PFO and Stroke: What Are the Data?

Post-Market Clinical Follow-Up With the Patent Foramen Ovale Closure Device IrisFIT (Lifetech) in Patients With Stroke, Transient Ischemic Attack, or Other Thromboembolic Events

BACKGROUND

A patent foramen ovale (PFO) has been associated with embolic strokes and transient ischemic attacks (TIAs). Catheter closure of PFO is effective in preventing recurrent events. Residual shunts and procedure or device related complications can occur, including atrial fibrillation and thrombus formation. This study examines the initial experience with a new PFO closure device, the IrisFIT PFO-Occluder (Lifetech Scientific, Shenzhen, China).

METHODS

95 patients with indications for PFO closure underwent percutaneous closure with the IrisFIT PFO-Occluder. The primary endpoint was the rate of accurate device placement with no/small residual shunt at 3 or 6 months follow-up. All patients underwent transoesophageal echocardiography (TEE) after 1 to 6 months. In case of a residual shunt, an additional TEE was performed after 12 months. Clinical follow-up was performed up to a mean of 33.1 ± 3.6 months.

RESULTS

The device was successfully implanted in 95 (100%) patients with no relevant procedural complications. At final TEE follow-up (7.6 ± 3.9 months) the effective closure rate was 96.8% with 1 moderate and 2 large residual shunts. There were 8 cases of new onset atrial fibrillation and 2 TIAs. There were no cases of device embolization or erosion.

CONCLUSION

The IrisFIT occluder is a new PFO closure device with several advantages compared to other devices. In this small study cohort, technical success rate, closure rate and adverse event rate were comparable to other devices. The rate of new onset atrial fibrillation was higher in comparison to other studies and warrants further investigation.

Clinical and infarction patterns of PFO-related cryptogenic strokes and a prediction model

Objectives

The higher than expected PFO rate in CS patients has raised concerns that paradoxical embolism maybe the pathophysiologic mechanism for strokes. However, only a small proportion of pathogenic PFOs cause CS. Therefore, accurate recognition of patients with pathogenic PFOs among all CS patients could guide clinical decision making in selecting the most appropriate treatment. The aim of this study was to devise a new algorithm to stratify cryptogenic stroke (CS) patients into pathogenic patent foramen ovale (p‐PFO)‐ and non‐p‐PFO‐related patients.

Methods

A total of 1201 patients with acute ischemic stroke were recruited from two different medical centers, and 253 CS patients were identified. Of the 253 patients, 111 were diagnosed with PFO using contrast transcranial Doppler. Data on medical histories, neuroimaging and laboratory tests were compared in CS patients with or without PFO.

Results

Compared with PFO‐negative CS patients, PFO‐positive CS patients showed younger onset age, lower incidence of hypertension and dyslipidemia, characteristic infarction pattern in magnetic resonance imaging and specifically altered platelet activity and coagulation function. Based on the above information, we constructed a PFO judgment formula (Hr‐PFOJ) by means of feature weight estimation and predictive performance evaluation to predict pathogenic PFO in CS patients with a sensitivity of 76.3% and a specificity of 66.5%.

Interpretations

Hr‐PFOJ judgment formula is a useful screening tool for identification of patients with pathogenic PFO who may benefit from PFO‐related treatment.

Cardiac Emboli Documented by Intraoperative Transesophageal Echocardiogram During Administration of a Topical Hemostatic Agent Prior to Pedicle Subtraction Osteotomy

STUDY DESIGN

This is a case report.

OBJECTIVE

Describe the occurrence of cardiac emboli recorded on transesophageal echocardiogram (TEE) after the injection of a topical hemostatic agent into a vertebra prior to performing a pedicle subtraction osteotomy (PSO).

SUMMARY OF BACKGROUND DATA

Hemostasis during spinal surgery is critical for adequate visualization and to reduce the risk of perioperative complications. Adult spinal deformity surgery can involve performing PSOs which are useful in cases of fixed spinal deformities and are associated with increased blood loss secondary to epidural and cancellous bleeding. Prior to performing a PSO, a topical hemostatic agent can be injected into the vertebra through the pedicle screw pilot holes in an attempt to decrease cancellous bleeding. Injected hemostatic agents can pressurize the vertebral body similar to cementation in vertebroplasty and during fracture reaming and prosthetic implantation in the femur. Patients with cardiac defects such as patent foramen ovale or atrial septal defect may be more prone to systemic embolic events resulting in morbidity or mortality.

METHODS

We injected a topical hemostatic matrix agent through the pedicle screw pilot holes into the L1 vertebral body prior to performing a PSO while simultaneously recording with TEE.

