Prevalence of Patent Foramen Ovale in Ischaemic Stroke in Italy: Results of SISIFO Study

Recent progress in patent foramen ovale and related neurological diseases: A narrative review

Patent foramen ovale (PFO) is a common congenital cardiac abnormality when the opening of the interatrial septum is not closed in adulthood. This abnormality affects 25% of the general population. With the development of precision medicine, an increasing number of clinical studies have reported that PFO is closely related to various neurological diseases such as stroke, migraine, obstructive sleep apnea, and decompression syndrome. It has also been suggested that PFO closure could be effective for preventing and treating these neurological diseases. Therefore, increasing attention has been given to the prevention, diagnosis, and treatment of PFO-related neurological diseases. By reviewing existing literature, this article focuses on the pathogenesis, epidemiology, and clinical characteristics of PFO-related neurological diseases, as well as the prevention and treatment of different neurological diseases to discuss, and aims to provide current progress for this field and decision-making evidence for clinical practice.

Advances in the management of cardioembolic stroke associated with patent foramen ovale

Patent foramen ovale (PFO) describes a valve in the interatrial septum that permits shunting of blood or thrombotic material between the atria. PFOs are present in approximately 25% of the healthy population and are not associated with any pathology in the vast majority of cases. However, comparisons between patients with stroke and healthy controls suggest that PFOs may be causative of stroke in certain patients whose stroke is otherwise cryptogenic. Options for the diagnosis of PFO include transthoracic echocardiography, transesophageal echocardiography, and transcranial Doppler ultrasonography. PFOs associated with an interatrial septal aneurysm seem to be more strongly linked to risk of recurrent stroke. Therapeutic options for secondary stroke prevention in the setting of a PFO include antiplatelet therapy, anticoagulation, and percutaneous device closure. Recent randomized clinical trials suggest that percutaneous closure reduces the subsequent risk of stroke in appropriately selected patients, with a large relative benefit but small absolute benefit. Referral for percutaneous PFO closure should therefore be considered in certain patients after a multidisciplinary, patient centered discussion. Areas for future study include structural biomarkers to aid in determining the role of PFO closure in older people with possible PFO associated stroke, the role of direct oral anticoagulants, and very long term outcomes after device closure.

Presence of Atrial Fibrillation in Stroke Patients With Patent Foramen Ovale: Systematic Review and Meta-Analysis

Purpose: Patent foramen ovale (PFO) is associated with ischemic stroke, especially in patients with embolic stroke of undetermined source. This study aims to evaluate the presence of atrial fibrillation (AF) in ischemic stroke patients with PFO. Methods: We systematically searched EMBASE and MEDLINE databases on May 21, 2020 for studies that analyzed the presence of AF in patients with PFO. The primary outcome was the presence of AF in patients with PFO compared with those without. Outcomes were pooled using a random-effects model using the method of DerSimonian and Laird. We recorded demographic characteristics and the methods used for AF detection in the studies included (unspecified, history/medical records review, ECG, Holter monitor, or loop recorder). Results: A total of 14 studies and 13,245 patients fulfilled the entry criteria. The average age was 61.2 years and 41.3% of the participants were female. There was a lower risk of AF in patients with PFO compared with those without (RR 0.52, 95% confidence interval, 0.41-0.63, p < 0.001). There was no evidence of heterogeneity. The lower risk of AF was found in cross-sectional and longitudinal studies and in studies stratified by average age (<60 or ≥60) and in cryptogenic stroke. Meta-regression by PFO detection technique suggested that studies using transoesophageal echocardiogram for PFO detection reported higher risk of AF (1.39, 95% confidence interval 1.14-1.70, p = 0.004). Conclusion: The presence of a PFO in patients with ischemic stroke/TIA may be associated with a lower risk of AF. Few studies have estimated the risk of future AF in patients with PFO.

Severity by National Institute of Health Stroke Scale Score and Clinical Features of Stroke Patients with Patent Foramen Ovale Stroke and Atrial Fibrillation

