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

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.

Management of the Patient With Patent Foramen Ovale in 2021: A Spectrum of Cases

Patients with patent foramen ovale can manifest in a variety of ways. These presentations and their resolution are discussed in this article.

Patent foramen ovale closure in the management of cryptogenic stroke: a review of current literature and guideline statements

OBJECTIVE

The management recommendations for patent foramen ovale (PFO) closure in cryptogenic stroke are rapidly evolving. The data has expanded recently with four major trials demonstrating superiority of percutaneous device closure over medical management in preventing cryptogenic stroke recurrence. This paper aims to review the current literature for referring physicians who may encounter patients with patent foramen ovale before referring these patients to stroke specialists and/or interventional cardiologists.

METHOD

For this Narrative review, we conducted a broad literature search with expert selection of relevant data. Our search included a review of the currently available trials, guideline statements, position papers, cost-effectiveness of device closure data, as well as the impact of device closure on quality of life.

RESULTS

Most European societies are now in favor of evaluating all patients aged 60 years or younger with recent cryptogenic stroke in the setting of a PFO after careful consideration of the patient's echocardiographic and clinical risk factors. On the other hand, American societies, except for the American Academy of Neurology, have not yet passed official updated recommendations.

CONCLUSION

PFO closure can be considered for the prevention of recurrent cryptogenic stroke in patients aged ≤60 years after a thorough evaluation and discussion about benefits and potential risks (including but not limited to atrial fibrillation) of the procedure. Accumulating evidence supports prognostic, quality of life, and economic benefit from percutaneous PFO closure with newer generation closure devices in the right subset of patients.

HIGHLIGHTS

Data from 4 major trials (RESPECT, CLOSE, DEFENSE-PFO, REDUCE) demonstrates the superiority of PFO closure over medical management alone in preventing cryptogenic stroke recurrence. Trials investigated mostly patients ≤60 years old, and therefore results may not be generalizable to the entire population. Further randomized trials evaluating the safety and efficacy of PFO closure in patients older than 60 years are warranted.Atrial fibrillation is one of the most common "occult" causes of cryptogenic stroke and should be excluded by ambulatory electrocardiographic monitoring. It is important to also rule out other causes of stroke, including hypercoagulable states, atherosclerotic lesions, other cardioembolic sources, and arterial dissection.Complications of PFO procedure include new-onset AF, development of scar tissue, risk of aortic root dilation and subsequent erosions, and potential thrombi formation on the device.PFO closure with medical therapy is more cost-effective than medical therapy alone.Patients who underwent PFO closure had lower rates of depression, anxiety, and stress compared to those who did undergo closure.Development of the RoPE score has helped clinicians identify patients with cryptogenic stroke and PFO who might be a candidate for PFO closure. A score of 7, 8, and 9-10 corresponds to a causal risk of 72%, 84%, and 88%, respectively, and defines a subset of patients who may benefit from PFO closure.Current guidelines recommend determining the need for PFO closure on a case-by-case basis, depending on risk factors, in patients age 60 or less with recent cryptogenic stroke in the setting of PFO.

Dual-center experiences with interventional closure of patent foramen ovale: A medium-term follow-up study comparing two patient groups aged under and over 60 years

Background

Current guidelines recommend interventional closure of patent foramen ovale (PFO) in patients with cryptogenic ischemic stroke who are under 60 years of age.

Hypothesis

The hypothesis of this study was to compare follow‐up results of PFO closure in patients over 60 years of age to those of patients under 60 years of age in order to determine whether the procedure is safe and effective for both age groups.

Methods

We included 293 patients who had a cryptogenic ischemic stroke and a PFO confirmed by transesophageal echocardiography (TEE) and who were scheduled for percutaneous closure of the PFO between 2014 and 2019. The device implantation was completed in all patients using an Amplatzer™, Occlutec™, or Cardia Ultrasept PFO occluder.

Results

Follow‐up TEE examinations were performed at intervals of 1, 3, and 6 months after implantation. Patients were followed for a median of 3.6 ± 1.2 years. Recurrent ischemic stroke or transient ischemic attack, cardiac death, arrhythmias, and residual shunt were reported equally in both groups.

Conclusions

Interventional closure of PFO can be as safe and effective in patients over 60 years of age as it is in patients under 60 years of age regardless of the device used. In this older patient group, rigorous discussion and a case‐by‐case decision‐making process including cardiologists and neurologists is warranted to ensure optimal procedure selection.

