Patent Foramen Ovale Closure vs Medical Therapy for Stroke Prevention: Meta-analysis of Randomized Trials and Review of Heterogeneity in Meta-analyses

Patent foramen ovale closure in children without cardiopathy: Child-PFO study

BACKGROUND

Closure of patent foramen ovale is well-managed in adults, but is performed less frequently in children.

AIM

To analyse all patent foramen ovale closures performed in the past 20 years in French paediatric centres.

METHODS

Retrospective study of patent foramen ovale closures in children without cardiopathy in nine centres between 2000 and 2019.

RESULTS

Forty-one procedures were carried out in children (median age: 14.9 years). Thirty-one patent foramen ovales were closed after a transient ischaemic attack or stroke, six for a left-to-right shunt and four for other reasons. Transthoracic echocardiography was used for 72.2% of the diagnoses and transoesophageal echocardiography for 27.8%. A substantial degree of shunting was found in 42.9% of patients and an atrial septal aneurysm in 56.2%. General anaesthesia with transoesophageal echocardiography guidance was performed in 68.3% of the procedures; local anaesthesia and transthoracic echocardiography or intracardiac echocardiography was performed in 31.7%. The success rate was 100%. The median fluoroscopy time was 4.14minutes: 3.55minutes with transoesophageal echocardiography; and 4.38minutes with transthoracic echocardiography (P=0.67). There was only one periprocedural complication (2.4%). Postoperatively, 80,5% of patients were treated with aspirin and 12,2% with an anticoagulant. The rate of complete occlusion was 56.8% immediately after the procedure, 68.6% at 1 year and 92.3% at the last follow-up. There were no delayed complications or cases of recurrent stroke during follow-up (median follow-up: 568 days).

CONCLUSION

Closure of patent foramen ovale in children appears to be safe and effective, as we noted a low rate of immediate complications, no delayed complications and no stroke recurrence in this indication.

Cardiac diagnostic work-up of ischaemic stroke

Cardioembolic sources account for 20-30% of ischaemic strokes and are important to identify considering their prognostic and therapeutic implications. During the past years, new developments have been made in the cardiac diagnostic evaluation and management of patients with ischaemic stroke, especially regarding strokes of unknown aetiology. These recent advances have had a major impact on our understanding of embolic strokes, their diagnostic work-up, and clinical management. Herein, we propose a cardiac diagnostic work-up scheme for patients with ischaemic stroke from definite cardioembolic sources and embolic strokes of undetermined source.

Cryptogenic Stroke and Significance of the Patent Foramen Ovale: A Case Series

Stroke is the second leading cause of death globally and can lead to significant adverse outcomes in patients following the acute illness. Due to this high morbidity and mortality, adequate interventions can play a significant role in health outcomes. Patent foramen ovale is one of the major proposed causes of cryptogenic strokes and can be present in up to 25% of general population. In cryptogenic strokes, the relation of this structural heart defect is inversely proportional to age of patient. Here, we present three cases of cryptogenic strokes in patients with patent foramen ovale where it possibly plays a significant role. We demonstrate that in the younger age spectrum, patent foramen ovale plays a more significant role and treatment could prevent future stroke episodes.

Patent foramen ovale closure versus medical therapy for stroke prevention: A systematic review and meta-analysis of randomized controlled trials

Background: Previous randomized trials on patent foramen ovale (PFO) closure versus medical therapy for stroke prevention were inconclusive. Recently, two new randomized trials and new findings from an extended follow-up of a previous trial have been published on this topic. We conducted a systematic review and meta-analysis of randomized trials comparing PFO closure with medical therapy for stroke prevention.

Methods: PubMed and Cochrane Library were searched until 16 ^th September 2017.  The following search terms were used for PubMed: "patent foramen ovale" AND (stroke OR embolism) and "randomized" AND "Trial". For Cochrane Library, the following terms were used: "patent foramen ovale" AND "closure" AND (stroke OR embolism).

