Assessment of Morphology of Patent Foramen Ovale with Transesophageal Echocardiography in Symptomatic and Asymptomatic Patients

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.

Change in patent foramen ovale height is associated with cryptogenic stroke and the construction of a morphology-based scoring system

Introduction

Current guidelines recommended patent foramen ovale (PFO) occlusion as the preferred treatment for PFO-related cryptogenic stroke (CS); however, finding the causative foramen ovale remains challenging. This study aimed to identify predictors and establish a scoring system by assessing PFO morphology and stroke-related factors.

Methods

Based on a prospective multicenter registered clinical trial, we compared data mainly derived from transesophageal echocardiography (TEE) and clinical history in patients with PFO-related CS and those without CS (non-CS) with incidental PFO. Subsequently, we explored independent predictors using logistic analysis, established a scoring system based on the results, and finally evaluated the scoring system using receiver operating characteristic (ROC) analysis and internal validation.

Results

75 patients with PFO-related CS and 147 non-CS patients were enrolled. Multivariate logistic analysis showed that the change in PFO height, large PFO, atrial septal aneurysm (ASA), and sustained right-to-left shunt (RLS) had independent relationships with CS. Based on the odds ratio value of each independent factor, a scoring system was built: change in PFO height ≥ 1.85 mm (3 points), large PFO (2 points), ASA (5 points), sustained RLS (2 points). 0–2 points correspond to low-risk PFO, 3–5 points medium-risk PFO, and 7–12 points high-risk PFO. ROC analysis showed an area under the curve of 0.80 to predict CS. The proportion of patients with CS is increasing based on these points.

Conclusions

Our study screened out the change in PFO height as an independent predictor of CS. A simple and convenient scoring system can provide constructive guidance for identifying whether the PFO is causal and consequently selecting patients more likely to benefit from closure.

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.

Effect of ASA on the risk of cerebrovascular ischemic events in patients with PFO

Background

Whether atrial septal aneurysm (ASA) increases the risk of cerebrovascular ischemic events in patients with patent foramen ovale (PFO) remains controversial.

Objective

We constructed a detailed meta‐analysis to assess the effect of ASA on risk of cerebrovascular ischemic events in patients with PFO.

Methods

Randomized controlled trials (RCTs) and observational studies (cohort studies and case‐control studies) that compared PFO‐ASA against PFO alone were included. Pooled odds ratios (OR) estimates and 95% CI were calculated using the fixed‐effect and random‐effect models.

Results

Four RCTs and twelve observational studies (five cohort studies and seven case‐control studies) contributed to the meta‐analysis. The pooled results of case‐control studies showed that ASA increased the risk of cerebrovascular ischemic events in patients with PFO (fixed‐effect model: OR = 3.69; 95% CI: 2.67–5.09; p < 0.01, random‐effect model: OR = 3.63; 95% CI: 2.51–5.24; p < 0.01). However, poole results from RCTs (fixed‐effect model: OR = 1.24; 95% CI: 0.78–1.95; p = 0.36, random‐effect model: OR = 1.27; 95% CI: 0.78–2.08; p = 0.34) and cohort studies (fixed‐effect model: OR = 1.35; 95% CI: 0.81–2.23; p = 0.25, random‐effect model: OR = 1.40; 95% CI: 0.84–2.33; p = 0.20) found no evidence. Overall analysis showed that ASA increased the risk of cerebrovascular ischemic events (fixed‐effect model: OR = 2.30; 95% CI: 1.84–2.87; p < 0.01, random‐effect model: OR = 2.11; 95% CI: 1.48–3.01; p < 0.01). The sensitivity analysis confirmed the stability of all results.

Conclusions

Although case‐control studies support ASA to increase the risk of cerebrovascular ischemic events in patients with PFO, RCTs and cohort studies challenged the credibility. Further prospective studies are needed to confirm the effect of ASA on patients with 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.