The comparative severity of patent foramen ovale (PFO)-related stroke in patients without atrial fibrillation (AF) and AF-related stroke in patients without PFO is unknown. Therefore, we compared the severity of PFO-related stroke and AF-related stroke. Twenty-six patients who underwent transesophageal echocardiography (TEE) were diagnosed with cardioembolic stroke from July 2018 to March 2020. Cases with AF detected by electrocardiograms or thrombus in the left atrium or left atrial appendage on TEE were included in the AF-related stroke group. Cases with a positive microbubble test on the Valsalva maneuver during TEE, and with no other factors that could cause stroke, were included in the PFO-related stroke group. This study was designed as a single-center, small population pilot study. The stroke severity of the two groups by the National Institute of Health Stroke Scale (NIHSS) score was compared by statistical analysis. Of the 26 cases, five PFO-related stroke patients and 21 AF-related stroke patients were analyzed. The NIHSS score was 2.2 ± 2.8 and 11.5 ± 9.2 (p-value < 0.01), the rate of hypertension was 20.0% and 85.7% (p-value = 0.01), and the HbA1c value was 5.5 ± 0.2% and 6.3 ± 1.3% (p-value = 0.02) in the PFO-related and AF-related stroke groups, respectively. Compared with AF-related stroke patients, stroke severity was low in PFO-related stroke patients.

The Correlation Between Migraine and Patent Foramen Ovale

Background: Migraine is a widespread neurological disorder. The patent foramen ovale (PFO) is a remnant of the fetal circulation. Multiple studies suggest that migraine is more prevalent in subjects with PFO and vice versa. It is unclear if there is a causal relationship or simply a co-existence of these two conditions. Furthermore, the treatment of migraine with percutaneous closure PFO remains controversial.

Methods: We reviewed studies pertaining to the relationship between PFO and migraine as well as the effects of treatments on migraine attacks.

Results: We briefly summarized potential pathophysiological mechanisms of migraine, and elaborated on migraine type, frequency, and clinical symptoms of migraine with PFO and the clinical features of PFO with migraine. We also addressed the effects of PFO closure on migraine attacks.

Conclusion: The evidence supports a “dose-response” relationship between migraine and PFO although more work needs to be done in terms of patient selection as well as the inclusion of an antiplatelet control group for PFO closure interventions to uncover possible beneficial results in clinical trials.

Clinical RoPE (cRoPE) score predicts patent foramen ovale detection among stroke patients: a multicenter observational study

BACKGROUD

The role of patent foramen ovale (PFO) in cryptogenic stroke (CS) is debated. Tools to predict PFO occurrence and attributable fraction are needed to guide cost-effective diagnostics and treatment. Risk of Paradoxical Embolism (RoPE) score relies on neuroimaging findings, which might be inconclusive in up to 30% of cases.

METHODS

We developed a clinical-based easy tool to predict the presence and attributable fraction of PFO in CS patients, without using neuroimaging. The clinical RoPE (cRoPE) score, ranging 1-10, was elaborated through Delphi method from the original RoPE score, replacing cortical infarction with the Oxfordshire Community Stroke Project (OCSP) classification (lacunar stroke = 0 points, other subtypes = 1 point). Then, from the SISIFO (Studio Italiano di prevalenza nello Stroke Ischemico di pervietà del Forame Ovale, or Prevalence of Patent Foramen Ovale in Ischemic Stroke in Italy) study, a multicenter, prospective study on consecutive acute ischemic stroke patients (n = 1130) classified by Trial of Org 10172 in Acute Stroke Treatment (TOAST) and OCSP criteria and undergoing PFO testing, we selected the VV-CDC cohort (Vibo Valentia, Città di Castello, n = 323) to test the accuracy of cRoPE in predicting PFO detection. We compared cRoPE with RoPE to verify cRoPE reliability. Finally, we tested, through ROC analysis, the performance of cRoPE depending on TOAST classification.

RESULTS

Overall, PFO was detected in 21% in VV-CDC and in 23.4% in remaining SISIFO cohort (n = 807). cRoPE_AUC and RoPE_AUC were similar in VV-CDC. cRoPE performance was comparable with RoPE among CS (cRoPE_AUC 0.76, 95%CI 0.67-0.85, RoPE_AUC 0.75, 95%CI 0.66-0.84). Moving to the remaining SISIFO cohort, cRoPE confirmed satisfactory accuracy in predicting PFO detection in CS patients (cRoPE_AUC 0.71, 95%CI 0.66-0.78, p = 0.032).

CONCLUSIONS

Conclusions: cRoPE might help in stratification of patients with CS, allowing accurate esteem of the likelihood of PFO to be found, especially in cases when neuroimaging is inconclusive.

