Residual Shunt After Patent Foramen Ovale Closure and Long-Term Stroke Recurrence: A Prospective Cohort Study

Association between patent foramen ovale morphology and clinical outcomes following transcatheter closure

BACKGROUND

Anatomic variations of the patent foramen ovale (PFO) are commonly observed, yet limited research has investigated their impact on clinical outcomes following transcatheter closure. We aimed to explore the association between PFO morphology and clinical outcomes.

METHODS

Consecutive patients with cryptogenic stroke who underwent PFO closure were prospectively enrolled at a single center from September 2019 to April 2023. Patients were categorized into simple and complex groups based on PFO morphology. Composite events were compared between the two groups during a median follow-up of 24 months, including all-cause mortality, recurrent stroke, residual moderate or severe shunt, and symptomatic atrial fibrillation.

RESULTS

A total of 247 patients were enrolled, with a mean age of 41.9 ± 13.0 years and 45.3% males. Ninety-one (36.8%) patients had complex PFO. These individuals were older (45.4 ± 12.5 years vs. 39.9 ± 12.9 years; P = 0.001), more males (56.0% vs. 39.1%; P = 0.010), had longer procedure times (54 ± 32 min vs 46 ± 29 min; P = 0.044), and had a higher rate of using delivery sheath-assisted crossing of the PFO (22.0% vs 12.8%; P = 0.040) than those with simple PFO. The estimated event rates were 27.9% and 11.3% (P = 0.006) in the complex and simple PFO groups, respectively (12.9 events and 5.2 events per 100 person-years; P = 0.001). After adjusting for age, sex, hypertension, diabetes, smoking, device type, and left atrial diameters, complex PFO remained independently associated with composite events (HR 2.10, 95%CI 1.06-4.17, P = 0.034).

CONCLUSIONS

Patients with complex PFO may suffer from a higher risk of adverse events following transcatheter PFO closure.

Relationship between patent foramen ovale anatomical features and residual shunt after patent foramen ovale closure

Transcatheter closure of patent foramen ovale (PFO) is an effective strategy for preventing recurrence of paradoxical embolism. However, PFO closure is often associated with residual shunt, which is a risk of recurrent stroke. This study aimed to evaluate the relationship between the anatomical features of PFO and residual shunt. The degree of residual shunt and its relationship with the anatomical features of PFO were evaluated in 106 patients who underwent PFO closure at our institution between March 2011 and January 2022 and in whom contrast transthoracic echocardiography was performed 1 year later. The mean PFO tunnel length was 9.3 ± 3.6 mm and the mean PFO height was 3.2 ± 2.2 mm. Atrial septal aneurysm (ASA) was found in 37 patients. After PFO closure, residual shunt was observed in 28 patients (grade 1, n = 8; grade 2, n = 16; grade 3, n = 3; grade 4, n = 1). Univariate logistic analysis identified ASA to be associated with residual shunt (odds ratio 2.78, 95% confidence interval 1.14 to 6.79; p = 0.024). There was no association of residual shunt with the size of the PFO, the length of PFO tunnel, or the size of the device used for closure. Two of four patients with a large residual shunt of grade 3 or grade 4 were found to have device size mismatch. Residual shunt after PFO closure was observed in a quarter of patients and was related to the presence of ASA. A few patients had a large residual shunt due to the device size mismatch.

Performance, safety, and biocompatibility of a novel PFO closure device in a long-term porcine model

BACKGROUND

As the catheter-based device closure of the patent foramen ovale (PFO) is expanding, novel devices aim to address the limitations of first-generation occluders (e.g. bulk, erosion, dislodgment). The second-generation device from Encore Medical (Eagan, MN, USA) features an articulating frame structure which allows the device to better conform to atrial anatomies, has lower disc thickness and metal mass/surface area, and is fully retrievable at any point in the procedure. The aim of the study was to evaluate the feasibility and safety of a novel low-profile, fully retrievable, Encore PFO closure device in the animal model.

METHODS

Six swine underwent implantation of the novel PFO occluder under fluoroscopic and intra-cardiac echocardiography guidance and survived for 140 days. Interim transthoracic echocardiography (TTE) was conducted on Day 29. Following terminal angiography and TTE at 140 days, the hearts were subjected to gross and histopathologic analysis.

RESULTS

All animals were successfully implanted and survived for 140 days. Interim TTE revealed proper device retention with no blood flow across the septum or thrombus in any of the animals. X-ray and pathology results showed preserved implant integrity with no fractures, and complete integration of the devices into the septum with complete re-endothelialization and nearly complete coverage by a mature, relatively thin neoendocardium. No surface fibrin deposition or thrombosis was reported.

CONCLUSIONS

In the standard porcine model, device retention and biocompatibility remained favorable following structural and functional device modifications exemplified by the second-generation PFO occluder from Encore Medical, including marked reduction of metal mass.