EACVI recommendations on cardiovascular imaging for the detection of embolic sources: endorsed by the Canadian Society of Echocardiography

Cardioaortic embolism to the brain accounts for approximately 15-30% of ischaemic strokes and is often referred to as 'cardioembolic stroke'. One-quarter of patients have more than one cardiac source of embolism and 15% have significant cerebrovascular atherosclerosis. After a careful work-up, up to 30% of ischaemic strokes remain 'cryptogenic', recently redefined as 'embolic strokes of undetermined source'. The diagnosis of cardioembolic stroke remains difficult because a potential cardiac source of embolism does not establish the stroke mechanism. The role of cardiac imaging-transthoracic echocardiography (TTE), transoesophageal echocardiography (TOE), cardiac computed tomography (CT), and magnetic resonance imaging (MRI)-in the diagnosis of potential cardiac sources of embolism, and for therapeutic guidance, is reviewed in these recommendations. Contrast TTE/TOE is highly accurate for detecting left atrial appendage thrombosis in patients with atrial fibrillation, valvular and prosthesis vegetations and thrombosis, aortic arch atheroma, patent foramen ovale, atrial septal defect, and intracardiac tumours. Both CT and MRI are highly accurate for detecting cavity thrombosis, intracardiac tumours, and valvular prosthesis thrombosis. Thus, CT and cardiac magnetic resonance should be considered in addition to TTE and TOE in the detection of a cardiac source of embolism. We propose a diagnostic algorithm where vascular imaging and contrast TTE/TOE are considered the first-line tool in the search for a cardiac source of embolism. CT and MRI are considered as alternative and complementary tools, and their indications are described on a case-by-case approach.

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.

Relationship between non-headache symptoms and right to left shunt in episodic migraine. A single-center cross-sectional study

The relationship between right to left shunt (RLS) and non-headache symptoms (NHS) in episodic migraine is unknown. This study aimed to investigate the incidence and classification of RLS in episodic migraineurs, calculate the occurrence rate of NHS, and analyze the associations between RLS and NHS. We consecutively recruited 204 episodic migraine patients. Contrast-enhanced transcranial doppler was adopted to screen RLS. Structured questionnaire via face-to-face survey was conducted to collect clinical data. A total of 172 episodic migraineurs were included in the final analysis, of which 20 cases were migraine with aura. The positive rate of RLS was 47.1%, of which 50 cases (29.0%) had small shunt (Grade 1) and 31 cases (18.1%) had mid-large shunt (Grade 2-4). The most common NHS was nausea (115 (66.9%)), followed by headache aggravation with physical activity (96 (55.8%)), dizziness (93 (54.1%)), vomiting (77 (44.8%)) and phonophobia (74 (43.0%)). Yawning was more common in Grade 2-4 group than Grade 0 group (p = 0.012), while no statistical differences among other groups. Grade 2-4 group had a higher rate of headache aggravation with physical activity than grade 0 group (p = 0.008). Binary logistic regression analysis showed that yawning at premonitory phase, headache aggravation with physical activity and cranial autonomic symptoms during attack are independent predictors of RLS. In conclusion, yawning and headache aggravation with physical activity are more common in migraine patients with RLS. Besides aura, particular NHS may also serve as indicators for screening RLS in episodic migraineurs.

The Value of Contrast-Enhanced Transesophageal Echocardiography in the Detection of Cardiac Right-to-Left Shunt Related with Cryptogenic Stroke and Migraine

Purpose

To analyze the characteristics of right-to-left shunt (RLS) in patients with cryptogenic stroke and migraine by contrast-enhanced transesophageal echocardiography (c-TEE).

Methods

The study population consisted of 330 patients with cryptogenic stroke and 330 patients with migraine who suspected PFO. All of them received c-TEE examination successfully. In terms of c-TEE analyses, RLS could be diagnosed when microbubbles were visualized in the transition from the right atrium to the left atrium. For semiquantitative analysis, a small amount of RLS was grade 1, indicating 1-10 microvesicles per frame could be seen in the left atrium, a moderate amount of RLS was grade 2, indicating 11-30 microvesicles per frame could be seen in the left atrium, and a large amount of RLS was grade 3, indicating more than 30 microvesicles per frame, or the left atrium is filled with microvesicles.