Point-of-care echocardiography for the evaluation of right-to-left cardiopulmonary shunts: a narrative review

Right-to-left pulmonary and cardiac shunts (RLS) are important causes of refractory hypoxia in the critically-ill perioperative patient. Using a point-of-care ultrasound (POCUS) agitated saline bubble study for an early diagnosis allows patients with clinically significant RLSs to receive expedited therapy. This narrative review discusses the principles of agitated saline ultrasonography as well as the role of POCUS in detecting the most common RLS types seen in the intensive care unit, including patent foramen ovale, atrial septal defects, and pulmonary arterio-venous malformations. An illustrated discussion of the procedure, as well as shunt-enhancing maneuvers (Valsalva or lung recruitment maneuver with subsequent rapid release) is provided. With the wide dissemination of bedside ultrasound within the perioperative and critical care arena, POCUS practitioners should be knowledgeable of the potential pitfalls leading to both false-positive and false-negative studies. False-positive studies may be due to congenital abnormalities, mischaracterization of intrapulmonary shunts as intracardiac shunts (and vice versa), or evidence of the Valsalva effect. False negatives are typically due to respiratory-phasic variation, performing an inadequate shunt-enhancing maneuver, inadequate injection of agitated saline, or pathophysiologic states of elevated left atrial pressure. Finally, alternative POCUS methods for determining presence of an RLS in patients with poor echocardiographic windows are discussed, with a focus on pulsed-wave Doppler interrogation of arterial signals.

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.

Paradoxical embolism: Experiences from a single center

OBJECTIVE

To present our treatment experiences and the follow-up data of patients with paradoxical embolism (PDE).

METHODS

The clinical characteristics, management, and follow-up data of all included patients who were diagnosed with PDE at Fuwai Hospital from January 1994 to October 2015 were recorded.

RESULTS

Twelve patients were included; all had a pulmonary embolism, and 8 had deep venous thrombosis. The artery embolisms involved the cerebral artery (7 patients), renal artery (2 patients), mesentery artery (2 patients), popliteal artery (1 patient), descending aorta thrombus (1 patient), and thrombus-straddled patent foramen ovale (PFO) (1 patient). PFO was found in 3 cases. One patient underwent thrombectomy and PFO closure; Six patients received thrombolysis; and 3 patients were implanted with a vena cava filter. Long-term anticoagulation with warfarin was recommended for each patient. One patient died from ventricular fibrillation despite cardiopulmonary resuscitation. Eleven patients were discharged with improvements. No late mortality occurred in 8 patients with a complete follow-up of 10.6-17.7 years. One had a recurrent deep venous thrombosis. No patient had a recurrent pulmonary or arterial embolism. Two patients changed their treatment from warfarin to aspirin; others remained on warfarin. Only 1 case had an occasional gum bleeding.

CONCLUSIONS

PDE treatment including thrombolysis, anticoagulation, and embolectomy should be individualized. We recommend long-term anticoagulation therapy to prevent the recurrence of PDE, especially to those with an intracardiac communication or persistent risk factors for re-thrombosis.

Migraine and risk of perioperative ischemic stroke and hospital readmission: hospital based registry study

OBJECTIVE

 To evaluate whether patients with migraine are at increased risk of perioperative ischemic stroke and whether this may lead to an increased hospital readmission rate.

DESIGN

 Prospective hospital registry study.

SETTING

 Massachusetts General Hospital and two satellite campuses between January 2007 and August 2014.

PARTICIPANTS

 124 558 surgical patients (mean age 52.6 years; 54.5% women).

MAIN OUTCOME MEASURES

 The primary outcome was perioperative ischemic stroke occurring within 30 days after surgery in patients with and without migraine and migraine aura. The secondary outcome was hospital readmission within 30 days of surgery. Exploratory outcomes included post-discharge stroke and strata of neuroanatomical stroke location.

RESULTS

 10 179 (8.2%) patients had any migraine diagnosis, of whom 1278 (12.6%) had migraine with aura and 8901 (87.4%) had migraine without aura. 771 (0.6%) perioperative ischemic strokes occurred within 30 days of surgery. Patients with migraine were at increased risk of perioperative ischemic stroke (adjusted odds ratio 1.75, 95% confidence interval 1.39 to 2.21) compared with patients without migraine. The risk was higher in patients with migraine with aura (adjusted odds ratio 2.61, 1.59 to 4.29) than in those with migraine without aura (1.62, 1.26 to 2.09). The predicted absolute risk is 2.4 (2.1 to 2.8) perioperative ischemic strokes for every 1000 surgical patients. This increases to 4.3 (3.2 to 5.3) for every 1000 patients with any migraine diagnosis, 3.9 (2.9 to 5.0) for migraine without aura, and 6.3 (3.2 to 9.5) for migraine with aura. : Patients with migraine had a higher rate of readmission to hospital within 30 days of discharge (adjusted odds ratio 1.31, 1.22 to 1.41).

CONCLUSIONS

 Surgical patients with a history of migraine are at increased risk of perioperative ischemic stroke and have an increased 30 day hospital readmission rate. Migraine should be considered in the risk assessment for perioperative ischemic stroke.