Is Moderate/Large Residual Shunt After PFO Closure Justifiable for a Patient with a Prior History of Cryptogenic Stroke and Transient Ischemic Attack?

A 36-year-old woman suffered from an embolic stroke of an undetermined source documented by magnetic resonance imaging with residual right arm weakness. She underwent percutaneous patent foramen ovale (PFO) closure with an 18/25 mm device in another center. One year later, the patient suffered from a transient ischemic attack with dysarthria. She asked for a second opinion at our institution and a contrast-transthoracic (cTTE) /transesophageal echocardiography showed a large residual right-to-left shunt (RLS) through a still patent tunnel after PFO closure. Written informed consent for a redo procedure was obtained from the patient. A catheter-based closure of the residual shunt was therefore planned under local anesthesia and rotational intracardiac echo monitoring. A second equally sized disc (18/18 mm) device was successfully implanted without complications. The patient was discharged home the following day in good clinical condition. Dual antiplatelet therapy was recommended for the first 2 months and then single antiplatelet therapy up to 6 months. At the 6-month follow-up, the cTTE color Doppler showed the stable position of the two nitinol double-disc devices and the c-transcranial Doppler confirmed the abolition of the residual RLS.

Patent Foramen Ovale Percutaneous Closure: Evolution and Ongoing Challenges

Patent foramen ovale (PFO) concerns nearly a quarter of the general population and incidence may reach up to 50% in patients with cryptogenic stroke. Recent randomized clinical trials confirmed that percutaneous closure of PFO-related stroke reduces the risk of embolic event recurrence. PFO also comes into play in other pathogenic conditions, such as migraine, decompression sickness or platypnea-orthodeoxia syndrome, where the heterogeneity of patients is high and evidence for closure is less well-documented. In this review, we describe the current indications for PFO percutaneous closure and the remaining challenges, and try to provide future directions regarding the technique and its indications.

Percutaneous suture-based patent foramen ovale closure: A state-of-the-art review

Percutaneous closure of a patent foramen ovale (PFO), a common variation of interatrial septum anatomy, is a commonly performed procedure in the catheterization laboratory to reduce the risk of recurrent stroke in selected patients and to treat other PFO-related syndromes. In the last twenty years, disc-based devices have represented the armamentarium of the interventional cardiologist; recently, suture-based devices have become an attractive alternative, despite limited data regarding their long-term performance. The present review gives an overview of the current evidence regarding suture-based PFO closure, the device's characteristics, the echocardiographic evaluation of the PFO anatomy, and recommendations for patient selection. A detailed procedural guide is then provided, and potential complications and future developments in the field are discussed.

Impact of the antiplatelet strategy following patent foramen ovale percutaneous closure

AIMS

Temporary dual antiplatelet therapy (DAPT) is recommended following patent foramen ovale (PFO) percutaneous closure although its benefit, compared to single antiplatelet therapy (SAPT), has not been demonstrated in this setting. We aimed at assessing outcomes following PFO closure according to the antiplatelet strategy at discharge.

METHODS AND RESULTS

The ambispective AIR-FORCE cohort included consecutive patients from seven centres in France and Canada undergoing PFO closure and discharged without anticoagulation. Patients treated in French and Canadian centres were mostly discharged with DAPT and SAPT, respectively. The primary endpoint was the composite of death, stroke, transient ischaemic attack, peripheral embolism, myocardial infarction, or BARC type ≥2 bleeding with up to 5 years of follow-up. The impact of the antiplatelet strategy on outcomes was evaluated with a marginal Cox model (cluster analyses per country) with inverse probability weighting according to propensity score. A total of 1532 patients (42.2% female, median age: 49 [40-57] years) were included from 2001 to 2022, of whom 599 (39.1%) were discharged with SAPT and 933 (60.9%) with DAPT, for ≤3 months in 894/923 (96.9%) cases. After a median follow-up of 2.4 [1.1-4.4] years, a total of 58 events were observed. In the weighted analysis, the rate of the primary endpoint up to 5 years was 7.8% in the SAPT strategy and 7.3% in the DAPT strategy (weighted hazard ratio 1.04, 95% confidence interval 0.59-1.83).

CONCLUSION

The antiplatelet strategy following PFO closure did not seem to impact clinical outcomes, thus challenging the current recommendations of temporary DAPT.

Impact of patent foramen ovale on short-term outcomes in children with biliary atresia undergoing living donor liver transplantation: a retrospective cohort study

OBJECTIVE

To investigate the impact of patent foramen ovale (PFO) on the short-term outcomes of living donor liver transplantation (LDLT) in children with biliary atresia.

