Patent Foramen Ovale: Echocardiographic Detection and Clinical Relevance in Stroke

Patent Foramen Ovale and Atrial Septal Defect

Patent foramen ovale (PFO) and atrial septal defects (ASDs) are two types of interatrial communications with unique clinical presentations and management strategies. The PFO is a normal part of fetal development that typically closes shortly after birth but may persist in as many as 25% to 30% of adults. The communication between atria may result in paradoxic embolism and embolic stroke. On the other hand, ASDs (anatomically defined as secundum, primum, sinus venosus, and coronary sinus in order of prevalence) typically result in right heart volume overload and are often associated with other congenital defects. The diagnostic methods, treatment options including surgical and percutaneous approaches, and potential complications are described. Both conditions underline the significance of precise diagnosis and appropriate management to mitigate risks and ensure optimal patient outcomes.

Percutaneous closure of simple congenital heart diseases under echocardiographic guidance

Congenital heart disease (CHD), birth defect with the highest incidence rates worldwide, and is mainly characterized by the abnormal internal structure of the heart or/and the anatomical structure of great vessels. In the past few decades, CHD repair surgery through standard median sternotomy incision combined with cardiopulmonary bypass (CPB) technology has been considered the gold standard for surgical correction of heart and great vessels. With the promotion and clinical application of interventional catheterization technology, transcatheter closure of CHD under radioactive radiation has gradually been recognized and applied. However, its radiation exposure and potential complications related to arteriovenous vessels still face challenges. In recent years, an increasing number of surgeons have explored new surgical procedures, for the safe and effective treatment of CHD, as far as possible to reduce surgical trauma, avoid radiation exposure, and improve the cosmetic effect. Therefore, on the premise of satisfactory exposure or guidance, how to integrate ultrasound and percutaneous interventional technology remained the focus of the exploration. This mini-review highlights and summarizes the signs of progress of ultrasound intervention in the last decade that have proven the effectiveness and operability of a well-established procedure for percutaneous closure of congenital heart diseases under echocardiographic guidance only. We discuss potential diseases that will benefit from this emerging procedure based on this progress. Owing to the crucial advantages played by this strategy in the treatment of CHD, better understanding and promotion of this less exploited field may contribute to the development of therapeutics targeting CHD, improve medical utilization rate, promote the optimization of medical resources, and ultimately achieve precise and efficient medical treatment.

Visualized Embolization of Inferior Vena Cava Thrombus During the Abdominal Compression Maneuver to Evaluate for a Patent Foramen Ovale

•IVC compression is an alternative to Valsalva to confirm the presence of a PFO. •A drawback of this method is reduced IVC compression in obese patients. •Use with caution in patients with low cardiac output and gastrointestinal diseases. •No complications while performing this maneuver have been reported. •We report visualized thrombus in the RA during the IVC compression maneuver.

Pearls and Pitfalls in the Transesophageal Echocardiographic Diagnosis of Patent Foramen Ovale

Large randomized controlled trials have shown the benefits of percutaneous closure of patent foramen ovale (PFO) in patients with cryptogenic stroke and PFO. Recent studies have highlighted the clinical significance and prognostic implication of various anatomical features of PFO and the adjacent atrial septum, such as atrial septal aneurysm (ASA), PFO size, large shunt, and hypermobility. Transthoracic echocardiography with contrast study is used for the indirect diagnosis of PFO, as it reveals the passage of the contrast into the left atrium. In contrast, transesophageal echocardiography (TEE) offers a direct demonstration of PFO by measuring its size using the maximum separation distance between the septum primum and septum secundum. Furthermore, TEE enables the acquisition of detailed anatomical features of the adjacent atrial septum including ASA, hypermobility, and PFO tunnel length, which carry significant prognostic implications. Transesophageal echocardiography also facilitates the diagnosis of pulmonary arteriovenous malformation, a relatively rare cause of paradoxical embolism. This review provides evidence for supporting TEE as a useful screening test for patients with cryptogenic stroke to identify suitable candidates for percutaneous device closure of PFO. Additionally, cardiac imaging specialists with proficiency in comprehensive TEE examination should be part of the heart-brain team for proper evaluation of and decision-making in patients with cryptogenic stroke.

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.

Transcranial Doppler ultrasound: Clinical applications from neurological to cardiological setting

Transcranial Doppler (TCD) ultrasonography is a rapid, noninvasive, real-time, and low-cost imaging technique. It is performed with a low-frequency (2 MHz) probe in order to evaluate the cerebral blood flow (CBF) and its pathological alterations, through specific acoustic windows. In the recent years, TCD use has been expanded across many clinical settings. Actually, the most widespread indication for TCD exam is represented by the diagnosis of paradoxical embolism, due to patent foramen ovale, in young patients with cryptogenic stroke. In addition, TCD has also found useful applications in neurological care setting, including the following: cerebral vasospasm following acute subarachnoid hemorrhage, brain trauma, cerebrovascular atherosclerosis, and evaluation of CBF and cerebral autoregulation after an ischemic stroke event. The present review aimed to describe the most recent evidences of TCD utilization from neurological to cardiological setting.

Short-term results of percutaneous closure of a patent foramen ovale guided by transoesophageal echocardiography in patients with cryptogenic stroke: a retrospective study

Background

A patent foramen ovale (PFO) is a risk factor for cryptogenic stroke (CS), and interventional therapy for PFO can reduce the recurrence rate of CS. However, interventional therapies are primarily guided by X-ray imaging, and data on regular post-surgical follow-up with the transthoracic ultrasound foaming test (UFT) are rare. Thus, this study aimed to assess the short-term (12 months) results of PFO occlusion guided by transoesophageal echocardiography (TEE) and the results of regular UFTs.