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

BACKGROUND AND PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

CLINICAL TRIAL REGISTRATION

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

Resuming anticoagulant therapy after intracerebral bleeding

The clinical benefit of resuming anticoagulant treatment after an anticoagulants-associated intracranial hemorrhage (ICH) is debated. No randomized trial has been conducted on this particular clinical issue. The risk of ICH recurrence from resuming anticoagulant therapy is expected to be higher after index lobar than deep ICH and in patients with not amendable risk factors for ICH. Retrospective studies have recently shown improved survival with resumption of treatment after index anticoagulants-associated ICH. Based on these evidences and on the risk for thromboembolic events without anticoagulant treatment, resumption of anticoagulation should be considered in all patients with mechanical heart valve prosthesis and in those with amendable risk factors for anticoagulants-associated ICH. Resumption with direct oral anticoagulants appears a reasonable option for non-valvular atrial fibrillation (NVAF) patients at moderate to high thromboembolic risk after deep ICH and for selected NVAF patients at high thromboembolic risk after lobar ICH. For VTE patients at high risk for recurrence, resumption of anticoagulation or insertion of vena cava filter should be tailored on the estimated risk for ICH recurrence.

The Role of Patent Foramen Ovale in Cryptogenic Stroke

INTRODUCTION

Almost one-third of ischemic strokes has an unknown etiology and are classified as cryptogenic stroke. Paradoxical embolism because of a patent foramen ovale (PFO) is detected in 40%-50% of these patients. Recently, PFO has been reported as a risk factor for patients of all age groups.

METHODS

In this study, 1080 ischemic stroke patients admitted to our clinic (2011-2013) were retrospectively evaluated. Age, sex, risk factors, complete blood count, vasculitis, biochemical and hypercoagulability tests, magnetic resonance imaging, magnetic resonance angiography, transthoracic echocardiography, transeosophageal echocardiography (TEE) findings, and therapeutic approaches were evaluated.

RESULTS

The age range of the participants (seven male and four female patients) was 20-60 years (mean=43.09±11.13 years). Hemiparesis (n=10), diplopia (n=2), hemianopsia (n=2), and dysarthria (n=2) were the main findings of the neurological examinations. Patient medical history revealed hypertension (n=3), asthma (n=1), deep venous thrombosis (n=1), and smoking (n=4). Diffusion-weighted imaging showed middle cerebral artery (n=8) and posterior cerebral artery (n=3) infarctions. In one case, symptomatic severe carotid stenosis was detected. In eight cases, TEE showed PFO without any other abnormalities, but PFO was associated with atrial septal aneurysm in two cases, and in one case it was associated with ventricular hypokinesia and pulmonary arterial hypertension. Antiplatelet therapy was applied to nine patients and percutaneous PFO closure operation to two patients. In a 2-year follow-up, no recurrent ischemic stroke was recorded.

CONCLUSION

PFO, especially in terms of the etiology of cryptogenic stroke in young patients, should not be underestimated. We want to emphasize the importance of TEE in identifying potential cardioembolic sources not only in young but also in all ischemic stroke patients with unknown etiology; we also discuss the controversial management options of PFO.

Risk of Recurrent Neurologic Stroke or Transient Ischemic Attack in Patients with Cryptogenic Stroke and Intrapulmonary Shunt

BACKGROUND AND PURPOSE

Cardio-embolic phenomenon is believed to underlie a significant proportion of cryptogenic strokes. We recently showed that intrapulmonary shunt (IPS) was associated with cryptogenic stroke and transient ischemic attack (TIA). We hypothesized that patients with prior cryptogenic stroke or TIA that had an IPS were at a higher risk for recurrent ischemic events.

METHODS

The population included subjects with cryptogenic cerebrovascular accident (CVA) or TIA. Inclusion criteria were age ≥18 years, sinus rhythm, and clinically indicated transesophageal echocardiography (TEE). Exclusion criteria were hemorrhagic CVA, septal defect, and patent foramen. Patients were followed from index TEE.

RESULTS

Of 71 patients, 8 were lost to follow-up. A total of 23 patients had and 40 were without IPS. Average follow-up duration was 38.3 ± 19.2 months. Groups were similar at baseline. There was no significant difference in the recurrence of ischemic CVA or TIA in the IPS versus non-IPS groups (0% vs. 7.5%; P = NS). There was no difference between the incidence of hemorrhagic CVA in the IPS and non-IPS groups (4.3% vs. 5.0%; P = NS). The proportion of patients on warfarin in the IPS group was significantly higher compared to the non-IPS group (17.4% vs. 0%; P < 0.05).

CONCLUSIONS

Patients with IPS and cryptogenic stroke or TIA did not have a higher recurrence of ischemic cerebral events. Warfarin was significantly higher at follow-up in the IPS compared to the non-IPS group, which may explain these findings. A study randomizing patients with IPS and cryptogenic stroke or TIA to warfarin or no warfarin would be of great interest.

PFO Closure for Cryptogenic Stroke

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

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.

