Patent foramen ovale in patients with cerebral infarction. A transesophageal echocardiographic study

A meta-analysis of the association of atrial septal abnormalities and atrial vulnerability

BACKGROUND

The mechanism of cryptogenic stroke (CS) in patients with atrial septal abnormalities remains unclear, and the increased incidence of atrial vulnerability may be one of the reasons. We performed this meta-analysis to clarify the association between atrial septal abnormalities and atrial vulnerability, and to provide evidence-based basis for the prevention and mechanism of CS.

METHODS

We systematically searched for studies on the association between atrial septal abnormalities and atrial vulnerability, and pooled available data on types of atrial septal abnormalities, types of atrial vulnerability, and methods of atrial vulnerability detection. The primary endpoints were the occurrence of atrial arrhythmias or P wave abnormalities. Random-effects models were used to calculate odds ratios (OR) and 95% confidence intervals (CI).

RESULTS

Twelve case-control studies were eligible. Compared with the control group, patients with atrial septal abnormalities had a higher risk of atrial vulnerability (OR: 1.93; 95% CI: 1.13-3.30, P = .02). Data based on stroke patients showed that the group with atrial septal abnormalities had a higher risk of atrial vulnerability than the control group (OR: 2.00; 95% CI: 1.13-3.53, P = .02). However, there was no significant difference in the incidence of atrial vulnerability between the 2 groups of nonstroke patients. Subgroup analysis showed that although atrial septal abnormality increased the risk of atrial vulnerability in the subgroup of atrial septal aneurysm (OR: 1.68; 95% CI: 0.47-5.95, P = .42), the subgroup of atrial fibrillation (AF)/atrial fluster (OR: 1.81; 95% CI: 0.94-3.46, P = .07) and the subgroup of subcutaneous recording system (OR: 1.33; 95% CI: 0.68-2.61, P = .41), the difference was not statistically significant.

CONCLUSIONS

Atrial septal abnormalities can increase the risk of atrial vulnerability, and atrial arrhythmia caused by atrial septal abnormalities may be one of the mechanisms of CS.

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.

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.

Therapeutic Utilities of Pediatric Cardiac Catheterization

In an era when less invasive techniques are favored, therapeutic cardiac catheterization constantly evolves and widens its spectrum of usage in the pediatric population. The advent of sophisticated devices and well-designed equipment has made the management of many congenital cardiac lesions more efficient and safer, while providing more comfort to the patient. Nowadays, a large variety of heart diseases are managed with transcatheter techniques, such as patent foramen ovale, atrial and ventricular septal defects, valve stenosis, patent ductus arteriosus, aortic coarctation, pulmonary artery and vein stenosis and arteriovenous malformations. Moreover, hybrid procedures and catheter ablation have opened new paths in the treatment of complex cardiac lesions and arrhythmias, respectively. In this article, the main therapeutic utilities of cardiac catheterization in children are discussed.

Patent foramen ovale and cryptogenic stroke: from studies to clinical practice: Position paper of the Italian Chapter, International Society Cardiovascular Ultrasound

BACKGROUND

Over the last two decades the interest on patent foramen ovale (PFO) as a cause of cardioembolism in cryptogenic stroke has tremendously increased, thanks to the availability of better techniques to diagnose cardiac right-to-left shunt by ultrasounds and of percutaneous means of PFO treatment with interventional techniques. Many studies have been published that have attempted to define diagnostic methodology, prognosis, and optimal treatment (pharmacological or percutaneous closure) of PFO patients with cryptogenic stroke. Unfortunately, even today, definitive evidence is still lacking, and clinical management is not consistent among cardiologists.

AIMS

This review aims to evaluate the role of PFO in cryptogenic stroke, the diagnostic accuracy of transcranial Doppler, contrast transthoracic and transesophageal echocardiography in the diagnosis of left-fright shunt and PFO; and discuss the indications to medical treatment and percutaneous closure of PFO.

METHODS

All studies published in the literature on PFO and cryptogenic stroke are considered and discussed.

RESULTS

We define an appropriate diagnostic and clinical management of PFO patients with cryptogenic stroke.

CONCLUSION

After many years of interest on PFO and many concluded studies, there are still no definitive data. However, we are on good track for an appropriate management of PFO patients and cryptogenic stroke.

