Patent foramen ovale and brain infarct. Echocardiographic predictors, recurrence, and prevention

Prognosis of Cryptogenic Stroke With Patent Foramen Ovale at Older Ages and Implications for Trials: A Population-Based Study and Systematic Review

Importance

Patent foramen ovale (PFO) closure may prevent recurrent stroke after cryptogenic transient ischemic attack (TIA) or stroke (TIA/stroke) in patients aged 60 years or younger. Patent foramen ovale is associated with cryptogenic stroke in the older population, but risk of recurrence is unknown. Data on prognosis of patients receiving medical treatment at older ages (≥60 years) are essential to justify trials of PFO closure.

Objective

To examine the age-specific risk of recurrence in patients with cryptogenic TIA/stroke with PFO.

Design, Setting, and Participants

A prospective study was nested in the population-based Oxford Vascular Study between September 1, 2014, and March 31, 2019, with face-to-face follow-up for 5 years. A total of 416 consecutive patients with a diagnosis of cryptogenic TIA or nondisabling stroke, screened for PFO at a rapid-access TIA/stroke clinic, were included. A systematic review and meta-analysis of cohort studies reporting on ischemic stroke recurrence after cryptogenic TIA/stroke in patients with PFO who were receiving medical therapy alone, or with PFO vs no-PFO was conducted. Sample size calculation for future trials on PFO closure was performed for patients aged 60 years or older.

Exposures

Patent foramen ovale and age as modifiers of risk of recurrent stroke after cryptogenic TIA/stroke in patients receiving only medical therapy.

Main Outcomes and Measures

Risk of ischemic stroke recurrence in patients with cryptogenic TIA/stroke and PFO receiving medical therapy only, and in patients with vs without PFO, stratified by age (<65 vs ≥65 years), as well as sample-size calculation for future trials of PFO closure in patients aged 60 years or older.

Results

Among the 153 Oxford Vascular Study patients with PFO (mean [SD] age, 66.7 [13.7] years; 80 [52.3%] men), recurrent ischemic stroke risk (2.05 per 100 patient-years) was similar to the pooled estimate from a systematic review of 23 other studies (9 trials and 14 observational studies) (2.00 per 100 patient-years; 95% CI, 1.55-2.58). However, there was heterogeneity between studies (P < .001 for heterogeneity), owing mainly to risk increasing with mean cohort age (meta-regression: R2 = 0.31; P = .003). In the pooled analysis of 4 studies including patients with or without PFO, increased risk of stroke recurrence with PFO was seen only at age 65 years or older (odds ratio, 2.5; 95% CI, 1.4-4.2; P = .001 for difference; P = .39 for heterogeneity). The pooled ischemic stroke risk was 3.27 per 100 patient-years (95% CI, 2.59-4.13) in 4 cohorts with mean age 60 years or older. Assuming the more conservative 2.0 per 100 patient-years ischemic stroke risk in the PFO nonclosure arms of future trials in patients aged 60 years or older, projected sample sizes were 1080 per arm for 80% power to detect a 33% relative risk reduction.

Conclusions and Relevance

The findings of this study suggest that age is a determinant of risk of ischemic stroke after cryptogenic TIA/stroke in patients with PFO, such that trials of PFO closure at older ages are justified; however, projected sample sizes are large.

Patent Foramen Ovale in Cryptogenic Ischemic Stroke: Direct Cause, Risk Factor, or Incidental Finding?

Patent foramen ovale (PFO) has been associated with cryptogenic stroke. There is conflicting data and it remains uncertain whether PFO is the direct cause, a risk factor or an incidental finding. Potential stroke mechanisms include paradoxical embolism from a venous clot which traverses the PFO, in situ clot formation within the PFO, and atrial arrhythmias due to electrical signaling disruption. Main risk factors linked with PFO-attributable strokes are young age, PFO size, right-to-left shunt degree, PFO morphology, presence of atrial septal aneurysm, intrinsic coagulation-anticoagulation systems imbalance, and co-existence of other atrial abnormalities, such as right atrial septal pouch, Eustachian valve and Chiari's network. These may act independently or synergistically, multiplying the risk of embolic events. The RoPE score, a scale that includes factors such as young age, cortical infarct location and absence of traditional stroke risk factors, is associated with the probability of a PFO being pathogenic and stroke recurrence risk after the index stroke. Multiple investigators have attempted to correlate other PFO features with the risk of PFO-related stroke, but further investigation is needed before any robust conclusions are reached. PFO presence in young patients with cryptogenic stroke should be considered as etiologically suspect. Caution should be exercised in interpreting the relevance of other PFO features.

Clinical relevance of atrial septal aneurysm and patent foramen ovale with migraine

AIM

To test the potential association between atrial septal aneurysm (ASA) and migraine in patent foramen ovale (PFO) closure patients through an observational, single-center, case-controlled study.

METHODS

We studied a total of 450 migraineurs who had right-to-left shunts and underwent PFO closure in a retrospective single-center non-randomized registry from February 2012 to October 2016 on the condition that they were aged 18-45 years old. Migraine was diagnosed according to the International Classification of Headache Disorders, 3^rd edition and evaluated using the Headache Impact Test-6 (HIT-6). All patients underwent preoperative transesophageal echocardiography, contrast transthoracic echocardiography, and computed tomography or magnetic resonance imaging examinations, with subsequent fluoroscopy-guided PFO closure. Based on whether they have ASA or not, the patients were divided into two groups: A (PFO with ASA, n = 80) and B (PFO without ASA, n = 370). Baseline characteristics and procedural and follow-up data were reviewed.

RESULTS

Compared to group B, group A had an increased frequency of ischemic lesions (11.3% vs 6.2%, P = 0.038) and migraine with aura (32.5% vs 21.1%, P = 0.040). The PFO size was significantly larger in group A (P = 0.007). There was no significant difference in HIT-6 scores between the two groups before and at the one-year follow-up after the PFO closure [61 (9) vs 63 (9), P = 0.227; 36 (13) vs 36 (10), P = 0.706].

CONCLUSION

Despite its small sample size, our study suggests that the prevalence of ASA in PFO with migraine patients is associated with ischemic stroke, larger PFO size, and migraine with aura.

