLS) in patients with PFO and cryptogenic stroke using transesophageal echocardiography and saline contrast transthoracic echocardiography (c-TTE). Of the 165 patients with PFO stroke, both the height and the length of PFO in the provoked RLS group were smaller than those in the constant RLS group. PFO height, interatrial septum mobility and proportion of atrial septal aneurysms were greater in the severe RLS group than in the mild and moderate RLS groups. Multivariate analysis revealed that PFO height and interatrial septum mobility were independent predictors of severe RLS. Multiple territorial ischemic lesions were more common in the severe RLS or constant RLS group. Our findings indicated that the severity of RLS was related to the anatomic features in PFO, inducing different cerebral ischemia lesion patterns in cryptogenic stroke patients with PFO.

[Patent foramen ovale. An update for primary care]

Patent foramen ovale (FOP) is the most prevalent cause of cryptogenic strokes in people under 60 years old. Although it is usually asymptomatic, it has a high risk of producing paradoxical embolism and, therefore, stroke with indeterminate outcomes. The study should be started based on clinical suspicion, and includes a multidisciplinary assessment and a determination of the type of treatment to be performed. The therapeutic possibilities range from conservative treatment (indefinite antithrombotic treatment), to its percutaneous closure (currently the most widely used). The first objective is to decrease the number of stroke recurrences. Conservative treatment should be reserved for those cases of low embolic risk. The risk assessment must be individualised, fundamentally based on the anatomical characteristics of the FOP and the patient clinic picture. The use of the RoPE risk scale (The Risk of Paradoxical Embolism) should be a tool to consider.

Patent Foramen Ovale in Fetal Life, Infancy and Childhood

A patent foramen ovale (PFO) is a common, incidental echocardiographic finding in otherwise healthy and asymptomatic infants and children. However, a variety of clinical conditions have been ascribed to the presence of a PFO in childhood, such as cryptogenic stroke, platypnea-orthodeoxia syndrome, decompression sickness and migraine, although the data on these are controversial and sometimes contradictory. This review discusses embryology and correlation with post-natal anatomy, anatomical variations of the atrial septum, diagnostic modalities in special circumstances of PFO associated clinical syndromes, and the role of PFO in congenital heart disease, pulmonary hypertension, dilated cardiomyopathy and heart failure in children who require an extracorporeal membrane oxygenator or ventricular assist device as life support.