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.

Differences in diffusion-weighted image and transesophageal echocardiographical findings in cardiogenic, paradoxical and aortogenic brain embolism

BACKGROUND AND PURPOSE

The purpose of the present study was to clarify the difference in the infarct topography on diffusion-weighted image (DWI) and cardiac and aortic findings on transesophageal echocardiography (TEE) in stroke patients with different embolic sources.

METHODS

We studied 270 consecutive patients with acute ischemic stroke who had DWI-documented cortical or subcortical infarcts without significant stenosis of the cerebral arteries. As embolic sources, cardiac diseases, right-to-left shunt diseases and an aortic arch atheroma ≥4.0 mm in thickness were identified using various diagnostic tools including TEE.

RESULTS

Seventy-eight (29%) patients had multiple embolic sources. Large infarcts were common in patients in whom cardiac disease was the only embolic source and uncommon in patients in whom aortic atheroma was the only embolic source (p < 0.0001). Vertebrobasilar infarcts were relatively common in patients only having aortic atheromas. Atrial septal aneurysms were more common in patients with a right-to-left shunt than in those with a shunt plus other embolic sources (p = 0.0036). Unique characteristics of the arch atheroma (mobile plaque, extension to branches, or ulcer formation; p < 0.0001) as well as small or moderate-sized infarcts (p = 0.0004) were more common in patients with arch atheromas as the only embolic source than in those with atheromas plus other embolic sources.

CONCLUSIONS

Embolic stroke patients often have multiple embolic sources. The present study suggests the possibility that embolic stroke has unique clinical features depending on its source. DWI and TEE findings might be helpful in characterizing cardiogenic, paradoxical and aortogenic brain embolism.

TEE monitoring for RA-horizontal paradoxical arterial air embolism during sitting-position surgery

A 36-year-old woman suffered meningioma in her right cerebellopontine angle. Air embolisms often complicate sitting-position surgeries. Because TEE guides the localization of central venous catheters and promptly locates air embolisms promptly enough for effective treatment, TEE is an effective monitoring method for sitting-position surgeries.

Pulmonary pathways and mechanisms regulating transpulmonary shunting into the general circulation: an update

Embolic insults account for a significant number of neurologic sequelae following many routine surgical procedures. Clearly, these post-intervention embolic events are a serious public health issue as they are potentially life altering. However, the pathway these emboli utilize to bypass the pulmonary microcirculatory sieve in patients without an intracardiac shunt such as an atrial septal defect or patent foramen ovale, remains unclear. In the absence of intracardiac routes and large diameter pulmonary arteriovenous malformations, inducible large diameter intrapulmonary arteriovenous anastomoses in otherwise healthy adult humans may prove to be the best explanation. Our group and others have demonstrated that inducible large diameter intrapulmonary arteriovenous anastomoses are closed at rest but can open during hyperdynamic conditions such as exercise in more than 90% of healthy humans. Furthermore, the patency of these intrapulmonary anastomoses can be modulated through the fraction of inspired oxygen and by body positioning. Of particular clinical interest, there appears to be a strong association between arterial hypoxemia and neurologic insults, suggesting a breach in the filtering ability of the pulmonary microvasculature under these conditions. In this review, we present evidence demonstrating the existence of inducible intrapulmonary arteriovenous anastomoses in healthy humans that are modulated by exercise, oxygen tension and body positioning. Additionally, we identify several clinical conditions associated with both arterial hypoxemia and an increased risk for embolic insults. Finally, we suggest some precautionary measures that should be taken during interventions to keep intrapulmonary arteriovenous anastomoses closed in order to prevent or reduce the incidence of paradoxical embolism.

Patent foramen ovale in cerebral infarction

Recent studies support the hypothesis of a close aetiological and pathogenic association between the presence of patent foramen ovale (PFO) and cryptogenic stroke. The therapeutic options currently used in the treatment of these patients range from standard antiaggregation and standard-dose anticoagulation to the percutaneous occlusion of the PFO. The use or recommendation of treatment is based both on clinical risk factors associated with PFO, such as age, detection of states of hypercoagulability and previous history of stroke, and on the risks associated to right-to-left shunt (RLSh) and PFO, such as the size of PFO, magnitude of RLSh and the presence of atrial septal aneurysm (ASA). However, there is currently no consensus regarding the most suitable treatment and it is surprising to observe the widespread use of certain therapeutic approaches which are not supported by clinical evidence. In this revision, we analyse the relevance of PFO in cryptogenic stroke, consider the main evidence available for determining the best management of these patients and make diagnostic and therapeutic management recommendations.