Results: A total of 91 and 55 entries were retrieved from each database using our search strategy respectively, of which six studies on five trials met the inclusion criteria. This meta-analysis included 1829 patients in the PFO closure arm (mean age: 45.3 years; 54% male) and 1972 patients in the medical therapy arm (mean age: 45.1 years; 51% male). The median follow-up duration was 50 ± 30 months. When compared to medical therapy, PFO closure significantly reduced primary endpoint events with a risk ratio [RR] of 0.60 (95% CI: 0.44-0.83, P < 0.0001; I²: 15%). It also reduced stroke (RR: 0.50, 95% CI: 0.35-0.73, P < 0.0001; I²: 32%) despite increasing the risk of atrial fibrillation/flutter (RR: 1.90, 95% CI: 1.23-2.93, P < 0.01; I²: 43%). However, it did not reduce transient ischemic accident events (0.75; 95% CI: 0.51-1.10, P = 0.14; I²: 0%), all-cause bleeding (RR: 0.89; 95% CI: 0.44-1.78, P = 0.74; I²: 51%) or gastrointestinal complications (RR: 0.92; 95% CI: 0.32-2.70, P = 0.88; I²: 0%).

Conclusions: PFO closure significantly reduces risk of stroke when compared to medical treatment and should therefore be considered for stroke prevention in PFO patients.

Management of stroke and pregnancy

Stroke continues to be one of the main causes of death in the developed countries and the incidence in pregnancy appears to be increasing. Pregnancy-related stroke has a relatively high mortality rate of 10% and so clinicians need to be mindful of appropriate investigations and referral of a pregnant woman with suspected stroke, so they can receive timely treatment. In this review we address the risk factors associated with stroke, diagnosis and appropriate management of the different stroke types. We also discuss implications for care around pregnancy and delivery as well as reviewing how a pregnancy with previous stroke should be managed.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

'Choosing Wisely' culture among Brazilian cardiologists

Objective

(i) To describe how aligned the 'Choosing Wisely' concept is with the medical culture among Brazilian cardiologists and (ii) to identify predictors for physicians' preference for avoiding wasteful care.

Design

Cross-sectional study.

Setting

Brazilian Society of Cardiology.

Participants

Cardiologists who agree to fill a web questionary.

Intervention

A task force of 12 Brazilian cardiologists prepared a list of 13 'do not do' recommendations, which were made available on the Brazilian Society of Cardiology website for affiliates to assign a supported score of 1 to 10 to each recommendation.

Main Outcome Measurement

Score average for supporting recommendations.

Results

Of 14 579 Brazilian cardiologists, 621 (4.3%) answered the questionnaire. The top recommendation was 'do not perform routine percutaneous coronary intervention in asymptomatic individuals' (mean score = 8.0 ± 2.9) while the one with the lowest support was 'do not use an intra-aortic balloon pump in infarction with cardiogenic shock' (5.8 ± 3.2). None of the 13 recommendations presented a mean grade >9 (strong support); 7 recommendations averaged 7-8 (moderate support) followed by 6 recommendations with an average of 5-7 (modest support). Multivariate analysis independently identified predictors of the score attributed to the top recommendation; being an interventionist and time since graduation were both negatively associated with support.

Conclusions

(i) The support of Brazilian cardiologists for the 'Choosing Wisely' concept is modest to moderate, and (ii) older generations and enthusiasm towards the procedure one performs may be factors against the 'Choosing Wisely' philosophy.

Meta-analysis of Randomized Controlled Trials on Patent Foramen Ovale Closure Versus Medical Therapy for Secondary Prevention of Cryptogenic Stroke