Prevalence of patent foramen ovale in ischemic stroke in Italy: the SISIFO study

Patent foramen ovale (PFO) is a common congenital anatomical defect in the general population with a mean prevalence of 20 %. Transcranial Doppler sonography and echocardiography, both with infusion of agitated saline as an echo contrast, have been introduced for the diagnosis of PFO. Transesophageal echocardiography is considered the gold standard. Several studies have suggested an association between cryptogenetic stroke and PFO, but the role of this condition as a risk factor for stroke is still debated. The aims of this prospective multicentre study are the evaluation of PFO prevalence in the whole ischemic stroke population and the identification of a stroke recurrence profile risk in patients with PFO. All consecutive patients admitted for acute ischemic stroke and with a confirmed diagnosis at discharge are eligible cases for the study. Demographic and vascular risk factors are registered. Clinical severity is summarized by the National Institute of Health stroke scale. Echocardiographic and transcranial studies are performed in each patient to detect the presence of PFO. Prevalence of PFO will be calculated with 95 % CIs. Univariate analysis will be performed to detect the correlation of PFO with different registered factors and multivariable analysis with PFO as independent variable. The present study should contribute to better identify the role of PFO in ischemic stroke risk and recurrence-related events. Qualifying findings of the study are represented by the high number of enrolled patients, the prospective methodology of the study and the presence of secondary instrumental endpoints.

Guidelines for the prevention of stroke in patients with stroke and transient ischemic attack: a guideline for healthcare professionals from the American Heart Association/American Stroke Association

The aim of this updated guideline is to provide comprehensive and timely evidence-based recommendations on the prevention of future stroke among survivors of ischemic stroke or transient ischemic attack. The guideline is addressed to all clinicians who manage secondary prevention for these patients. Evidence-based recommendations are provided for control of risk factors, intervention for vascular obstruction, antithrombotic therapy for cardioembolism, and antiplatelet therapy for noncardioembolic stroke. Recommendations are also provided for the prevention of recurrent stroke in a variety of specific circumstances, including aortic arch atherosclerosis, arterial dissection, patent foramen ovale, hyperhomocysteinemia, hypercoagulable states, antiphospholipid antibody syndrome, sickle cell disease, cerebral venous sinus thrombosis, and pregnancy. Special sections address use of antithrombotic and anticoagulation therapy after an intracranial hemorrhage and implementation of guidelines.

Ischaemic stroke with patent foramen ovale

BACKGROUND

There is no sound scientific documentation of current guidelines for the treatment of cerebral infarction assumed to be due to patent foramen ovale. In this article, we present a young patient with this condition. In addition, we provide a general overview of the prevalence, recommended assessment and indications for treatment of patent foramen ovale in ischaemic stroke patients.

METHOD

The article is based on a non-systematic search in PubMed. We emphasise three recently published randomised trials on the subject.

RESULTS

Transoesophageal echocardiography with saline contrast is the gold standard for detecting patent foramen ovale. Just who will benefit from the diagnosis and treatment of this condition remains unclear, however. None of the three randomised studies of antithrombotic treatment versus transcatheter closure in patients who have suffered ischaemic stroke show a difference in outcomes, but subgroup analyses indicate that closure in young patients (age <50 years) with a large foramen ovale reduces the number of recurrent ischaemic events. Two other randomised studies of antithrombotic treatment alone versus closure are presently ongoing.

INTERPRETATION

For stroke patients with patent foramen ovale, the choice between lifelong antithrombotic therapy alone and transcatheter closure is a difficult one. Treatment with antiplatelet agents remains the first choice in most cases. Well-designed studies are needed to identify which patients will benefit most from closure.

Risk of stroke in patients with patent foramen ovale: an updated meta-analysis of observational studies

BACKGROUND

Although patent foramen ovale (PFO) is considered to be associated with cryptogenic stroke (CS), there remains an ongoing disputation on this issue because of unstable results from randomized controlled trials. The aim of this study was to reassess the PFO effect on stroke through observational data.

METHODS

An electronic search of PubMed, Web of Science, and China National Knowledge Infrastructure (CNKI) were finished. Only case-control studies and cohort studies in Chinese or English were included in the analysis. Then random-effected meta-analysis models were performed to assess the association between PFO and stroke.

RESULTS

Twelve case-control studies and 6 cohort studies were eligible. Case-control studies showed strong association between PFO and CS (odds ratio [OR]: 2.94, 95% confidence interval [CI]: 2.06, 4.20; P < .001), but cohort studies failed to demonstrate a significant association (hazard ratio [HR]: 1.28, 95% CI: .91, 1.80; P = .155). Subgroup analysis revealed that the pooled OR decreased significantly when the region was limited to the United States (OR: 1.52, 95% CI: 1.00, 2.32; P = .083). OR of studies that adjusted major confounders was 1.74 (95% CI: 1.22, 2.47; P = .119) and high-quality studies was 1.68 (95% CI: 1.14, 2.47; P = .072). For cohort studies, a weak statistical association was observed in using transesophageal echocardiography (TEE) studies (HR: 1.45, 95% CI: 1.06, 2.01; P = .138) and follow-up years less than 4 years' studies (HR: 1.45, 95% CI: 1.00, 2.09; P = .064).