Atrial dyssynchrony and left atrial stiffness are risk markers for cryptogenic stroke in patients with patent foramen ovale

OBJECTIVE

The clinical and echocardiographic parameters associated with the risk predictors of cryptogenic stroke (CS) in patients with patent foramen ovale (PFO) still diverse and with a great debate. We hypothesized that left atrial stiffness (LASt) and atrial dyssynchrony may increase the risk of CS in patients with PFO.

METHODS

A total of 129 consecutive patients presented without clinical reasoning of stroke were recruited. Transesophageal echocardiographic assessment was performed to investigate the presence of PFO. PFO was identified in 52% (group I) and absent in 48% (group II). Utilizing speckle-tracking imaging LASt and atrial dyssynchrony was evaluated among patients with PFO (group I) vs those without PFO (group II).

RESULTS

LASt was significantly increased in group I patients compared with group II (P < .001). Likewise patients with PFO had a significant LA dyssynchrony compared with those in group II (P < .001). Interatrial dyssynchrony and left atrial dyssynchrony were correlated with LASt (r = .47 and 0.51, respectively; P < .001). Cardiac arrhythmias were significantly encountered in group I patients (at presentation and with Holter monitoring) P < .001. Besides significantly increase in atrial dyssynchrony and in LASt in patients with arrhythmias compared with those without (P < .001). ROC analysis revealed that LASt index ≥ 0.61 and LA dyssynchrony ≥ 23.5 predicts cardiac arrhythmias in CS patients with PFO with (AUC: 0.85 and 0.87, respectively, P < .001).

CONCLUSION

In conclusion, we demonstrated that LASt and atrial dyssynchrony might be risk markers of cryptogenic stroke in patients with PFO.

Patent foramen ovale in idiopathic pulmonary arterial hypertension: Long-term risk and morbidity

INTRODUCTION

Little is known about the presence of patent foramen ovale in idiopathic pulmonary arterial hypertension. While there is suspected worsening of hypoxemia confounding assessment and management of pulmonary hypertension, as well as possible increased morbidity from paradoxical emboli, there may be theoretical relief of worsening right-sided pressures by the same mechanism of right-to-left shunting.

METHODS

Retrospective review of consecutive patients diagnosed with idiopathic pulmonary arterial hypertension (WHO Group 1) via right heart catheterization, from 1998 to 2010. All patients also underwent a four chamber transthoracic echocardiogram with agitated saline contrast for the evaluation of patent foramen ovale. Primary clinical data was collected and compared between patients with and without patent foramen ovale along with univariable and multivariable predictors of long term survival.

RESULTS

One hundred and fifty five patients were included in the study, 42 with patent foramen ovale (27%). Patients with patent foramen ovale were younger at pulmonary arterial hypertension diagnosis and trended towards higher right ventricular systolic pressures on echocardiography and mean pulmonary arterial pressures by right heart catheterization. Predictors of mortality included age, diffusing capacity for carbon monoxide, and severe hypoxemia. Only diffusing capacity and age were predictive of mortality after adjustment for a priori covariables.

CONCLUSION

Patent foramen ovale is seen in a quarter of patients with idiopathic pulmonary arterial hypertension and associated with increased prevalence of severe hypoxemia but had no effect on long term survival.

Long-Term Contrast Echocardiography and Clinical Follow-Up after Percutaneous Closure of Patent Foramen Ovale Using Two Different Atrial Septal Occluder Devices

INTRODUCTION

Percutaneous patent foramen ovale (PFO) closure by means of a septal occluder device (SOD) is a well-known therapeutic strategy for the secondary prevention of paradoxical embolic neurological events. The aim of this study was to provide long-term echocardiographic and clinical follow-up data on patients who had undergone percutaneous PFO closure with 2 different SOD.

METHODS

We selected 2 groups of patients treated with 2 different SOD: Group A: 52 patients with an Amplatzer(®) PFO Occluder and Group B: 49 patients with a Figulla Flex(®) device. All patients underwent follow-up Bubble Test Transthoracic Echocardiography (BTTE) and clinical examination. The results were compared with those recently reported in a group of patients with similar characteristics, but that had been treated conservatively, which acted as a control group.

RESULTS

The mean follow-up after PFO closure was 53 months. The Amplatzer(®) PFO Occluder and the Figulla Flex were used in 52 (51.5%) and 49 (48.5%) of patients, respectively. We found no significant difference in the rate of effective PFO closure between the devices: Amplatzer 91.4%, Figulla 93.9% (P = 0.71). One patient (1.0%) suffered a recurrent neurologic event. BTTE was positive (BTTE+) in 8 patients (8%), 5 with an Amplatzer, and 3 with a Figulla device (P = 0.516). Only 1 patient with BTTE+ had a recurrent TIA (12.5%). No significant relationship was found between device dimensions and BTTE+ (P = 0.062). In the control group (163 patients), the recurrence of neurologic events was 9.2% (15 events), that was significantly higher in respect to the patients who had undergone percutaneous closure of the PFO.

CONCLUSIONS

Percutaneous PFO closure was associated with a remarkably low risk of recurrent embolic neurological events, and no long-term device-related major complications. No statistically significant difference emerged between the 2 different SODs regarding BTTE positivity. Long-term follow-up showed that the recurrence of neurological events has been significantly higher in the group treated in a conservative way.