The optimal management of patients with cryptogenic stroke (CS) and patent foramen ovale (PFO) remains controversial. We conducted a meta-analysis to assess the effect of PFO closure for secondary prevention of stroke on patients with CS. We searched the literature for randomized control trials assessing the recurrence of stroke after PFO closure compared with medical therapy (antiplatelet and/or anticoagulation). Five randomized control trials with a total of 3,440 patients were included. The mean age was 45.2 ± 9.7 years and follow-up duration ranged from 2.0 to 5.9 years. PFO closure significantly reduced the risk of stroke compared with the medical therapy (2.8% vs 5.8%; relative risk [RR] 0.48, confidence interval [CI] 0.27 to 0.87, p = 0.01, I² = 56%). The number needed to treat for stroke prevention was 10.5. PFO closure was associated with an increased risk of atrial fibrillation compared with medical therapy (4.2% vs 0.7%; RR 4.55, CI 2.16 to 9.6, p = 0.0001, I² = 25%). There was no significant difference in all-cause mortality (RR 1.33, CI 0.56 to 3.16, p = 0.52, I² = 0%), as well as no difference in bleeding risk between the 2 groups (RR 0.94, CI 0.49 to 1.83, p = 0.86, I² = 29%). In conclusion, our meta-analysis demonstrates that PFO closure is associated with significantly lower risk of recurrent stroke in patients with PFO and CS compared with medical therapy. However, atrial fibrillation was more common among closure patients.

Transcatheter closure of patent foramen ovale following cryptogenic stroke: An updated meta-analysis of randomized controlled trials

BACKGROUND

Transcatheter closure of patent foramen ovale (PFO) after cryptogenic stroke has long been a contentious issue. Herein, we pool aggregate data examining safety and efficacy of transcatheter closure of PFO compared with medical therapy following initial cryptogenic stroke.

METHODS

We searched for randomized clinical trials (RCT) that compared device closure with medical management and reported on subsequent stroke and adverse events. Stroke was considered as the primary efficacy endpoint, whereas bleeding and atrial fibrillation were considered primary safety endpoints. Data were pooled by the random effects model and I2 was used to assess heterogeneity.

RESULTS

A total of 5 RCT investigating 3630 patients met inclusion criteria. Pooled analysis revealed that device closure compared to medical management was associated with a significant reduction in stroke (RR=0.3, 95% CI=0.02-0.57). There was, however, a significant increase in atrial arrhythmias with device therapy (RR=4.8, 95% CI=2.2-10.7). We found no increase in bleeding (RR=0.80, 95% CI=0.5-1.4), death (RR=0.76, 95% CI=0.3-1.99) or "any adverse events" (RR=1.02, 95% CI=0.85-1.23) with device therapy. Sub-group analysis revealed that device closure significantly reduced the incidence of the composite primary endpoint among patients who had moderate to large shunt sizes (RR=0.22, 95% CI=0.02-0.42).

CONCLUSIONS

Transcatheter closure is associated with a significant reduction in the risk of stroke compared to medical management at the expense of an increased risk of atrial arrhythmias.

Closure of patent foramen ovale or medical therapy alone for secondary prevention of cryptogenic cerebrovascular events

AIMS

About one-third of ischemic stroke are cryptogenic. Paradoxical embolism through patent foramen ovale (PFO) has been identified as a possible cause of cryptogenic stroke. Therefore, PFO closure has been considered for secondary prevention of cryptogenic stroke. However, randomized clinical trials (RCTs) comparing PFO closure versus medical therapy led to conflicting results. Our objectives were to examine if PFO closure is superior to medical therapy alone for secondary prevention of cryptogenic stroke and to investigate whether PFO closure is associated with an increased incidence of atrial fibrillation/atrial flutter (AFL).

METHODS

The authors systematically searched MEDLINE for RCTs that compared PFO closure with medical therapy. Efficacy outcome was cerebrovascular event (CVE) recurrence and safety outcome was new-onset atrial fibrillation/AFL. The outcomes of interest were investigated according to device type with subgroup analyses and meta-regression.

RESULTS

The authors included eight RCTs constituting 4114 patients. Patients who underwent PFO closure had a lower risk of CVE recurrence compared with medically treated patients [relative risk (RR): 0.56; 95% confidence interval (CI) 0.40-0.80; P = 0.001; I = 30%]. This protective effect was consistent across the different device types. Patients who underwent PFO closure developed more frequently atrial fibrillation/AFL (RR 4.96; 95% CI 2.74-8.99; P < 0.00001; I = 0%), which was mainly transient and within 1 month. Atrial fibrillation/AFL risk was consistent according to device types, although marginally significant in the Amplatzer subgroup.