Prevention of Stroke in Patients with Patent Foramen Ovale

Patent foramen ovale is found in 24% of healthy adults and 38% of patients with cryptogenic stroke. This ratio and case reports indicate that patent foramen ovale and stroke are associated, probably because of paradoxical embolism. In healthy people with patent foramen ovale, embolic events are not more frequent than in controls, and therefore no primary prevention is needed. However, once ischaemic events occur, the risk of recurrence is substantial and prevention becomes an issue. Acetylsalicylic acid and warfarin reduce this risk to the same level as in patients without patent foramen ovale. Patent foramen ovale with a coinciding atrial septal aneurysm, spontaneous or large right-to-left shunt, or multiple ischaemic events potentiates the risk of recurrence. Transcatheter device closure has therefore become an intriguing addition to medical treatment, but its therapeutic value still needs to be confirmed by randomised-controlled trials.

Patent foramen ovale in cryptogenic stroke: incidental or pathogenic?

BACKGROUND AND PURPOSE

Patent foramen ovale (PFO) is significantly associated with cryptogenic stroke (CS). However, even in patients with CS, a PFO can be an incidental finding. We sought to estimate the probability that a PFO in a patient with CS is incidental.

METHODS

A systematic search identified 23 case-control studies examining the prevalence of PFO in patients with CS versus control subjects with stroke of known cause. Using simple assumptions and Bayes' theorem, we calculated the probability a PFO is incidental in patients with CS. Random effects meta-analyses estimated the odds ratio (OR) of a PFO in CS versus control subjects in different age populations, with or without atrial septal aneurysms, and were used to summarize across studies the probability that a PFO in CS is incidental.

RESULTS

The summary OR (95% CIs) for PFO in CS versus control subjects was 2.9 (CI, 2.1 to 4.0). The corresponding ORs for young and old patients (< or >or=55 years) were 5.1 (3.3 to 7.8) and 2.0 (>1.0 to 3.7), respectively. The corresponding probabilities that a PFO in patients with CS is incidental were 33% (28% to 39%) in age-inclusive studies, 20% (16% to 25%) in younger patients, and 48% (34% to 66%) in older patients. These probabilities were much lower when an atrial septal aneurysm was present.

CONCLUSIONS

In patients with otherwise CS, approximately one third of discovered PFOs are likely to be incidental and hence not benefit from closure. This probability is sensitive to patient characteristics such as age and the presence of an atrial septal aneurysm, suggesting the importance of patient selection in therapeutic decision-making.

Cardioembolic stroke

Cardiac sources of emboli account for over one quarter of all ischemic strokes. Strokes due to cardioembolism are in general severe and prone to early and long-term recurrence. Nonvalvular atrial fibrillation remains the most common cause of cardioembolic stroke. Despite the proven efficacy of oral anticoagulation, it is prescribed for less than half of the patients with risk factors for embolism and no contraindications for anticoagulation. The embolic risk of patent foramen ovale is low except when combined with an atrial septal aneurysm. Aortic arch atheroma as an independent risk factor for ischemic stroke is the subject of ongoing debate. As the risk of embolism is heterogeneous for the various potential cardioembolic conditions, accurate definition of stroke mechanism is very important to guide the most effective therapy.

Population-based study of the relationship between patent foramen ovale and cerebrovascular ischemic events

OBJECTIVE

To determine whether patent foramen ovale (PFO) is a risk factor for a cryptogenic cerebrovascular ischemic event (CIE).

METHODS

This case-control study of 1072 residents of Olmsted County, Minnesota, who underwent contrast transesophageal echocardiography between 1993 and 1997 included 519 controls without CIE randomly selected from the population, 262 controls without CIE referred for transesophageal echocardiography because of cardiac disease, 158 cases with incident CIE of obvious cause (noncryptogenic), and 133 cases with incident CIE of uncertain cause (cryptogenic).