Methods

Clinical records, echocardiographic data, and UFT results of 75 patients who underwent interventional therapy for PFO and CS were retrospectively analysed. The patients were grouped according to their preoperative UFT results: group A (n = 21), small volume of right-to-left shunts; group B (n = 22), moderate volume of right-to-left shunts; and group C (n = 32), large volume of right-to-left shunts. All patients were treated with an Amplatzer occluder under TEE guidance. UFT follow-up was conducted regularly until 12 months after surgery.

Results

No significant differences in preoperative data, length of hospital stay, or operative time were noted between the groups (p > 0.05). The length of the PFO and diameter of the occluder differed between the groups as follows: group A = group B < group C (p < 0.001). Notably, 1 patient in group C developed recurrent stroke 11 months postoperatively, and 2 patients in group C developed atrial arrhythmia, which improved after 3 months of antiarrhythmic treatment. However, 19 patients still had positive UFT results 12 months postoperatively. Furthermore, the positive UFT rate 12 months postoperatively differed between the groups as follows: group A = group B < group C (p < 0.05). A preoperative large-volume shunt was negatively associated with a negative UFT rate 12 months postoperatively (OR = 0.255, 95% CI: 0.104–0.625).

Conclusions

In patients with PFO and CS, interventional therapy guided by TEE could lead to satisfactory short-term (12 months) outcomes. Although the positive UFT rate gradually decreased, some patients still had positive UFT results 12 months postoperatively. Preoperatively, a large volume of right-to-left shunts and a longer PFO were the two risk factors for positive UFT results postoperatively. Further studies are required to clarify the relationship between postoperative positive UFT results and stroke recurrence.

Increased Mobility of the Atrial Septum in Aortic Root Dilation: An Observational Study on Transesophageal Echocardiography

Background: There is a growing interest in the relationship between atrial septal anatomy and cardioembolic stroke. Anecdotal reports suggest that the enlargement of the aortic root could interfere with atrial septal mobility (ASM). We sought to investigate the association between ASM and aortic root dilation.

Methods and Findings: From all consecutive clinically requested transesophageal echocardiogram (TEE) studies performed during the study period in a single institution, we were able to review and evaluate the ASM and anteroposterior length, aortic root diameter, and the prevalence of atrial septal aneurysm (ASA) and of patent foramen ovale (PFO) in 336 studies. Additional variables, such as left ventricular ejection fraction, left atrial diameter, diastolic dysfunction, age, sex, weight, height, previous stroke, atrial fibrillation, and TEE indication, were extracted from patient medical records and echocardiographic clinical reports. In 336 patients, we found a mean ASM of 3.4 mm, ranging from 0 to 21 mm; 15% had ASA and 14% had PFO. There was a 1.0 mm increase in ASM for every 10-mm increase in aortic root diameter adjusted for age, sex, weight, height, ejection fraction, and left atrial size (B = 0.1; P = 0.04). Aortic diameter was not associated with a smaller septal length (B = 0.03; P = 0.7).

Conclusion: An increased motion of the atrial septum can occur in association with aortic dilation. These findings deserve attention for the relevance of aortic root anatomy in future studies involving atrial septal characteristics and embolic stroke risk.

The correlation between patent foramen ovale and brain ischemia in plateau residents

Background

It has been suggested that patent foramen ovale (PFO) contributes to the majority of cryptogenic stroke cases in young people, however, the direct link is still undetermined. Here we analyzed the correlation between PFO and brain ischemia lesions in a cohort of cases that were long-term residents in the plateau to provide solid evidence to support the causal relation between PFO and brain ischemia lesion or cryptogenic stroke.

Methods

Long-term residents with young age from Qinghai Plateau were recruited and separated by PFO positivity. Brain MRI was used to image 100 PFO positive cases and 100 healthy controls. The diameter of PFO was measured by echocardiography. The location, number and anterior/posterior circulation of ischemia lesions were also evaluated. The correlation between PFO (including positivity and diameter) and brain ischemia lesion (including positivity and other characteristics) was analyzed by chi-square test. Further, the chi-square test for the trend test was used to analyze the linear correlation between these groups.

Results

We found a strong correlation between the positivity of PFO and brain ischemia lesion, with 71% of PFO cases showing the presence of brain ischemia lesions, and only 19% for healthy controls (p < 0.001). The diameter of PFO is strongly and linearly correlated with the incidence rate of brain ischemia lesion (RR = 3.737 (95%CI 2.496 to 5.767).

Conclusion

We found a convincing correlation between the positivity of PFO and brain ischemia lesion in residents of the plateau. Our findings provide another solid evidence of the direct causal relation between PFO and brain ischemia lesion.

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.

Central Retinal Artery Occlusion Secondary to Patent Foramen Ovale: The Unexpected Journey of a Paradoxical Embolus

Central retinal artery occlusion (CRAO) represents one of the most devastating ophthalmic emergencies, since the inner two-thirds of the retina lose their blood supply. The acute obstruction of the central retinal artery is characterized by severe, sudden and unilateral painless visual loss and usually occurs secondary to an embolus of cardiovascular origin. A paradoxical thromboembolic event of the central retinal artery through patent foramen ovale is an exceptionally unusual clinical entity as well as a great diagnostic challenge since the source of initial thrombus formation requires extensive investigation. Herein, we aim to describe a patient with no significant comorbidities who experienced a paradoxical thromboembolic episode of central retinal artery associated with patent foramen ovale.