RESULTS

The TEE recorded large visible emboli traveling through the heart into the pulmonary vasculature. The patient remained stable throughout the remainder of the case and a postoperative spiral computed tomography (CT) scan was negative for filling defects. The patient had an uneventful hospital course.

CONCLUSION

Questions remain about the exact consistency of these emboli, when they are most likely to occur, how much cardiopulmonary insult can be tolerated without resulting in complications, or how to prevent their occurrence. Patients undergoing spinal surgery with the plan to inject hemostatic matrix agents into the vertebral body may benefit from a preoperative TEE to reduce the risk of complications associated with embolic events, especially in patients with undiagnosed patent foramen ovale or atrial septal defect.

LEVEL OF EVIDENCE

5.

Prevalence of Patent Foramen Ovale in Ischaemic Stroke in Italy: Results of SISIFO Study

BACKGROUND

Although several authors have studied the association between patent foramen ovale (PFO) and ischaemic stroke, the matter is still controversial; few have suggested an association between cryptogenetic stroke and PFO, while others have denied this association. The aim of this study was to evaluate PFO prevalence in the whole ischaemic stroke population, independently from age and stroke subtypes and to identify the characteristics associated with the presence of PFO.

METHODS

SISIFO study was a multicenter, prospective, single-wave, cross-sectional survey conducted on consecutive patients with acute ischemic stroke admitted to selected clinical centres. Data regarding vascular risk factors were registered for each patient; all patients underwent computed tomography scan and/or magnetic resonance imaging of the brain; an electrocardiogram and standard laboratory blood tests were performed. A Doppler ultrasound study of extra-cranial arteries was performed too. The cases were classified according to TOAST and OCSP criteria. Each patient underwent transcranial Doppler or transcranial color-coded duplex sonography with bubble test as diagnostic tool for right-to-left-shunt. Where right-to-left shunt was detected, PFO presence was confirmed by echocardiography.

FINDINGS

1,130 consecutive patients were included. We found a PFO in 247 (21.9%; 95% CI, 19.5-24.3%) patients; PFO was present in 23.5% of patients with cryptogenic stroke and in 21.3% of patients with stroke of known causes; this difference was not statistically significant. At the univariate analysis, decreasing age, hypertension, diabetes mellitus, and atrial fibrillation, and stroke characteristics such as NIHSS, OCSP and TOAST were predictors of PFO presence. At the multivariate analysis, we found a significant interaction between age and OCSP syndrome. Being LACI the reference category, the prevalence of PFO in PACI and POCI decreased significantly along with age, whereas there was no change in TACI.

CONCLUSION

If any relationship exists between stroke and PFO, this is more likely in PACI and POCI at a younger age. Our results are consistent with recent findings that underline PFO alone must not be considered a significant independent predictor for stroke; so the presence of PFO alone doesn't permit rushed causal correlations or 'therapeutic aggressiveness'.

Cerebellar infarction in a patient with cerebral vein thrombosis and patent foramen ovale: brain-to-brain embolism?

Although the association between PFO and cryptogenic stroke is well shown in young adults, the causality is still unclear. The pathogenetic mechanism of ischemic stroke related to PFO is not entirely understood. Indeed, besides the well-known paradoxical embolism, formations of thrombi in situ, especially in the presence of ASA, a higher incidence of atrial fibrillation have been often observed. Cerebral sinus venous thrombosis may be due to local inflammation or to acquired or genetic thrombophilia including hyperhomocysteinemia. We report a case of a young man presenting with a cerebellar infarction probably secondary to a paradoxical brain-to-brain embolism, in which the only detectable embolic source was a cerebral vein thrombosis.

A case of paradoxical embolic ST-segment elevation myocardial infarction triggered by sleep apnea

This report describes an obese 39-year-old man who experienced ST-segment elevation myocardial infarction with total thrombotic occlusion of the right coronary artery. Culprit vessel flow was improved by aspiration. Data suggested that myocardial infarction had resulted from paradoxical embolus via a patent foramen ovale triggered by the Mueller maneuver, which had induced negative intrathoracic pressure following an acute increase of right-heart volume in the context of obesity and sleep-disordered breathing (SDB). Obesity is increasing among younger populations and it represents a risk for SDB and thrombosis. Thus, this mechanism should be included within the differential diagnosis for myocardial infarction in young patients.

Neurologic complications of cardiac surgery and interventional cardiac procedures

Neurologic complications of cardiac surgery and interventional cardiac procedures may affect the central nervous system or the peripheral nervous system. The most common central nervous system complications are strokes and seizures. This article provides a succinct neuroanatomic and pathophysiologic approach to a wide array of neurologic complications associated with cardiac procedures.