Meta-analysis of net long-term benefit of different therapeutic strategies in patients with cryptogenic stroke and patent foramen ovale

We pooled available data on follow-up events in patients with patent foramen ovale and cryptogenic stroke to evaluate the net clinical benefit of different therapeutic strategies (percutaneous closure vs antiplatelet vs anticoagulant therapy). MEDLINE/PubMed and Cochrane databases and reviewed cited references to identify relevant studies were used; 3,311 patients from 21 clinical studies, both observational and randomized, with follow-up ≥12 months were overall included. Net clinical benefit was evaluated considering the cumulative incidence of both stroke and/or transient ischemic attack and major bleeding events. Anticoagulant therapy was more effective than antiplatelet therapy in preventing recurrent stroke and/or transient ischemic attack (event rates: 7.7% vs 9.8%, respectively, p = 0.03), but at the price of more than sixfold greater risk of major bleeding (7.1% vs 1.3%; odds ratio 6.49, 95% confidence interval 3.25 to 12.99, p <0.00001). Patent foramen ovale closure was associated over the long term with significant net clinical benefit versus both antiplatelet and anticoagulant therapy; such benefit was driven by 50% relative reduction of stroke and/or transient ischemic attack versus antiplatelet therapy and by 82% relative reduction of major bleeding versus anticoagulant therapy. In conclusion, results of this large study-level meta-analysis may influence practice patterns in patients with patent foramen ovale and cryptogenic stroke; an individualized approach tailored on both the risk of recurrent cerebral events and the bleeding risk should be used to identify the best therapeutic option (percutaneous closure vs antiplatelet therapy vs anticoagulant therapy).

Recurrent Stroke/TIA in Cryptogenic Stroke Patients with Patent Foramen Ovale

Background:

Patent foramen ovale (PFO) is present in 40% of patients with cryptogenic stroke and may be associated with paradoxical emboli to the brain. Therapeutic options include antiplatelet agents, anticoagulation, percutaneous device and surgical closure. We assessed the hypothesis that there are differences in rates of recurrent TIA or stroke between patients in the four treatment groups.

Methods:

Patients presenting from January 1997 with cryptogenic stroke or TIA and PFO were followed prospectively until June 2003. Treatment choice was made on an individual case basis. The primary outcome was recurrent stroke. The secondary outcome was a composite of stroke, TIA, and vascular death.

Results:

Baseline. Our cohort consisted of 121 patients; 64 (53%) were men. Median age was 43 years. Sixty-nine percent presented with stroke and 31% with TIA. One or more vascular risk factor was present in 40%. Atrial septal aneurysm (ASA) was present in 24%. Treatment consisted of antiplatelet agents (34%), anticoagulation (17%), device (39%) and surgical closure (11%). Follow-up. Recurrent events occurred in 16 patients (9 antiplatelet, 3 anticoagulation, 4 device closure); 7 were strokes, 9 were TIA. Comparing individual treatments there was a trend toward more strokes in the antiplatelet arm (p=0.072); a significant difference was seen for the composite endpoint (p=0.012). Comparing closure versus combined medical therapy groups, a significant difference was seen for primary (p=0.014) and secondary (p=0.008) outcomes, favoring closure. Age and pre-study event predicted outcome.

Conclusion:

Patent foramen ovale closure was associated with fewer recurrent events. Complications of surgical and device closure were self-limited.

Seven-year follow-up of percutaneous closure of patent foramen ovale

Background

Observational studies favor percutaneous closure of patent foramen ovale (PFO) over medical treatment to reduce recurrent stroke while randomized trials fail to demonstrate significant superiority of percutaneous PFO closure. Few long-term studies are available post PFO closure. This study reports long-term clinical outcomes after percutaneous PFO closure.

Methods

Between 1997 and 2006, 86 consecutive eligible patients with cerebrovascular events, presumably related to PFO, underwent percutaneous PFO closure. All 86 patients were invited to a long-term follow-up, which was carried out during 2011 and 2012.

Results

Percutaneous PFO closure was successfully performed in 85 of 86 patients. The follow-up rate was 100%. No cardiovascular or cerebrovascular deaths occurred. Two patients (both women) died from lung cancer during follow-up. Follow-up visits were conducted for 64 patients and the remaining 20 patients were followed up by phone. The mean follow-up time was 7.3 years (5 to 12.4 years). Mean age at PFO closure was 49 years. One patient had a minor stroke one month after PFO closure and a transient ischemic attack (TIA) two years afterwards. One other patient suffered from a TIA six years after closure. No long-term device-related complications were observed.

Conclusions

Percutaneous PFO closure was associated with very low risk of recurrent stroke and is suitable in most patients. We observed no mortality and no long-term device-related complications related to PFO closure, indicating that percutaneous PFO closure is a safe and efficient treatment even in the long term.

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

BACKGROUND

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

METHODS AND RESULTS

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

CONCLUSIONS

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

Multidisciplinary management of patent foramen ovale (PFO) and cryptogenic stroke/TIA

PURPOSE

Patent foramen ovale (PFO) has been implicated as a risk factor for cryptogenic ischemic stroke (CS). However, there is still a lack of widely accepted, undisputed indications for PFO closure. The present study describes the concept of the multidisciplinary PFO conference and a decision making process for closure versus no closure that was developed into a formalized clinical algorithm, and presents the results of implementing these, in terms of number and proportion of PFO closures as well as repeat referrals.

DESIGN

Five specialists in neurology, cardiology, internal medicine, thromboembolism, and echocardiography evaluated the clinical data of 311 patients at PFO conferences during 2006 to 2009. The main criteria for closure were patients with first-ever CS with PFO and atrial septal aneurysm, or patients with recurrent CS and PFO without atrial septal aneurysm.

RESULTS

A total of 143 patients (46%) were accepted for closure and 167 patients were rejected. Patients accepted for closure were younger (mean 50 years versus 58 years) (P < 0.001). The acceptance rate for PFO closure was similar throughout these years, with an average of 45%. Three of 167 patients (1.8%) initially rejected for PFO closure were re-referred due to recurrent stroke, and the PFO closure was subsequently performed.

CONCLUSION

The acceptance rate of less than 50% in the present study underscores the complex relationship between CS and PFO. Whatever the criteria used for PFO closure, any unit caring for these patients needs to have a rigorous process to avoid overtreatment as well as undertreatment and to ensure that personal preferences and economic incentives do not steer the selection process. Our algorithm provides a stable acceptance rate and a low rate of repeat referrals.

Meta-analysis of transcatheter closure versus medical therapy for patent foramen ovale in prevention of recurrent neurological events after presumed paradoxical embolism

OBJECTIVES

In this study, a meta-analysis of observational studies was performed to compare the rate of recurrent neurological events (RNE) between transcatheter closure and medical management of patients with cryptogenic stroke/transient ischemic attack (TIA) and concomitant patent foramen ovale (PFO).

