Patent Foramen Ovale Closure in Older Patients With Stroke: Patient Selection for Trial Feasibility.

BACKGROUND AND OBJECTIVES: Whether patent foramen ovale (PFO) closure benefits older patients with PFO and cryptogenic stroke is unknown because randomized controlled trials (RCTs) have predominantly enrolled patients younger than 60 years of age. Our objective was to estimate anticipated effects of PFO closure in older patients to predict the numbers needed to plan an RCT. METHODS: Effectiveness estimates are derived from major observational studies (Risk of Paradoxical Embolism [RoPE] Study and Oxford Vascular Study, together referred to as the "RoPE-Ox" database) and all 6 major RCTs (Systematic, Collaborative, PFO Closure Evaluation [SCOPE] Consortium). To estimate stroke recurrence risk, observed outcomes were calculated for patients older than 60 years in the age-inclusive observational databases (n = 549). To estimate the reduction in the rate of recurrent stroke associated with PFO closure vs medical therapy based on the RoPE score and the presence of high-risk PFO features, a Cox proportional hazards regression model was developed on the RCT data in the SCOPE database (n = 3,740). These estimates were used to calculate sample sizes required for a future RCT. RESULTS: Five-year risk of stroke recurrence using Kaplan-Meier estimates was 13.7 (95% CI 10.5-17.9) overall, 14.9% (95% CI 10.2-21.6) in those with high-risk PFO features. Predicted relative reduction in the event rate with PFO closure was 12.9% overall, 48.8% in those with a high-risk PFO feature. Using these estimates, enrolling all older patients with cryptogenic stroke and PFO would require much larger samples than those used for prior PFO closure trials, but selectively enrolling patients with high-risk PFO features would require totals of 630 patients for 90% power and 471 patients for 80% power, with an average of 5 years of follow-up. DISCUSSION: Based on our projections, anticipated effect sizes in older patients with high-risk features make a trial in these subjects feasible. With lengthening life expectancy in almost all regions of the world, the utility of PFO closure in older adults is increasingly important to explore.

Open Chest Approach Lead Extraction in a Patient with a Large Vegetation: The Importance of Multidisciplinary Approach, Advanced Imaging, and Procedural Planning.

We present a complex case of cardiac implantable electronic device infection and extraction in the setting of bacteremia, large lead vegetation, and patent foramen ovale. Following a comprehensive preprocedural workup including transesophageal echocardiogram and computed tomography lead extraction protocol, in addition to the involvement of multiple subspecialties, an open chest approach to extraction was deemed a safer option for eradication of the patient's infection. Despite percutaneous techniques having evolved as the preferred extraction method during the last few decades, this case demonstrates the importance of a thorough evaluation at an experienced center to determine the need for open chest extraction.

[Management of patent foramen ovale in non-cardiac surgery]. / Gestione della pervietà del forame ovale nella chirurgia non cardiaca.

Patent foramen ovale (PFO) is a remnant of normal fetal anatomy which may persist into adulthood, mostly asymptomatic. In some adults, PFO may result in a potential for shunting venous thromboembolism to the arterial circulation; less frequently it can cause interatrial, right-to-left shunting of deoxygenated blood. The pathogenesis of several medical conditions is related to the presence of PFO. Some randomized clinical trials have shown evidence of benefit for device closure as compared with medical therapy in patients with cryptogenic stroke. The literature reported several cases of carbon dioxide embolism during general laparoscopic surgery and sometimes stroke after laparoscopic or neurosurgery but there are neither prospective studies addressing these issues, nor randomized clinical trials assessing the effectiveness of pharmacotherapy or interventional procedures at decreasing risk. The European position paper suggests routine monitoring in non-cardiac surgery of patients with a PFO and no actual indications for closure. This article aims to further stratify the risk of periprocedural stroke and paradoxical embolism in this category of patients.

Construction and validation of a nomogram for predicting remission of migraine patients with patent foramen ovale after closure.