CONCLUSIONS

Although case-control studies still show a positive effect of PFO on stroke, the results of cohort challenged the credibility. Further trial data are needed to confirm the effect of PFO on stroke.

Ischaemic stroke secondary to paradoxical emboli through an arteriovenous malformation of the lung in a patient with known breast cancer

We presented an unusual case of a young woman who suffered an ischaemic stroke while receiving chemotherapy postsurgery for breast cancer. No cause was identified at that time and a year later an incidental pulmonary arteriovenous malformation (PAVM) was diagnosed during an MR review of her breasts. This was confirmed on the CT and she subsequently underwent successful endovascular embolisation. Ischaemic stroke as a presenting symptom of an undiagnosed PAVM or hereditary haemorrhagic telangiectasia is rare. PAVM is a clinically important and treatable cause of ischaemic stroke and should therefore be considered in young patients with ischaemic stroke, with or without concurrent venous thrombotic risk factors. As far as we are aware, this is the first reported incidental finding of PAVM on MR of the breast.

Intrapulmonary shunt is a potentially unrecognized cause of ischemic stroke and transient ischemic attack

BACKGROUND

Ischemic stroke is a major cause of mortality and disability. Transient ischemic attack (TIA) is a harbinger of stroke. The etiology of stroke in as many as 40% of patients remains undetermined after extensive evaluation. It was hypothesized that intrapulmonary shunt is a potential facilitator of cerebrovascular accident (CVA) or TIA.

METHODS

Patients undergoing clinically indicated transesophageal echocardiography were prospectively enrolled. Comprehensive multiplane transesophageal echocardiographic imaging was performed and saline contrast done to assess for intrapulmonary shunt and patent foramen ovale.

RESULTS

Three hundred twenty-one patients with either nonhemorrhagic CVA (n = 262) or TIA (n = 59) made up the stroke group. Three hundred twenty-one age-matched and gender-matched patients made up the control group. Intrapulmonary shunt occurred more frequently in the stroke group (72 of 321) compared with the control group (32 of 321) (22% vs 10%, P < .0001). Intrapulmonary shunt was an independent predictor of CVA and/or TIA (odds ratio, 2.6; P < .0001). In subjects with cryptogenic CVA or TIA (n = 71), intrapulmonary shunt occurred more frequently (25 of 71) than in the control group (5 of 71) (35% vs 7%, P < .0001). Intrapulmonary shunt was an independent multivariate predictor of CVA or TIA in patients with cryptogenic CVA or TIA (odds ratio, 6.3; P < .005).

CONCLUSIONS

These results suggest that intrapulmonary shunt is a potentially unrecognized facilitator of CVA and TIA, especially in patients with cryptogenic CVA and TIA. Future studies assessing the prognostic significance of intrapulmonary shunt on cerebral vascular event recurrence rates in patients after initial CVA or TIA would be of great interest.

Fibrinolytic activity and platelet function in subjects with obstructive sleep apnoea and a patent foramen ovale: is there an option for prevention of ischaemic stroke?

Obstructive sleep apnoea (OSA) carries an increased risk of ischaemic stroke, but the underlying mechanism is not clear. As right-to-left shunting can occur through a patent foramen ovale (PFO) during periods of apnoea, we investigated nocturnal changes in fibrinolytic activity and platelet function in subjects who had OSA with or without PFO and in controls. We determined plasminogen activator inhibitor 1 (PAI-1) activity and antigen and platelet activation parameters. The severity of OSA was verified by polygraphy and PFO was detected by ear oximetry. We found a higher PAI-1 activity and antigen and a lower ratio of 2,3-dinor-PGF(1α) to 2,3-dinor-TXB(2) in the subjects with OSA than in the controls. Linear regression analysis showed the apnoea-hypopnoea index (β-coefficient, 0.499; P = 0.032) and PFO (β-coefficient, 0.594; P = 0.015) to be associated independently with PAI-1 activity in the morning, while the increment in PAI-1:Ag from evening to morning was significantly associated with the presence of PFO (r(s) = 0.563, P = 0.002). Both OSA and PFO reduce fibrinolytic activity during nocturnal sleep. We hypothesize that subjects having both OSA and PFO may develop a more severe prothrombotic state during sleep than those having either OSA or PFO alone.

Patent foramen ovale, ischemic stroke and migraine: systematic review and stratified meta-analysis of association studies

BACKGROUND

Observational data have reported associations between patent foramen ovale (PFO), cryptogenic stroke and migraine. However, randomized trials of PFO closure do not demonstrate a clear benefit either because the underlying association is weaker than previously suggested or because the trials were underpowered. In order to resolve the apparent discrepancy between observational data and randomized trials, we investigated associations between (1) migraine and ischemic stroke, (2) PFO and ischemic stroke, and (3) PFO and migraine.