METHODS

With the approval of the hospital ethics committee, 304 children with biliary atresia who underwent LDLT in our center from January 2020 to December 2021 were enrolled. According to the results of echocardiography before the operation, the subjects were divided into the PFO group (n = 73) and the NoPFO group (n = 231). The baseline characteristics; intraoperative recipient-related data and donor-related data; incidence of postreperfusion syndrome (PRS); postoperative mechanical ventilation time; ICU stay duration; postoperative hospital stay duration; liver function index; incidences of postoperative complications including acute renal injury (AKI), graft dysfunction, hepatic artery thrombosis (HAT) and portal vein thrombosis (PVT); and one-year survival rate were compared between the two groups.

RESULTS

The median age in the PFO group was 6 months and that in the NoPFO group was 9 months (P < 0.001), and the median height (65 cm) and weight (6.5 kg) in the PFO group were significantly lower than those in the NoPFO group (68 cm, 8.0 kg) (P < 0.001). The preoperative total bilirubin level (247 vs. 202 umol/L, P = 0.007) and pediatric end-stage liver disease (PELD) score (21 vs. 16, P = 0.001) in the PFO group were higher than those in the NoPFO group. There were no significant differences in the intraoperative PRS incidence (46.6% vs. 42.4%, P = 0.533 ), postoperative mechanical ventilation time (184 vs. 220 min, P = 0.533), ICU stay duration (3.0 vs. 2.5 d, P = 0.267), postoperative hospital stay duration (22 vs. 21 d, P = 0.138), AKI incidence (19.2% vs. 24.7%, P = 0.333), graft dysfunction incidence (11.0% vs. 12.6%, P = 0.716), HAT incidence (5.5% vs. 4.8%, P = 0.762), PVT incidence (2.7% vs. 2.2%, P = 0.675) or one-year survival rate (94.5% vs. 95.7%, P = 0.929) between the two groups.

CONCLUSION

The presence of PFO has no negative impact on short-term outcomes in children with biliary atresia after LDLT.

Patent foramen ovale closure with the Occlutech Figulla flex II device: A long-term (up to 10-years) follow-up

BACKGROUND

Percutaneous closure represents the first line of treatment in patients with cryptogenic stroke and documented patent foramen ovale (PFO). Scarce data report the long-term outcomes of patients undergoing PFO closure with the Figulla Flex II device (Occlutech, Germany).

METHODS

Consecutive patients undergoing PFO closure with a Figulla Flex II device at a single, high-volume Institution were included. Baseline clinical and procedural features were collected and patients were followed up for up to 10 years. The device's long-term safety was assessed, as well as mortality, recurrent cerebrovascular events, new-onset atrial fibrillation (AF) and residual shunt.

RESULTS

Overall, 442 patients were included. The main indication for PFO closure was cryptogenic stroke/transitory ischemic attack (65.5%), followed by migraine (21.7%), silent lesions at MRI (10.8%), and decompression disease (2.0%). Atrial septal aneurysm was present in 20.8% of cases, Eustachian valve in 9.0%, Chiari network in 19.9%. The most frequently implanted device was the 23/25 mm (49.5% of cases). One procedural failure due to device embolization; in-hospital complications occurred in 15 cases (3.4%; 4 minor access site complications, 11 transient supraventricular tachycardias (SVT)/AF). After a follow-up of 9.2 years, 2 patients suffered recurrent TIA (with no residual R-L shunt detected). A moderate or severe residual shunt was observed in 3 patients after discharge.

CONCLUSIONS

Figulla Flex II devices for PFO closure are associated with high procedural success and low incidence of adverse events even at long-term follow-up.

The 2022 FASEB Virtual Catalyst Conference on the Cardiac Interatrial Septum and Stroke Risk, December 7, 2022

There is emerging evidence that the cardiac interatrial septum has an important role as a thromboembolic source for ischemic strokes. There is little consensus on treatment of patients with different cardiac interatrial morphologies or pathologies who have had stroke. In this paper, we summarize the important background, diagnostic, and treatment considerations for this patient population as presented during the Federation of American Societies for Experimental Biology (FASEB) Virtual Catalytic Conference on the Cardiac Interatrial Septum and Stroke Risk, held on December 7, 2022. During this conference, many aspects of the cardiac interatrial septum were discussed. Among these were the embryogenesis of the interatrial septum and development of anatomic variants such as patent foramen ovale and left atrial septal pouch. Also addressed were various mechanisms of injury such as shunting physiologies and the consequences that can result from anatomic variants, as well as imaging considerations in echocardiography, computed tomography, and magnetic resonance imaging. Treatment options including anticoagulation and closure were addressed, as well as an in-depth discussion on whether the left atrial septal pouch is a stroke risk factor. These issues were discussed and debated by multiple experts from neurology, cardiology, and radiology.

Experience in patent foramen ovale closure with the CERA Lifetech occluder in patients with cryptogenic stroke

Introduction

Nowadays, percutaneous closure of patent foramen ovale (PFO) in patients after cryptogenic stroke is becoming a dominating strategy. The most commonly used and investigated device is the Amplatzer occluder. However, several other devices have been designed for transcatheter closure of PFO, which are not so well examined.