BACKGROUND

A significant controversy surrounds the optimal strategy for treatment of cryptogenic stroke/TIA and coexistent PFO.

METHODS

We conducted a MEDLINE search with standard search terms to determine eligible studies.

RESULTS

Adjusted incidence rates of RNE were 0.8 (95% confidence interval [CI]: 0.5 to 1.1) events and 5.0 (95% CI: 3.6 to 6.9) events/100 person-years (PY) in the transcatheter closure and medical management arms, respectively. Meta-analysis of the limited number of comparative studies and meta-regression analysis suggested that the transcatheter closure might be superior to the medical therapy in prevention of RNE after cryptogenic stroke. Comparison of the anticoagulation and antiplatelet therapy subgroups of the medical arm yielded a significantly lower risk of RNE within patients treated with anticoagulants. Device-related complications were encountered at the rate of 4.1 (95% CI: 3.2 to 5.0) events/100 PY, with atrial arrhythmias being the most frequent complication. After transcatheter closure, RNE did not seem to be related to the pre-treatment shunt size or the presence of residual shunting in the follow-up period. Significant benefit of transcatheter PFO closure was apparent in elderly patients, patients with concomitant atrial septal aneurysm, and patients with thrombophilia.

CONCLUSIONS

Rates of RNE with transcatheter closure and medical therapy in patients presenting with cryptogenic stroke or TIA were estimated at 0.8 and 5.0 events/100 PY. Further randomized controlled trials are needed to conclusively compare these 2 management strategies.

Patent foramen ovale closure and medical treatments for secondary stroke prevention: a systematic review of observational and randomized evidence

BACKGROUND AND PURPOSE

Patients discovered to have a patent foramen ovale in the setting of a cryptogenic stroke may be treated with percutaneous closure, antiplatelet therapy, or anticoagulants. A recent randomized trial (CLOSURE I) did not detect any benefit of closure over medical treatment alone; the optimal medical therapy is also unknown. We synthesized the available evidence on secondary stroke prevention in patients with patent foramen ovale and cryptogenic stroke.

METHODS

A MEDLINE search was performed for finding longitudinal studies investigating medical treatment or closure, meta-analysis of incidence rates (IR), and IR ratios of recurrent cerebrovascular events.

RESULTS

Fifty-two single-arm studies and 7 comparative nonrandomized studies and the CLOSURE I trial were reviewed. The summary IR of recurrent stroke was 0.36 events (95% confidence interval [CI], 0.24-0.56) per 100 person-years with closure versus 2.53 events (95% CI, 1.91-3.35) per 100 person-years with medical therapy. In comparative observational studies, closure was superior to medical therapy (IR ratio=0.19; 95% CI, 0.07-0.54). The IR for the closure arm of the CLOSURE I trial was higher than the summary estimate from observational studies; there was no significant benefit of closure over medical treatment (P=0.002 comparing efficacy estimates between observational studies and the trial). Observational and randomized data (9 studies) comparing medical therapies were consistent and suggested that anticoagulants are superior to antiplatelets for preventing stroke recurrence (IR ratio=0.42; 95% CI, 0.18-0.98).

CONCLUSIONS

Although further randomized trial data are needed to precisely determine the effects of closure on stroke recurrence, the results of CLOSURE I challenge the credibility of a substantial body of observational evidence strongly favoring mechanical closure over medical therapy.

The Coherex FlatStent: an advance in patent foramen ovale closure

A patent foramen ovale (PFO) is a remnant tunnel between the right and left atrium that has been found to be present more frequently in young patients with stroke and in sufferers of migraines. Percutaneous closure of the tunnel has become commonplace, replacing surgical closure. Various devices have been developed, most of which consist of atrial discs joined by a connecting wire. The Coherex FlatStent provides a new paradigm for PFO closure as it consists of a nitinol frame covered with polyurethane foam that is deployed within the PFO tunnel. Animal and Phase I and II studies have shown this device to be safe, effective and easy to use. More than 100 patients have now received such a device with excellent closure rates such that it may become an attractive and important development in patients with the clinical sequelae of PFO.

Transcranial Doppler detection of venous-to-arterial circulation shunts: criteria for patent foramen ovale

PURPOSE

As paradoxical embolism is associated with stroke in young adults, migraine, and decompression sickness, the detection of venous-to-arterial circulation shunt (v-aCS), such as patent foramen ovale (PFO), is increasingly important. We compared a rigorous transcranial Doppler (TCD) protocol with transesophageal echocardiography (TEE) to develop criteria for PFO.

METHODS

Standardized TCD was performed 2 weeks before simultaneous TEE and TCD in 39 patients aged 15-39 following ischemic stroke (n = 33) or myocardial infarction (n = 6). V-aCS was investigated by contrast sonography. During standardized TCD, contrast injections were performed twice, at rest and with cough and Valsalva maneuvers. TCD and TEE were recorded and analyzed independently by 'blinded' observers.

RESULTS

All 16 of the 39 patients with PFO on TEE had more than 15 micro-emboli on standardized TCD; in 14 of these 16, paradoxical embolization required no provocation. Three of 9 patients with 'major' v-aCS (>50 microbubble emboli at rest or >10 at rest with >80 on provocation) on standardized TCD were not identified by TEE as having large shunts.

CONCLUSION

The standardized TCD protocol is sensitive in the diagnosis of PFO and with the use of provocation maneuvers measures the functional importance of v-aCS more accurately than TEE.

Paradoxical embolism secondary to ovarian carcinoma resulting in stroke

A middle aged woman presented with a posterior fossa stroke after an elective ear nose and throat procedure. The occurrence of a paradoxical embolism was suspected. The evidence for this and a discussion about this condition are presented.