OBJECTIVE: This study aimed to construct and validate a nomogram model that predicts the remission of migraine attacks by screening factors that affect the prognosis of migraine patients with patent foramen ovale (PFO) after closure. METHOD: Retrospective analysis was conducted in migraine patients with PFO who underwent PFO closure in the Department of Cardiology of Jiangsu Province Hospital from September 2020 to April 2023. Based on the Migraine Disability Assessment (MIDAS) scores from the 1-year follow-up after PFO closure, all patients who met the inclusion criteria were categorized into a remission group and a non-remission group. The primary efficacy endpoint was remission of migraine headache. After collecting clinical data, transcranial doppler sonography (TCD) results and MIDAS scores, LASSO (least absolute shrinkage and selection operator) regression and multivariable logistic regression analysis were used to filter variables predictive to migraine remission and construct the nomogram model. The Nomogram's accuracy and consistency were respectively assessed through Receiver Operating Characteristic (ROC) curves and calibration curves. Additionally, an analysis of decision curves (DCA) was conducted to evaluate the clinical utility of this newly developed model. RESULT: A total of 241 consecutive patients were included in the study. The remission group included 21 males and 93 females, with a median age of 39 (30.25,50) years. The non-remission group included 26 males and 101 females, with a median age of 35 (25.5,47.5) years. All Patients were randomly divided into a training cohort and a validation cohort. Multivariable logistic regression analysis showed that 5 independent predictors, including MIDAS before closure (p = 0.0002), mitigating factors (p = 0.0057), number of attacks/month (p = 0.0058), TCD (p = 0.0093) and Platelet Crit (PCT) (p = 0.0351), played a significant role in the prediction of remission of migraine patients with PFO after closure. Based on these independent predictors, the predictive nomogram model of migraine remission in PFO patients was constructed. The application of the nomogram in the training cohort exhibited good discrimination (area under the ROC curve was 0.7763[95% CI 0.7108-0.8418]), which was confirmed in the validation cohort (AUC was 0.704[95% CI 0.5533-0.8547]). The calibration curve showed that the nomogram model demonstrated good calibration performance. Additionally, the decision curve analysis indicated the clinical utility of the nomogram model. CONCLUSION: The construction of the nomogram model had a considerable predictive accuracy for migraine remission in patients after PFO closure, which may provide constructive guidance for clinical decision making.

Successful surgical treatment of impending paradoxical embolism with pulmonary embolism and myocardial infarction.

BACKGROUND: Paradoxical embolism is a rare cause of acute arterial occlusion. This phenomenon arises when embolic material travels from the venous system crosses an abnormal shunt such as patent foramen ovale, atrial septal defects, ventricular septal defects, or pulmonary arteriovenous malformations, into the arterial system. Impending paradoxical embolism refers to the presence of an entrapped thrombus in the patent foramen ovale. CASE PRESENTATION: We report a case of a 68-year-old female patient who presented with an impending paradoxical embolism, alongside both concomitant pulmonary embolism and myocardial infarction with ST-segment elevation. Swiftly addressed through emergency cardiac surgery and systemic anticoagulation, the patient's condition was effectively treated. CONCLUSIONS: While the ideal treatment strategy for impending paradoxical embolism remains a topic of debate due to limited and inconclusive evidence, emergent open surgery should be contemplated in patients as it signifies a critical clinical emergency.

Platypnea-orthodeoxia syndrome (POS) in a patient who had undergone partial liver resection.

A South Asian male in his early 60s presented with acute-onset dyspnoea on postoperative day 4 after undergoing middle hepatic vein sacrificing partial liver resection for epithelioid angiomyolipoma. The patient's SpO2 on presentation was 65% in standing position which improved to 90% in left lateral decubitus. He was suspected of having platypnea-orthodeoxia syndrome (POS) which was confirmed on echocardiogram with microbubble contrast showing a large intracardiac right-to-left shunt. The patient was taken up for transcatheter closure of patent foramen ovale (PFO). A 30 mm Amplatzer PFO Occluder was deployed across the PFO which reduced the intracardiac shunt resulting in an improved arterial saturation as well as immediate relief of patient's symptoms. This case illustrates the importance of suspecting and recognising POS clinically as well as the efficacy of transcatheter closure of PFO in such cases leading to resolution of hypoxaemia in a short span of time.

Various techniques for transcatheter retrieval of the atrial septal defect or patent foramen ovale closure devices: a systematic review.

Atrial septal abnormalities are common congenital lesions that remain asymptomatic in many patients until adulthood. Adults with atrial septal defects (ASD) most commonly have ostium secundum ASD. Transcatheter closure has become increasingly popular in recent years as a successful alternative method to surgery for treating ASD and patent foramen ovale (PFO). The overall rate of ASD transcatheter closure device embolization has been reported to be less than 1%; however, retrieving the device via surgery or by trans-catheter route can be necessary. The current manuscript describes a systematic review of the techniques used to retrieve ASD closure devices, as well as their success rates, complications, and limitations. A comprehensive search was performed covering various databases including PubMed, MEDLINE, SCOPUS, Google Scholar, and Cochrane Library from inception until April 2022 for English-published case reports, case series, and experimental studies investigating the indications, safety, and limitations of ASD closure and ASD device retrieval by trans-catheter approaches. Finally, 20 studies were included in our review. Our findings showed that most of the studies used a single snare technique; of these, all but one reported 100% success. Double tool retrieval methods (snare plus snare, snare plus bioptome, or snare plus forceps) and the gooseneck snare technique yielded 100% success. One study that used the lasso technique reported unsuccessful retrieval and the need for surgical intervention. More recently, the novel "coronary wire trap technique" was introduced, which provides a simpler method for embolized device removal by trapping the device for retrieval using coronary wire.

