Spontaneous large right-to-left shunt and migraine headache with aura are risk factors for recurrent stroke in patients with a patent foramen ovale

Importance of Persistent Right-to-Left Shunt After Patent Foramen Ovale Closure in Cryptogenic Stroke Patients

Percutaneous closure of patent foramen ovale (PFO) is widely performed to prevent recurrent stroke or transient ischemic attack in patients with cryptogenic stroke. However, the influence of different degrees of right-to-left shunting (RLS) has rarely been reported. We retrospectively evaluated the cases of 268 patients with cryptogenic stroke who underwent PFO closure at our hospital from April 2012 through April 2015. In accordance with RLS severity, we divided the patients into 2 groups: persistent RLS during normal breathing and the Valsalva maneuver (n=112) and RLS only during the Valsalva maneuver (n=156). Baseline characteristics, morphologic features, and procedural and follow-up data were reviewed. The primary endpoint was stroke or transient ischemic attack. More patients in the persistent group had multiple or bilateral ischemic lesions, as well as a larger median PFO diameter (2.5 mm [range, 1.8-3.9 mm]) than did patients in the Valsalva maneuver group (1.3 mm [range, 0.9-1.9 mm]) (P <0.001). Atrial septal aneurysm was more frequent in the persistent group: 25 patients (22.3%) compared with 18 (11.5%) (P=0.018). Three patients in the persistent group had residual shunting. The annual risk of recurrent ischemic stroke was similar between groups: 0.298% (persistent) and 0.214% (Valsalva maneuver). Our findings suggest that patients with persistent RLS have more numerous severe ischemic lesions, larger PFOs, and a higher incidence of atrial septal aneurysm than do those without. Although our persistent group had a greater risk of residual shunting after PFO closure, recurrence of ischemic events did not differ significantly from that in the Valsalva maneuver group.

Impact of Patent Foramen Ovale Anatomic Features on Right-to-Left Shunt in Patients with Cryptogenic Stroke

The purpose of this study was to investigate the impact of the morphologic characteristics of patent foramen ovale (PFO) on right-to-left shunt (RLS) in patients with PFO and cryptogenic stroke using transesophageal echocardiography and saline contrast transthoracic echocardiography (c-TTE). Of the 165 patients with PFO stroke, both the height and the length of PFO in the provoked RLS group were smaller than those in the constant RLS group. PFO height, interatrial septum mobility and proportion of atrial septal aneurysms were greater in the severe RLS group than in the mild and moderate RLS groups. Multivariate analysis revealed that PFO height and interatrial septum mobility were independent predictors of severe RLS. Multiple territorial ischemic lesions were more common in the severe RLS or constant RLS group. Our findings indicated that the severity of RLS was related to the anatomic features in PFO, inducing different cerebral ischemia lesion patterns in cryptogenic stroke patients with PFO.

Right-to-Left Shunt Does Not Increase the Incidence of Silent Lacunar Infarcts in Patients with Migraine

Right-to-left shunt (RLS) is associated with cryptogenic stroke and migraine. Herein we investigated the relationship between RLS and silent lacunar infarcts in patients with migraine. A total of 263 patients with migraine who met eligibility criteria were enrolled from January 2010 to December 2011, among which 127 subjects fell into RLS group. Baseline demographics were comparable between RLS and non-RLS groups (P > 0.05). The incidence of silent lacunar infarcts in RLS group was not significantly different from that of the non-RLS group (25.2% versus 21.3%, P > 0.05). Furthermore, we found that the incidence of silent lacunar infarcts in permanent and latent RLS subgroups was comparable with non-shunt RLS subgroup (28.6% versus 24% versus 21.3%, P > 0.05). Similarly, the incidence of silent lacunar infarcts in the non-RLS group, mild-shunt group, and large-shunt group was also comparable (21.3% versus 23.8% versus 29.3%, P > 0.05). In addition, RLS did not increase the incidence of silent lacunar infarcts in migraine patients with elder age (<50 years age group: 15.8% versus 17.9%; ≥50 years age group: 53.1% versus 37.5%, both P > 0.05). In conclusion, RLS does not increase the incidence of silent lacunar infarcts in patients with migraine. Further prospective studies are warranted to validate this finding.

Pathophysiology of paradoxical embolism: evaluation of the role of interatrial septum anatomy based on the intracardiac echocardiography assessment of patients with right-to-left shunting

BACKGROUND

Detailed anatomic variants of the interatrial septum in patients with right-to-left shunt and contribution of specific anatomies to the risk of ischaemic recurrences has not yet been comprehensively classified.