Five-year experience with percutaneous closure of patent foramen ovale

Patent foramen ovale (PFO) has been implicated in the pathogenesis of cryptogenic stroke, arterial desaturation, decompression illness, and migraine headache (MH). This study evaluated the safety of percutaneous transcatheter PFO closure in patients with cryptogenic stroke, transient ischemic attack, or arterial desaturation. Additionally, symptomatic reduction in MH was determined after interatrial shunt closure. Of the 252 patients referred to the University of California, Los Angeles, with PFO, 131 underwent closure of the interatrial communication with a CardioSEAL (n = 30) or Amplatzer (n = 101) device. PFO morphology was evaluated with transesophageal echocardiography. Follow-up was conducted at 1 to 2 months with echocardiography, with clinical assessment annually thereafter. At an average follow-up of 30 months, there was no recurrence of any thromboembolic event (transient ischemic attack, stroke, or peripheral). There was a reduction in MH, defined as the complete resolution of headache or a >50% reduction in the number of headache days, in 85% of patients after PFO closure. Temporary problems after device implantation, including chest discomfort and palpitations, were reported in 23% of patients and occurred more frequently in patients with nickel hypersensitivity (p <0.05). In conclusion, transcatheter PFO closure is an effective and safe therapeutic modality in the prevention of thromboembolic events and MH associated with interatrial shunting in patients who present with cryptogenic stroke. Pending randomized, controlled trials are necessary to determine if this invasive approach is preferable to medical therapy for the prevention of recurrent stroke or as primary treatment for patients with MH.

Single-vessel Versus Multivessel Territory Acute Ischemic Stroke: Value of Transesophageal Echocardiography in the Differentiation of Embolic Stroke

OBJECTIVES

We sought to assess the presence of potential aortic or cardiac sources of embolism in patients presenting with acute ischemic stroke in one or more vascular territories.

BACKGROUND

In patients with acute ischemic stroke, involvement of multiple vascular territories has been used to implicate a cardiac or aortic source of embolus. It remains unclear whether patients with multivessel stroke have a higher frequency of cardiac or aortic embolic sources on transesophageal echocardiography (TEE) compared with patients with single-territory stroke.

METHODS

We identified 210 patients with acute ischemic stroke documented by neuroimaging undergoing TEE for identification of a potential embolic source. Patients were divided into 3 groups (lacunar stroke, nonlacunar stroke/single-vessel involvement, nonlacunar stroke/multivessel involvement) and the frequency of potential embolic sources on TEE was compared.

RESULTS

Of the 210 patients, 121 (58%) were male and the mean age was 61 years. In all, 139 patients (66%) were classified as having single-vessel stroke, 47 (22%) as having multivessel stroke, and 24 (11%) as having lacunar stroke. On TEE, 87 patients (41%) had at least one potential source of embolism. Patients with multivessel strokes had fewer potential embolic sources on TEE than patients with single-vessel or lacunar strokes (26% vs 46% and 46%, respectively; P = .043).

CONCLUSIONS

In patients with acute ischemic stroke, the incidence of a potential cardiac or aortic source of embolism is high, regardless of the vascular distribution of the stroke. TEE may be a useful tool to assess the source of stroke in single-vessel, multivessel, and lacunar territory stroke distribution. We aimed to assess the presence of potential aortic or cardiac sources of embolism in patients presenting with acute ischemic stroke in one or more vascular territories. A total of 210 patients with acute ischemic stroke were divided into 3 groups (lacunar stroke, nonlacunar stroke/single-vessel involvement, nonlacunar stroke/multivessel involvement) and the frequency of potential embolic sources on transesophageal echocardiography was compared. Patients with multivessel strokes had fewer potential embolic sources on transesophageal echocardiography than patients with single-vessel or lacunar strokes, but the frequency of a potential cardiac or aortic source of embolism was high, regardless of the vascular distribution of stroke.

Transcatheter closure versus medical therapy of patent foramen ovale and cryptogenic stroke

OBJECTIVES

The purpose of this study was to evaluate the efficacy and safety of device closure of patent foramen ovale (PFO) versus antiplatelet therapy in patients with cryptogenic stroke (CS).

BACKGROUND

There are no controlled data to support the therapeutic value of PFO closure with a device compared to medical treatment in patients with CS.

METHODS

We performed a nonrandomized, prospective, patient preference case series comparing the recurrence rate in 92 patients with PFO and CS who were treated either with antiplatelet agents (44 patients) or underwent catheter closure (48 patients) using the Amplatzer PFO occluder (APFOO). All patients completed a 2-year follow-up.

RESULTS

PFO closure group. Immediate complete closure (CC) was observed in 44/48 (91%) patients. Four (9%) patients had a minimal residual shunt immediately after the procedure. One patient developed hemopericardium that was successfully managed by pericardiocentesis. No other complication was observed. Follow-up. PFO closure group. Contrast bubble study at 6-month follow-up confirmed CC in all 48 patients. No complications were observed. Antiplatelet therapy group. Three (6%) and 6 (13%) patients had a major and minor hemorrhagic event, respectively. The average incidence of embolic events/year was 0 and 14.75% for the PFO closure group and the antiplatelet therapy group, respectively (P < 0.001).

CONCLUSIONS

PFO closure using the APFOO is a rational alternative to medical treatment in patients with CS. Larger randomized clinical trials are required to support the use of this device over the other PFO occluders and medical therapy.

Percutaneous closure of patent foramen ovale

AIM

To review the safety and efficacy of percutaneous closure of patent foramen ovale (PFO) in symptomatic patients without the use of general anaesthesia or echocardiographic guidance.

METHOD

All patients accepted for percutaneous PFO closure by our service from August 2002 to August 2004 were included. Patient demographics and clinical information were obtained from clinical records and by telephone interview. Follow-up outcomes recorded were recurrence of systemic thromboembolism, residual shunt, and change in pattern of migraines.

RESULTS

Forty consecutive adult patients, of whom 19 (48%) had an atrial septal aneurysm (ASA), underwent PFO closure using the Amplatzer occluder device with fluoroscopic guidance alone. Their mean age was 45 +/- 10 years (range 23-63 years) and 24 (60%) were male. The indications for closure were ischaemic stroke (n = 26), transient ischaemic attack (TIA) (n = 8), both stroke and TIA (n = 2), refractory hypoxia (n = 2), platypnoea-orthodeoxia (n = 1) and severe migraine with seizures (n = 1). Twenty patients suffered a single neurological event and 16 suffered >1 event, including six with only radiographic evidence of >1 event. Mean procedure time was 17.7 +/- 9.6 min and fluoroscopy time was 6.7 +/- 7.3 min. Implanted device sizes were 18 mm (n = 1), 25 mm (n = 37) and 35 mm (n = 2). In 33 patients, the procedure was performed as a day-case. No complications were encountered. No further neurological events occurred in 39 patients at a mean follow-up time of 11 +/- 7 months (3-25 months) nor was a significant shunt detected in the 34 who underwent follow-up echocardiography.