Aim

To assess the effectiveness and safety of PFO closure with the Lifetech CERA occluder.

Material and methods

A prospective, single-arm registry of patients with PFO treated with CERA occluder (Lifetech Scientific, Shenzhen, China) implantation was conducted. We assessed peri-procedural and 12-month follow-up. Patients were screened for the residual shunt in transcranial Doppler/transesophageal echocardiography.

Results

Ninety-six patients entered the registry. Most patients were women (76%) and the analyzed group was relatively young (mean age of 42.3 ±13.6 years). Before closure, most patients had a large shunt through the PFO. Procedures of PFO closure were performed under TEE guidance. All procedures were made under local anesthesia and all patients had the PFO successfully closed. No device-related complications were reported in the peri-procedural period or during follow-up. No recurrent neurological ischemic events were reported at 12 months. During follow-up we observed a 9% rate of residual shunts, which were mostly small.

Conclusions

The study confirmed excellent immediate and 12-month results of CERA occluder implantation in patients with PFO.

Comparison of the short-term efficacy of different Amplatzer models and similar occluders in the treatment of patent foramen ovale

Objective

To compare the recent efficacy and safety of different Amplatzer models and similar occluder in the treatment of patent foramen ovale (PFO).

Methods

Patients with PFO complicated with cryptogenic stroke or migraine who underwent transcatheter closure of PFO in the First Affiliated Hospital of Nanjing Medical University from September 2019 to March 2021 were selected. Patients were grouped according to the type of occluder device. The basic data of the patients were collected and followed up within 1 year after occlusion. Effectiveness was defined as no recurrence of stroke/remission of migraine symptoms and a negative postoperative foaming test, and safety events were counted as the combined results of serious adverse events.

Results

A total of 92 patients were selected, including 45 cases in the symmetrical group and 47 cases in the asymmetric group. There were no serious adverse events in the 2 groups during follow-up. 3 days and 1 month after occlusion, the number of shunt patients in the asymmetric group was significantly less than that in the symmetric group (χ² = 5.484, P = 0.019; χ² = 5.146, P = 0.023). The negative rate of blocked residual shunts in the asymmetric group was higher than that in the symmetric group at 1, 3, 6 and 12 months after occlusion (χ² = 6.473, P = 0.011; χ² = 4.305, P = 0.038; χ² = 4.842, P = 0.027; χ² = 4.034, P = 0.045). Headache in migraine patients in the asymmetric group was significantly better than headache in patients in the symmetric group (P = 0.038; P = 0.049).

Conclusion

Asymmetric Amplatzer and similar occluders provide greater efficacy in short-term occlusion than symmetric ones.

Percutaneous atrial shunt closure and the risk of recurrent ischemic stroke: A register-based, nationwide cohort study

OBJECTIVES

We aimed to investigate the risk of recurrent stroke in patients with transcatheter closure of an atrial shunt (ASCIos), compared to patients with an atrial shunt and cerebrovascular event (CVE) but only medical treated (ASMed), and to age- and sex-matched control individuals without a previous CVE.

METHODS

In total, 663 ASCIos patients were identified in the Swedish National Patient Register from 1997 to 2016 and matched by using propensity score with 663 ASMed patients. Nine age- and sex-matched controls to ASCIos patients (n = 6,302) without a diagnosis of atrial shunt or history of CVE were randomly selected from the general population.

RESULTS

At a mean follow-up of 6.5 years, the incidence rate of recurrent stroke in the ASCIos group vs ASMed group was 0.9 vs 0.7 per 100 patient-years. The hazard ratio of recurrent stroke in the ASCIos group compared with index stroke in the control group was 9.9 (95% confidence interval, 5.5-17.9). The incidence of atrial fibrillation was similar in the ASCIos and the ASMed group, however four times higher in the ASCIos than in the control group.

CONCLUSIONS

Our large nationwide, register-based cohort study showed that, unexpectedly, the risk of recurrent stroke in the ASCos group was as high as in the ASMed group and almost ten times higher than the risk of an index stroke in matched controls without previous stroke.

SA Heart consensus statement on closure of patent foramen ovale 2021

A patent foramen ovale (PFO) is associated with numerous clinical conditions. The most severe of these is cryptogenic stroke. This consensus statement aims to provide a clinical guideline on which patients should be offered PFO closure.

Three-dimensional Transesophageal Echocardiography for Transcatheter Patent Foramen Ovale Closure: Standardizing Anatomic Nomenclature and Novel Sizing Concepts

•

Terminology for PFO tunnel sizing remains unstandardized.

•

Device size selection for transcatheter PFO closure is highly variable.

