Is the search for right-to-left shunt still worthwhile?

Every Patent Foramen Ovale Should Be Closed

At present, the patent foramen ovale (PFO) does not receive the deserved medical attention. The PFO poses a serious threat to health and even the life of mankind. The first respective case report in the medical literature dates back to the 19th century. It led to death. The fact that a PFO is present in roughly 25% of people underscores its overall potential to cause harm. Yet at the same time, the sheer number discourages the medical community from screening for it and from treating it. About 5% of the population have particularly dangerous forms of PFOs. Such PFOs portray a high enough risk for clinical events, the likes of death, stroke, myocardial infarction, or ocular, visceral, and peripheral embolism, to justify screening for them. Highly significant health incidents being at stake, it appears obvious that PFO closure should be used for primary prevention. This is supported by the fact that closing a PFO is the simplest intervention in cardiology, with presumably the highest clinical yield. Being mainly a preventive measure, PFO closure represents a mechanical vaccination. When closing PFOs for one of the rarer therapeutic indications (migraine, platypnea orthodeoxia, etc.), patients automatically profit from the collateral benefit of getting, at the same time, mechanically vaccinated for life against paradoxical embolism. Vice versa, closing a PFO for the prevention of paradoxical embolism betters or cures migraine or exercise dyspnea not infrequently, thereby improving quality of life as a collateral benefit.

Percutaneous Patent Foramen Ovale Closure: Stroke and Beyond

Over 750,000 individuals suffer from stroke annually in the United States, with 87% of these strokes being ischemic in nature. Roughly 40% of ischemic strokes occur in individuals 60 years of age or under. A quarter of all ischemic strokes have no identifiable cause despite extensive workup and are deemed cryptogenic in nature. Patent Foramen Ovales (PFO) has been postulated in stroke causation by either paradoxical embolization or platelet activation in the tunnel of the defect. The incidence of PFO is reported to be 15-25% in the general population but rises to 40% in patients with cryptogenic stroke. While the initial trials evaluating PFO closures were non-revealing, subsequent long-term follow-ups, as well as recent trials evaluating PFO closures in cryptogenic stroke patients 60 years of age or under, demonstrated the superiority of percutaneous closure compared to medical therapy alone, leading to FDA approval of PFO closure devices. In this review, we review the diagnosis of PFO, postulated stroke mechanisms, literature supporting PFO closure, patient selection for percutaneous closure, procedural considerations, and associated procedural complications.

Association of Shunt Size and Long-Term Clinical Outcomes in Patients with Cryptogenic Ischemic Stroke and Patent Foramen Ovale on Medical Management

INTRODUCTION

Patent foramen ovale (PFO) is a potential source of cardiac embolism in cryptogenic ischemic stroke, but it may also be incidental. Right-to-left shunt (RLS) size may predict PFO-related stroke, but results have been controversial. In this cohort study of medically-managed PFO patients with cryptogenic stroke, we aimed to investigate the association of shunt size with recurrent stroke, mortality, newly detected atrial fibrillation (AF), and to identify predictors of recurrent stroke.

METHODS

Patients with cryptogenic stroke who screened positive for a RLS using a transcranial Doppler bubble study were included. Patients who underwent PFO closure were excluded. Subjects were divided into two groups: small (Spencer Grade 1, 2, or 3; n = 135) and large (Spencer Grade 4 or 5; n = 99) shunts. The primary outcome was risk of recurrent stroke, and the secondary outcomes were all-cause mortality and newly detected AF.

RESULTS

The study cohort included 234 cryptogenic stroke patients with medically-managed PFO. The mean age was 50.5 years, and 31.2% were female. The median period of follow-up was 348 (IQR 147-1096) days. The rate of recurrent ischemic stroke was higher in patients with large shunts than in those with small shunts (8.1% vs. 2.2%, p = 0.036). Multivariate analyses revealed that a large shunt was significantly associated with an increased risk of recurrent ischemic stroke [aOR 4.09 (95% CI 1.04-16.0), p = 0.043].

CONCLUSIONS

In our cohort of cryptogenic stroke patients with medically managed PFOs, those with large shunts were at a higher risk of recurrent stroke events, independently of RoPE score and left atrium diameter.