Reducing the incidence of venous air embolism in contrast-enhanced CT angiography using preflushing of the power injector

AIM

To evaluate whether preflushing before connecting a power injector to a patient's catheter reduces the incidence of venous air embolism (VAE) in contrast-enhanced computed tomography (CT) angiography (CTA).

MATERIALS AND METHODS

With the approval from the local ethics committee, consecutive patients were divided randomly into a control group and a preflushing group and underwent CTA from June to November 2017. The control group underwent the conventional injection procedure. In the preflushing group, the injector tubes were flushed at high speed (10 ml/s) with saline before being connected to the patients' indwelling catheters. The locations, number, and sizes of VAE were analysed. The difference in the incidence of VAE between the two groups was compared.

RESULTS

A total of 4,900 adults (control/preflushing, 2,190/2,710) were included and 228 (4.65%) patients were found to have 318 VAEs (285 bubbles and 33 gas-liquid plane VAEs). The incidence of VAE in the preflushing group (3.21%) was lower than that in the control group (6.44%); a similar trend was observed for multiple VAEs (p<0.05). VAEs occurred in the following locations from high to low frequency: right atrium>pulmonary artery trunk>superior vena cava>right ventricle>left brachial vein>right brachial vein. There was no significant difference in the location, shape, or diameters (p=0.19) of VAEs between the two groups.

CONCLUSIONS

The proposed preflushing procedure is simple yet effective in reducing the incidence of VAE by 50.16% in patients with CTA, thus improving safety during power injection.

Cost-effectiveness of percutaneous closure of a patent foramen ovale compared with medical management in patients with a cryptogenic stroke: from the US payer perspective

Aims: To evaluate the cost-effectiveness of percutaneous patent foramen ovale (PFO) closure, from a US payer perspective. Lower rates of recurrent ischemic stroke have been documented following percutaneous PFO closure in properly selected patients. Stroke in patients aged <60 years is particularly interesting because this population is typically at peak economic productivity and vulnerable to prolonged disability. Materials and methods: A Markov model comprising six health states (Stable after index stroke, Transient ischemic attack, Post-Transient Ischemic Attack, Clinical ischemic stroke, Post-clinical ischemic stroke, and Death) was constructed to evaluate the cost-effectiveness of PFO closure in combination with medical management versus medical management alone. The base-case model employed a 5-year time-horizon, with transition probabilities, clinical inputs, costs, and utility values ascertained from published and national costing sources. Incremental cost-effectiveness ratio (ICER) was evaluated per US guidelines, utilizing a discount rate of 3.0%. Results: At 5 years, overall costs and quality-adjusted life-years (QALYs) obtained from PFO closure compared with medical management were $16,323 vs $7,670 and 4.18 vs 3.77, respectively. At 5 years, PFO closure achieved an ICER of $21,049, beneficially lower than the conventional threshold of $50,000. PFO closure reached cost-effectiveness at 2.3 years (ICER = $47,145). Applying discount rates of 0% and 6% had a negligible impact on base-case model findings. Furthermore, PFO closure was 95.4% likely to be cost-effective, with a willingness-to-pay (WTP) threshold of $50,000 and a 5-year time horizon. Limitations: From a cost perspective, our economic model employed a US patient sub-population, so cost data may not extrapolate to other non-US stroke populations. Conclusion: Percutaneous PFO closure plus medical management represents a cost-effective approach for lowering the risk of recurrent stroke compared with medical management alone.

Multiorgan paradoxical embolism in an elderly female with a patent foramen ovale: a case report

Paradoxical embolism is an uncommon cause of arterial occlusion with a high mortality burden. Current evidence suggests that patent foramen ovale is the most important etiological factor of paradoxical embolism, by acting as a pathway for a thromboembolic material originating from the peripheral veins, passing through the lungs and entering the systemic circulation. Here we present a case of paradoxical embolism in the mesenteric and renal arteries associated with pulmonary embolism and deep vein thrombosis in an elderly woman with no predisposing risk factor. A diagnosis of paradoxical embolism was considered and the presence of a patent foramen ovale was consequently confirmed with a transesophageal echocardiography. Urgent thrombolysis saved the life of the patient. Paradoxical embolism represents an emergency and therefore prompt diagnosis and initiation of therapy may prevent adverse outcomes.

Ischaemic Stroke and the Echocardiographic "Bubble Study": Are We Screening the Right Patients?

BACKGROUND

Patent foramen ovale (PFO) is a potential mechanism for paradoxical embolism in cryptogenic ischaemic stroke or transient ischaemic attack (TIA). PFO is typically demonstrated with agitated saline ("bubble study", BS) during echocardiography. We hypothesised that the BS is frequently requested in patients that have a readily identifiable cause of stroke, that any PFO detected is likely incidental, and its detection often does not alter management.

METHODS

This was a retrospective observational study of patients with recent ischaemic stroke/TIA referred for a BS. Patient demographics, stroke risk factors, vascular/cerebral imaging results and transoesophageal echocardiogram (TOE) reports were recorded. A "modified" Risk of Paradoxical Embolism (RoPE) score was calculated. Change in management was defined as antiplatelet/anticoagulant therapy alteration or referral for PFO closure. Bubble Study complications were recorded.