•

Tunnel width measurements may be a better descriptor of PFO size.

•

Wire sizing may be a useful technique for assessment of PFO dimensions.

•

PFO sizing strategies based on tunnel width need to be better studied.

Residual Right-to-Left-Shunt Following Transcatheter Patent Foramen Ovale Closure: The Role of Antithrombotic Treatment

BACKGROUND

Transcatheter closure of patent foramen ovale (PFO) is a highly effective therapy for patients with left circulation thromboembolism, not attributable to other conditions.

OBJECTIVES

This retrospective cohort study investigates the impact of baseline foramen ovale anatomy on the severity of the postclosure shunt.

METHODS

Patients with PFO, who underwent percutaneous closure, were followed up for at least 5 years postimplantation. Patients were classified into two groups based on the presence of high-risk features of the baseline PFO anatomy. At the follow-up follow-up, residual right-to-left shunt was assessed for the high and non-highrisk anatomy groups, via transcranial Doppler at rest and after performing the Valsalva maneuver, with the injection of agitated saline.

RESULTS

38 patients were examined after a mean follow-up period of 9 ± 3 years after implantation. After retrospective evaluation of the baseline transthoracic and transesophageal echo studies, 14 patients with high-risk PFO anatomy were identified. The degree of the residual right-to-left shunt, as assessed by the number of microbubbles was higher in the high-risk PFO anatomy group compared to the non-high-risk group, both at rest [1.50 (IQR: 0.00-3.25) vs. 0.00 (IQR: 0.00-0.00), p < 0.001] and post-Valsalva maneuver [7.50 (IQR: 1.50- 10.25) vs. 0.00 (IQR: 0.00-3.75), p = 0.003]. Furthermore, in the high-risk group, more microbubbles were detected at rest (p = 0.008) and post-Valsalva (p = 0.002) in subjects without antiplatelet treatment compared to subjects on prolonged antiplatelet therapy.

CONCLUSION

Baseline PFO anatomy affects the severity of the residual right-to-left shunt. Prolonged antiplatelet therapy may benefit patients with high-risk anatomical features.

Application of Transesophageal Echocardiography in Amplatzer Atrial Septal Defect Occluder for Percutaneous Closure of Large Patent Foramen Ovale

Objective. The Amplatzer patent foramen ovale (PFO) occluder is the most commonly used device for percutaneous closure of a large PFO. However, its use may predispose the patient to postoperative residual shunting. To reduce the incidence of residual shunting, we investigated the safety and effectiveness of the Amplatzer atrial septal defect (ASD) occluder for percutaneous closure of a large PFO measured by transesophageal echocardiography (TEE) and evaluated the value of TEE in this procedure. Methods. Overall, 118 patients who were diagnosed with a large PFO (all with $a\ge 2$  mm left atrial side height after the Valsalva maneuver (VM) excluding those with a small ASD) using contrast transthoracic echocardiography (c-TTE) and TEE underwent closure under TEE guidance at The First Affiliated Hospital of Xi’an Jiaotong University. An ASD device was used in 48 patients (group I) and a PFO device in 70 (group II). After the procedure, we verified the safety and efficacy of different devices using c-TTE, TTE, and TEE. Results. In both groups, the preoperative TEE results showed a significantly increased left height of the PFO after VM compared with that at rest (all $P<0.01$ ). Compared with the left height of the PFO measured using TEE after VM, the PFO-stretch diameter (SD) measured by TEE after the delivery sheath passed the PFO was higher (all $P<0.01$ ). We selected the ASD occluder size according to this PFO-SD. In group II, most patients underwent the implantation of the larger PFO devices. Interventional treatment was successfully performed on all patients. The effective occlusion rate in group I at 12 months after the procedure was significantly higher than that in group II (93.7% vs. 78.6%, $P<0.05$ ). The TEE results showed that 18 patients with a medium and large residual shunt at 12 months after the procedure exhibited an intradisc tunnel-like shunt. Conclusion. The Amplatzer ASD device and Amplatzer PFO device are safe for large PFO closure, but the Amplatzer ASD device has a higher effective occlusion rate. TEE plays a crucial role in the use of the Amplatzer ASD occluder for percutaneous closure of a large PFO.

Characteristics of Patent Foramen Ovale: Analysis from a Single Center

Objective

To collect and analyze data of patent foramen ovale (PFO).

Methods

This study included a total of 260 patients diagnosed with PFO. We analyzed basic clinical data such as sex, age, transesophageal echocardiography as well as other symptoms.

Results

Our data showed that females accounted for the highest proportion of PFO (166 females, 64%), with the highest number of patients (65 patients) having between 45 and 55 years. Transesophageal echocardiography examination demonstrated frequent occurrence of tunnel-like anatomical structures. In addition, PFO was associated with symptoms such as migraine, stroke or TIA, syncope, chest tightness, and palpitations, with dizziness being the most common symptom in the patients with PFO.