Epidemiology of Patent Foramen Ovale in General Population and in Stroke Patients: A Narrative Review

Introduction: Percutaneous closure of patent foramen ovale (PFO) in selected patients with cryptogenic cerebrovascular ischemic events (CEs) decreases the risk of recurrent stroke; however, optimal patient selection criteria are still under investigation. Candidates for PFO closure are usually selected from the pool of CE patients with a high risk of Paradoxical Embolism (RoPE) score. The RoPE score calculates the probability that PFO is causally related to stroke, based on PFO prevalence in patients with CE compared with that in healthy subjects. The latter has been set at 25% based on the average of autopsy and transesophageal echocardiography (TEE) studies.

Methods: We conducted a comprehensive review of studies investigating PFO prevalence in general population and in patients with CE and non-CE using autopsy, TEE, transcranial Doppler (TCD) or transthoracic echocardiography (TTE). Studies were excluded if they (1) reported data from referred subjects with underlying cerebrovascular disease or (2) did not specify etiologically the events.

Results: In healthy/control subjects, PFO prevalence was 24.2% (1,872/7,747) in autopsy studies, 23.7% (325/1,369) in TEE, 31.3% (111/355) in TCD, and 14.7% (186/1,267) in TTE studies. All diagnostic modalities included PFO prevalence was higher in CE compared with healthy/control population [odds ratio (OR) = 3.1, 95% confidence interval (CI) = 2.5–3.8] and compared with non-CE (OR = 2.3, 95% CI = 2.0–2.6). In patients with CE, PFO prevalence in the young compared to the old was higher when the diagnostic modality was TEE (48.9 vs. 27.3%, p < 0.0001, OR = 2.6 with 95% CI = 2.0–3.3) or TCD (58.1 vs. 41%, OR = 1.9, 95% CI = 1.6–2.5), but not TTE (53.3 vs. 37.5%, p = 0.16). Regarding non-CE, PFO prevalence in the young compared to the old was higher when the diagnostic modality was TEE (20 vs. 12.9%, OR = 1.7, 95% CI = 1.0–2.8) but not TTE (10.4 vs. 7.8%, p = 0.75) or TCD (22.8 vs. 20.1%, p = 0.56).

Conclusions: Given the limitations of autopsy and TEE studies, there is good reason not to take a fixed 25% PFO prevalence for granted. The estimation of degree of causality may be underestimated or overestimated in populations with PFO prevalence significantly lower or higher than the established. Given the high sensitivity, non-invasive nature, low cost, and repeatability of TCD, future large-scale TCD-based studies should investigate potential heterogeneity in PFO prevalence in different healthy racial/ethnic populations.

Migraine with visual aura is a risk factor for incident atrial fibrillation: A cohort study

OBJECTIVE

Migraine with visual aura is associated with cardioembolic stroke risk. The aim of this study was to test association between migraine with visual aura and atrial fibrillation (AF), in the Atherosclerosis Risk in Communities study.

METHODS

In the Atherosclerosis Risk in Communities study, a longitudinal, community-based cohort study, participants were interviewed for migraine history in 1993-1995 and were followed for incident AF through 2013. AF was adjudicated using ECGs, discharge codes, and death certificates. Multivariable Cox proportional hazards models were used to study the relation between migraine and its subtypes with incident AF, compared with controls without headaches. Mediation analysis was conducted to test whether AF was a mediator of migraine with visual aura-associated stroke risk.

RESULTS

Of 11,939 participants assessed for headache and without prior AF or stroke, 426 reported migraines with visual aura, 1,090 migraine without visual aura, 1,018 nonmigraine headache, and 9,405 no headache. Over a 20-year follow-up period, incident AF was noted in 232 (15%) of 1,516 with migraine and 1,623 (17%) of 9,405 without headache. After adjustment for multiple confounders, migraine with visual aura was associated with increased risk of AF compared to no headache (hazard ratio 1.30, 95% confidence interval 1.03-1.62) as well as when compared to migraine without visual aura (hazard ratio 1.39, 95% confidence interval 1.05-1.83). The data suggest that AF may be a potential mediator of migraine with visual aura-stroke risk.

CONCLUSIONS

Migraine with aura was associated with increased risk of incident AF. This may potentially lead to ischemic strokes.