RESULTS

Among 715 patients with ischaemic stroke/TIA referred for a BS, 8.7% had atrial fibrillation and 9.2% had carotid stenosis ≥70%. At least three stroke risk factors were present in 39.3% and only 47.1% of patients screened had a "modified" RoPE score of >5. A PFO was detected in 248 patients of whom only 31% (77/248) had a subsequent change in management. Of BS performed, 1/924 patients (0.1%) suffered a TIA as a complication.

CONCLUSIONS

The echocardiographic BS is frequently performed in patients that have a readily identifiable cause of stroke and whose PFO unlikely relates to the stroke/TIA. Bubble Study findings resulted in a change in management in the minority. The procedure is safe but the complication rate warrants informed consent.

The use of point-of-care ultrasound to diagnose patent foramen ovale in elective hip and knee arthroplasty patients and its association with postoperative delirium

PURPOSE

Hip and knee arthroplasty surgeries are associated with embolism of materials such as air, cement, and fat. Patent foramen ovale (PFO) is a common congenital cardiac condition that has been reported to lead to paradoxical embolism. This observational study aimed to investigate if the presence of a PFO was associated with an increased risk of postoperative delirium in patients undergoing primary elective hip or knee arthroplasties.

METHOD

This was a prospective cohort study at a tertiary teaching hospital. We enrolled patients undergoing primary elective hip or knee arthroplasty who did not have any risk factors for embolism or delirium. Bedside transthoracic echocardiography (TTE) with a bubble study was performed on all patients to detect the presence of PFO. The primary outcome was postoperative delirium as assessed by the standardized Confusion Assessment Method. Secondary outcomes included the ease of performing a TTE bubble study in the perioperative setting, the quality of the TTE images, length of stay, major cardiovascular and neurologic complications, and effects of anesthetic or analgesic management techniques on delirium.

RESULTS

Two hundred two patients completed the study. The median [interquartile range] duration of stay was 2 [2-3] days. Only 16 patients (8%) had a positive bubble study. Postoperative delirium was observed in only one patient. Major adverse events were not seen. The inter-rater reliability for the TTE image quality scores was fair (kappa statistic = 0.22).

CONCLUSION

Given the very low incidence of PFO and postoperative delirium in this study, we could not form any conclusions regarding the impact of a PFO on important outcomes including delirium or other major adverse events. No recommendation can be made regarding screening for PFO in patients scheduled for lower extremity arthroplasty surgery.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT02400892). Registered 27 March 2015.

Patent Foramen Ovale and Stroke

A patent foramen ovale (PFO) is common and found in nearly 25% of healthy individuals. The majority of patients with PFO remain asymptomatic and they are not at increased risk for developing a stroke. The presence of PFO, however, has been found to be higher in patients with cryptogenic stroke, suggesting there may be a subset of patients with PFO who are indeed at risk for stroke. Paradoxical embolization of venous thrombi through the PFO, which then enter the arterial circulation, is hypothesized to account for this relationship. Although aerated-saline transesophageal echocardiography is the gold standard for diagnosis, aerated-saline transthoracic echocardiography and transcranial Doppler are often used as the initial diagnostic tests for detecting PFO. Patients with cryptogenic stroke and PFO are generally treated with antiplatelet therapy in the absence of another condition for which anticoagulation is necessary. Based on the findings of 3 large randomized clinical trials, current consensus guidelines do not recommend percutaneous closure, though this is an area of controversy. The following review discusses the relationship of PFO and cryptogenic stroke, focusing on the epidemiology, pathophysiological mechanisms, diagnostic tools, associated clinical/anatomic factors and treatment. (Circ J 2016; 80: 1665-1673).

Patent foramen ovale

Patent foramen ovale (PFO) is the most common congenital heart abnormality of fetal origin and is present in approximately ∼25% of the worldwide adult population. PFO is the consequence of failed closure of the foramen ovale, a normal structure that exists in the fetus to direct blood flow directly from the right to the left atrium, bypassing the pulmonary circulation. PFO has historically been associated with an increased risk of stroke, the mechanism of which has been attributed to the paradoxical embolism of venous thrombi that shunt through the PFO directly to the left atrium. However, several studies have failed to show an increased risk of stroke in asymptomatic patients with a PFO, and the risk of stroke recurrence is low in patients who have had a stroke that may be attributed to a PFO. With the advent of transoesophageal and transthoracic echocardiography, as well as transcranial Doppler, a PFO can be routinely detected in clinical practice. Medical treatment with either antiplatelet or anticoagulation therapy is recommended. At the current time, closure of the PFO by percutaneous interventional techniques does not appear to reduce the risk of stroke compared to conventional medical treatment, as shown by three large clinical trials. Considerable controversy remains regarding the optimal treatment strategy for patients with both cryptogenic stroke and PFO. This Primer discusses the epidemiology, mechanisms, pathophysiology, diagnosis, screening, management and effects on quality of life of PFO.

Closure versus medical therapy for preventing recurrent stroke in patients with patent foramen ovale and a history of cryptogenic stroke or transient ischemic attack

BACKGROUND

The optimal therapy for preventing recurrent stroke in people with cryptogenic stroke and patent foramen ovale (PFO) has not been defined. The choice between medical therapy (antithrombotic treatment with antiplatelet agents or anticoagulants) and transcatheter device closure has been the subject of intense debate over the past several years. Despite the lack of scientific evidence, a substantial number of people undergo transcatheter device closure (TDC) for secondary stroke prevention.