RESULTS

Large PFOs were detected in 108 randomly selected controls (20.8%), 22 referred controls (8.4%), 17 noncryptogenic CIE cases (10.8%), and 22 cryptogenic CIE cases (16.5%). After adjustment for age, sex, hypertension, smoking, atrial fibrillation, ischemic heart disease, and number of contrast injections, the presence of a large PFO was not significantly associated with group status (P=.07). Using the odds of the presence of large PFO in the randomly selected controls as the reference, the odds ratio (95% confidence interval) of the presence of large PFO was 0.47 (0.26-0.87) for referred controls, 0.69 (0.37-1.29) for noncryptogenic CIE cases, and 1.10 (0.63-1.90) for cryptogenic CIE cases.

CONCLUSIONS

Patent foramen ovale is not a risk factor for cryptogenic ischemic stroke or transient ischemic attack in the general population. The PFO's importance in the genesis of cryptogenic CIE may have been overestimated in previous studies because of selective referral of cases and underascertainment of PFO among comparison groups of patients referred for echocardiography for clinical indications other than cryptogenic CIE.

The management of patients with patent foramen ovale and stroke

The management of patients with patent foramen ovale (PFO) and stroke remains uncertain. What is known is that PFO is a very common finding in the general population. The risk of initial and recurrent stroke in individuals with PFO is relatively low. With the advent of transesophageal echocardiography, PFO is more commonly being diagnosed. There are insufficient data to support a benefit of warfarin over aspirin in preventing recurrent stroke in most patients with PFO. In those with PFO and a history of a procoagulant state or deep venous thrombosis, anticoagulation may be indicated after weighing the risks of anticoagulation against potential benefits in preventing recurrent stroke. PFO closure does not guarantee the prevention of future stroke and should be addressed case by case, with consideration of patients for entry into ongoing clinical trials of safety, efficacy, and durability.

Patent Foramen Ovale and Stroke: Prognosis and Treatment in Young Adults

A patent foramen ovale (PFO) is found with increased frequency in patients with stroke of undetermined origin but the significance and therapeutic implications of this observation remain unclear. Several lines of evidence suggest a role for the PFO in stroke pathophysiology for some cryptogenic stroke patients, such as those whose PFO is accompanied by a prothrombotic state, atrial septal aneurysm, or lower extremity/pelvic DVT. Diagnostic evaluation of the patient with cryptogenic stroke and PFO is directed at identifying these subgroups. Appropriate therapy for primary and secondary stroke prevention in a subject with a PFO remains unclear given current uncertainties as to the pathophysiological significance of PFO. Additional studies are needed, such as those focused on lower extremity veins or the cardiac interatrial septum, to guide therapy in specific stroke subpopulations.

Patent foramen ovale and its relationship to stroke

This article discusses the relationship between patent foramen ovale and stroke, particularly in reference to paradoxical embolism as a cause of cryptogenic stroke.

Does transesophageal echocardiographic demonstration of a patent foramen ovale in patients with a recent cerebral ischemic event change anticoagulation therapy?

BACKGROUND

Patent foramen ovale (PFO) is commonly demonstrated by transesophageal echocardiography (TEE) in patients with a recent transient ischemic attack or stroke. Our purpose was to determine how the TEE visualization of a PFO alters anticoagulation therapy.

METHODS

We retrospectively identified 100 patients with transient ischemic attack or stroke referred for TEE; 50 had a PFO and 50 did not (control patients).

RESULTS

Both groups were similar in regard to age, sex, the occurrence of transient ischemic attack versus stroke, and history of stroke. The PFO group had a higher incidence of a mobile interatrial septum, interatrial septal aneurysm, or both ( P < .001 by Fisher exact test). Both groups had similar pre-TEE aspirin, other antiplatelet, and warfarin use. After TEE, warfarin was instituted in 8 of 50 patients with PFO versus 2 of 50 in the control group ( P = .05) and aspirin use was discontinued in 9 of 50 patients with PFO versus 3 of 50 in the control group ( P = .12).

CONCLUSION

The main effect of demonstrating a PFO by TEE after an ischemic cerebral event was the institution of warfarin; there was a trend toward discontinuing aspirin.

