Effect of Patent Foramen Ovale Closure After Stroke on Circulatory Biomarkers

Cryptogenic stroke and patent foramen ovale: endeavoring for clarity

This review aims to summarize current knowledge and highlight recent findings on the association between cryptogenic stroke (CS) and patent foramen ovale (PFO). By presenting sometimes conflicting data, the review underscores the necessity for further research to clarify the complex mechanisms behind PFO-related CS and optimize its management. Results from research identifies specific conditions and scores, such as the risk of paradoxical embolism (RoPE) score, that help assess the likelihood of PFO-related cryptogenic stroke and guide treatment decisions. PFO closure has demonstrated substantial benefits in select cases, especially those with high-risk PFO features, though complications such as atrial fibrillation were frequently documented. Biomarker measurements, such as reduced total homocysteine (tHcy) level after PFO closure or high D-dimer levels indicating a higher risk of stroke recurrence, represent newer areas of study with a promising future in medical practice. Cryptogenic stroke (CS) remains a diagnostic challenge. This article reviews the current understanding of PFO-related CS, focusing on the interplay of concomitant pathological conditions, PFO closure, stroke recurrence, and some of the related biomarkers.

Increased burden of enlarged perivascular spaces in patients with patent foramen ovale

INTRODUCTION

Patent foramen ovale (PFO) patients may experience states of hypoxia and hypoperfusion, which may increase the burden of enlarged perivascular spaces (EPVS). However, to our knowledge, no data are available regarding EPVS in PFO patients. This study sought to investigate if patients with PFO exhibit a heightened burden of EPVS and to identify the mediating factors between PFO and EPVS.

METHODS

A total of 108 consecutive PFO patients (PFO group) and 110 healthy controls (HC group) from January 2022 to February 2024 were enrolled. The differences in centrum semiovale EPVS (CSO-EPVS) and basal ganglia EPVS (BG-EPVS) scores between PFO and HC groups were compared. The correlations among PFO diameters, laboratory indexes, and EPVS burdens were analyzed. The relationships among them were obtained using mediation analysis.

RESULTS

Mean age of PFO and HC group was 47.68 ± 14.47 and 48.14 ± 12.84 years. The CSO-EPVS and BG-EPVS scores were higher in PFO group than HC group (P < 0.001). The CSO-EPVS and BG-EPVS scores for PFO group were concentrated in the ranges 1-3 and 1-2 points, while for HC group were concentrated in the range 0-1 points. A positive correlation among PFO diameters and CSO-EPVS score (r = 0.62, P < 0.001), BG-EPVS score (r = 0.63, P < 0.001), and homocysteine (HCY)(r = 0.21, P = 0.03) was observed. Mediation analysis indicated that higher HCY significantly mediated the relationship between PFO diameter and BG-EPVS burden in PFO patients (P < 0.05).

CONCLUSION

These findings revealed the presence of glymphatic dysfunction in patients with PFO. HCY may mediate the impact of PFO diameter on glymphatic function.

Case Report: Persistent residual shunt after a first percutaneous PFO closure followed by minimally invasive surgical failure: third time is a charm

Background

Even though the optimal management of a moderate or large residual shunt following patent foramen ovale (PFO) closure is open to question, recent data confirmed that it is associated with an increased risk of stroke recurrence.

Case summary

A 48-year-old woman, a migraineur with visual aura, was diagnosed with a PFO associated with a huge multifenestrated atrial septal aneurysm (mfASA) and a moderate right-to-left shunt, detectable only after a Valsalva maneuver on contrast-transthoracic echocardiography. Brain magnetic resonance imaging showed a 1-mm silent white matter lesion in the right frontal lobe. Although the indication was not supported by guidelines, a transcatheter PFO closure was performed at another center with implantation of a large, equally sized, double-disc device (Figulla UNI 33/33 mm). At 6-month follow-up, a 2D/3D transesophageal echocardiography (TEE) color Doppler showed incorrect orientation of the device, which was not parallel to the interatrial septum, with two discs failing to capture the aortic muscular rim and partially protruding in the right atrium; furthermore, a 4 mm × 7 mm ASA fenestration was documented with a residual bidirectional shunt. Thereafter, the same team performed a minimally invasive cardiac surgery under femoro-femoral cardiopulmonary bypass; however, the procedure proved ineffective and was complicated by postoperative pericarditis with pericardial effusion, requiring further rehospitalization 1 month later due to persistent pericarditis, bilateral pleuritis, phrenic nerve palsy, and atrial flutter, which was treated with amiodarone. The patient asked for a second opinion, and our multidisciplinary heart team decided to offer a percutaneous redo intervention. An uneventful implantation of a regular PFO occluder (Figulla Flex II 16/18 mm) across the septal defect was performed successfully. Twelve-month follow-up with 2D TTE color Doppler and contrast transcranial Doppler showed correct position and good interaction between the two devices, with no residual shunt.