OBJECTIVES

To: 1) compare the safety and efficacy of TDC with best medical therapy alone for preventing recurrent stroke (fatal or non-fatal) or transient ischemic attacks (TIAs) in people with PFO and a history of cryptogenic stroke or TIA; 2) identify specific subgroups of people most likely to benefit from closure for secondary prevention; and 3) assess the cost-effectiveness of this strategy, if possible.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (July 2014), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 2, 2014), MEDLINE (1950 to July 2014) and EMBASE (1980 to July 2014). In an effort to identify unpublished and ongoing trials we searched seven trials registers and checked reference lists.

SELECTION CRITERIA

We included randomized controlled trials (RCTs), irrespective of blinding, publication status, and language, comparing the safety and efficacy of device closure with medical therapy for preventing recurrent stroke or TIA in people with PFO and a history of cryptogenic stroke or TIA.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials for inclusion, assessed quality and risk of bias, and extracted data. The primary outcome measures of this analysis were the composite endpoint of ischemic stroke or TIA events as well as recurrent fatal or non-fatal ischemic stroke. Secondary endpoints included all-cause mortality, serious adverse events (atrial fibrillation, myocardial infarction, bleeding) and procedural success and effective closure. We used the Mantel-Haenszel method to obtain pooled risk ratios (RRs) using the random-effects model regardless of the level of heterogeneity. We pooled data for the primary outcome measure with the generic inverse variance method using the random-effects model, yielding risk estimates as pooled hazard ratio (HR), which accounts for time-to-event outcomes.

MAIN RESULTS

We included three RCTs involving a total of 2303 participants: 1150 participants were randomized to receive TDC and 1153 participants were randomized to receive medical therapy. Overall, the risk of bias was regarded as high. The mean follow-up period of all three included trials was less than five years. Baseline characteristics (age, sex, and vascular risk factors) were similar across trials. Intention-to-treat analyses did not show a statistically significant risk reduction in the composite endpoint of recurrent stroke or TIA in the TDC group when compared with medical therapy (RR 0.73, 95% CI 0.45 to 1.17). A time-to-event analysis combining the results of two RCTs also failed to show a significant risk reduction with TDC (HR 0.69, 95% CI 0.43 to 1.13). When assessing stroke prevention alone, TDC still did not show a statistically significant benefit (RR 0.61, 95% CI 0.29 to 1.27) (HR 0.55, 95% CI 0.26 to 1.18). In a sensitivity analysis including the two studies using the Amplatzer PFO occluder, TDC showed a possible protective effect on recurrent stroke compared with medical therapy (HR 0.38, 95% CI 0.14 to 1.02); however, it did not reach statistical significance. Safety analysis found that the overall risks for all-cause mortality and adverse events were similar in both the TDC and medical therapy groups. However, TDC increased the risk of new-onset atrial fibrillation (RR 3.50, 95% CI 1.47 to 8.35) and may be associated with the type of device used.

AUTHORS' CONCLUSIONS

The combined data from recent RCTs have shown no statistically significant differences between TDC and medical therapy in the prevention of recurrent ischemic stroke. TDC closure was associated with an increased risk of atrial fibrillation but not with serious adverse events.

The RoPE Score and Right-to-Left Shunt Severity by Transcranial Doppler in the CODICIA Study

BACKGROUND

For patients with cryptogenic stroke (CS) and patent foramen ovale (PFO), it is unknown whether the magnitude of right-to-left shunt (RLSh) measured by contrast transcranial Doppler (c-TCD) is correlated with the likelihood an identified PFO is related to CS as determined by the Risk of Paradoxical Embolism (RoPE) score. Additionally, for patients with CS, it is unknown whether PFO assessment by c-TCD is more sensitive for identifying RLSh compared with transesophageal echocardiography (TEE). Our aim was to determine the significance of RLSh grade by c-TCD in patients with PFO and CS.

METHODS

We evaluated patients with CS who had RLSh quantified by c-TCD in the Multicenter Study into RLSh in Cryptogenic Stroke (CODICIA) to determine whether there is an association between c-TCD shunt grade and the RoPE Score. For patients who underwent c-TCD and TEE, we determined whether there is agreement in identifying and grading RLSh between these two modalities.

RESULTS

The RoPE score predicted the presence versus the absence of RLSh documented by c-TCD (c-statistic = 0.66). For patients with documented RLSh by c-TCD, shunt severity was correlated with increasing RoPE score (rank correlation (r) = 0.15, p = 0.01). Among 293 patients who had both c-TCD and TEE performed, c-TCD was more sensitive (98.7%) for detecting RLSh. Of the 97 patients with no PFO identified on TEE, 28 (29%) had a large amount of RLSh seen on c-TCD.

CONCLUSIONS

For patients with CS, severity of RLSh by c-TCD is positively correlated with the RoPE score, indicating that this technique for shunt grading identifies patients more likely to have pathogenic rather than incidental PFOs. c-TCD is also more sensitive in detecting RLSh than TEE. These findings suggest an important role for c-TCD in the evaluation of PFO in the setting of CS.

Prevention of recurrent stroke in patients with patent foramen ovale

Patent foramen ovale (PFO) is common and only rarely related to stroke. The high PFO prevalence in healthy individuals makes for difficult decision making when a PFO is found in the setting of a cryptogenic stroke, because the PFO may be an incidental finding. Recent clinical trials of device-based PFO closure have had negative overall summary results; these trials have been limited by low recurrence rates. The optimal antithrombotic strategy for these patients is also unknown. Recent work has identified a risk score that estimates PFO-attributable fractions based on individual patient characteristics, although whether this score can help direct therapy is unclear.