OBJECTIVE

To report a classification of the anatomic variants of the interatrial septum as observed by intracardiac echocardiography and its correlation with clinical and functional characteristics.

METHODS

We retrospectively reviewed the medical and instrumental data of 520 consecutive patients (mean age 44±15. 5 years, 355 women) who had over a 10-year period undergone intracardiac echocardiography and right-to-left shunt catheter-based closure. The four main features used to analyse were: (a) diameter of the oval fossa, (b) presence and length of the channel, (c) presence and degree of atrial septal aneurysm, and (d) rim thickness. The presence of Eustachian valve was also tabulated.

RESULTS

The combinations of interatrial septum anatomical features were classified into six main anatomical subgroups. Recurrent embolism, multiple ischaemic foci on brain magnetic resonance imaging, high grade shunt, and permanent shunt before transcatheter closure procedure were associated with type 2, type 4, and type 6. Type 4 anatomical subtype (OR 4.1, 1.5-8 [95% CI], p<0.001) and type 2+presence of Eustachian valve (OR 4.3, 1.6-9 [95% CI], p<0.001) were the strongest predictors of recurrent ischaemic events before transcatheter closure.

CONCLUSION

Our study showed that interatrial septum anatomy greatly differs among patients with right-to-left shunt, as well as the risk of ischaemic recurrences in different anatomies.

Compromised dynamic cerebral autoregulation in patients with a right-to-left shunt: a potential mechanism of migraine and cryptogenic stroke

BACKGROUND AND PURPOSE

The relationship between right-to-left shunts (RLS) and migraine and cryptogenic stroke is not well understood. In this study, we investigated whether RLS are associated with impairment of dynamic cerebral autoregulation (dCA), which may play a role in migraine and cryptogenic stroke.

METHODS

Sixty-six migraineurs were enrolled in the study, including 36 non-RLS patients and 30 RLS patients. Non-invasive continuous cerebral blood flow velocity and arterial blood pressure were recorded simultaneously from each patient by using transcranial Doppler and servo-controlled plethysmograph, respectively. Transfer function analysis was applied to derive autoregulatory parameters of gain, phase difference (PD), and autoregulation index.

RESULTS

The PD in migraineurs with RLS was 50.6 ± 22.9 degrees, which was significantly lower than that observed in the non-RLS group (67.2 ± 18.2 degrees, P<0.001). The PD in the large RLS group (45.4 ± 22.6 degrees) was significantly lower than that of the small RLS group (64.9 ± 17.1 degrees, P<0.01) and non-RLS group (P<0.001); however, the PD in the small RLS group was similar to that of the non-RLS group. The PD in the permanent group (48.8 ± 19.9 degrees) was similar to that of the latent group (52.6 ± 26.1 degrees), and both were significantly lower than that of the non-RLS group (P<0.05). The autoregulation index results were similar to the PD findings.

CONCLUSIONS

dCA is impaired in migraineurs with large RLS, and this may represent a potential mechanism linking RLS, migraine, and cryptogenic stroke.

Toward understanding the atrial septum in cryptogenic stroke

Ischemic stroke in younger people is common, and often remains unexplained. There is a well-documented association between unexplained stroke in younger people, and the presence of a patent foramen ovale. Therefore, in the absence of a clear cause of stroke, the heart is often assessed in detail for such lower risk causes of stroke. This usually involves imaging with a transesophageal echo, and investigation for a right-to-left shunt. An understanding of the anatomy of the atrial septum, and its associated abnormalities, is important for the stroke neurologist charged with decision making regarding appropriate secondary prevention. In this paper, we review the development and anatomy of the right heart with a focus on patent foramen ovale, and other associated abnormalities. We discuss how the heart can be imaged in the case of unexplained stroke, and provide examples. Finally, we suggest a method of investigation, in light of the recent European Association of Echocardiography guidance. Our aim is to provide the neurologist with an understanding on how the heart can be investigated in unexplained stroke, and the significance of abnormalities detected.

Permanent right-to-left shunt is the key factor in managing patent foramen ovale

OBJECTIVES

We sought to prospectively evaluate risk of stroke and impact of transcatheter patent foramen ovale (PFO) closure in patients with permanent right-to left shunt compared with those with Valsalva maneuver-induced right-to-left shunt.

