Expert consensus statement for the management of patients with embolic stroke of undetermined source and patent foramen ovale: A clinical guide by the working group for stroke of the Hellenic Society of Cardiology and the Hellenic Stroke Organization

Management of patent foramen ovale; findings from a nationwide survey

OBJECTIVES

Several clinical trials have provided evidence supporting the transcatheter closure of patent foramen ovale (PFO) in selected patients following a cryptogenic stroke. However, it remains unknown to what extent these guidelines have been implemented in everyday clinical practice and the familiarity of physicians from different specialties with PFO closure. The aim of our nationwide survey is to explore the implementation of transcatheter PFO occlusion in Greek clinical practice.

MATERIALS AND METHODS

Attending level cardiologists, internal medicine physicians and neurologists involved in the management of PFO-related strokes working in Greece were invited to complete an online questionnaire. The questionnaire consisted of 19 questions and was designed to obtain comprehensive data on provider demographics, PFO characteristics, and specific clinical scenarios.

RESULTS

A total of 51 physicians (56.9 % cardiologists, 25.5 % neurologists and 17.6 % internal medicine physicians) completed the survey, resulting in a response rate of 53 %. Cardiologists, internal medicine physicians and neurologists agree on several issues regarding PFO closure, such as PFO closure as first line treatment, management of patients with DVT or prior decompression sickness, and post-closure antithrombotic treatment, but different approaches were reported regarding closure in patients with thrombophilia treated with oral anticoagulation (p=0.012) and implantable loop recorder placement for atrial fibrillation exclusion (p=0.029 and p=0.020).

CONCLUSIONS

Our findings show that cardiologists, internal medicine physicians and neurologists agree in numerous issues, but share different views in the management of patients with thrombophilia and rhythm monitoring duration. These results highlight the significance of collaboration among physicians from different medical specialties for achieving optimal results.

Potential Embolic Sources in Embolic Stroke of Undetermined Source Patients with Patent Foramen Ovale

INTRODUCTION

A patent foramen ovale (PFO) may coexist with other potential embolic sources (PESs) in patients with embolic stroke of undetermined source (ESUS), leading to difficulty in attributing the stroke to either the PFO or other PESs. We aimed to investigate the prevalence and predictors of concomitant PESs in ESUS patients with PFOs.

METHODS

A retrospective cohort study was conducted in a tertiary stroke centre. Consecutive patients with ESUS and a concomitant PFO admitted between 2012 and 2021 were included in the study. Baseline characteristics and investigations as a part of stroke workup including echocardiographic and neuroimaging data were collected. PESs were adjudicated by 2 independent neurologists after reviewing the relevant workup.

RESULTS

Out of 1,487 ESUS patients, a total of 309 patients who had a concomitant PFO with mean age of 48.8 ± 13.2 years were identified during the study period. The median Risk of Paradoxical Embolism (RoPE) score for the study cohort was 6 (IQR 5-7.5). Of the 309 patients, 154 (49.8%) only had PFO, 105 (34.0%) patients had 1 other PES, 34 (11.0%) had 2 PES, and 16 (5.2%) had 3 or more PES. The most common PESs were atrial cardiopathy (23.9%), left ventricular dysfunction (22.0%), and cardiac valve disease (12.9%). The presence of additional PESs was associated with age ≥60 years (p < 0.001), RoPE score ≤6 (p ≤0.001), and the presence of comorbidities including diabetes mellitus (p = 0.004), hypertension (p≤ 0.001), and ischaemic heart disease (p = 0.011).

CONCLUSION

A large proportion of ESUS patients with PFOs had concomitant PESs. The presence of concomitant PESs was associated with older age and a lower RoPE score. Further, large cohort studies are warranted to investigate the significance of the PES and their overlap with PFOs in ESUS.

Echocardiographic characteristics of transcatheter closure of patent foramen ovale with mallow biodegradable occluder: A single-center, phase III clinical study

Background

Transcatheter occlusion of patent foramen ovale (PFO) has become a recognized treatment option for high-risk PFO-related diseases. However, traditional metal occluders have some disadvantages, such as permanent retention in the body, abrasion of tissues, and obstruction of access to the left side of the heart for interventional procedures. With biodegradable occluders that release non-toxic degradation products and are absorbable by the body, the risk of long-term complications could be greatly reduced. The experimental results of using a PFO-degradable occluder in beagle dogs in early stages, independently developed by Shanghai Mallow Medical Instrument Co., Ltd., showed that the occluding umbrella disc network was degraded 6 months after occlusion. The occluder also showed good memory, biocompatibility, and mechanical properties.

Methods

As one of the multi-center research units, this prospective Phase III clinical trial study included 16 patients with PFO-related complications who were treated with a degradable occluder. The follow-up period lasted for 12 months to analyze the echocardiographic characteristics and procedural feasibility.

Results

The immediate success rate of the procedure was 100% with no serious complications. Postoperative color Doppler transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) at 12 months showed that one patient with atrial septal aneurysm (ASA) had a residual shunt at the edge of the occluder, and contrast transcranial Doppler (cTCD) showed that all patients were grade I or 0 right-to-left shunts (RLS), indicating that the occlusion success rate was 100%. The occluder gradually degraded after the procedure, particularly when the umbrella disc structure became vague, and the size of the occluder decreased significantly 6 months after occlusion.

Conclusions

PFO closure with a Mallow degradable occluder has a high plugging success rate, is safe and effective, and has no serious complications. However, for PFO closure with special anatomical features, further research with a larger sample size is required. TTE can dynamically, conveniently, and accurately observe the entire degradation process of the occluder.

Clinical Trial Registration

ChiCTR1900024036.

Nickel Hypersensitivity to Atrial Septal Occluders: Smoke Without Fire?

Nickel is one of the most common contact allergens worldwide; it is used as the main component of the devices used for atrial septal defects (ASDs) and patent foramen ovale (PFO) closure. Developing nickel hypersensitivity after PFO/ASD occlusion is significantly rarer described in medical literature than typical nickel contact sensitization. The exact pathophysiological mechanism of this "device syndrome" remains unknown, and many question the real incidence or even the existence of this clinical entity. Nevertheless, it has been associated with a wide spectrum of symptoms, including chest pain, migraines, palpitation, and dyspnea. Skin patch tests are the first-line approach to diagnose nickel hypersensitivity. However, diagnostic criteria for the device syndrome have not been developed, and diagnosis in reported cases is established by a process of elimination. Management-drug therapy (corticosteroids, clopidogrel, etc.) or even surgical explantation in severe cases-of patients developing such clinical manifestations after percutaneous PFO/ASD occlusion is empirical. Undoubtedly, endocardiac device-related nickel hypersensitivity requires more focused research to discover the underlying mechanism as well as to develop reliable prognostic tests for detecting high-risk patients and preventing severe nickel hypersensitivity reactions.