CONCLUSION

PFO closure might have a role in secondary CVE prevention of patients with PFO and cryptogenic stroke. However, it is associated with an increased incidence of new-onset atrial fibrillation/AFL especially within 1 month.

Reduced Stroke After Transcatheter Patent Foramen Ovale Closure: A Systematic Review and Meta-analysis

BACKGROUND

Recent randomized control trials (RCTs) have suggested benefit with transcatheter patent foramen ovale (PFO) closure plus antiplatelet therapy over medical treatment alone for secondary stroke prevention.

MATERIAL AND METHODS

Data sources: we searched PubMed and Ovid MEDLINE from the inception until November 10, 2017 for RCTs comparing TPFO closure to medical therapy in patients with a PFO and a history of cryptogenic stroke.

RESULTS

Five RCTs with 3,627 patients (TPFO closure = 1,829 versus medical therapy =1,798) were included. There was a decreased number of post-TPFO closure strokes compared to the medical therapy arm; 53 versus 80 strokes (odds ratio [OR] = 0.61, CI: 0.39-0.94, P = 0.03, I² = 17%). Transient ischemic attacks occurred in 43 patients after TPFO closure versus 60 patients in the medical therapy group (OR = 0.80, CI: 0.53-1.19, P = 0.26, I² = 0%). There was a higher incidence of atrial fibrillation in the TPFO closure group, which occurred in 75 patients, compared to 12 patients in the medical therapy group (OR = 5.23, CI: 2.17-12.59, P = 0.0002, I² = 43%). There was a trend toward a decreased number of neuropsychiatric events in the TPFO closure closure group compared to the medical therapy group; 42 versus 67 neuropsychiatric events (OR = 0.71, CI: 0.48-1.06, P = 0.09, I² = 0%).

CONCLUSIONS

TPFO closure plus antiplatelet therapy is superior to medical therapy in patients with a PFO and cryptogenic stroke. PFO closure is associated with new-onset atrial fibrillation and a trend toward reduced neuropsychiatric events.

Transcatheter Closure of Patent Foramen Ovale versus Medical Therapy after Cryptogenic Stroke: A Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Patent foramen ovale (PFO) with atrial septal aneurysm is suggested as an important potential source for cryptogenic strokes. Percutaneous PFO closure to reduce the recurrence of stroke compared to medical therapy has been intensely debated. The aim of this study is to assess whether PFO closure in patients with cryptogenic stroke is safe and effective compared with medical therapy.

METHOD

A search of PubMed, Medline, and Cochrane Central Register from January 2000 through September 2017 for randomized controlled trails (RCT), which compared PFO closure to medical therapy in patients with cryptogenic stroke was conducted. We used the items "PFO or patent foramen ovale", "paradoxical embolism", "PFO closure" and "stroke". Data were pooled for the primary outcome measure using the random-effects model as pooled rate ratio (RR). The primary outcome was reduction in recurrent strokes.

RESULT

Among 282 studies, 5 were selected. Our analysis included 3,440 patients (mean age 45 years, 55% men, mean follow-up 2.9 years), 1,829 in the PFO closure group and 1,611 in the medical therapy group. The I2 heterogeneity test was found to be 48%. A random effects model combining the results of the included studies demonstrated a statistically significant risk reduction in risk of recurrent stroke in the PFO closure group when compared with medical therapy (RR 0.42; 95% CI 0.20-0.91, p = 0.03).

CONCLUSION

Pooled data from 5 large RCTs showed that PFO closure in patients with cryptogenic stroke is safe and effective intervention for prevention of stroke recurrence compared with medical therapy.

Patent foramen ovale closure versus medical therapy after cryptogenic stroke: An updated meta-analysis of all randomized clinical trials

BACKGROUND

Cryptogenic strokes can be attributed to paradoxical emboli through patent foramen ovale (PFO). However, the effectiveness of PFO closure in preventing recurrent stroke is uncertain and the results of previous randomized clinical trials (RCTs) have been inconclusive. Hence, this study pro- vides an updated meta-analysis of all RCTs comparing PFO closure with medical therapy for secondary prevention of cryptogenic stroke.