Preventing a second stroke in the young

In the United States, more than 220,000 adults under the age of 45 have had a stroke. Secondary stroke prevention is critical in this population because of the potential impact of a second stroke on productivity and future quality of life. In addition to conventional stroke risk factors, younger patients have special risk factors inherent to genetic and environmental elements, such as the use of illicit drugs and cardiac abnormalities; in women, risk factors include pregnancy, migraine, and the use of oral contraceptives.

Cardioembolic stroke: an update

Cardioembolic stroke accounts for approximately 15% of all strokes and is thought to be one of the more preventable types of strokes. Features that have been reported to support cardioembolism as a mechanism for ischemic stroke have included documented cardiac source of embolism, maximal neurologic deficit at onset, multiple cerebrovascular territories involved, enhanced tendency toward hemorrhagic transformation, enhanced risk of syncope or seizure associated with presentation, and lower likelihood of premonitory transient ischemic attacks. Features that tend to make cardioembolic stroke less likely include significant cerebral atherosclerosis, step-wise progression of the neurologic deficit within a finite period of time, vascular distribution such as entire internal carotid artery territory with combined middle cerebral artery and anterior cerebral artery involvement or watershed distribution, and premonitory transient ischemic attacks. A number of cardiac conditions can promote thromboembolism, and there is risk stratification reflective of the specific condition or coexistent conditions. Anticoagulant therapy generally has been found to be the most effective means of preventing cardiogenic brain embolism, but the intensity of anticoagulation needs to be optimized to reflect the risk-to-benefit ratio for the particular patient.

Genetic risk factors in young adults with 'cryptogenic' ischemic cerebrovascular disease

Mutations such as factor V Leiden G1691A (FVL), prothrombin G20210A (FIIM), methylenetetrahydrofolate reductase (MTHFR) C677T, cystathionine beta-synthase (CBS) 844ins68 and endothelial cell protein C receptor (EPCR) 4031ins23 are risk factors for thromboembolism. To assess the role of these mutations in young adults with cerebral ischemia of otherwise undetermined etiology, 93 patients younger than 50 years old with thromboembolic strokes or transient ischemic attacks were studied. One hundred and eighty-six healthy age-matched and sex-matched blood donors served as controls. The FVL mutation was detected in 15/93 patients and 13/186 controls. After adjustment for smoking, arterial hypertension, and hyperlipidemia, the association of the FVL mutation with cerebral ischemia [odds ratio (OR), 3.19; 95% confidence interval (CI), 1.38-7.39] remained significant. One of 93 patients and 6/186 controls were carriers of FIIM (OR, 0.33; 95% CI, 0.04-2.75). We detected the MTHFR TT677 genotype in 9/93 patients and 26/186 controls (OR, 0.66; 95% CI, 0.30-1.47), a CBS 844ins68 mutation in 12/93 patients and 19/186 controls (OR, 1.30; 95% CI, 0.60-2.81), and an EPCR 4031ins23 mutation in 1/93 patients and in no control individual (P = 0.33). In conclusion, in younger adults the FVL mutation is a risk factor for cerebrovascular disease. FIIM, the MTHFR TT677 genotype and the CBS 844ins68 mutation did not contribute to the risk in this group of patients. The EPCR 4031ins23 mutation is very rare, its possible role needs further investigation.

Transcatheter closure of interatrial communications for secondary prevention of paradoxical embolism: single-center experience

BACKGROUND

Patients with a patent foramen ovale (PFO) after cerebral, coronary, or systemic embolic events of presumed paradoxical origin are at risk for recurrent thromboembolism. We report our single-center experience of interventional closure of interatrial communications for secondary prevention of presumed paradoxical embolism. Methods and Results- Since 1997, percutaneous closure of interatrial communications was performed at our institution in 66 patients (mean age 47.8+/-12.7 years; 31 males) with a PFO or an atrial septal defect and at least 1 documented presumed paradoxical thromboembolic event. Fifty-eight patients had cerebral embolism, 10 had coronary embolism, and 3 had peripheral embolism. Several patients experienced multilocal arterial embolism. Fifty-four patients had a PFO, 33 of them with an atrial septal aneurysm, and 12 had an atrial septal defect. The implantation procedure was successful and without complication in all patients. After 3 months, only 2 patients showed a residual shunt, which disappeared in both cases after 12 months. In 112.2 patient-years of follow-up (range, 5 weeks to 3.5 years), we have not seen any recurrent thromboembolic event.