Results

A total of 660 patients were analyzed in the study. PFO-RLS was detected in 348 (348/660, 52.7%) cases by TEE, while in 392 (392/660, 59.3%) cases by c-TEE. Simultaneously, P-RLS was detected in 239 (239/660, 36.2%) cases by c-TEE. Among 330 patients with cryptogenic stroke, PFO-RLS was detected in 198 cases; according to the c-TTE method (198/330, 60.0%), concurrently, 83 participants suffered from PFO-RLS and P-RSL (83/330, 25.1%), including 1 case with PFO and pulmonary arteriovenous fistula. Among 330 patients with migraine, PFO-RLS was detected in 194 cases; according to the c-TTE method (194/330, 58.7%), specifically, 90 participants suffered from PFO-RLS and P-RSL (90/330, 27.2%). There was no statistical significance between the two groups. P-RLS singly was detected in 28 cases with cryptogenic stroke, while in 38 cases with migraine, excluding from pulmonary arteriovenous fistula by CTA examination. In addition, semiquantitative results on c-TTE grading of RLS were compared between the two groups: grade 1 RLS in the migraine group (144/322) was significantly higher than that in the cryptogenic stroke group (71/309) (P < 0.05). Grade 3 RLS in the cryptogenic stroke group (113/309) was significantly higher than that in the migraine group (67/322) (P < 0.05). For grade 2 RLS, there was no statistical difference between the two groups (P = 0.12).

Conclusions

c-TEE can increase the positive rate of PFO diagnosis compared with TEE color Doppler. There is no significant difference in the incidence of PFO-PLS and P-RLS between the cryptogenic stroke group and the migraine group. The grades 2-3 RLS are mainly detected in the cryptogenic stroke group, while grades 1-2 RLS are mostly detected in the migraine group.

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.

Thromboembolism in the Absence of Atrial Fibrillation

Atrial fibrillation (AF) is associated with thrombus formation in the left atrial appendage and systemic embolic events including ischemic stroke. Cardiogenic thromboembolism can also occur in the absence of clinical AF as a result of various pathological conditions affecting the endocardium. The inconsistent temporal relation between AF and ischemic events has stimulated exploration for factors other than clinical AF that contribute to thromboembolism. These include subclinical AF, a thrombogenic atrial cardiomyopathy, and left atrial appendage dysfunction and embolism from other sources. In conclusion, thromboembolism during normal sinus rhythm is likely multifactorial, involving intertwined pathologic processes. Patients at risk, if accurately identified, could theoretically benefit from anticoagulation.

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.

Percutaneous transcatheter closure of high-risk patent foramen ovale in the elderly

The efficacy of percutaneous transcatheter closure for preventing recurrent cerebrovascular events in elderly patients with high-risk patent foramen ovale (PFO) remains unclear, whereas in young patients, it has been shown to effectively prevent the recurrence of embolic stroke. The aim of this study was to investigate the safety and efficacy of percutaneous PFO closure in elderly patients with high-risk PFO. Between September 2012 and October 2018, 14 patients ≥ 60 years old with high-risk PFO underwent percutaneous closure to prevent recurrence of cerebrovascular events. The primary end point was recurrence of cerebrovascular events after closure in elderly patients with high-risk PFO, and the secondary end points were occurrence of device-related complications, cerebral hemorrhage, and new-onset atrial fibrillation (AF). The mean patient age and number of cerebrovascular events before closure were 75.2 ± 6.5 years and 1.7 ± 0.7, respectively. All procedures were successfully performed under general anesthesia by transesophageal echocardiography and using a 25-mm Amplatzer Cribriform device. No procedure-related complications occurred. Patients were followed up for a mean 2.6 ± 1.8 years. No patients experienced device-related complications or recurrent cerebrovascular events. However, one patient had AF-related device closure complications at 1 month postoperatively. In addition, other patient had a cerebral hemorrhage with unknown relationship to PFO closure 3 years postoperatively. Percutaneous closure of high-risk PFO in elderly patients may be as effective and safe as in younger patients. It is crucial to evaluate PFO morphology regardless of age in cases of paradoxical embolism.