Amplatzer or Figulla Flex II Occluder: a comparative study of outcomes after transcatheter patent foramen ovale closure.

OBJECTIVES: Percutaneous closure of a patent foramen ovale (PFO) for the prevention of recurrent paradoxical thromboembolic events has been shown to be safe and effective in randomized controlled trials. However, it remains uncertain if differences in the structure and design of the occluder devices impact the outcomes. The aim of this study was to compare results of percutaneous PFO closure using 2 widely used double-disc occluders. METHODS: Consecutive patients who underwent percutaneous PFO closure with the Abbott Amplatzer occluder (APO) or the Occlutech Figulla-Flex-II occluder (OPO) at the Heart Center Lucerne between February 2017 and December 2022 were included in a registry. The primary endpoint was effective closure of the PFO, defined as a residual shunt grade 0 or 1, assessed by contrast echocardiogram at 6-month follow-up. Secondary endpoints included procedural efficacy/safety and major adverse cardiovascular events during the hospital stay and at 6-month follow-up. RESULTS: One hundred ninety-three consecutive patients (mean age 51.7 ± 12.5 years; 39% women; Risk of Paradoxical Embolism (RoPE) score = 7, IQR = 6-8) underwent percutaneous PFO closure with the APO (120 patients, 62.2%) or the OPO (73 patients, 37.8%). Main indications for closure were crypotogenic stroke in 168 patients (87.1%) and peripheral embolism in 13 patients (6.7%). At baseline, right-to-left shunt (RLS) greater than or equal to grade 2 was present in 189 patients (97.9%). Immediate procedural success was 99.5%. In 1 patient, an air embolism occurred during positioning of the APO occluder with transient chest pain and electrocardiogram changes, but without further sequelae to the patient. At 6-month follow-up, effective closure was achieved in 185 patients (95.8%; APO: 96.6% vs OPO: 94.5%, P = .30). Rates of atrial fibrillation and recurrent thromboembolic events were 4.2 and 0.5%, respectively. CONCLUSIONS: PFO closure is safe and effective when performed with either the self-expanding Abbott Amplatzer or Occlutech Figulla Flex II PFO occluder.

A matching-adjusted indirect comparison of results from REDUCE and RESPECT-two randomized trials on patent foramen ovale closure devices to prevent recurrent cryptogenic stroke.

AIMS: Two randomized clinical trials, REDUCE and RESPECT, demonstrated that patent foramen ovale (PFO) closure in combination with antithrombotic therapy was more effective for the prevention of recurrent ischemic stroke compared with antithrombotic therapy alone. The aim of this study was to determine the relative efficacy and safety of the PFO closure devices used in REDUCE (HELEX and CARDIOFORM Septal Occluders) compared with the device used in RESPECT (Amplatzer PFO Occluder). METHODS: An unanchored matching-adjusted indirect comparison (MAIC) of the PFO closure arms of the REDUCE and RESPECT trials was performed using patient-level data from REDUCE weighted to match baseline characteristics from RESPECT. Comparisons of the following outcomes were made between the devices assessed in the trials: risk of recurrent ischemic stroke; recurrent ischemic stroke one year after randomization; any serious adverse event (SAE) related to the procedure or device; and atrial fibrillation or atrial flutter as an SAE related to the procedure or device. RESULTS: After conducting the MAIC, baseline characteristics were well-matched between the two trials. Compared to RESPECT, PFO closure using the devices from REDUCE resulted in a hazard ratio of 0.46 (95% confidence interval [CI] 0.15-1.43; p = 0.17) for the risk of recurrent stroke. For the recurrence of stroke after one year, SAE related to the procedure or device, and atrial fibrillation or atrial flutter as SAE related to the procedure or device, the MAIC resulted in a rate difference of -0.68 (95%CI -2.06 to 0.70; p = .34), -1.29 (95%CI -3.82 to 1.25; p = .32), and -0.19 (95%CI -1.16 to 0.78; p = .71), respectively. These findings were consistent across scenario analyses. CONCLUSIONS: This MAIC analysis found no statistically significant differences in efficacy and safety outcomes between PFO closure with the HELEX and CARDIOFORM Septal Occluders versus the Amplatzer PFO Occluder, as used in the REDUCE and RESPECT trials.