Conclusion

Our data demonstrated that females accounted for the highest proportion of PFO patients, with those aged between 45 and 55 years being most affected. The most frequently encountered clinical symptom was dizziness. Taken together, these findings may help doctors to better understand and screen for PFO patients.

Amplatzer Patent Foramen Ovale Occluder Device-Related Complications

Patent foramen ovale (PFO) is a standard variant that is present in 25% of the whole adult population. In a certain population, PFO can lead to cerebrovascular accidents. Mechanism of cerebrovascular accidents can be by paradoxical embolization from the right circulation or in situ thrombosis. Diagnosis of a PFO-responsible cerebrovascular accident is based on a thorough work-up to exclude other possible etiologies and detect PFO on trans-thoracic or trans-esophageal echocardiography with bubble study and/or Doppler. Over the last few years, multiple studies have supported that percutaneous PFO closure is superior to medical therapy in the secondary prevention of cerebrovascular accidents. However, numerous adverse events have been linked to PFO closure devices in general compared to medical therapy as new-onset atrial fibrillation, residual shunt, device-related thrombus, bleeding, deep vein thrombosis, pulmonary embolism, and inter-atrial septal erosions. Amplatzer device is one of the PFO occluder devices approved by the FDA. Device-related adverse events have been addressed by comparing the Amplatzer device with other PFO occluder devices. Based on the new data, we expect to see more complications related to PFO closure in the coming few years. We reviewed different studies that looked at the PFO closure-related complications and the trials comparing adverse events in the Amplatzer PFO occluder device compared to other devices. Amplatzer PFO occluder device is either superior or non-statistically different from other PFO occluder devices related to new-onset atrial fibrillation and residual shunt. More studies are needed to address the other less common adverse events. Since many of the device-related complications appear many years after device placement, a long-term follow-up is recommended.

Advances in the management of cardioembolic stroke associated with patent foramen ovale

Patent foramen ovale (PFO) describes a valve in the interatrial septum that permits shunting of blood or thrombotic material between the atria. PFOs are present in approximately 25% of the healthy population and are not associated with any pathology in the vast majority of cases. However, comparisons between patients with stroke and healthy controls suggest that PFOs may be causative of stroke in certain patients whose stroke is otherwise cryptogenic. Options for the diagnosis of PFO include transthoracic echocardiography, transesophageal echocardiography, and transcranial Doppler ultrasonography. PFOs associated with an interatrial septal aneurysm seem to be more strongly linked to risk of recurrent stroke. Therapeutic options for secondary stroke prevention in the setting of a PFO include antiplatelet therapy, anticoagulation, and percutaneous device closure. Recent randomized clinical trials suggest that percutaneous closure reduces the subsequent risk of stroke in appropriately selected patients, with a large relative benefit but small absolute benefit. Referral for percutaneous PFO closure should therefore be considered in certain patients after a multidisciplinary, patient centered discussion. Areas for future study include structural biomarkers to aid in determining the role of PFO closure in older people with possible PFO associated stroke, the role of direct oral anticoagulants, and very long term outcomes after device closure.

Incidence, persistence, and clinical relevance of iatrogenic atrial septal defects after percutaneous left atrial appendage occlusion

OBJECTIVE

To investigate the rate and clinical impact of a persisting iatrogenic atrial septal defect (iASD) after percutaneous left atrial appendage occlusion (LAAO).

BACKGROUND

Percutaneous LAAO is an alternative to oral anticoagulation (OAC) for the prevention of ischemic stroke and systemic embolism in patients with atrial fibrillation (AF). Data regarding incidence and persistence of iASD after LAAO procedures and its clinical relevance is scarce.

METHODS

We retrospectively analyzed 144 patients that underwent LAAO at our center between 2009 and 2020 who had at least one follow-up including transesophageal echocardiography (TEE). Baseline clinical, procedural data and echocardiographic characteristics in patients with and without evidence of an iASD were compared. We furthermore determined the rate of iASD persistence over time and evaluated outcomes of patients with and without spontaneous iASD closure.

RESULTS

After a median of 92 days (IQR 75-108 days) after LAAO, 50 patients (50/144, 34.7%) showed evidence of an iASD. Patients with iASD had higher CHADS-VASc-scores (4.9±1.5 vs 4.2±1.2, p = 0.03), larger left atrial volumes (80.5±30.5 ml vs 67.1±19.7 ml, p = 0.01) and were more likely to have relevant mitral regurgitation (≥° II) (46.0% vs 12.3%, p = 0.001). LAAO procedures took longer (50.1±24.3 vs 41.1±17.8 min, p = 0.06) in patients with a persisting iASD. Furthermore, larger device sizes were implanted (24.3±3.4 mm vs 22.1±2.8 mm, p = 0.03). The presence of an iASD had no impact on RV dysfunction, thromboembolism or mortality. Spontaneous closure of an iASD was documented in 52.0% (26/50). Hereby, similar risk factors were identified for the persistence of an iASD in follow-up.