METHODS

All RCTs were identified by a comprehensive literature search of PubMed, Embase, the Cochrane Collaboration Central Register of Controlled Trials, Scopus, and Clinicaltrials.gov. The primary outcome was recurrent ischemic stroke and secondary outcomes were transient ischemic at- tack (TIA), all-cause mortality, new-onset atrial fibrillation (AF), serious adverse events, and major bleeding.

RESULTS

Five RCTs with 3440 participants were included in the present study (1829 patients under- went PFO closure and 1611 were treated medically). Pooled analysis showed a statistically significant reduction in the rate of recurrent stroke with PFO closure in comparison to medical therapy (OR 0.41; 95% CI 0.19-0.90; p = 0.03). However, there were no statistically significant reductions of recurrent TIAs (OR 0.77; 95% CI 0.51-1.14; p = 0.19) or all-cause mortality (OR 0.76; 95% CI 0.35-1.65; p = 0.48). The risk of developing new-onset AF was increased significantly with PFO closure (OR 4.74; 95% CI 2.33-9.61; p < 0.0001), but no significant differences in terms of serious adverse events or major bleeding between both groups.

CONCLUSIONS

Patent foramen ovale closure in adults with recent cryptogenic stroke was associated with a lower rate of recurrent strokes in comparison with medical therapy alone.

Meta-Analysis Comparing Patent Foramen Ovale Closure Versus Medical Therapy to Prevent Recurrent Cryptogenic Stroke

New evidence suggests that closure of a patent foramen ovale (PFO) plus medical therapy (MT; antiplatelet or anticoagulation) is superior to MT alone to prevent recurrent cryptogenic stroke. We performed a meta-analysis of randomized controlled trials that compared PFO closure plus MT with MT alone in patients with cryptogenic stroke. The efficacy end points were recurrent stroke, transient ischemia attack, and death. The safety end points were major bleeding and newly detected atrial fibrillation. Trials were pooled using random effects and fixed effects models. A trial sequential analysis was performed to assess if the current evidence is sufficient. Risk ratios (RR) were calculated for pooled estimates of risk. Five randomized controlled trials (3,440 patients) were included. Mean follow-up was 4.1 years. PFO closure reduced the risk of recurrent stroke by 58% (RR 0.42, 95% CI 0.20 to 0.91, p = 0.03). The number needed to treat was 38. The cumulative Z-line crossed the trial sequential boundary, suggesting there is adequate evidence to conclude that PFO closure reduces the risk of recurrent stroke by 60%. PFO closure did not reduce the risk of transient ischemia attack (RR 0.78, 95% CI 0.53 to 1.15, p = 0.21), mortality (RR 0.74, 95% CI 0.35 to 1.60, p = 0.45), or major bleeding (RR 0.96, 95% CI 0.42 to 2.20, p = 0.93); it did increase the risk of atrial fibrillation (RR 4.69, 95% CI 2.17 to 10.12, p <0.0001).

Patent foramen ovale closure versus medical therapy for stroke prevention: A systematic review and meta-analysis of randomized controlled trials