METHODS

Eligibility criteria were consistent; including all studies with specifically defined exposures and outcomes unrestricted by language. We focused on studies at lowest risk of bias by stratifying analyses based on methodological design and quantified associations using fixed-effects meta-analysis models.

RESULTS

We included 37 studies of 7,686 identified. Compared to reports in the literature as a whole, studies with population-based comparators showed weaker associations between migraine with aura and cryptogenic ischemic stroke in younger women (OR 1.4; 95% CI 0.9-2.0; 1 study), PFO and ischemic stroke (HR 1.6; 95 CI 1.0-2.5; 2 studies; OR 1.3; 95% CI 0.9-1.9; 3 studies), or PFO and migraine (OR 1.0; 95% CI 0.6-1.6; 1 study). It was not possible to look for interactions or effect modifiers. These results are limited by sources of bias within individual studies.

CONCLUSIONS

The overall pairwise associations between PFO, cryptogenic ischemic stroke and migraine do not strongly suggest a causal role for PFO. Ongoing randomized trials of PFO closure may need larger numbers of participants to detect an overall beneficial effect.

Toward understanding the atrial septum in cryptogenic stroke

Ischemic stroke in younger people is common, and often remains unexplained. There is a well-documented association between unexplained stroke in younger people, and the presence of a patent foramen ovale. Therefore, in the absence of a clear cause of stroke, the heart is often assessed in detail for such lower risk causes of stroke. This usually involves imaging with a transesophageal echo, and investigation for a right-to-left shunt. An understanding of the anatomy of the atrial septum, and its associated abnormalities, is important for the stroke neurologist charged with decision making regarding appropriate secondary prevention. In this paper, we review the development and anatomy of the right heart with a focus on patent foramen ovale, and other associated abnormalities. We discuss how the heart can be imaged in the case of unexplained stroke, and provide examples. Finally, we suggest a method of investigation, in light of the recent European Association of Echocardiography guidance. Our aim is to provide the neurologist with an understanding on how the heart can be investigated in unexplained stroke, and the significance of abnormalities detected.

Antithrombotic and thrombolytic therapy for valvular disease: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines

BACKGROUND

Antithrombotic therapy in valvular disease is important to mitigate thromboembolism, but the hemorrhagic risk imposed must be considered.

METHODS

The methods of this guideline follow those described in Methodology for the Development of Antithrombotic Therapy and Prevention of Thrombosis Guidelines. Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines in this supplement.

RESULTS

In rheumatic mitral disease, we recommend vitamin K antagonist (VKA) therapy when the left atrial diameter is > 55 mm (Grade 2C) or when complicated by left atrial thrombus (Grade 1A). In candidates for percutaneous mitral valvotomy with left atrial thrombus, we recommend VKA therapy until thrombus resolution, and we recommend abandoning valvotomy if the thrombus fails to resolve (Grade 1A). In patients with patent foramen ovale (PFO) and stroke or transient ischemic attack, we recommend initial aspirin therapy (Grade 1B) and suggest substitution of VKA if recurrence (Grade 2C). In patients with cryptogenic stroke and DVT and a PFO, we recommend VKA therapy for 3 months (Grade 1B) and consideration of PFO closure (Grade 2C). We recommend against the use of anticoagulant (Grade 1C) and antiplatelet therapy (Grade 1B) for native valve endocarditis. We suggest holding VKA therapy until the patient is stabilized without neurologic complications for infective endocarditis of a prosthetic valve (Grade 2C). In the first 3 months after bioprosthetic valve implantation, we recommend aspirin for aortic valves (Grade 2C), the addition of clopidogrel to aspirin if the aortic valve is transcatheter (Grade 2C), and VKA therapy with a target international normalized ratio (INR) of 2.5 for mitral valves (Grade 2C). After 3 months, we suggest aspirin therapy (Grade 2C). We recommend early bridging of mechanical valve patients to VKA therapy with unfractionated heparin (DVT dosing) or low-molecular-weight heparin (Grade 2C). We recommend long-term VKA therapy for all mechanical valves (Grade 1B): target INR 2.5 for aortic (Grade 1B) and 3.0 for mitral or double valve (Grade 2C). In patients with mechanical valves at low bleeding risk, we suggest the addition of low-dose aspirin (50-100 mg/d) (Grade 1B). In valve repair patients, we suggest aspirin therapy (Grade 2C). In patients with thrombosed prosthetic valve, we recommend fibrinolysis for right-sided valves and left-sided valves with thrombus area < 0.8 cm(2) (Grade 2C). For patients with left-sided prosthetic valve thrombosis and thrombus area ≥ 0.8 cm(2), we recommend early surgery (Grade 2C).

CONCLUSIONS

These antithrombotic guidelines provide recommendations based on the optimal balance of thrombotic and hemorrhagic risk.