Patent Foramen Ovale Closure Versus Medical Therapy in Cryptogenic Strokes and Transient Ischemic Attacks: A Meta-Analysis of Randomized Trials

Cryptogenic strokes account for about 25% to 40% of total ischemic strokes, and 1 of the 3 of these have a patent foramen ovale (PFO). A meta-analysis concerning the effectiveness and safety of PFO closure in cryptogenic strokes or transient ischemic attacks (TIAs) was performed. We systematically searched Medline, Embase, and the Cochrane Library through April 2018. Eligible studies were randomized clinical trials. Primary and secondary end points were, respectively, stroke or TIA and stroke recurrences. We calculated risk ratios (RRs) and 95% confidence intervals (CIs) for all end points using fixed- and random-effects meta-analyses. Data were included from 6 trials involving 3560 patients. In the pooled analysis, PFO closure was superior to medical treatment for both primary (RR: 0.39; 95% CI: 0.18-0.82; P < .02) and secondary end points (RR: 0.58; 95% CI: 0.44-0.76; P < .001). Transcatheter closure significantly increased the risk of new-onset atrial fibrillation (AF; RR: 5.74; P < .001). Percutaneous closure is superior to medical treatment in reducing stroke and TIA recurrence, even if with a significant risk increasing for new-onset AF. These findings suggest that transcatheter closure is indicated in patients with cryptogenic strokes and large PFO.

Clinical and infarction patterns of PFO-related cryptogenic strokes and a prediction model

Objectives

The higher than expected PFO rate in CS patients has raised concerns that paradoxical embolism maybe the pathophysiologic mechanism for strokes. However, only a small proportion of pathogenic PFOs cause CS. Therefore, accurate recognition of patients with pathogenic PFOs among all CS patients could guide clinical decision making in selecting the most appropriate treatment. The aim of this study was to devise a new algorithm to stratify cryptogenic stroke (CS) patients into pathogenic patent foramen ovale (p‐PFO)‐ and non‐p‐PFO‐related patients.

Methods

A total of 1201 patients with acute ischemic stroke were recruited from two different medical centers, and 253 CS patients were identified. Of the 253 patients, 111 were diagnosed with PFO using contrast transcranial Doppler. Data on medical histories, neuroimaging and laboratory tests were compared in CS patients with or without PFO.

Results

Compared with PFO‐negative CS patients, PFO‐positive CS patients showed younger onset age, lower incidence of hypertension and dyslipidemia, characteristic infarction pattern in magnetic resonance imaging and specifically altered platelet activity and coagulation function. Based on the above information, we constructed a PFO judgment formula (Hr‐PFOJ) by means of feature weight estimation and predictive performance evaluation to predict pathogenic PFO in CS patients with a sensitivity of 76.3% and a specificity of 66.5%.

Interpretations

Hr‐PFOJ judgment formula is a useful screening tool for identification of patients with pathogenic PFO who may benefit from PFO‐related treatment.

Migraine as possible red flag of PFO presence in suspected demyelinating disease

OBJECTIVES

To investigate a possible association between isolated white matter lesions suggestive of demyelinating disease in magnetic resonance imaging (MRI) and patent foramen ovale (PFO) evidence in migraine patients, with or without aura.

MATERIALS

31 migraine patients, 28 females and 3 males, with MRI evidence of white matter lesions suggestive of demyelinating disease according to the Barkhof Criteria. All patients underwent further diagnostics including lumbar puncture, autoimmunity panel and cardiological evaluation to detect the presence of PFO. The mean duration of follow-up was 3.46 years and MIPAV software was used to analyze MRI imaging.

RESULTS

14 of the 31 patients (45%) had PFO. A significant association was found between PFO and migraine with visual aura (p < 0.001). No difference in lesion number, volume or area between patients with and without PFO was found, but the distribution was mainly occipital (p < 0.001) in patients with PFO. The follow-up showed a stationary lesion load in all PFO patients; no infratentorial or spinal cord lesion and no enhancement or corpus callosum lesion was ever detected. At the end of follow-up four patients developed multiple sclerosis: younger age at first MRI and oligoclonal bands were associated risk factors.

CONCLUSIONS

Migraine is often one of the main symptoms leading to MRI, and in many cases white matter lesions of unspecific significance are discovered, thus placing demyelinating diseases in the differential diagnosis. Our study underlines the potential pathogenetic role of PFO in generating white matter lesions in migraine patients (45%), particularly those with visual aura and occipital lesions. For this reason, we affirm that PFO represents a cardinal point in the differential diagnosis of suspected demyelinating disease.

Posterior versus Anterior Circulation Stroke in Young Adults: A Comparative Study of Stroke Aetiologies and Risk Factors in Stroke among Young Fabry Patients (sifap1)

BACKGROUND

Although 20-30% of all strokes occur in the posterior circulation, few studies have explored the characteristics of patients with strokes in the posterior compared to the anterior circulation so far. Especially data on young patients is missing.