Background: Previous randomized trials on patent foramen ovale (PFO) closure versus medical therapy for stroke prevention were inconclusive. Recently, two new randomized trials and new findings from an extended follow-up of a previous trial have been published on this topic. We conducted a systematic review and meta-analysis of randomized trials comparing PFO closure with medical therapy for stroke prevention. Methods: PubMed and Cochrane Library were searched until 16 th September 2017.  The following search terms were used for PubMed: "patent foramen ovale" AND (stroke OR embolism) and "randomized" AND "Trial". For Cochrane Library, the following terms were used: "patent foramen ovale" AND "closure" AND (stroke OR embolism). Results: A total of 91 and 55 entries were retrieved from each database using our search strategy respectively, of which six studies on five trials met the inclusion criteria. This meta-analysis included 1829 patients in the PFO closure arm (mean age: 45.3 years; 54% male) and 1972 patients in the medical therapy arm (mean age: 45.1 years; 51% male). The median follow-up duration was 50 ± 30 months. When compared to medical therapy, PFO closure significantly reduced primary endpoint events with a risk ratio [RR] of 0.60 (95% CI: 0.44-0.83, P < 0.0001; I 2: 15%). It also reduced stroke (RR: 0.50, 95% CI: 0.35-0.73, P < 0.0001; I 2: 32%) despite increasing the risk of atrial fibrillation/flutter (RR: 1.90, 95% CI: 1.23-2.93, P < 0.01; I 2: 43%). However, it did not reduce transient ischemic accident events (0.75; 95% CI: 0.51-1.10, P = 0.14; I 2: 0%), all-cause bleeding (RR: 0.89; 95% CI: 0.44-1.78, P = 0.74; I 2: 51%) or gastrointestinal complications (RR: 0.92; 95% CI: 0.32-2.70, P = 0.88; I 2: 0%). Conclusions: PFO closure significantly reduces risk of stroke when compared to medical treatment and should therefore be considered for stroke prevention in PFO patients.

Patent foramen ovale and stroke in childhood: A systematic review of the literature

BACKGROUND

Stroke in association with a patent foramen ovale (PFO) may be due to paradoxical embolization via a right to left intracardiac shunt but the exact contribution of PFO to stroke or stroke recurrence in childhood remains unclear.

METHODS

To review the relationship of a PFO with stroke, and evaluate associated co-morbidities. An electronic database literature search of Pubmed, Cochrane and EMBASE was performed from January 2000-December 2014.

RESULTS

149 articles were retrieved, with overlap for diagnosis, management, treatment and outcome. 65 reports were utilized for the comprehensive review. Majority of childhood arterial ischemic stroke and transient ischemic attacks are associated with prothrombotic disorders or arteriopathy. Transthoracic echocardiography with a Valsalva maneuver is highly sensitive as a screening tool but may be falsely positive. Transthoracic echocardiography with color Doppler and a concurrent bubble contrast study are excellent for visualizing the atrial septum and PFO and identifying a right to left shunt. Current literature does not support PFO closure for cryptogenic stroke in young adults without an associated risk of thromboembolism.

CONCLUSIONS

High quality research in the pediatric population is lacking and most of the data is extrapolated from adults. Paradoxical embolism from a PFO as a cause of transient ischemic attack or stroke is a diagnosis of exclusion. PFO closure should be individualized based on significant shunting and risk factors such that maximum benefit is derived from the procedure. A young person with a PFO and stroke should be thoroughly investigated to rule out other etiologies.

Patent Foramen Ovale and Stroke

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

Transcatheter closure of PFO as secondary prevention of cryptogenic stroke

This article covers the main unsolved issues regarding the potential role that the patent foramen ovale (PFO) plays in the genesis of so-called cryptogenic stroke. Some brief notions of the anatomy and epidemiology of the PFO are outlined. Subsequently, the results of the three trials on secondary prevention (medical therapy vs. transcatheter closure) in patients with PFO and a history of cryptogenic stroke are presented. The conflicting results of numerous meta-analyses derived from the three randomized controlled trials are discussed. Official scientific guidelines dispute an alleged superior efficacy of transcatheter PFO occlusion in comparison with antithrombotic therapy alone (anticoagulants or antiplatelet agents), except for selected cases of patients with documented PFO and a concomitant clinical-instrumental picture of deep venous thrombosis. Nevertheless, considering recent doubts about the presumptive thrombogenic and arrhythmogenic potential of PFO occlusion, which concerns only one of the septal occluders previously used, further in-depth investigations are warranted, centered on the use of newer dedicated devices to be tested in comparison with antithrombotic regimens alone.