BACKGROUND

Pathophysiology and properly management of PFO still remain far from being fully clarified: in particular, the contribution of permanent right-to-left shunt remains unknown.

METHODS

Between March 2006 and October 2010, we enrolled 180 (mean age 44 ± 10.9 years, 98 women) of 320 consecutive patients referred to our center for transcatheter PFO closure, who had spontaneous permanent right-to-left shunt on transcranial Doppler and transthoracic/transesophageal echocardiography. All patients fulfilled the standard current indications for transcatheter closure and underwent preoperative transesophageal echocardiography and brain magnetic resonance imaging, with subsequent intracardiac echocardiographic-guided transcatheter PFO closure. We compared the clinical echocardiographic characteristics of these patients (Permanent Group) with the rest of 140 patients with right-to-left shunt only during Valsalva maneuver (Valsalva Group).

RESULTS

Compared with the Valsalva Group patients, patients of the Permanent Group had increased frequency of multiple ischemic brain lesions on magnetic resonance imaging, previous recurrent stroke, previous peripheral arteries embolism, migraine with aura, and-more frequently-atrial septal aneurysm and prominent Eustachian valve. The presence of permanent shunt confers the highest risk of recurrent stroke (odds ratio: 5.9, 95% confidence interval: 2.0 to 12, p < 0.001). No differences were recorded between the 2 groups with regard to recurrence of ischemic events after the closure procedure.

CONCLUSIONS

Despite its small-sample nature, our study suggests that patients with permanent right-to-left shunt have potentially a higher risk of paradoxical embolism compared with those without.

Percutaneous closure of patent foramen ovale in patients with anatomical and clinical high-risk characteristics: long-term efficacy and safety

BACKGROUND

Transcatheter closure of patent foramen ovale (PFO) is a widespread procedure, but no randomized study on its outcome in high-risk patients is available. Our aims were to determine the efficacy and safety of this procedure in a cohort of high-risk patients through the observation of clinical adverse events and residual shunt, to evaluate the impact of transesophageal echocardiography (TEE) guidance during the procedure, and investigate the relationship between the anatomical and clinical characteristics and the outcome.

METHODS AND RESULTS

Ninety-five patients underwent PFO closure for cryptogenic cerebral ischemia; each of them presented one or more of the following risk factors: recurrent cerebral ischemia (9.5%), atrial septum aneurysm (ASA, 74.5%), prominent Eustachian valve (EV, 23.2%), severe basal shunt (9.5%), thrombophilic factors (20%), deep vein thrombosis (4.2%). The procedure was performed successfully in all patients. On median follow-up of 18 months, the neurologic recurrent events rate was 1.1% and the major adverse cardiac event (MACE) rate was 1.1%. At 6-month TEE follow-up, the residual shunt rate was 12.6% (3.1% moderate to severe). A significant correlation was found between residual shunt and prominent EV alone (P = 0.036) or in association with ASA (P = 0.021). All adverse events occurred in the first 8 months, and the event-free survival rate was 86.2%.

CONCLUSIONS

Our study suggests that transcatheter PFO closure is a safe procedure even in a selected population of high-risk patients, presenting satisfactory efficacy and safety. The presence of a prominent EV alone or with ASA correlates positively with the occurrence of residual shunt.

Headache and cardiovascular disease: old symptoms, new proposals

Evidence of a link between headache symptoms and cardiovascular disease has rapidly grown in recent years and it is of utmost importance for the cardiologist and neurologist to be aware of this intimate connection. A brief overview of different cardiovascular diseases (namely hypertension, stroke, coronary heart disease, patent foramen ovale, atrial septal defects, atrial septal aneurisms, mitral valve prolapse, and aortic and carotid disease) that may be related to headache is presented in this article. Proposed pathophysiological mechanisms for this association and landmark studies are reviewed and discussed.

Migraine and patent foramen ovale: state of the science

Migraine is a prominent cause of recurrent pain, affecting 12% of the population. In several case series, approximately 50% of migraineurs with aura were found to have patent foramen ovale (PFO). The pathophysiological mechanism is speculated to be passage of microemboli and vasoactive chemicals through the PFO, thereby evading pulmonary filtration and triggering migraine symptoms. This article presents the results of retrospective and prospective research studies documenting the effects of PFO closure on migraine symptoms and presents emerging theories on possible pathologic mechanisms that may partially explain the increased risk of ischemic stroke in the migraine population. Finally, evidence-based recommendations are presented for health care providers for managing patients who have migraine and PFO.