CONCLUSIONS

Percutaneous closure of PFO with or without ASA, under local anaesthesia and without echocardiographic guidance, is a safe and effective procedure which can be performed as a day-case. This has now become our standard clinical practice.

Interventional closure with Amplatzer PFO occluder of patent foramen ovale in patients with paradoxical cerebral embolism

Percutaneous transcatheter closure has been proposed as an alternative to surgical closure or long-term anticoagulation in patients with presumed paradoxical embolism and patent foramen ovale (PFO). We report our mid-term results of 55 consecutive symptomatic patients (mean age: 47 years, range: 20-79) who underwent percutaneous transcatheter closure of PFO after at least one event of cerebral ischemia; 16 (29%) patients had at least one transient ischemic attack and 39 (71%) patients at least one embolic stroke. Multiple embolic events had occurred in 6 (11%) patients. Percutaneous transcatheter closure was technically successful in all 55 patients (100%). For the majority of patients, an Amplatzer PFO occluder measuring 25 mm in diameter (n=49) or an Amplatzer PFO occluder measuring 35 mm in diameter (n=6) was used. Complete occlusion by color Doppler and transesophageal contrast echocardiography investigation was achieved in 96% at follow-up 3-6 months after implantation; only 2 patients had a trivial residual shunt at follow-up. Mean fluoroscopy time was 6.7 minutes (range: 1.7-47.1), and in-hospital follow-up was uneventful except for 1 patient who developed a cardiac tamponade requiring uneventful and successful needle pericardiocentesis. At a mean follow-up of 19 months (range: 3-32) no recurrent embolic neurological events was observed. Transcatheter closure of PFO with Amplatzer PFO occluder devices is a safe and effective therapy for patients with previous paradoxical embolism and aneurysmatic or nonaneurysmatic PFO. Percutaneous closure is associated with a high success rate, low incidence of hospital complications, and freedom of cerebral ischemia events.

Secondary prevention after cryptogenic cerebrovascular events in patients with patent foramen ovale

BACKGROUND

Patients with patent foramen ovale and cryptogenic stroke are at risk of recurrence, but there are few data on strategies to prevent this.

METHODS

We studied 280 consecutive patients with cryptogenic cerebrovascular events and a patent foramen ovale examined by multiplane transesophageal echocardiography. Patients received platelet inhibitors (n = 66) or anticoagulation (n = 47) or underwent device closure (n = 167). During the mean follow-up of 2.6 years, we compared the frequency of recurrent events, death and severe treatment complications.

RESULTS

A total of 33 (12%) patients had a recurrent cerebrovascular event. The annual recurrence rates were 13% in patients treated with platelet inhibitors, 5.6% in those on oral anticoagulation, and 0.6% in those after device closure. Independent predictors of recurrent cerebrovascular events were a patent foramen ovale larger than 4 mm (hazard ratio 3.8, 95% CI 1.2-11.2; p = 0.017) or previous strokes (hazard ratio 4.3, 95% CI 2.0-9.2; p < 0.001). Interventional closure of the patent foramen ovale decreased the risk of a recurrent event compared with oral anticoagulation (hazard ratio 0.06, 95% CI 0.12-0.29; p < 0.001), whereas antiplatelet therapy showed a trend to an increased risk (hazard ratio 2.3; 95% CI 0.9-5.5; p = 0.055). Major side effects occurred in 7 anticoagulated patients and in 13 patients after device closure. There were two non-vascular deaths and one fatal hemorrhagic stroke.

CONCLUSIONS

Patients with a large patent foramen ovale and a cryptogenic cerebrovascular event had a substantial risk of recurrence even with medical treatment. Risk of recurrence was lower after device closure of the patent foramen ovale.

Antithrombotic and Thrombolytic Therapy for Ischemic Stroke

This chapter about treatment and prevention of stroke is part of the 7th ACCP Conference on Antithrombotic and Thrombolytic Therapy: Evidence Based Guidelines. Grade 1 recommendations are strong and indicate that the benefits do, or do not, outweigh risks, burden, and costs. Grade 2 suggests that individual patients' values may lead to different choices (for a full understanding of the grading see Guyatt et al). Among the key recommendations in this chapter are the following: For patients with acute ischemic stroke (AIS), we recommend administration of i.v. tissue plasminogen activator (tPA), if treatment is initiated within 3 h of clearly defined symptom onset (Grade 1A). For patients with extensive and clearly identifiable hypodensity on CT, we recommend against thrombolytic therapy (Grade 1B). For unselected patients with AIS of > 3 h but < 6 h, we suggest clinicians not use i.v. tPA (Grade 2A). For patients with AIS, we recommend against streptokinase (Grade 1A) and suggest clinicians not use full-dose anticoagulation with i.v. or subcutaneous heparins or heparinoids (Grade 2B). For patients with AIS who are not receiving thrombolysis, we recommend early aspirin therapy, 160 to 325 mg qd (Grade 1A). For AIS patients with restricted mobility, we recommend prophylactic low-dose subcutaneous heparin or low molecular weight heparins or heparinoids (Grade 1A); and for patients who have contraindications to anticoagulants, we recommend use of intermittent pneumatic compression devices or elastic stockings (Grade 1C). In patients with acute intracerebral hematoma, we recommend the initial use of intermittent pneumatic compression (Grade 1C+). In patients with noncardioembolic stroke or transient ischemic attack (TIA) [ie, atherothrombotic, lacunar or cryptogenic], we recommend treatment with an antiplatelet agent (Grade 1A) including aspirin, 50 to 325 mg qd; the combination of aspirin and extended-release dipyridamole, 25 mg/200 mg bid; or clopidogrel, 75 mg qd. In these patients, we suggest use of the combination of aspirin and extended-release dipyridamole, 25/200 mg bid, over aspirin (Grade 2A) and clopidogrel over aspirin (Grade 2B). For patients who are allergic to aspirin, we recommend clopidogrel (Grade 1C+). In patients with atrial fibrillation and a recent stroke or TIA, we recommend long-term oral anticoagulation (target international normalized ratio, 2.5; range, 2.0 to 3.0) [Grade 1A]. In patients with venous sinus thrombosis, we recommend unfractionated heparin (Grade 1B) or low molecular weight heparin (Grade 1B) over no anticoagulant therapy during the acute phase.