CONCLUSIONS

Interventional closure of interatrial communications is a safe and effective therapeutic option for the secondary prevention of presumed paradoxical embolism. To further evaluate this strategy, randomized trials comparing interventional closure with anticoagulation have been initiated by us and others.

Patent foramen ovale transcatheter closure device thrombosis

The role of patent foramen ovale (PFO) in patients with cryptogenic stroke (stroke of unknown cause) remains controversial, although an association seems likely in younger patients with atrial septal aneurysms and PFO. The mechanism of cryptogenic stroke in these patients is presumed to be paradoxical embolism via right-to-left shunt across the PFO. The available options for treatment include medical therapy with antiplatelet or anticoagulant therapy or closure of the PFO surgically or with use of transcatheter PFO closure devices. We describe 2 cases of bilateral device thrombosis associated with use of a transcatheter PFO closure device (CardioSEAL). To our knowledge, only 1 other case of thrombosis associated with use of this device has been reported.

Potential source of cerebral embolism in migraine with aura: a transcranial Doppler study

BACKGROUND

The recently found association between patent foramen ovale (PFO) and transient global amnesia (TGA) has suggested that paradoxical microembolization in the terminal vertebrobasilar territory might underlie at least some TGA cases. Migraine with visual aura is another paroxysmal disturbance in which a sudden dysfunction of cortical areas fed by the terminal branches of the basilar artery is believed to trigger the attack. Therefore we investigated the prevalence of PFO in a consecutive unselected cohort of migraine patients.

OBJECTIVE

To investigate the prevalence of PFO in a consecutive unselected cohort of migraine patients to search for a possible mechanism for the reported association of migraine with stroke.

METHODS AND RESULTS

A total of 113 patients, consecutively referred by the Headache Outpatient Clinic for migraine with aura (MA+, mean age 34+/-12 years) were compared with 53 patients with migraine without aura (MA-, mean age 36+/-13 years) and with 25 age-matched nonmigraine subjects (mean age 31+/-10 years) selected from the hospital staff. PFO was assessed with transcranial Doppler sonography with IV injection of agitated saline, a technique that is 90% sensitive and 100% specific. The prevalence of PFO was 48% (54/113) in MA+ patients, 23% (12/53) in MA- patients, and 20% (5/25) in control subjects. The difference between MA+ and MA- patients was significant (odds ratio [OR] = 3.13, 95% confidence interval [CI] = 1.41 to 7.04, chi2 = 9.52,p = 0.002) as was the difference between MA+ patients and controls (OR = 3.66, 95% CI = 1.21 to 13.25, chi2 = 6.46, p = 0.01), whereas MA- patients did not differ from controls (OR = 1.17, 95% CI = 0.32 to 4.45, chi2 = 0.07). MRI was negative in 22 MA+ and 8 MA- patients.

CONCLUSIONS

Patency of the foramen ovale is associated with migraine with aura but not with migraine without aura. The increased risk of stroke found in epidemiologic studies in patients with migraine with aura may be explained by an increased propensity to paradoxical cerebral embolism.

The need to quantify right-to-left shunt in acute ischemic stroke: a case-control study

BACKGROUND AND PURPOSE

Although right-to-left shunt (RLSh) has been reported to be significantly more frequent in young stroke patients with cryptogenic stroke, its relevance in a nonselected population of acute ischemic stroke is not well known. The aim of this study was to determine the importance of the RLSh magnitude as a risk factor for stroke in nonselected patients.

METHODS

Two hundred eight patients hospitalized consecutively with transient ischemic attack or acute cerebral infarction and 100 healthy control subjects were studied. Transcranial Doppler ultrasonography (TCD) was performed in both middle cerebral arteries (MCAs) after intravenous application of agitated saline solution. The magnitude of RLSh was quantified by counting the number of signals in 1 MCA during a Valsalva maneuver. RLSh was classified as "no shunt," "small" (< 10 signals), and "large" (> 10 signals), with the latter including the "shower" (> 25 signals) and "curtain" (uncountable signals) patterns. Extensive investigations, including contrast transesophageal echocardiography, were carried out on patients diagnosed as suffering from stroke of an uncertain etiology. The importance of RLSh for stroke was assessed by logistic regression analysis.