Ongoing paradoxical particulate embolism during megaprosthesis placement

Pulmonary embolism (PE) by solid particles is an infrequent complication encountered during orthopedic procedures. A patent foramen ovale (PFO) allows embolic material into the left-sided circulation, potentially affecting several organs. A case of a 33-year-old woman undergoing total proximal femur resection with megaprosthesis reconstruction is presented. Towards the end of surgery, cement was injected to stabilize the prosthesis. Echodense particulate matter was first seen in the right atrium, subsequently in the right ventricle, and also in significant quantities in the left atrium and ventricle. This was accompanied by significant changes in partial pressure of arterial oxygen. Despite the aforementioned disturbances, hemodynamic stability was observed throughout the event. Postoperative follow-up showed persistent hypoxemia but no other abnormalities. This intriguing case of embolism via particulate material in a patient with PFO during hip replacement surgery allows review of the physiology and pathophysiology of PE phenomena.

Embolic implications of combined risk factors in patients with patent foramen ovale (the CARPE criteria): consideration for primary prevention closure?

BACKGROUND

Large patent foramen ovale (PFO), spontaneous right-to-left shunt, large atrial septal aneurysm (ASA), coagulation abnormalities, and prominent eustachian valve (EV) have all been independently suggested as risk factors for recurrent stroke. We sought to retrospectively evaluate risk of stroke and impact of transcatheter PFO closure in patients with concurrent large PFO, spontaneous right-to-left shunt, large ASA, coagulation abnormalities, and prominent EV.

METHODS

Between March 2006 and October 2008, 36 (mean age 44 +/- 10.9 years, 28 females) out of 120 consecutive patients referred to our center for transcatheter PFO closure had concomitant diagnosis of (a) large PFO on transcranial Doppler (TCD) and transesophageal echocardiography (TEE), (b) spontaneous right-to-left shunt on TCD, (c) large ASA, (d) prominent EV, and (e) coagulation abnormalities. All patients fulfilled the standard current indications for transcatheter closure and underwent preoperative TEE and brain magnetic resonance imaging (MRI), with subsequent intracardiac echocardiographic-guided transcatheter PFO closure.

RESULTS

Compared to the remaining PFO population in the same period, patients with all five concomitant features had more ischemic brain lesions on MRI, previous history of recurrent stroke, more frequently a history of venous thromboembolism, and more severe migraine with aura. The concomitance of all the features confers the highest risk of recurrent stroke (OR 9.9, 3.0-18 [95% CI], P < 0.001).

CONCLUSIONS

Despite its small sample size and nonrandomized retrospective nature, this is the first study to suggest that patients with concurrence of all the investigated characteristics have potentially a higher risk of stroke compared to controls. We thus propose the CARP criteria as a basis for further larger, longitudinal studies to assess the potential benefits of transcatheter closure in this patient subset in the absence of clinical recurrent stroke.

Migraine and patent foramen ovale: connecting flight or one-way ticket?

CONTEXT

The genesis of migraine in patients with patent foramen ovale (PFO) and its relationship with paradoxical stroke is still debated. Some authors agree that migraine with aura and PFO have higher coincidences than would be expected by chance and that it is possible that both conditions are inherited together.

OBJECTIVE

The present review aims to make a comprehensive attempt at clarifying the PFO-migraine connection in light of recent evidence from literature.

EVIDENCE ACQUISITION

A Medline search using both OVID and PubMed was performed by searching for literature in English regarding randomized trials, prospective cohort studies, meta-analyses, reviews and editorials about PFO and migraine between 1998 and 2008. Search key words were 'migraine' and 'patent foramen ovale' matched with 'prevalence', 'echocardiography', 'transcranial Doppler ultrasound', 'magnetic resonance imaging', 'coagulation abnormalities' and 'transcatheter closure treatment'. Additional reference material was obtained from the proceedings of relevant conferences on PFO and migraine, and the author's personal experience.

EVIDENCE SYNTHESIS

Echocardiographic, transcranial Doppler and MRI studies suggest that migraine patients are at higher risk of stroke compared with the normal population and often have white matter brain lesions on MRI. A large proportion of PFO patients have migraine, in particular migraine with aura, and migraine with aura patients plus PFO have larger shunts compared with migraine-free patients. It has been suggested that patients with migraine and large PFO have an increased risk of paradoxical embolism. Most patients with PFO and migraine respond well to transcatheter closure and this fact is unlikely to be caused just by a placebo effect.