Patent Foramen Ovale in Cryptogenic Ischemic Stroke: Direct Cause, Risk Factor, or Incidental Finding?

Patent foramen ovale (PFO) has been associated with cryptogenic stroke. There is conflicting data and it remains uncertain whether PFO is the direct cause, a risk factor or an incidental finding. Potential stroke mechanisms include paradoxical embolism from a venous clot which traverses the PFO, in situ clot formation within the PFO, and atrial arrhythmias due to electrical signaling disruption. Main risk factors linked with PFO-attributable strokes are young age, PFO size, right-to-left shunt degree, PFO morphology, presence of atrial septal aneurysm, intrinsic coagulation-anticoagulation systems imbalance, and co-existence of other atrial abnormalities, such as right atrial septal pouch, Eustachian valve and Chiari's network. These may act independently or synergistically, multiplying the risk of embolic events. The RoPE score, a scale that includes factors such as young age, cortical infarct location and absence of traditional stroke risk factors, is associated with the probability of a PFO being pathogenic and stroke recurrence risk after the index stroke. Multiple investigators have attempted to correlate other PFO features with the risk of PFO-related stroke, but further investigation is needed before any robust conclusions are reached. PFO presence in young patients with cryptogenic stroke should be considered as etiologically suspect. Caution should be exercised in interpreting the relevance of other PFO features.

[Patent foramen ovale with a license to kill]

A patent foramen ovale (PFO) is present in about one of four, and one of its dangerous forms (large or associated with atrial septal aneurysm, Eustachian valve, or Chiari network) in one of twenty people. About 140 years ago, the PFO was shown to have the potential to result in death due to stroke and also myocardial infarction. The described decrease of the prevalence of a PFO with age may be a consequence of this. Therefore, it comes somewhat as a surprise that the PFO is taken rather lightly by the medical community. Percutaneous PFO closure with implantable devices has been around for over two decades and since then has proven to be the simplest and safest technique in interventional cardiology. Nonetheless, it is rarely applied and not recommended in current guidelines except for a few situations. Countless nonrandomised comparisons have invariably pointed to a clinical benefit of PFO closure in the secondary prevention of paradoxical cerebral events in patients with or without competitive reasons for stroke. Even a survival benefit of PFO closure was shown in a comparison over 10 years. However, the first three publications of randomised trials were not significant in the protocolled sense. PFO closure did reduce recurrent events compared to medical therapy by up to 80% but the statistical significance postulated was only reached in one of the three trials when the results were analyzed as treated or per predefined subgroups, like patients with atrial septal aneurysm, large PFO, or all PFO closure patients compared to treatment with acetylsalicylic acid only. Recently, a preplanned longer-term analysis of this trial and two additional randomised trials including higher risk PFOs reached the hypothesised statistical significance. This may be a turning point in the attitude towards PFO closure. In addition, PFO closure improves migraine and dyspnoea in certain patients. It appears, though, that it will take time until the full potential of PFO closure will be reflected in respective guidelines and reimbursement algorithms and adequately exploited by referring physicians (mostly neurologists) and interventional cardiologists. This reluctance will continue to cost innumerable preventable strokes, myocardial infarctions, and deaths around the world. The low risk of PFO closure must be weighed against even death if a PFO is left open; it is much more likely that one regrets not having closed a PFO than having closed it.

Paroxysmal Symptoms As the First Manifestation of Multiple Sclerosis Mimicking a Transient Ischemic Attack: A Report of Two Cases

Paroxysmal symptoms are unusual manifestations of multiple sclerosis (MS). When presented as the first clinical manifestation, paroxysmal symptoms may easily be mistaken for transient ischemic attack (TIA). Previously, several cases of MS that reported with paroxysmal symptoms were misdiagnosed as TIA. Here, we report two additional cases, focusing on the clinical characteristics of paroxysmal symptoms in MS. Both cases had paroxysmal symptoms as their first manifestation; one presented with transient dizziness, left face numbness, and right limb weakness, and the other presented with episodic lightheadedness, blurred vision, nausea, palpitations, and tremulousness upon standing. Both of the patients' symptoms were mistaken for TIA at first, based on microembolic signals recorded by transcranial Doppler, but were later correctly diagnosed with MS based on neuroimaging and lumbar puncture. The paroxysmal symptoms responded to carbamazepine and were relieved completely after administration of intravenous methylprednisolone and interferon. Herein, we aim to summarize the differences between paroxysmal symptoms seen in MS and TIA, to facilitate a timely differential diagnosis and recommend an early appropriate treatment.