RESULTS

Contrast TCD detected a large RLSh in 40 (19.7%) patients and in 21 (21%) control subjects, all with cardiac RLSh characteristics. A large RLSh was present in 4.7% of atherothrombotic strokes, 10.5% of cardioembolic strokes, 15.4% of lacunar strokes, and 45.3% of cryptogenic strokes (P<0.001). Although the overall frequency of RLSh was not significantly different between patients and control subjects, the detection of curtain or shower patterns by contrast TCD was associated with a higher risk of stroke (odds ratio, 3.5; 95% confidence interval, 1.29 to 9.87), particularly with cryptogenic stroke (odds ratio, 12.4; 95% confidence interval, 4.08 to 38.09) after adjustment for concomitant vascular risk factors.

CONCLUSIONS

It is essential to quantify RLSh by contrast TCD during the Valsalva maneuver given that only those with shower and curtain patterns are associated with a higher risk of ischemic stroke in a nonselected population.

Patent foramen ovale size and embolic brain imaging findings among patients with ischemic stroke

BACKGROUND AND PURPOSE

Although the cause of stroke among patients with patent foramen ovale (PFO) may be due to paradoxical cerebral embolism (PCE), this mechanism is often difficult to prove. The aim of our study was to evaluate the association between brain imaging findings suggestive of embolism and PFO among ischemic stroke patients.

METHODS

As part of the Northern Manhattan Stroke Study, 95 patients with first ischemic stroke over age 39 underwent transesophageal echocardiography (TEE) for evaluation of a cardiac source of embolism. The stroke subtype was determined by modified NINDS Stroke Data Bank criteria. Stroke subtype and MRI/CT imaging data were evaluated blind to the presence of a PFO. These findings were compared between two groups: patients with medium to large PFO (> or =2 mm) and small (<2 mm) or no PFO.

RESULTS

Of the 95 patients who underwent TEE, 31 (33%) had a PFO. The frequency of PFO was significantly greater among patients with cryptogenic infarcts (19 of 42; 45%) compared with patients with determined cause of stroke (12 of 53, 23%; P=0.02). Medium to large PFOs were found more often among cryptogenic strokes than among infarcts of determined cause (26% versus 6%; P=0.04). Superficial infarcts occurred more often in the group with larger PFOs than in the group with small or no PFOs (50% versus 21%; P=0.02). Patients with medium or large PFOs more frequently had occipital and infratentorial strokes (57% versus 27%; P=0.02).

CONCLUSIONS

Stroke patients with larger PFOs show more brain imaging features of embolic infarcts than those with small PFOs. Larger PFOs may be more likely to cause paradoxical embolization and may help explain the stroke mechanism among patients with no other definite cause.

Cardiac disorders and stroke

Cardiac disorders are increasingly recognised as an important source of cerebral embolism. Atrial fibrillation is the most common cardiac dysrrhythmia that can predispose to stroke. Recent advances have significantly increased the identification of clinical, hematological and echocardiographic risk factors that predict the occurrence of atrial fibrillation related stroke. Also, clinical risk stratification has been used to determine medical therapy (aspirin or warfarin) for prevention of atrial fibrillation related brain embolization. Among the various structural heart diseases causing stroke, the role of patent foramen ovale remains controversial. Strides have been made in the use of ultrasonographic techniques such as transesophageal echocardiography and contrast transcranial doppler to detect patent foramen ovale. Coronary artery bypass grafting is often performed in patients with concomitant aortic atheroma and carotid stenosis that may predispose to stroke in the perioperative period. It is now possible to identify perioperatively significant aortic atherosclerosis (using transesophageal echocardiography and aortic ultrasound) and significant carotid disease (using carotid ultrasound) and make appropriate modifications in surgical technique to reduce the incidence of coronary artery bypass grafting related stroke. Because of shared risk factors it is not surprising that coronary artery disease is frequently found in stroke patients. Recent studies suggest that more than one-third of stroke patients have asymptomatic coronary artery disease. Conversely, the brain damaged by infarction may itself be responsible for the production of cardiac structural and electrical abnormalities. Both these factors may contribute to the finding that cardiac events are the leading cause of death in stroke patients on long term follow-up. Recognition of these correlations has enhanced our ability to treat and prevent stroke related mortality.