CONCLUSIONS

Although many gray areas are still present, migraine with aura and large PFO seem to be strictly related to both anatomic and functional states at least in a proportion of patients.

Migraine and stroke: current perspectives

OBJECTIVE

The purpose of this article is to review the latest concepts regarding migraine and ischemic stroke. In addition, focal neurological deficits and MRI changes in migraine patients will be reviewed.

METHODS

A PubMed search of neurological literature pertaining to this study was conducted using specific keyword search terms pertaining to migraine and ischemic stroke.

RESULTS

Migraine, especially with aura, is a relative risk factor for stroke. Neuroimaging demonstrates the posterior circulation as being most vulnerable, although the reason for this distribution is unclear. Factors that may contribute to stroke in migraine include changes during cortical spreading depression with hyper- or hypoperfusion of neural tissue, vasospasm and endothelial dysfunction. Estrogen affects migraine expression as well as cerebral circulation, yet most women with migraine without aura are not at increased risk. Co-morbidity with patent foramen ovale can be mechanism of both disorders via presumed lack of filtration of microemboli or toxic substances; however, closure with reversal of right to left shunt seems to be more beneficial for cryptogenic stroke than migraine. Migraine and stroke are found in specific genetic disorders such as CADASIL, HERNS and MELAS giving clues to genetic factors. Stroke associated with migraine treatments such as ergots or triptans is rare, and usually associated with special circumstances such as overuse or concomitant thrombogenic conditions.

CONCLUSION

Although true migrainous infarction is rare, our understanding of the subtle associations between migraine and cerebrovascular behavior is expanding.

Frequency of migraine headache relief following patent foramen ovale "closure" despite residual right-to-left shunt

Retrospective studies have shown improvement in migraines after patent foramen ovale (PFO) closure. To date, no study has evaluated whether the completeness of closure affects headache status; therefore, the objective of this study was to evaluate the impact of residual right-to-left shunt (RLS) on migraine symptoms after transcatheter PFO closure in migraineurs with and without aura. This was a small-series, single-center, retrospective analysis of late follow-up data on 77 patients with presumed paradoxical embolism and migraine who underwent PFO closure for secondary stroke prevention. Power M-mode transcranial Doppler was used to assess RLS at baseline and 6 and 12 months after closure. A standardized migraine questionnaire was administered at baseline and 6, 12, and 24 months after closure. Fifty-five (71%) patients had migraine with aura. Final closure and migraine status were available for 67 patients; 23 (34%) had incomplete PFO closure, defined as 30 embolic tracks detected at final power M-mode transcranial Doppler examination (median 366 days, 95% confidence interval 332 to 474). Migraine relief (> or = 50% reduction in frequency) was independent of closure status (77% complete closure vs 83% incomplete closure, p = 0.76) at late follow-up (540 days, 95% confidence interval 537 to 711). Migraineurs with aura were 4.5 times more likely to experience migraine relief than migraineurs without aura. In conclusion, migraine relief may occur despite residual RLS after transcatheter PFO closure, which may suggest a reduction in RLS burden below a neuronal threshold that triggers migraine; however, this warrants further investigation. Migraine with aura may be an independent predictor of relief after PFO closure.

Migraineurs with patent foramen ovale have larger right-to-left shunt despite similar atrial septal characteristics

The objective of the study was to assess differences in proportion of large right-to-left shunt (RLS) and atrial septal characteristics between migraineurs and non-migraineurs referred for transcatheter closure of patent foramen ovale (PF0). This retrospective study took place in a large metropolitan medical centre. The patients were migraineurs with aura (n=52), migraineurs without aura (n=19) and non-migraineurs (n=149). RLS was evaluated before closure using bilateral power m-mode transcranial Doppler at rest and after calibrated, sustained Valsalva manoeuvre, and graded with a validated 0–5 scale. Intracardiac echocardiography was used to assess atrial septal characteristics. Migraineurs had a higher proportion of large RLS (Grade IV or V) than nonmigraineurs at rest and after calibrated Valsalva (rest, p=0.04; Valsalva, p=0.01). Atrial septal characteristics were similar between groups. Migraine is associated with larger RLS at rest and strain; however migraine status does not predict PFO characteristics.