Patent foramen ovale closure in India; Feasibility, challenges and mid-term outcomes

Patent foramen ovale closure (PFO) is an underutilized therapy, and our study explored the challenges and feasibility of PFO closure in the Indian setting. Eighty patients with Embolic Stroke of Undetermined Source (ESUS) were screened by transcranial Doppler (TCD) for PFO. Twenty-nine patients underwent successful closure. High-risk features of a long tunnel, inter-atrial septal aneurysm, and large defect were present in 31%, 28%, and 59%. Transcranial Doppler had a sensitivity and specificity of 78% and 53% (p = 0.02) to detect PFO. Anticoagulation was withdrawn in 85% of patients post closure. Two patients had residual shunts at follow-up of 19 (9,34) months.

Contemporary Management of Patent Foramen Ovale: A Multinational Survey on Cardiologists' Perspective

Objectives

The purpose of our survey is to analyze the clinical approach used by interventional and imaging cardiologists to diagnose, treat, and follow-up patients with PFO-related left circulation thromboembolism in different parts of the world with particular emphasis on adherence to current guidelines.

Background

Firm guidelines do not cover many aspects of PFO-related patient care. Consequently, very disparate approaches exist among clinicians in the real-world.

Methods

A 24-item electronic questionnaire was sent directly to experienced cardiology specialists practicing at consultant/attending positions directly involved in PFO closure management in the United States, United Kingdom, Gulf countries, and other countries. There were no unanswered questions. Responses were recorded between October 2019 and July 2020.

Results

Seventy-one responses were obtained: 31 from the UK, 19 from the US, 16 from Gulf countries, 2 from Poland, and 1 response from Australia, Italy, and Switzerland. The overall response rate was 76%. Significant differences between regions were noted in the duration of ECG monitoring during the diagnostic process, PFO closure for left circulation thromboembolism other than stroke/transient ischemic attack, and intraoperative use of intracardiac echocardiography. A similar pattern was noted in the lack of routine screening for thrombophilia and the use of the long-term single antiplatelet therapy.

Conclusions

The study shows a vast spectrum of opinions on the optimal approach to PFO closure with significant differences between the US, UK, and Gulf countries. The results stress the need for systematic, high-quality data on the diagnostic work-up and follow-up strategies to inform the standardized approach.

Secondary stroke prevention in patients with patent foramen ovale

PURPOSE OF REVIEW

Although a patent foramen ovale (PFO) is an established risk factor for cryptogenic ischemic stroke, strategies for secondary prevention remain controversial. Increasing evidence over the past decade from well designed clinical trials supports transcatheter PFO closure for selected patients whose stroke was likely attributable to the PFO. However, patient selection using imaging findings, clinical scoring systems, and in some cases, thrombophilia testing, is crucial for determining patients most likely to benefit from closure, anticoagulation, or antiplatelet therapy.

RECENT FINDINGS

Recent studies have found that patients with a high Risk of Paradoxical Embolism (RoPE) score and those with a thrombophilia benefit more from closure than medical therapy (including antiplatelet or anticoagulant therapy) alone. Meta-analyses have demonstrated an increased short-term risk of atrial fibrillation in closure patients, and that residual shunt after closure predicts stroke recurrence. Last, recent data have been inconclusive as to whether patients receiving medical therapy only benefit more from anticoagulation or antiplatelet therapy, so this remains an area of controversy.

SUMMARY

Transcatheter PFO closure is an evidence-based, guideline-supported therapy for secondary stroke prevention in patients with a PFO and cryptogenic stroke. However, proper patient selection is critical to achieve benefit, and recent studies have helped clarify those patients most likely to benefit from closure.

Effect of Patent Foramen Ovale Closure After Stroke on Circulatory Biomarkers

OBJECTIVE

To determine the influence of patent foramen ovale (PFO) closure on circulatory biomarkers.

METHODS

Consecutive patients with PFO-related stroke were prospectively enrolled and followed with serial sampling of cardiac atrial and venous blood pre- and post-PFO closure over time. Candidate biomarkers were identified by mass spectrometry in a discovery cohort first, and lead candidates were validated in an independent cohort.