Sudden onset hemiplegia at high altitude

Travel to high altitude and the incumbent exposure to hypobaric hypoxia leads to a prothrombotic state. This may increase the likelihood of thromboembolic events, including stroke, in otherwise healthy individuals. While there have been sporadic anecdotal reports of 'stroke-like' syndromes at high altitude for over 100 years, there are surprisingly few detailed reports supported by imaging.This report describes a case of posterior circulation infarct thought to be due to a paradoxical embolus through a patent foramen ovale. The relationship between high-altitude physiology, increased incidence of thromboembolism and the significance of patent foramen are discussed in the report.

Controversies in cardioembolic stroke

OPINION STATEMENT

Cardioembolic (CE) stroke mechanisms account for a significant number of ischemic strokes; however, the true burden is likely underestimated. It is critically important to identify patients with CE strokes because these individuals have high recurrence rates and represent a subgroup of patients who may benefit from targeted therapy in the form of anticoagulation or device based treatments. Current guidelines offer recommendations for diagnosis and treatment of these patients; however, important questions remain. First, appropriate cardiac testing in the setting of CE must be individualized and the optimal duration of electrocardiographic monitoring to rule out atrial fibrillation (AF) is unclear. Second, risk stratification tools for AF remain understudied, and there is controversy about which anticoagulant agents are most appropriate. Lastly, important potential CE sources of stroke such as patent foramen ovale have garnered significant attention recently, and debate regarding how to manage these patients persists. In this review, we discuss some of the important controversies in diagnosing and treating patients with possible CE stroke, pointing to areas where future research might be particularly valuable.

Transesophageal echocardiography in cryptogenic stroke and patent foramen ovale: analysis of putative high-risk features from the risk of paradoxical embolism database

BACKGROUND

Patent foramen ovale (PFO) is associated with cryptogenic stroke (CS), although the pathogenicity of a discovered PFO in the setting of CS is typically unclear. Transesophageal echocardiography features such as PFO size, associated hypermobile septum, and presence of a right-to-left shunt at rest have all been proposed as markers of risk. The association of these transesophageal echocardiography features with other markers of pathogenicity has not been examined.

METHODS AND RESULTS

We used a recently derived score based on clinical and neuroimaging features to stratify patients with PFO and CS by the probability that their stroke is PFO-attributable. We examined whether high-risk transesophageal echocardiography features are seen more frequently in patients more likely to have had a PFO-attributable stroke (n=637) compared with those less likely to have a PFO-attributable stroke (n=657). Large physiologic shunt size was not more frequently seen among those with probable PFO-attributable strokes (odds ratio [OR], 0.92; P=0.53). The presence of neither a hypermobile septum nor a right-to-left shunt at rest was detected more often in those with a probable PFO-attributable stroke (OR, 0.80; P=0.45; OR, 1.15; P=0.11, respectively).

CONCLUSIONS

We found no evidence that the proposed transesophageal echocardiography risk markers of large PFO size, hypermobile septum, and presence of right-to-left shunt at rest are associated with clinical features suggesting that a CS is PFO-attributable. Additional tools to describe PFOs may be useful in helping to determine whether an observed PFO is incidental or pathogenically related to CS.

Determination of the optimum number of cardiac cycles to differentiate intra-pulmonary shunt and patent foramen ovale by saline contrast two- and three-dimensional echocardiography

INTRODUCTION

Patent foramen ovale (PFO) and intra-pulmonary shunt (IPS) are potential causes of stroke. The most optimum cardiac cycle cutoff for bubbles to appear in the left heart on saline contrast transthoracic echocardiography (TTE) as criteria to differentiate the 2 entities is unknown.

METHODS

Ninety-five adult patients had saline contrast transesophageal echocardiography (TEE), two-dimensional (2D) and 3DTTE. Sensitivity and specificity of each cardiac cycle as cutoff to differentiate a PFO and IPS were obtained.

RESULTS

Transesophageal echocardiography showed IPS in 28 and PFO in 15 patients. If bubbles appeared in the left heart within the first 4 cardiac cycles (the 4th cardiac cycle rule) as compared to alternate cutoffs, a PFO was most accurately diagnosed by both 2D and 3DTTE. Bubbles appearing at or after the 5th cardiac cycle most accurately determined an IPS. 3D versus 2DTTE had a trend for a higher sensitivity (61% vs. 36%, P = 0.06), but similar specificity (94% vs. 91%) for IPS. Accuracy of 3DTTE was 84% and 2DTTE was 75% (P = 0.08) for IPS. For PFO, 2DTTE sensitivity (87%) and specificity (98%) did not differ (P = NS) from that of 3DTTE sensitivity (73%) and specificity (100%).

CONCLUSIONS

This study demonstrates for the first time that the 4th cardiac cycle rule differentiates PFO and IPS most optimally by 2D and 3DTTE. 3DTTE appears to have higher sensitivity for diagnosing IPS. These data suggest that 3DTTE is preferable when IPS is to be diagnosed. Both methods are similar for diagnosing PFO.

Patent foramen ovale, subclinical cerebrovascular disease, and ischemic stroke in a population-based cohort

OBJECTIVES

The purpose of this study was to evaluate the relationship between patent foramen ovale (PFO), ischemic stroke, and subclinical cerebrovascular disease in the general population.