The individual efficacy and safety of medical devices used for patent foramen ovale (PFO) closure in patients with stroke of unknown origin has been demonstrated in two independent trials: REDUCE (using the HELEX Septal Occluder and the CARDIOFORM Septal Occluder) and RESPECT (using the Amplatzer PFO Occluder). In the absence of a direct head-to-head trial for these devices, indirect treatment comparisons offer an alternative to assess their relative efficacy and safety. This study used a matching-adjusted indirect comparison to demonstrate that there were no significant differences between the devices used for PFO closure in the REDUCE and RESPECT trials in terms of safety outcomes.

Approval, Evidence, and "Off-Label" Device Utilization: The Patent Foramen Ovale Closure Story.

BACKGROUND: Following regulatory approval, medical devices may be used "off-label." Patent foramen ovale (PFO) closure is indicated to reduce recurrent stroke but has been proposed for other indications, including migraine, transient ischemic attack, and diving decompression illness. We sought to evaluate PFO closure rates and indications relative to the timing of regulatory approval and publication of key randomized trials. METHODS: We performed a retrospective cohort study using the OptumLabs Data Warehouse of US commercial insurance enrollees from 2006 to 2019. We quantified PFO closure among individuals with ≥2 years of preprocedure coverage to establish indications, classified hierarchically as stroke/systemic embolism, migraine, transient ischemia attack, or other. RESULTS: We identified 5315 patients undergoing PFO closure (51.8% female, 29.2%≥60 years old), which increased from 4.75 per 100 000 person-years in 2006 to 6.60 per 100 000 person-years in 2019. Patients aged ≥60 years accounted for 29.2% of closures. Procedure volumes corresponded weakly with supportive clinical publications and device approval. Among patients with PFO closure, 58.6% underwent closure for stroke/systemic embolism, 10.2% for transient ischemia attack, 8.8% for migraine, and 22.4% for other indications; 17.6% of patients had atrial fibrillation at baseline; and 11.9% developed atrial fibrillation postprocedure. Those aged ≥60 years and male were less likely to undergo closure for migraine than stroke/systemic embolism. CONCLUSIONS: From 2006 to 2019, PFO closure use was consistently low and corresponded weakly with clinical trial publications and regulatory status. Nearly half of patients underwent PFO closure for indications unapproved by the Food and Drug Administration. Regulators and payers should coordinate mechanisms to promote utilization for approved indications to ensure patient safety and should facilitate clinical trials for other possible indications.

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.

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.

Large regional variation in cardiac closure procedures to prevent ischemic stroke in Switzerland a population-based small area analysis.

BACKGROUND: Percutaneous closure of a patent foramen ovale (PFO) or the left atrial appendage (LAA) are controversial procedures to prevent stroke but often used in clinical practice. We assessed the regional variation of these interventions and explored potential determinants of such a variation. METHODS: We conducted a population-based analysis using patient discharge data from all Swiss hospitals from 2013-2018. We derived hospital service areas (HSAs) using patient flows for PFO and LAA closure. We calculated age-standardized mean procedure rates and variation indices (extremal quotient [EQ] and systematic component of variation [SCV]). SCV values >5.4 indicate a high and >10 a very high variation. Because the evidence on the efficacy of PFO closure may differ in patients aged <60 years and ≥60 years, age-stratified analyses were performed. We assessed the influence of potential determinants of variation using multilevel regression models with incremental adjustment for demographics, cultural/socioeconomic, health, and supply factors. RESULTS: Overall, 2574 PFO and 2081 LAA closures from 10 HSAs were analyzed. The fully adjusted PFO and LAA closure rates varied from 3 to 8 and from 1 to 9 procedures per 100,000 persons per year across HSAs, respectively. The regional variation was high with respect to overall PFO closures (EQ 3.0, SCV 8.3) and very high in patients aged ≥60 years (EQ 4.0, SCV 12.3). The variation in LAA closures was very high (EQ 16.2, SCV 32.1). In multivariate analysis, women had a 28% lower PFO and a 59% lower LAA closure rate than men. French/Italian language areas had a 63% lower LAA closure rate than Swiss German speaking regions and areas with a higher proportion of privately insured patients had a 86% higher LAA closure rate. After full adjustment, 44.2% of the variance in PFO closure and 30.3% in LAA closure remained unexplained. CONCLUSIONS: We found a high to very high regional variation in PFO closure and LAA closure rates within Switzerland. Several factors, including sex, language area, and insurance status, were associated with procedure rates. Overall, 30-45% of the regional procedure variation remained unexplained and most probably represents differing physician practices.