Discussion

In addition to the incorrect indication for PFO closure and the failure of minimally invasive surgery, the procedural mishap in this case could have been due to the inappropriate implantation of the first large device within the tunnel. It would have been better to deploy the same large device in the most central fenestration, covering the PFO and a greater part of the remaining mfASA at the same time.

PFO-spectrum disorder: two different cerebrovascular diseases in patients with PFO as detected by AI brain imaging software

Background

Patent foramen ovale (PFO) is a prevalent cardiac remnant of fetal anatomy that may pose a risk factor for stroke in some patients, while others can present with asymptomatic white matter (WM) lesions. The current study aimed to test the hypothesis that patients with a PFO who have a history of stroke or transient ischemic attack, compared to those without such a history, have a different burden and distribution of cerebral WM hyperintensities. Additionally, we tested the association between PFO morphological characteristics and severity of shunt, and their impact on the occurrence of ischemic cerebral vascular events and on the burden of cerebral WM lesions.

Patients and methods

Retrospective, case-control study that included patients with PFO confirmed by transesophageal echocardiography. Right-to-left shunt size was assessed using transcranial Doppler ultrasound. Cerebral MRIs were analyzed for all participants using the semi-automated Quantib NDTM software for the objective quantification of WM lesions. WM lesions volume was compared between patients with and without a history of stroke. Additionally, the anatomical characteristics of PFOs were assessed to explore their relation to stroke occurrence and WM lesions volume.

Results

Of the initial 264 patients diagnosed with PFO, 67 met the inclusion criteria and were included in the analysis. Of them, 62% had a history of PFO-related stroke/TIA. Overall burden of WM lesions, including stroke volume, was not significantly different (p = 0.103). However, after excluding stroke volume, WM lesions volume was significantly higher in patients without stroke (0.27 cm3, IQR 0.03-0.60) compared to those with stroke/TIA (0.08 cm3, IQR 0.02-0.18), p = 0.019. Patients with a history of PFO-related stroke/TIA had a tendency to larger PFO sizes by comparison to those without, in terms of length and height, and exhibited greater right-to-left shunt volumes.

Discussion

We suggest that PFO may be associated with the development of two distinct cerebrovascular conditions (stroke and "silent" WM lesions), each characterized by unique imaging patterns. Further studies are needed to identify better the "at-risk" PFOs and gain deeper insights into their clinical implications.

Changes in cerebral autoregulation, stroke-related blood biomarkers, and autonomic regulation after patent foramen ovale closure in severe migraine patients

AIMS

This study aimed to investigate changes in dynamic cerebral autoregulation (dCA), 20 stroke-related blood biomarkers, and autonomic regulation after patent foramen ovale (PFO) closure in severe migraine patients.

METHODS

Patent foramen ovale severe migraine patients, matched non-PFO severe migraine patients, and healthy controls were included. dCA and autonomic regulation were evaluated in each participant at baseline, and within 48-h and 30 days after closure in PFO migraineurs. A panel of stroke-related blood biomarkers was detected pre-surgically in arterial-and venous blood, and post-surgically in the arterial blood in PFO migraineurs.

RESULTS

Forty-five PFO severe migraine patients, 50 non-PFO severe migraine patients, and 50 controls were enrolled. The baseline dCA function of PFO migraineurs was significantly lower than that of non-PFO migraineurs and controls but was rapidly improved with PFO closure, remaining stable at 1-month follow-up. Arterial blood platelet-derived growth factor-BB (PDGF-BB) levels were higher in PFO migraineurs than in controls, which was immediately and significantly reduced after closure. No differences in autonomic regulation were observed among the three groups.

CONCLUSION

Patent foramen ovale closure can improve dCA and alter elevated arterial PDGF-BB levels in migraine patients with PFO, both of which may be related to the preventive effect of PFO closure on stroke occurrence/recurrence.

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.