BACKGROUND

PFO is found more frequently in stroke patients than in stroke-free controls. However, the PFO-related stroke risk in the general population is not well established, and the relationship between PFO and silent brain infarcts (SBI) is not known.

METHODS

PFO presence was assessed by transthoracic echocardiography with saline contrast injection in 1,100 stroke-free individuals over age 39 of a community-based sample followed for a mean of 11 years. In addition, 360 participants underwent brain magnetic resonance imaging (MRI) for SBI detection. We evaluated the risk of stroke associated with PFO after adjusting for established stroke risk factors and examined the odds of having SBI among those with and without PFO.

RESULTS

PFO was present in 164 participants (14.9%). Over a mean follow-up of 11.0 ± 4.5 years, 111 ischemic strokes occurred (10.1%), 15 (9.2%) in the PFO+ and 96 (10.3%) in the PFO- groups. The 12.5-year cumulative risk of stroke was 10.1% (standard error: 2.5%) in the PFO+ and 10.4% (standard error: 1.1%) in the PFO- group (p = 0.46). The adjusted hazard ratio for PFO and stroke was 1.10 (95% confidence interval [CI]: 0.64 to 1.91). In the MRI subcohort, PFO was not associated with SBI (adjusted odds ratio: 1.15, 95% CI: 0.50 to 2.62).

CONCLUSIONS

In this community-based cohort, PFO was not associated with an increased risk of clinical stroke or subclinical cerebrovascular disease.

Patent foramen ovale screening by ear oximetry in divers

The aim of this study was to test the hypothesis that ear oximetry immediately after the release of a sustained Valsalva maneuver accurately detects patent foramen ovale (PFO). One hundred sixty-five scuba divers underwent transesophageal echocardiography (TEE; reference method) for PFO assessment. Ear oximetry of the right earlobe was performed in a different room within a time frame of 2 hours before or after TEE. The subject and the oximetry operator were unaware of the results of TEE. Oxygen saturation (SO(2)) measurements were obtained at baseline and during the release phase of 4 Valsalva maneuvers within 10 minutes, and the average SO(2) change (SO(2) at baseline minus SO(2) at Valsalva release) was determined as the primary study end point. One hundred seventeen divers had no PFO, and 48 (29%) had PFO by TEE (mean age 39 ± 8 years). The average SO(2) change was 0.79 ± 1.13% (i.e., a slight absolute SO(2) decrease in response to the Valsalva maneuver) in the group without PFO and 1.67 ± 1.19% in the PFO group (p <0.0001). Using receiver-operating characteristic curve analysis, a PFO as defined by TEE could be detected at a threshold of a Valsalva-induced decrease in SO(2) of ≥0.825 percentage points in comparison to baseline (sensitivity 0.756, specificity 0.706, area under the receiver-operating characteristic curve 0.763, p <0.0001, negative predictive value 0.882). In conclusion, the entirely noninvasive method of ear oximetry in response to repetitive Valsalva maneuvers is accurate and useful as a screening method for the detection of a PFO, as shown in this study of divers.

Preimplant transthoracic echocardiographic assessment of continuous flow left ventricular assist device

For many patients with end-stage heart failure, heart transplantation is the only remaining option to prolong survival and provide symptom relief. Transthoracic echo is the modality of choice in assessing a patient for potential left ventricular assist device (LVAD) insertion. There are currently no guidelines available, and assessing this specific patient population can prove extremely challenging. As such, an understanding of LVAD mechanism, the important physiological consequences of device implantation together with the related echocardiographic examination is vital to accurately and effectively gauge correct patient selection and also improve implantation success. This review aims to highlight the common devices implanted, how these devices affect cardiac physiology and hemodynamics, and therefore discuss the major echocardiographic variables that should be assessed predevice implantation. (Echocardiography 2012;29:52-58).

Clinical impact of the baseline echocardiogram in children with high-risk acute lymphoblastic leukemia

BACKGROUND

It is common practice to hold anthracycline induction chemotherapy in children with high-risk acute lymphoblastic leukemia (HR-ALL) until an echocardiogram is performed and interpreted. It is unclear whether withholding therapy in HR-ALL children is justified by echocardiogram findings. We reviewed the initial echocardiograms in a cohort of children with HR-ALL to determine the incidence of contraindications for anthracycline treatment.

PROCEDURE

We identified 50 consecutive children (<21 years old) with HR-ALL presenting at our institution over a 10-year period. One didn't have an initial echocardiogram, 39 had pre-therapy studies, and 10 were studied within 6 days of beginning chemotherapy. These 49 studies were reviewed to determine the incidence and clinical significance of abnormalities.

RESULTS

All 49 patients had normal cardiac function. Initial echocardiogram findings had no impact on induction chemotherapy administration in any patient. However, only 22(45%) of the studies were completely normal. Echocardiographic abnormalities included pericardial effusion (17/49), trivial or mild mitral or aortic insufficiency (13/49), left ventricular enlargement (3/49), and structural heart disease (4/49). Twelve percent of the children had a patent foramen ovale. None of the cardiac findings required therapeutic intervention other than repositioning of indwelling lines (6/49) due to intracardiac positioning.

CONCLUSIONS

In our experience, findings on echocardiograms in childhood HR-ALL did not impact anthracycline administration. This study suggests that induction chemotherapy should not be delayed for an echocardiogram. However, whenever possible, a pre-therapy echocardiogram is still recommended for determining baseline function and to identify associated problems like pericardial effusions which were common in this study.