METHODS

In this secondary analysis of data of the prospective multi-centre European sifap1 study that investigated stroke and transient ischemic attack (TIA) patients aged 18-55 years, we compared vascular risk factors, stroke aetiology, presence of white matter hyperintensities (WMH) and cerebral microbleeds (CMB) between patients with ischaemic posterior circulation stroke (PCS) and those having suffered from anterior circulation stroke (ACS) based on cerebral MRI.

RESULTS

We diagnosed PCS in 612 patients (29.1%, 407 men, 205 women) and ACS in 1,489 patients (70.9%). Their age (median 46 vs. 47 years, p = 0.205) and stroke severity (modified Rankin Scale: both 2, p = 0.375, Barthel Index 90 vs. 85, p = 0.412) were similar. PCS was found to be more frequent among the male gender (66.5 vs. 60.1% with ACS, p = 0.003). Vertebral artery (VA) dissection was more often the cause of PCS (16.8%) than was carotid artery dissection of ACS (7.9%, p < 0.001). Likewise, small vessel disease (Trial of Org 10172 in Acute Stroke Treatment [TOAST] = 3, PCS: 14.7%, ACS: 11.8%) and stroke of other determined aetiology (TOAST = 4, PCS: 24.5%, ACS: 16.0%) were more frequent in those with PCS. Furthermore, patent foramen ovale (PFO; PCS: 31.1%, ACS: 25.4%, p = 0.029) was more often detected in patients with PCS. In contrast, large-artery atherosclerosis (TOAST = 1, PCS: 15.4%, ACS: 22.2%) and cardio-embolic stroke (TOAST = 2, PCS: 15.6%, ACS: 18.0%) were less frequent in those with PCS (p < 0.001) as were preceding cerebrovascular events (10.1 vs. 14.1%, p = 0.014), TIA (4.8 vs. 7.7%, p = 0.016) and smoking (53.2 vs. 61.0%, p = 0.001). The presence, extent, and location of WMH and CMB did not differ between the 2 groups.

CONCLUSIONS

Our data suggested a different pattern of aetiology and risk factors in young patients with PCS compared to those with ACS. These findings especially call for a higher awareness of VA dissection and potentially for more weight of a PFO as a risk factor in young patients with PCS. Clinical trial registration-URL: http://www.clinicaltrials.gov; NCT00414583.

Patent Foramen Ovale With Atrial Septal Aneurysm Is Strongly Associated With Migraine With Aura: A Large Observational Study

BACKGROUND

A patent foramen ovale (PFO) with atrial septal aneurysm (ASA) has been identified as a risk factor for cryptogenic stroke. Patients with migraine with aura (MA) appear to be at risk for silent brain infarction, which might be related to the presence of a PFO. However, the association between MA and PFO with ASA has never been reported. We examined this association in a large observational study.

METHODS AND RESULTS

Patients (>18 years) who underwent an agitated saline transesophageal echocardiography (cTEE) at our outpatient clinics within a timeframe of 4 years were eligible to be included. Before cTEE they received a validated headache questionnaire. Two neurologists diagnosed migraine with or without aura according to the International Headache Criteria. A total of 889 patients (mean age 56.4±14.3 years, 41.7% women) were included. A PFO was present in 23.2%, an isolated ASA in 2.7%, and a PFO with ASA in 6.9%. The occurrence of migraine was 18.9%; the occurrence of MA was 8.1%. The prevalence of PFO with ASA was significantly higher in patients with MA compared to patients without migraine (18.1% vs 6.1%; OR 3.72, 95% CI 1.86-7.44, P<0.001). However, a PFO without ASA was not significantly associated with MA (OR 1.50, 95% CI 0.79-2.82, P=0.21). Interestingly, a PFO with ASA was strongly associated with MA (OR 2.71, 95% CI 1.23-5.95, P=0.01).

CONCLUSION

In this large observational study, PFO with ASA was significantly associated with MA only. PFO closure studies should focus on this specific intra-atrial anomaly.

Low Incidence of Atrial Fibrillation in Patients with Transient Ischemic Attack

Background

Atrial fibrillation (AF) is a major cause of stroke. Therefore, all patients with ischemic stroke or transient ischemic attack (TIA) should be examined with 12-lead electrocardiogram (ECG) and continuous monitoring to detect AF. Current guidelines recommend at least 24 h continuous ECG monitoring, which is primarily based on studies investigating patients with ischemic stroke. The aim of our study was to investigate the diagnostic yield of 12-lead ECG and Holter monitoring in patients with TIA.