Patent foramen ovale (PFO), stroke and pregnancy

Patent foramen ovale (PFO)-related stroke is increasingly recognized as an important etiology of ischemic embolic stroke-accounting for up to 50% of strokes previously considered 'cryptogenic' or with an unknown mechanism. As a 'back door to the brain,' PFO can allow venous clots to enter arterial circulation via interatrial right-to-left shunting, potentially resulting in ischemic stroke. We observe that clinically, PFO-related stroke affects women of childbearing age, and that pregnancy-owing to major changes in hemocoagulative, hormonal, and cardiovascular parameters-can enhance stroke risks. However, no systematic study has been performed and little is known regarding complications, pregnancy outcomes and treatment for PFO-related stroke during pregnancy. To identify and characterize the complications and clinical outcomes related to PFOs during pregnancy, we performed a literature review and analysis from all reported cases of pregnancy with PFO-related complications in the medical literature from 1970 to 2015. We find that during pregnancy and post-partum, PFO is associated with complications affecting multiple organs, including the brain, heart and lung. The three principal complications reported are stroke, pulmonary emboli and myocardial infarction. In contrast to other pregnancy-related stroke etiologies, which peak during later pregnancy and postpartum, PFO-related stroke peaks during early pregnancy (first and second trimester-60%), and most patients had good neurological outcome (77%). In patients with PFO with recurrent stroke during pregnancy, additional key factors include high-risk PFO morphology (atrial septal aneurysm), larger right-to-left shunt, multiple gestation and concurrent hypercoagulability. Compared to strokes of other etiologies during pregnancy, most PFO stroke patients experienced uneventful delivery (93%) of healthy babies with a good clinical outcome. We conclude with recommended clinical treatment strategies for pregnant patients with PFO suggested by the data from these cases, and the clinical experience of our Cardio-Neurology Clinic.

Unresolved or Contradictory Issues About Management of Patients With Patent Foramen Ovale and Previous Cryptogenic Stroke: Additional Randomized Controlled Trials Are Eagerly Awaited

Stating a well-codified and widely accepted therapeutic conduct for patients with patent foramen ovale (PFO) and previous cryptogenic stroke is made difficult and somewhat controversial by several issues remained unresolved so far. In this short review, some aspects of the possible role played by the PFO in the pathogenesis of cryptogenic stroke are succinctly analyzed. First, some aspects of cardiovascular anatomy of the human fetus and the adult are outlined. Subsequently, the three randomized controlled trials (RCTs) that have been accomplished so far to compare the implant of a transeptal occluding device with a simple medical therapy in patients with PFO and history of cryptogenic stroke are briefly examined. These RCTs, when assessed using the “intention to treat” method, do not show a greater protective effect of therapy with transeptal device as regards the recurrences of stroke. Afterwards, there is a brief presentation of the findings of several meta-analyses that have been derived from the three above mentioned RCTs, whose results are strikingly discordant with each other. In fact, some of them come to the conclusion that the transcatheter closure of PFO does not offer significant advantages compared to antithrombotic therapy for the secondary prevention of cryptogenic stroke, while others based on subgroup analyses argue that the transcatheter closure of PFO with Amplatzer device, differently from the one performed using the STARFlex device, would be associated with significantly lower incidence of cerebrovascular events compared with medical therapy alone. Finally, the authors argue the need to adhere to the current scientific guidelines. They substantially deny an alleged superior efficacy of transcatheter PFO occlusion compared to medical therapy with antithrombotic agents (anticoagulants or antiplatelet agents), except for selected cases of patients with documented PFO and concomitant clinical-instrumental picture of deep venous thrombosis.

Patent Foramen Ovale and Migraine: Closing the Debate--A Review

BACKGROUND

A link between patent foramen ovale (PFO) and migraine as well as the utility of closure of PFO and its effect on migraine have been subjects of debate. The present review is an effort to gather the available evidence on this topic and formulate recommendations.

METHODS

A systematic search of electronic databases (Medline, Embase, Cochrane Library) was performed. A separate search in associated reference lists of identified studies was done. Observational studies and clinical trials published in English using the International Headache Society criteria for diagnosis of migraine were included in the analysis. The search was performed in 3 categories: prevalence of migraine in patients with PFO, prevalence of PFO in migraine patients, and effect of PFO closure and its effect on migraine. The quality of evidence and strength of recommendations during review of these studies was analyzed.