Recurrent strokes under anticoagulation therapy: Sticky platelet syndrome combined with a patent foramen ovale

The sticky platelet syndrome (SPS) is a congenital disorder characterized by platelet hyperaggregability to epinephrine and/or adenosine diphosphate; this predisposes affected individuals to acute myocardial infarction, ischemic optic neuropathy, recurrent venous thromboembolism, and transient ischemic cerebral attacks and strokes. Here, we describe an unusual case with recurrent cerebrovascular accidents due to SPS, in the presence of a patent foramen ovale (PFO). We report an unusual case of a 56-year-old female patient with a PFO, who suffered from recurrent strokes despite long-term medication with clopidogrel for SPS. The patient underwent successful transcatheter closure of the PFO, and, in addition, she has been placed on low-dose acetylsalicylic acid. After 18-month follow-up, she demonstrated an intact atrial septum without any vegetations on the percutaneous device until today. She has had no further thromboembolic events.

Paradoxical embolism after declotting of hemodialysis fistulae/grafts in patients with patent foramen ovale

BACKGROUND AND OBJECTIVES

The safety of percutaneous endovascular declotting procedures for thrombosed hemodialysis fistulae/grafts is well described in the general population; however, its safety in the presence of a patent foramen ovale (PFO) is not known. The objective of this study is to assess the incidence of symptomatic paradoxical embolic events associated with declotting procedure of thrombosed arteriovenous (AV) graft or fistula in patients with documented PFO.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This was a retrospective study in a hospital-based, academic practice. It included 23 patients (10 men; mean age, 65) with PFO and thrombosed hemodialysis graft/fistula who underwent a standardized declotting procedure with 2 mg of Alteplase and balloon thrombectomy. Twenty patients (87%) had AV grafts, and three (13%) had AV fistulae. The PFO shunt was right to left in two (9%), left to right in eight (34%), and bidirectional in ten (44%). The shunt direction was not specified in three patients (13%). The technical success of the declotting procedure and the frequency of clinically manifested paradoxical embolic events in this patient population were calculated.

RESULTS

Fifty declotting procedures were performed on 23 patients with a technical success rate of 96% (48 of 50, 96%). No symptomatic paradoxical embolic events were found in any of the 23 patients with PFO.

CONCLUSIONS

Symptomatic paradoxical embolic events after percutaneous endovascular declotting procedures of thrombosed AV grafts and fistulae in patients with documented PFO are rare. This procedure appears to be safe in patients with a PFO.

Diagnosing a Patent Foramen Ovale in Children

Background and Purpose—

Transesophageal echocardiography (TEE) is the gold standard for the diagnosis of a patent foramen ovale in adults. In children, acoustic windows on transthoracic echocardiography (TTE) are better than in adults; thus, an invasive TEE may not be necessary. Our goal was to assess the validity of TTE with agitated saline injection for the diagnosis of a patent foramen ovale in children using TEE as the gold standard.

Methods—

Fifty consecutive pediatric patients >1 year of age referred for TEE were prospectively enrolled. Imaging included 2-dimensional, color Doppler, and agitated saline contrast injections with and without Valsalva by TTE followed by TEE. Interpreters of the TTE were blinded to TEE results. Studies were categorized as “inconclusive” if the TTE images were inadequate for definitive diagnosis by the blinded interpreter.

Results—

TTE results were considered conclusive in 43 of 50 (86%) patients. Among the 43 conclusive studies, the 2 modalities disagreed in 1 patient. TTE had a positive predictive value of 100%, negative predictive value 97%, sensitivity of 88%, and specificity of 100% for detecting a patent foramen ovale.

Conclusions—

TTE with agitated saline injection is diagnostic for the assessment of atrial septal integrity in the majority of children.

Headache and cardiovascular disease: old symptoms, new proposals

Evidence of a link between headache symptoms and cardiovascular disease has rapidly grown in recent years and it is of utmost importance for the cardiologist and neurologist to be aware of this intimate connection. A brief overview of different cardiovascular diseases (namely hypertension, stroke, coronary heart disease, patent foramen ovale, atrial septal defects, atrial septal aneurisms, mitral valve prolapse, and aortic and carotid disease) that may be related to headache is presented in this article. Proposed pathophysiological mechanisms for this association and landmark studies are reviewed and discussed.

Stroke in younger patients: the heart of the matter

Stroke in young adults is not a rare entity, and often provides difficult management decisions for neurologists. The knowledge gained from stroke in older adults does not transfer easily to this younger group given the different causes of stroke observed. Cardiac causes of stroke are common in this group, but often consist of low risk cardiac lesions such as a patent foramen ovale. Appropriate investigation should follow a stepwise approach to initially exclude higher risk pathology for recurrent stroke such as arterial dissection. Similarly, stepwise application of cardiac investigations will allow early identification of significant pathology, with investigation for abnormalities of the inter-atrial septum reserved for those with no other identified cause of stroke. Bubble contrast echo is now widely available, and with improved image quality may be performed with either transthoracic or transoesophageal echo, as well as with transcranial Doppler. Following this approach, patients can be best categorised by the expected rate of recurrent stroke, as informed by observational studies. Appropriate secondary prevention can then be tailored to the recurrence rate, with anticoagulation and possibly device closure reserved for those at highest risk of recurrence.