Incidence and clinical course of thrombus formation on atrial septal defect and patient foramen ovale closure devices in 1,000 consecutive patients

OBJECTIVES

The purpose of this study was to investigate the incidence, morphology, and clinical course of thrombus formation after catheter closure of intra-atrial shunts.

BACKGROUND

Post-procedure detailed information about thrombotic material on different devices for transcatheter closure is missing.

METHOD

A total of 1,000 consecutive patients were investigated after patent foramen ovale (PFO) (n = 593) or atrial septal defect (ASD) (n = 407) closure. Transesophageal echocardiography (TEE) was scheduled after four weeks and six months. Additional TEEs were performed as clinically indicated.

RESULTS

Thrombus formation in the left atrium (n = 11), right atrium (n = 6), or both (n = 3) was found in 5 of the 407 (1.2%) ASD patients and in 15 of the 593 (2.5%) PFO patients (p = NS). The thrombus was diagnosed in 14 of 20 patients after four weeks and in 6 of 20 patients later on. The incidence was: 7.1% in the CardioSEAL device (NMT Medical, Boston, Massachusetts); 5.7% in the StarFLEX device (NMT Medical); 6.6% in the PFO-Star device (Applied Biometrics Inc., Burnsville, Minnesota); 3.6% in the ASDOS device (Dr. Ing, Osypka Corp., Grenzach-Wyhlen, Germany); 0.8% in the Helex device (W.L. Gore and Associates, Flagstaff, Arizona); and 0% in the Amplatzer device (AGA Medical Corp., Golden Valley, Minnesota). The difference between the Amplatzer device on one hand and the CardioSEAL device, the StarFLEX device, and the PFO-Star device on the other hand was significant (p < 0.05). A pre-thrombotic disorder as a possible cause of the thrombus was found in two PFO patients. Post-procedure atrial fibrillation (n = 4) and persistent atrial septal aneurysm (n = 4) had been found as significant predictors for thrombus formation (p < 0.05). In 17 of the 20 patients, the thrombus resolved under anticoagulation therapy with heparin or warfarin. In three patients, the thrombus was removed surgically.

CONCLUSIONS

The incidence of thrombus formation on closure devices is low. The thrombus usually resolves under anticoagulation therapy.

Management of patients with stroke and a patent foramen ovale

Observational studies have established a strong association between the presence of patent foramen ovale (PFO) and increased risk of ischemic stroke. The mechanism involved is presumed to be a paradoxical embolism from a venous thrombus that travels via the PFO to the systemic circulation. The best treatment modality to prevent recurrent stroke in patients with PFO remains undefined. There are four major choices: 1) medical therapy with anticoagulants, 2) medical therapy with antiplatelet agents, 3) surgical closure, and 4) percutaneous device closure. The Patent Foramen Ovale in Cryptogenic Stroke Study has demonstrated that antiplatelet and anticoagulant therapies are of equal benefit in preventing recurrent neurologic events in stroke patients with a PFO. Medical therapy should remain as the initial choice of secondary prophylactic therapy. PFO closure, either surgical or percutaneous, may further reduce event rates; however, this remains to be demonstrated because no randomized trial to date has compared PFO closure with medical therapy.

Management of patients with stroke and a patent foramen ovale

Observational studies have established a strong association between the presence of patent foramen ovale (PFO) and increased risk of ischemic stroke. The mechanism involved is presumed to be a paradoxical embolism from a venous thrombus that travels via the PFO to the systemic circulation. The best treatment modality to prevent recurrent stroke in patients with PFO remains undefined. There are four major choices: 1) medical therapy with anticoagulants, 2) medical therapy with antiplatelet agents, 3) surgical closure, and 4) percutaneous device closure. The Patent Foramen Ovale in Cryptogenic Stroke Study has demonstrated that antiplatelet and anticoagulant therapies are of equal benefit in preventing recurrent neurologic events in stroke patients with a PFO. Medical therapy should remain as the initial choice of secondary prophylactic therapy. PFO closure, either surgical or percutaneous, may further reduce event rates; however, this remains to be demonstrated because no randomized trial to date has compared PFO closure with medical therapy.

Indication and Techniques of Transcatheter Closure of Patent Foramen Ovale

A potential causal relationship of a patent foramen ovale (PFO) and a stroke was first suggested by Cohnheim in 1877.1 Today, this correlation is generally accepted. However, there is still no "gold standard" for the treatment of patients with presumed paradoxical embolism. This article reviews the epidemiology of and the diagnostic methods for PFO, the clinical relationship between PFO and cerebral ischemia, as well as indications and techniques for transcatheter closure of PFO. In the author's opinion, transcatheter PFO closure represents an elegant management for selected patients at risk.

[Prevalence of patent foramen ovale in young patients with cerebral ischemic accident of unknown origin]

INTRODUCTION AND OBJECTIVE

Patent foramen ovale has been associated with stroke in young patients with cryptogenic stroke. The purpose of this study is to examine the prevalence of patent foramen ovale in this group of patients, as well as their anatomical and functional characteristics by contrast echocardiography, trying to determine ictus risk markers in young patients with acute ischemic stroke.

PATIENTS AND METHOD

Prospective study of 90 patients under the age of 50 who were hospitalised consecutively due to a clinical presentation suggestive of stroke. No cause was found in 55 out of 90 (group I) and the rest, in which an stroke was finally disregarded, were used as the control group (group II). A transthoracic and transesophageal echocardiography examination with 2 types of contrast agents was performed in all patients to determine the presence of a patent foramen ovale and its anatomical and functional characteristics.