Different Valsalva Manoeuvre Procedures for the Diagnosis of Right-to-Left Shunt by Contrast-Transcranial Doppler

The main purpose of this study was to compare two contrast agent injection times during the Valsalva manoeuvre (VM) for the diagnosis of right-to-left shunt using contrast-transcranial Doppler (c-TCD). In total, 992 consecutive patients underwent testing. All patients underwent step 1, and then a coin toss was used to determine the order of steps 2 and 3. The following testing steps were repeated twice: (1) a contrast agent (CA) was infused at rest (CA at rest testing); (2) the VM was initiated immediately after CA injection and released 10 s after CA injection (CA pre-VM testing); and (3) a CA was injected 5 s after initiating the VM, which was released 5 s after CA injection (CA mid-VM testing). For the CA at rest, pre-VM and mid-VM groups, significant differences were observed in the positive right-to-left shunt diagnosis rates (11.49% vs. 23.08% vs. 26.11%, respectively, with an inter-group significance of p < 0.05) and grade classifications (p < 0.05). Although the times to first microbubble appearance were similar between the CA at rest and the CA pre-VM groups (8.96 ± 3.40 s vs. 8.42 ± 3.72 s, p > 0.05), it was shorter (6.4 ± 2.75 s, p < 0.05) for the CA mid-VM group than for the other two groups. For the c-TCD testing, the CA mid-VM group yielded different results for diagnosing right-to-left shunts relative to the CA pre-VM group.

Transcatheter Closure of Patent Foramen Ovale: A Single Center Experience

BACKGROUND

Percutaneous transcatheter closure (PTC) of patent foramen ovale (PFO) is implicated in cryptogenic stroke, transitional ischemic attack (TIA) and treatment of a migraine.

AIM

Our goal was to present our experience in the interventional treatment of PFO, as well as to evaluate the short and mid-term results in patients with closed PFO.

MATERIAL AND METHODS

Transcatheter closure of PFO was performed in 52 patients (67.3% women, mean age 40.7 ± 11.7 years). Patients were interviewed for subjective grading of the intensity of headaches before and after the PFO closure.

RESULTS

During 2 years of follow-up, there was no incidence of new stroke, TIA and/or syncope. Follow-up TCD performed in 35 patients showed complete PFO closure in 20 patients (57.1%). Out of 35 patients, 22 (62.9%) reported having a migraine before the procedure with an intensity of headaches at 8.1 ± 1.9 on a scale from 1 to 10. During 2 years of follow-up, symptoms of a migraine disappeared in 4 (18.2%) and the remaining 18 patients reported the significant decrease in intensity 4.8 ± 2.04 (p = 0.0001). In addition, following PFO closure the incidence of the headaches decreased significantly (p = 0.0001).

CONCLUSIONS

Percutaneous transcatheter closure of PFO is a safe and effective procedure showing mid-term relief of neurological symptoms in patients as well as significant reduction of migraine symptoms.

Effective Valsalva maneuvering during TCCD and unrevealed etiology of RLS

Either transcranial color-coded Doppler (TCCD) or contrast echocardiography (CE) is the bests of clinically applicable and reproducible methods to evaluate the functionality of right-to-left shunts that can be found in different localization on atrial septum. As the anatomical features of right-to-left shunts could vary in many forms, detection of RLS by functional tests may aid the clinician to do risk prediction and management of patients. Sensitivity of TCDD or CE can be increased by performing effective Valsalva maneuvering during the test procedure. Timing of RLS during the cardiac cycles may help interpreting about the etiology of RLS, atrial septum or intrapulmonary shunts. Intrapulmonary shunts have been recently reported to be associated with RLS and frequently overlooked unless the tests prolonged up to 10th cardiac beat. Migraine, cryptogenic strokes, and paradoxic embolism are closely associated with RLS which should be evaluated by the collaboration of cardiologists and neurologists. Success of diagnostic procedure depends on high suspicion of index for RLS and application of contrast-enhanced tests that are effectively performed at each step.