Antithrombotic medication for cardioembolic stroke prevention

Embolism of cardiac origin accounts for about 20% of ischemic strokes. Nonvalvular atrial fibrillation is the most frequent cause of cardioembolic stroke. Approximately 1% of population is affected by atrial fibrillation, and its prevalence is growing with ageing in the modern world. Strokes due to cardioembolism are in general severe and prone to early recurrence and have a higher long-term risk of recurrence and mortality. Despite its enormous preventive potential, continuous oral anticoagulation is prescribed for less than half of patients with atrial fibrillation who have risk factors for cardioembolism and no contraindications for anticoagulation. Available evidence does not support routine immediate anticoagulation of acute cardioembolic stroke. Anticoagulation therapy's associated risk of hemorrhage and monitoring requirements have encouraged the investigation of alternative therapies for individuals with atrial fibrillation. New anticoagulants being tested for prevention of stroke are low-molecular-weight heparins (LMWH), unfractionated heparin, factor Xa inhibitors, or direct thrombin inhibitors like dabigatran etexilate and rivaroxaban. The later exhibit stable pharmacokinetics obviating the need for coagulation monitoring or dose titration, and they lack clinically significant food or drug interaction. Moreover, they offer another potential that includes fixed dosing, oral administration, and rapid onset of action. There are several concerns regarding potential harm, including an increased risk for hepatotoxicity, clinically significant bleeding, and acute coronary events. Therefore, additional trials and postmarketing surveillance will be needed.

Patent foramen ovale and obstructive sleep apnoea: from pathophysiology to diagnosis of a potentially dangerous association

Patent foramen ovale and obstructive sleep apnoea are frequently encountered in the general population. Owing to their prevalence, they may coexist fortuitously; however, the prevalence of patent foramen ovale seems to be higher in patients with obstructive sleep apnoea. We have reviewed the epidemiological data, pathophysiology, and the diagnostic and therapeutic options for both patent foramen ovale and obstructive sleep apnoea. We focus on the interesting pathophysiological links that could explain a potential association between both pathologies and their implications, especially on the risk of stroke.

Paradoxical emboli--clinical importance of transcranial Doppler for detection of patent foramen ovale

A patent foramen ovale has been reported to be more frequently detected in cryptogenic stroke, with paradoxical embolism as the major pathogenetic mechanism. The standard procedure for the detection of a patent foramen ovale is transesophageal echocardiography. Transcranial Doppler sonography with bubble test is almost as reliable as transesophageal echocardiography. Seventeen patients with acute ischemic stroke and transient ischemic attacks hospitalized at the Department of Neurology in Novi Sad underwent examinations to detect a patent foramen ovale, which was found in 55.6% of patients with cryptogenic stroke. The average age of these patients was 30.6 years. Transcranial Doppler sonography showed 100% sensitivity and 100% specificity for the prediction of right-to-left shunts proven by transesophageal contrast echocardiography. Both positive and negative predictive values in our group of patients were 1. Transcranial Doppler with bubble test is a reliable method for the detection of a patent foramen ovale, with a high level of sensitivity and specificity which is comparable with transesophageal echocardiography. Moreover, it is cheaper and more comfortable than transesophageal echocardiography, and should be used routinely in neurological practice.

Guidelines for the primary prevention of stroke: a guideline for healthcare professionals from the American Heart Association/American Stroke Association

BACKGROUND AND PURPOSE

This guideline provides an overview of the evidence on established and emerging risk factors for stroke to provide evidence-based recommendations for the reduction of risk of a first stroke.

METHODS

Writing group members were nominated by the committee chair on the basis of their previous work in relevant topic areas and were approved by the American Heart Association (AHA) Stroke Council Scientific Statement Oversight Committee and the AHA Manuscript Oversight Committee. The writing group used systematic literature reviews (covering the time since the last review was published in 2006 up to April 2009), reference to previously published guidelines, personal files, and expert opinion to summarize existing evidence, indicate gaps in current knowledge, and when appropriate, formulate recommendations using standard AHA criteria (Tables 1 and 2). All members of the writing group had the opportunity to comment on the recommendations and approved the final version of this document. The guideline underwent extensive peer review by the Stroke Council leadership and the AHA scientific statements oversight committees before consideration and approval by the AHA Science Advisory and Coordinating Committee.

RESULTS

Schemes for assessing a person's risk of a first stroke were evaluated. Risk factors or risk markers for a first stroke were classified according to potential for modification (nonmodifiable, modifiable, or potentially modifiable) and strength of evidence (well documented or less well documented). Nonmodifiable risk factors include age, sex, low birth weight, race/ethnicity, and genetic predisposition. Well-documented and modifiable risk factors include hypertension, exposure to cigarette smoke, diabetes, atrial fibrillation and certain other cardiac conditions, dyslipidemia, carotid artery stenosis, sickle cell disease, postmenopausal hormone therapy, poor diet, physical inactivity, and obesity and body fat distribution. Less well-documented or potentially modifiable risk factors include the metabolic syndrome, excessive alcohol consumption, drug abuse, use of oral contraceptives, sleep-disordered breathing, migraine, hyperhomocysteinemia, elevated lipoprotein(a), hypercoagulability, inflammation, and infection. Data on the use of aspirin for primary stroke prevention are reviewed.