A Nomogram for Predicting Patent Foramen Ovale-Related Stroke Recurrence

Background

The high prevalence of patent foramen ovale (PFO) in cryptogenic stroke suggested a stroke-causing role for PFO. As risk factors for recurrence of such stroke are not recognized, clinicians cannot sufficiently identify, treat, and follow-up high-risk patients. Therefore, this study aimed to establish a prediction model for PFO-related stroke recurrence.

Methods

This study included 392 patients with PFO-related stroke in a training set and 164 patients with PFO-related stroke in an independent validation set. In the training set, independent risk factors for recurrence identified using forward stepwise Cox regression were included in nomogram 1, and those identified using least absolute shrinkage and selection operator(LASSO)regression were included in nomogram 2. Nomogram performance and discrimination were assessed using the concordance index (C-index), area under the curve (AUC), calibration curve, and decision curve analyses (DCA). The results were also validated in the validation set.

Results

Nomogram 1 was based on homocysteine (Hcy), high-sensitivity C-reactive protein (hsCRP), and albumin (ALB), and nomogram 2 was based on age, diabetes, hypertension, right-to-left shunt, ALB, prealbumin, hsCRP, and Hcy. The C-index of nomogram 1 was 0.861, which was not significantly different from that of nomogram 2 (0.893). The 2- and 5-year AUCs of nomogram 1 were 0.863 and 0.777, respectively. In the validation set, nomogram 1 still had good discrimination (C-index, 0.862; 2-year AUC, 0.839; 5-year AUC, 0.990). The calibration curve showed good homogeneity between the prediction by nomogram 1 and the actual observation. DCA demonstrated that nomogram 1 was clinically useful. Moreover, patients were successfully divided into two distinct risk groups (low and high risk) for recurrence rate by nomogram 1.

Conclusions

Nomogram 1, based on Hcy, hsCRP, and ALB levels, provided a more clinically realistic prognostic prediction for patients with PFO-related stroke. This model could help patients with PFO-related stroke to facilitate personalized prognostic evaluations.

Ischemic Stroke and Pulmonary Arteriovenous Malformations: A Review

The potential of covert pulmonary arteriovenous malformations (PAVMs) to cause early onset, preventable ischemic strokes is not well known to neurologists. This is evident by their lack of mention in serial American Heart Association/American Stroke Association (AHA/ASA) Guidelines and the single case report biased literature of recent years. We performed PubMed and Cochrane database searches for major studies on ischemic stroke and PAVMs published from January 1, 1974, through April 3, 2021. This identified 24 major observational studies, 3 societal guidelines, 1 nationwide analysis, 3 systematic reviews, 21 other review/opinion articles, and 18 recent (2017-2021) case reports/series that were synthesized. Key points are that patients with PAVMs have ischemic stroke a decade earlier than routine stroke, losing 9 extra healthy life-years per patient in the recent US nationwide analysis (2005-2014). Large-scale thoracic CT screens of the general population in Japan estimate PAVM prevalence to be 38/100,000 (95% confidence interval 18-76), with ischemic stroke rates exceeding 10% across PAVM series dating back to the 1950s, with most PAVMs remaining undiagnosed until the time of clinical stroke. Notably, the rate of PAVM diagnoses doubled in US ischemic stroke hospitalizations between 2005 and 2014. The burden of silent cerebral infarction approximates to twice that of clinical stroke. More than 80% of patients have underlying hereditary hemorrhagic telangiectasia. The predominant stroke mechanism is paradoxical embolization of platelet-rich emboli, with iron deficiency emerging as a modifiable risk factor. PAVM-related ischemic strokes may be cortical or subcortical, but very rarely cause proximal large vessel occlusions. Single antiplatelet therapy may be effective for secondary stroke prophylaxis, with dual antiplatelet or anticoagulation therapy requiring nuanced risk-benefit analysis given their risk of aggravating iron deficiency. This review summarizes the ischemic stroke burden from PAVMs, the implicative pathophysiology, and relevant diagnostic and treatment overviews to facilitate future incorporation into AHA/ASA guidelines.

Uncertainties and Controversies in the Management of Ischemic Stroke and Transient Ischemic Attack Patients With Patent Foramen Ovale

Multiple randomized clinical trials have demonstrated the benefit of patent foramen ovale closure over medical therapy alone for patients who have had a stroke that has been attributed to the patent foramen ovale. Nevertheless, there are many areas of uncertainty and controversy related to patient selection, pathophysiology, diagnosis, and treatment. We summarize the available data on these challenging topics and attempt to provide some clarity and future directions for clinicians and investigators.