Differences and similarities in interatrial shunts management.

Atrial septal defects (ASD) and Patent foramen ovale (PFO) represent the most common congenital heart diseases (CHD) adulthood. These two clinical entities, having different embryological origin, as well as clinical manifestations, clinical course and treatment must be carefully distinguished. Right heart failure and pulmonary hypertension are considered the major determinants of morbidity and mortality in ASD. Conversely, new pathophysiology concepts have been raised in the management of PFO as left atrium cardiopathy. New diagnostic tools, including cardiac magnetic resonance and intracardiac echocardiography have joint transthoracic and transesophageal echocardiography in the diagnostic definition of both ASD and PFO as well as in guiding their percutaneous closure. Moreover, several innovations have been developed in the field of percutaneous ASD and PFO closure devices including new evidence supporting the safety and efficacy of device-based closure. Aim of the present review is to present review we provided and update overview on ASD and PFO, focusing on the novel concepts regarding their pathophysiological and therapeutic aspects.

Transcatheter closure of patent foramen ovale using the Cocoon occluder: A multicenter retrospective study.

BACKGROUND: The Cocoon patent foramen ovale (PFO) occluder is a new device especially designed for transcatheter closure of PFO. This occluder has some distinctive structural modifications aimed at reducing the risk of major complications of transcatheter PFO closure. In this report we present our initial experience to evaluate the efficacy and safety of the Cocoon PFO occluder in 253 patients who underwent transcatheter PFO closure. METHODS: The study cohort included 253 patients (median age 45 years) with embolic stroke of undetermined source who underwent attempted transcatheter closure of PFO for secondary prevention of paradoxical embolism. Patients were enrolled retrospectively from five sites in Greece and one in Romania between December 2016 and January 2021, and the median follow-up period was 28 months (range 12-48 months). Clinical and laboratory data from each participating center were sent to an electronic registry for evaluation and statistical analysis. RESULTS: The Cocoon PFO occluder was permanently implanted in all patients. At 6 months, complete occlusion of PFO was observed in 251/253 (99.2%) patients. Three (1.2%) patients had a trivial residual shunt. Thrombus formation on the device, which was successfully treated with recombinant tissue plasminogen activator infusion, was observed in one (0.4%) patient. No other complications occurred. During a median follow-up period of 28 months, 3 (1.2%) patients, aged 64-67 years, developed new onset paroxysmal atrial fibrillation. No neurologic events, cardiac erosions, allergic reactions to nickel, or thrombus formation occurred. CONCLUSION: The Cocoon PFO occluder is an effective and safe device that adds to our armamentarium for transcatheter closure of PFO.

Quality control in treating patients with patent foramen ovale: 7-year-experience of the Heart and Brain team of the Careggi University Hospital.

BACKGROUND: The right comprehension of ischemic stroke pathogenesis guarantees the best prevention therapy. The term "patent foramen ovale (PFO) related stroke" has been proposed for those events where PFO is supposed to be pathogenetic, but their definition is challenging. A multidisciplinary evaluation in a "Heart & Brain" team (HBteam) including stroke neurologists and interventional cardiologists was therefore highly recommended in the recent guidelines of secondary stroke prevention. OBJECTIVE: We aimed at describing the organization of the HBteam of Careggi-University-Hospital of Florence (Italy), and the results of the first seven years of activity. METHODS: In 2016 Interventional Cardiologists and Stroke Neurologists set up an outpatient clinic for the joined evaluation of patients with PFO and other cardio/neurological conditions. A specific diagnostic-therapeutic hospital plan was produced for PFO patients. Patient empowerment was guaranteed by a hospital explicative webpage, a booklet regarding risks/benefits of PFO closure and a 3D heartmodel to simulate the intervention. Data were collected in a dedicated registry. RESULTS: We evaluated 594 patients for PFO, 40 for left atrial appendage closure and 38 for other conditions. In 20% of PFO-patients, HBteam diagnosis was discordant from that of referring physicians, 14% were stroke misdiagnoses. We advised against closure in 53% of patients. At follow-up 94% of closed patients had no/minimum residual shunt; 3 patients had a cerebral ischemic event. CONCLUSIONS: A dedicated HBteam represents a unique opportunity to share decisions with patients after a thorough empowerment process. The joining of cardioneurological skills allows a better classification of PFO-patients, reducing futile interventions.

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.