CONCLUSIONS

Extensive evidence identifies a variety of specific factors that increase the risk of a first stroke and that provide strategies for reducing that risk.

Echocardiographic evaluation of patent foramen ovale prior to device closure

High-quality imaging of the atrial septum has never been so relevant to the adult cardiologist. This article focuses on the role of echocardiography in the evaluation of patent foramen ovale for closure. It provides a systematic and comprehensive approach to transesophageal echocardiographic study in such a patient. The salient information required for planning the device and equipment needed for the closure procedure are discussed.

Guidelines for the prevention of stroke in patients with stroke or transient ischemic attack: a guideline for healthcare professionals from the american heart association/american stroke association

The aim of this updated statement is to provide comprehensive and timely evidence-based recommendations on the prevention of ischemic stroke among survivors of ischemic stroke or transient ischemic attack. Evidence-based recommendations are included for the control of risk factors, interventional approaches for atherosclerotic disease, antithrombotic treatments for cardioembolism, and the use of antiplatelet agents for noncardioembolic stroke. Further recommendations are provided for the prevention of recurrent stroke in a variety of other specific circumstances, including arterial dissections; patent foramen ovale; hyperhomocysteinemia; hypercoagulable states; sickle cell disease; cerebral venous sinus thrombosis; stroke among women, particularly with regard to pregnancy and the use of postmenopausal hormones; the use of anticoagulation after cerebral hemorrhage; and special approaches to the implementation of guidelines and their use in high-risk populations.

Patent foramen ovale and stroke: Should PFOs be closed in otherwise cryptogenic stroke?

Since initial reports of its association with ischemic stroke appeared in 1988, there has been continued controversy regarding the existence and strength of the association between patent foramen ovale (PFO) and ischemic stroke. Many case-control studies have reported an association between incident cryptogenic ischemic stroke and PFO, yet population-based studies have failed to confirm this association. Studies of the risk of recurrent stroke in patients with cryptogenic stroke with or without PFO have not shown an increased risk of recurrent stroke in patients with PFO. Meanwhile, use of devices to close PFOs and atrial septal defects percutaneously has increased dramatically since their introduction. Completion of the randomized clinical trials of PFO closure currently in progress is vital to determine if the benefits of PFO closure in cryptogenic stroke outweigh its risks.

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, systemic embolization, and closure

Patent foramen ovale has become the subject of increasing interest in modern cardiovascular disease. This has been the result of several factors including, among others, description of paradoxical embolism, documentation of patent foramen ovale with right to left shunt, the rather ubiquitous use of echocardiography, the issue of stroke prevention, and more recently, the relationship between patent foramen ovale and migraine.

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.

Percutaneous closure of patent foramen ovale and atrial septal defect in adults: the impact of clinical variables and hospital procedure volume on in-hospital adverse events

BACKGROUND

Percutaneous closure of patent foramen ovale/atrial septal defect (PFO/ASD) is an increasingly common procedure perceived as having minimal risk. There are no population-based estimates of in-hospital adverse event rates of percutaneous PFO/ASD closure.

METHODS

We used nationally representative data from the 2001-2005 Nationwide Inpatient Sample to identify patients >or-=20 years old admitted to an acute care hospital with an International Classification of Diseases, Ninth Revision code designating percutaneous PFO/ASD closure on the first or second hospital day. Variables analyzed included age, sex, number of comorbidities, year, same-day use of intracardiac or other echocardiography, same-day left heart catheterization, hospital size and teaching status, PFO/ASD procedural volume, and coronary intervention volume. Outcomes of interest included length of stay, charges, and adverse events.

RESULTS

The study included 2,555 (weighted to United States population: 12,544 +/- 1,987) PFO/ASD closure procedures. Mean age was 52.0 +/- 0.4 years, and 57.3% +/- 1.0% were women. Annual hospital volume averaged 40.8 +/- 7.7 procedures (range, 1-114). Overall, 8.2 +/- 0.8% of admissions involved an adverse event. Older patients and those with comorbidities were more likely to sustain adverse events. Use of intracardiac echocardiography was associated with fewer adverse events. The risk of adverse events was inversely proportional to annual hospital volume (odds ratio [OR] 0.91, 95% confidence interval [CI] 0.86-0.96, per 10 procedures), even after limiting the analysis to hospitals performing >or=10 procedures annually (OR 0.91, 95% CI 0.85-0.98). Adverse events were more frequent at hospitals in the lowest volume quintile as compared with the highest volume quintile (13.3% vs 5.4%, OR 2.42, 95% CI 1.55-3.78).

CONCLUSIONS

The risk of adverse events of percutaneous PFO/ASD closure is inversely correlated with hospital volume. This relationship applies even to hospitals meeting the current guidelines, performing >or=10 procedures annually.