RESULTS

Patent foramen ovale was observed more frequently in group I than in group II (43 versus 21%; p < 0.05). Among patients with a patent foramen ovale those with an ischemic stroke showed greater mobility of the oval membrane, more frequent large shunts of contrast in a single frame in the left heart, and more frequent shunts at rest. Transesophageal echocardiography without contrast showed a high sensitivity (90%) and specificity (93%) for detecting anatomically permeable foramen ovale whereas contrast transthoracic echocardiography showed a low sensitivity (13%). There were no differences between the two contrasts used.

CONCLUSIONS

Near half of young patients with ischemic stroke of an unknown origin have a patent foramen ovale. A bigger mobility of the membrane of the oval cavity and a large degree of shunt contrast as well as shunt at rest detected by contrast transesophageal echocardiography, seem to identify patent foramen ovale patients with ischemic stroke. In these patients, transthoracic echocardiography has low sensibility for detecting permeability of the foramen ovale.

Patent Foramen Ovale and Stroke

Observational data from prospective and retrospective trials indicate that a patent foramen ovale (PFO) is associated with the risk of ischemic stroke. The mechanism involved is presumed to be paradoxical embolism from a venous thrombus that travels via the PFO to the systemic circulation causing an ischemic stroke. Primary stroke prevention data for patients with a PFO are nonexistent. Given the substantial prevalence of PFO in the total population (~ 25% to 30%), a primary prevention study may not be feasible. However, whether targeted primary prevention for patients with PFOs of certain morphologic characteristics (eg, larger size, greater degree of shunt) would be possible remains undefined. Given the large number of asymptomatic subjects, no therapy is currently recommended. The best treatment modality to prevent recurrent stroke in patients with PFO has not been defined. There are four major treatment choices: surgical closure, percutaneous device closure, medical therapy with anticoagulants, and medical therapy with antiplatelet agents. Regarding medical therapy, the Patent Foramen Ovale in Cryptogenic Stroke Study has demonstrated that antiplatelet and anticoagulant therapies are of equal benefit in preventing recurrent adverse events. Although closure of the PFO, either surgical or percutaneous, may further reduce the event rates, this remains to be demonstrated because no randomized trial to date has compared PFO closure with medical therapy.

Suspected pulmonary embolism: enhancement of pulmonary arteries at deep-inspiration CT angiography--influence of patent foramen ovale and atrial-septal defect

PURPOSE

To investigate if abnormal early contrast enhancement of the aorta and decreased attenuation of pulmonary arteries at deep-inspiration spiral computed tomographic (CT) angiography might be caused by a patent foramen ovale (PFO).

MATERIALS AND METHODS

Two hundred forty-four spiral CT angiographic images of the pulmonary arteries obtained during deep inspiration in patients suspected of having pulmonary embolism (PE) were reviewed for evidence of abnormal early enhancement of the aorta. In 45 patients, enhancement of the ascending aorta was equal to or more than that of the pulmonary arteries. Nonenhanced or contrast material-enhanced echocardiography was performed in 39 of these cases. All CT images with abnormal enhancement patterns were graded for contrast quality with respect to sufficient enhancement of pulmonary arteries (four grades) at three anatomic levels: right and left main and lobar and segmental branches. In addition, all spiral CT angiographic images were evaluated concerning the diagnosis of PE and the grouping of central (main pulmonary artery to proximal lobar arteries) and peripheral (beyond proximal lobar branches) locations of emboli. Mean attenuation values of ascending aortas and main pulmonary arteries in group 1 (n = 244) were compared with those in groups 2 and 3 (n = 45) by means of the two-tailed Student t test for unpaired data (P <.05).

RESULTS

Attenuation values for ascending aortas in group 1 were significantly lower than those in groups 2 and 3 (P <.001). Attenuation values in main pulmonary arteries were significantly higher in group 1 than in groups 2 and 3 (P <.001). Echocardiographic images showed an intracardiac right-to-left shunt in all 39 cases with abnormal contrast dynamics in the CT study (16% of the whole study population). Three patients had an atrial-septal defect, and 36 had a PFO. Images with a shunt had good (9%), intermediate (37%), fair (33%), and poor (23%) contrast of the pulmonary arteries. Sufficient vessel contrast for the diagnosis of PE could not be achieved in 27 of 45 patients with a shunt, but severe central PE could be ruled out. PE could be diagnosed in 31% of the 244 images, 58% were negative, and 11% were indeterminate.

CONCLUSION

A PFO may frequently lead to insufficient attenuation of the pulmonary arteries, which potentially limits the diagnosis of PE if the examination is performed during deep inspiration.

Transcranial Doppler and risk of recurrence in patients with stroke and patent foramen ovale

The importance of patent foramen ovale (PFO) in stroke of unknown cause remains disputed, as PFO may be present in up to 20% of normal people and in a high proportion of patients with non-vascular disorders. Recent evidence suggests that the amount of right-to-left shunt (RLS) may be the crucial factor for stroke occurrence and relapse. The aim of the study was to assess predictors of recurrence in PFO-related stroke patients with particular emphasis on amount of shunting. Patients less than 61 years old who had been admitted for a PFO-related stroke within the previous 5 years, were re-evaluated on a follow-up visit. The clinical syndrome, residual disability, vascular risk factors and number of relapses as the index event were assessed. RLS sizing was semi-quantitatively performed with saline-enhanced transcranial Doppler (TCD), by assuming a cut-off of more or less 10 bubbles recorded in the cerebral vessels as a criterion to discriminate large versus small shunt, respectively. Thereafter patients were prospectively followed-up for a median time of 23 months. Total follow-up was 61 months. Fifty-nine patients (M/F = 23/36, mean age 43 +/- 13) were studied. Overall there were 23 relapses in 13 patients. The amount of shunting was the only significant independent variable associated with relapse: at the end of the follow-up period the recurrence rate was 0.66 and 8.2% per patient per year in patients with small and large shunt, respectively. This difference was statistically significant (chi2 = 10.39, P = 0.0012; OR 17.05, 95% CI 2.10-755.22). In patients with PFO-related stroke, the amount of RLS as assessed with TCD is the only independent predictor of relapse. PFO sizing is mandatory in patients with PFO.