RESULTS

Patients with PFO-related stroke (n = 254) were recruited and followed up to 4 years (median 2.01; interquartile range 0.77-2.54). Metabolite profiling in the discovery cohort (n = 12) identified homocysteine as the most significantly decreased factor in intracardiac plasma after PFO closure (false discovery rate 0.001). This was confirmed in a validation cohort (n = 181), where intracardiac total homocysteine (tHcy) was immediately reduced in patients with complete closure, but not in those with residual shunting, suggesting association of PFO shunting with tHcy elevation (β 0.115; 95% confidence interval [CI] 0.047-0.183; p = 0.001). tHcy reduction was more dramatic in left atrium than right (p < 0.001), suggesting clearance through pulmonary circulation. Long-term effect of PFO closure was also monitored and compared to medical treatment alone (n = 61). Complete PFO closure resulted in long-term tHcy reduction in peripheral blood, whereas medical therapy alone showed no effect (β -0.208; 95% CI -0.375∼-0.058; p = 0.007). Residual shunting was again independently associated with persistently elevated tHcy (β 0.184; 95% CI 0.051-0.316; p = 0.007).

CONCLUSIONS

PFO shunting may contribute to circulatory tHcy elevation, which is renormalized by PFO closure. PFO is not just a door for clots, but may itself enhance clot formation and injure neurovasculature by clot-independent mechanisms. Biomarkers such as tHcy can potentially serve as cost-effective measures of residual shunting and neurovascular risk for PFO stroke.

Transcatheter closure of patent foramen ovale: Current evidence and future perspectives

Recent prospective controlled studies have demonstrated that transcatheter closure of a patent foramen ovale (PFO) reduces recurrent stroke risk in select patients, especially in patients younger than 60 years with PFO and embolic-appearing infarct and where no other mechanism of stroke was identified. Detection of PFO depends on the intensity of the Valsalva maneuver, and not all PFOs can be diagnosed using transesophageal echocardiography. Transthoracic contrast echocardiography using abdominal compression during the Valsalva maneuver is an easy method that can increase the detection sensitivity of PFO shunt. PFO with two or more of the following factors is most likely considered a "high-risk PFO" and as such, has a significantly higher probability of cryptogenic stroke: (1) a long-tunnel PFO (≥10 mm in length), (2) atrial septal aneurysm and/or hypermobile interatrial septum, (3) prominent Eustachian valve or Chiari's network, (4) large right-to-left shunt at rest and during the Valsalva maneuver, and (5) low-angle PFO. In order to establish the benefit of catheter-based PFO closure as a safe and effective treatment in clinical practice, the degree of accuracy of PFO diagnosis and its long-term safety need to be confirmed.

Risk of Paradoxical Embolism (RoPE)-Estimated Attributable Fraction Correlates With the Benefit of Patent Foramen Ovale Closure: An Analysis of 3 Trials

BACKGROUND AND PURPOSE

In patients with cryptogenic stroke and patent foramen ovale (PFO), the Risk of Paradoxical Embolism (RoPE) Score has been proposed as a method to estimate a patient-specific "PFO-attributable fraction"-the probability that a documented PFO is causally-related to the stroke, rather than an incidental finding. The objective of this research is to examine the relationship between this RoPE-estimated PFO-attributable fraction and the effect of closure in 3 randomized trials.

METHODS

We pooled data from the CLOSURE-I (Evaluation of the STARFlex Septal Closure System in Patients With a Stroke and/or Transient Ischemic Attack due to Presumed Paradoxical Embolism through a Patent Foramen Ovale), RESPECT (Randomized Evaluation of Recurrent Stroke Comparing PFO Closure to Established Current Standard of Care Treatment), and PC (Clinical Trial Comparing Percutaneous Closure of Patent Foramen Ovale [PFO] Using the Amplatzer PFO Occluder With Medical Treatment in Patients With Cryptogenic Embolism) trials. We examine the treatment effect of closure in high RoPE score (≥7) versus low RoPE score (<7) patients. We also estimated the relative risk reduction associated with PFO closure across each level of the RoPE score using Cox proportional hazard analysis. We estimated a patient-specific attributable fraction using a PC trial-compatible (9-point) RoPE equation (omitting the neuroradiology variable), as well as a 2-trial analysis using the original (10-point) RoPE equation. We examined the Pearson correlation between the estimated attributable fraction and the relative risk reduction across RoPE strata.

RESULTS

In the low RoPE score group (<7, n=912), the rate of recurrent strokes per 100 person-years was 1.37 in the device arm versus 1.68 in the medical arm (hazard ratio, 0.82 [0.42-1.59] P=0.56) compared with 0.30 versus 1.03 (hazard ratio, 0.31 [0.11-0.85] P=0.02) in the high RoPE score group (≥7, n=1221); treatment-by-RoPE score group interaction, P=0.12. The RoPE score estimated attributable fraction anticipated the relative risk reduction across all levels of the RoPE score, in both the 3-trial (r=0.95, P<0.001) and 2-trial (r=0.92, P<0.001) analyses.

CONCLUSIONS

The RoPE score estimated attributable fraction is highly correlated to the relative risk reduction of device versus medical therapy. This observation suggests the RoPE score identifies patients with cryptogenic stroke who are likely to have a PFO that is pathogenic rather than incidental.