Methods

We retrospectively investigated all patients diagnosed with TIA at Odense University Hospital, Denmark, from January 1, 2014 to December 31, 2014. TIA was a clinical diagnosis according to the WHO definition. Patients received admission ECG and 72-hour Holter monitoring after discharge.

Results

171 patients without known AF were diagnosed with TIA. Four (2.3%) were diagnosed with AF on admission ECG. Another 2 (1.2%) were diagnosed with AF on Holter monitoring. In total, 6 patients (3.5%) were diagnosed with AF. Patients with AF were significantly older (mean age 79.4 [95% CI 65.1-93.6] years) than patients without AF (mean age 67.6 [95% CI 65.6-69.5] years) but otherwise showed no difference in baseline characteristics.

Conclusion

In this retrospective study, patients with TIA had a low incidence of AF detected with ECG and 72-hour Holter monitoring. Prospective studies are needed to confirm these findings.

Patent Foramen Ovale and Cryptogenic Strokes in the Stroke in Young Fabry Patients Study

BACKGROUND AND PURPOSE

A patent foramen ovale (PFO) is disproportionately prevalent in patients with cryptogenic stroke. Without alternative explanations, it is frequently considered to be causative. A detailed stratification of these patients may improve the identification of incidental PFO.

METHODS

We investigated the PFO prevalence in 3497 transient ischemic attack and ischemic stroke patients aged 18 to 55 years in the prospective multicenter SIFAP1 study (Stroke in Young Fabry Patients 1) using the ASCO classification. Patients without an obvious cause for transient ischemic attack/stroke (ASCO 0) were divided into subgroups with and without vascular risk factors (ASCO 0+ and 0-). In addition, we looked for PFO-related magnetic resonance imaging lesion patterns.

RESULTS

PFO was identified in 25% of patients. Twenty percent of patients with a definite or probable cause of transient ischemic attack/stroke (≥1 grade 1 or 2 ASCO criterion; n=1769) had a PFO compared with 29% of cryptogenic stroke patients (ASCO 0 and 3; n=1728; P<0,001); subdivision of cryptogenic strokes revealed a PFO in 24% of 978 ASCO 3 patients (n.s. versus ASCO 1 and 2) and a higher prevalence of 36% in 750 ASCO 0 cases (P<0.001 versus ASCO 3 and versus ASCO 1 and 2). PFO was more commonly observed in ASCO 0- (n=271) than in ASCO 0+ patients (n=479; 48 versus 29%; P<0.001). There was no PFO-associated magnetic resonance imaging lesion pattern.

CONCLUSIONS

Cryptogenic stroke patients demonstrate a heterogeneous PFO prevalence. Even in case of less conclusive diseases like nonstenotic arteriosclerosis, patients should preferentially be considered to have a non-PFO-mediated stroke.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00414583.

The Epidemiology of Atrial Fibrillation and Stroke

The burden of stroke is increasing due to aging population and unhealthy lifestyle habits. The considerable rise in atrial fibrillation (AF) is due to greater diffusion of risk factors and screening programs. The link between AF and ischemic stroke is strong. The subtype most commonly associated with AF is cardioembolic stroke, which is particularly severe and shows the highest rates of mortality and permanent disability. A trend toward a higher prevalence of cardioembolic stroke in high-income countries is probably due to the greater diffusion of AF and the control of atherosclerotic of risk factors.

The potential role of the left atrial septal pouch in cryptogenic stroke

The left atrial septal pouch (LASP) is an anatomic variant of the atrial septum that forms a blind-ending pouch, communicating exclusively with the left atrium (LA). Case reports have demonstrated thrombus within LASP and in the setting of cryptogenic stroke. Initial epidemiologic results are mixed, one study showing and others not showing an association between LASP and cryptogenic stroke. Additional investigation should take place to determine the clinical significance of LASP and what interventions are required to prevent ischemic stroke in at-risk individuals.

PFO Closure for Cryptogenic Stroke

A patent foramen ovale (PFO) is a common finding in the general population and has been theorized to be a mechanism for ischemic stroke primarily due to a deep venous thrombus embolizing through the shunt into the arterial circulation. There has been much debate regarding the association between PFO and stroke, especially in the case of a cryptogenic stroke (i.e., stroke of unknown etiology) in a younger patient without other risk factors. Traditionally, when a PFO is detected, antithrombotic therapy to mitigate risk of a future ischemic event has been the mainstay of treatment. More recently, both surgical and transcatheter closure of a PFO have been widely utilized. However, there are only few randomized controlled trials assessing the efficacy of PFO closure for stroke prevention.