RESULTS

About 14 observational studies with 2602 subjects who had PFO were identified. Migraine prevalence ranged from 16% to 64%. Another 20 studies reported 2444 patients with migraine; the prevalence of PFO ranged from 15% to 90%. About 20 observational studies (1194 patients) that examined the effect of PFO closure on migraine were identified. Resolution of migraine was reported in 10% to 83% of patients, improvement in 14% to 83%, no change in 1% to 54%, and worsening in 4% to 8%. The overall quality of these observational studies was poor. Finally, 3 randomized clinical trials included a total of 238 patients who underwent PFO closure compared with 234 patients in the control groups. All 3 trials failed to meet their primary end points defined as migraine resolution and greater than 50% reduction in migraine days at 1 year. In 2 of the clinical trials, there was some benefit noted in a small subset of migraine patients with aura, but the numbers were too small to extrapolate the findings to the general migraine population.

CONCLUSIONS

There is no good quality evidence to support a link between migraine and PFO. Closure of PFO for migraine prevention does not significantly reduce the intensity and severity of migraine. We do not recommend the routine use of this procedure in current practice.

Isolated asymptomatic pulmonary arteriovenous malformation presenting with ischaemic stroke

Young onset stroke is uncommon, and may be due to conditions other than traditional vascular risk factors. A 42-year-old woman with an ischaemic stroke was found to have left atrial bubble study positivity on transthoracic echocardiogram (TTE) suggestive of patent foramen ovale, however she also had low peripheral oxygen saturation. Investigation revealed an isolated pulmonary arteriovenous malformation (PAVM), visible on admission chest radiograph. This can cause embolic stroke and is an alternate cause of the TTE findings. The PAVM was able to be closed via endovascular intervention, removing the shunt and therefore removing her risk of recurrent stroke events. This is a rare cause of embolic stroke in young people which can be easily missed on investigation yet is amenable to treatment.

Patent foramen ovale

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

Patent foramen ovale: Unanswered questions

The foramen ovale is a remnant of the fetal circulation that remains patent in 20-25% of the adult population. Although long overlooked as a potential pathway that could produce pathologic conditions, the presence of a patent foramen ovale (PFO) has been associated with a higher than expected frequency in a variety of clinical syndromes including cryptogenic stroke, migraines, sleep apnea, platypnea-orthodeoxia, deep sea diving associated decompression illness, and high altitude pulmonary edema. A unifying hypothesis is that a chemical or particulate matter from the venous circulation crosses the PFO conduit between the right and left atria to produce a variety of clinical syndromes. Although observational studies suggest a therapeutic benefit of PFO closure compared to medical therapy alone in patients with cryptogenic stroke, 3 randomized controlled trials (RCTs) did not confirm the superiority of PFO closure for the secondary prevention of stroke. However, meta-analyses of these RCTs demonstrate a significant benefit of PFO closure over medical therapy alone. Similarly, observational studies provide support for PFO closure for symptomatic relief of migraines. But one controversial randomized study failed to replicate the results of the observational studies while another two demonstrated a partial benefit. The goal of this review is to discuss the clinical conditions associated with PFO and provide internists and primary care physicians with current data on PFO trials, and clinical insight to help guide their patients who are found to have a PFO on echocardiographic testing.

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

BACKGROUND

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

OBJECTIVES

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

SEARCH METHODS

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

Leptin receptor action and mechanisms of leptin resistance

The adipose tissue-derived hormone leptin regulates energy balance and neuroendocrine function. Resistance to the appetite-suppressing effects of leptin is associated with common forms of obesity. Here, we review the mechanisms by which leptin activates intracellular signals and the roles that these signals play in leptin action in vivo. Furthermore, we discuss potential mechanisms of leptin resistance, specifically focusing on data regarding the neuroanatomical locus of leptin resistance and potential mechanisms by which expression of the suppressor of cytokine signaling-3 may impair leptin action.