Is patent foramen ovale a modifiable risk factor for stroke recurrence?

Morphological Features of Patent Foramen Ovale Compared Between Older and Young Patients With Cryptogenic Ischemic Stroke

BACKGROUND

The morphology of a patent foramen ovale (PFO) with a high-risk for cryptogenic ischemic stroke (CS) is an important factor in the selection of patients for transcatheter closure, but the morphological features of PFO in older patients with a history of CS are less known because the most data are obtained from younger patients.

METHODS AND RESULTS

The study included 169 patients who had a history of CS and PFO. The prevalence of high-risk morphologies of PFO assessed by transesophageal echocardiography was compared between patients aged ≥60 years and patients aged <60 years. We also assessed the presence of septal malalignment of PFO on the aortic wall. The probability of CS due to PFO was evaluated using the PFO-Associated Stroke Causal Likelihood classification system. Patients aged ≥60 years had a significantly higher prevalence of atrial septal aneurysm than patients aged <60 years. The prevalence of large right-to-left shunt, long-tunnel of PFO, or Eustachian valve or Chiari's network was similar between patients aged ≥60 years and <60 years. Septal malalignment was observed more frequently in patients aged ≥60 years than in those <60 years old. Nearly 90% of patients aged ≥60 years were classified as 'possible' in the PFO-Associated Stroke Causal Likelihood classification system.

CONCLUSIONS

High-risk morphologies of PFO are common in older patients with a history of CS, as well as in younger patients.

Advances in the management of cardioembolic stroke associated with patent foramen ovale

Patent foramen ovale (PFO) describes a valve in the interatrial septum that permits shunting of blood or thrombotic material between the atria. PFOs are present in approximately 25% of the healthy population and are not associated with any pathology in the vast majority of cases. However, comparisons between patients with stroke and healthy controls suggest that PFOs may be causative of stroke in certain patients whose stroke is otherwise cryptogenic. Options for the diagnosis of PFO include transthoracic echocardiography, transesophageal echocardiography, and transcranial Doppler ultrasonography. PFOs associated with an interatrial septal aneurysm seem to be more strongly linked to risk of recurrent stroke. Therapeutic options for secondary stroke prevention in the setting of a PFO include antiplatelet therapy, anticoagulation, and percutaneous device closure. Recent randomized clinical trials suggest that percutaneous closure reduces the subsequent risk of stroke in appropriately selected patients, with a large relative benefit but small absolute benefit. Referral for percutaneous PFO closure should therefore be considered in certain patients after a multidisciplinary, patient centered discussion. Areas for future study include structural biomarkers to aid in determining the role of PFO closure in older people with possible PFO associated stroke, the role of direct oral anticoagulants, and very long term outcomes after device closure.

Uses of ultrasound in stroke prevention

Ultrasound methods are useful in stroke prevention in several ways. Measurement of carotid plaque burden, as either total plaque area (TPA) or total plaque volume (TPV) are strong predictors of cardiovascular risk: much stronger than intima-media thickness, which does not represent true atherosclerosis, but a biologically and genetically distinct phenotype. Measurement of plaque burden is also useful for the study of genetics, and of new risk factors such as toxic products of the intestinal microbiome. Carotid plaque burden is highly correlated with and as predictive of risk as coronary calcium scores, but is less costly and does not require radiation. Furthermore, because carotid plaques change in time over a period of months, they can be used for a new approach to vascular prevention: "Treating arteries instead of treating risk factors". In high-risk patients with asymptomatic carotid stenosis (ACS), this approach, implemented in 2003 in our clinics, was associated with a >80% reduction of stroke and myocardial infarction over 2 years. "Treating arteries without measuring plaque would be like treating hypertension without measuring blood pressure". Ultrasound methods can also be used to assess plaque vulnerability, by detecting echolucency, ulceration and plaque inhomogeneity on assessment of plaque texture. Transcranial Doppler (TCD) embolus detection is useful for risk stratification in patients with ACS; patients with two or more microemboli in an hour of monitoring have a 1-year risk of 15.6%, vs. 1% without microemboli, so this very clearly distinguishes which patients with ACS could benefit from intervention. TCD saline studies are more sensitive than trans-esophageal echocardiography for detection of patent foramen ovale, and more predictive of recurrent stroke. These methods should be more widely used, to reduce the increasing burden of stroke in our aging populations.

Acute cerebral infarction with acute myocardial infarction due to patent foramen ovale: A case report

RATIONALE

Patent foramen ovale (PFO) is not considered to be the main cause of stroke and is classified as the infarction of undetermined cause. The relationship between PFO and cerebral embolism is still unclear and cerebral embolism accompanied with coronary artery embolization in PFO patient is rare. In this case, we reported a patient with PFO suffered acute cerebral and myocardial infarction simultaneously, and analyzed the source of emboli and potential pathogenesis.

PATIENT CONCERNS

A 53-year-old female presented with chief complaints of intermittent palpitations and chest tightness for 6 years, aggravated for 3 days.

DIAGNOSES

During the hospitalization, acute cerebral infarction and acute myocardial infarction occurred at the same time in the patient. The patient felt paroxysmal abdominal pain repeatedly. Finally, we detected PFO in the patient INTERVENTIONS:: Double antiplatelet therapy was given to the patient of acute cerebral and myocardial infarction with PFO.

OUTCOMES

Two weeks after the onset of the disease, the condition was relatively stable. But after 2 months, the patient experienced repeated heart failure, transthoracic echocardiography manifested no significant change in the PFO gap but significant cardiac function reduction.

LESSONS

Although a growing number of people are aware that PFO is a risk factor for arterial embolization especially when coexisting with atrial septal aneurysm, a significant proportion of patients have paradoxical embolism after PFO closure. Therefore, transesophageal echocardiography should be routinely performed to find the possible cause of embolism when infarction of undetermined cause occurs, and PFO closure and anti-platelet aggregation or anticoagulant therapy should be given at the same time in order to reduce the occurrence of arterial thrombosis.

Advances in Stroke Prevention

There have been recent advances in stroke prevention in nutrition, blood pressure control, antiplatelet therapy, anticoagulation, identification of high-risk asymptomatic carotid stenosis, and percutaneous closure of patent foramen ovale. There is evidence that the Mediterranean diet significantly reduces the risk of stroke and that B vitamins lower homocysteine, thus preventing stroke. The benefit of B vitamins to lower homocysteine was masked by harm from cyanocobalamin among study participants with impaired renal function; we should be using methylcobalamin instead of cyanocobalamin. Blood pressure control can be markedly improved by individualized therapy based on phenotyping by plasma renin and aldosterone. Loss of function mutations of CYP2D19 impair activation of clopidogrel and limits its efficacy; ticagrelor can avoid this problem. New oral anticoagulants that are not significantly more likely than aspirin to cause severe bleeding, and prolonged monitoring for atrial fibrillation (AF), have revolutionized the prevention of cardioembolic stroke. Most patients (~90%) with asymptomatic carotid stenosis are better treated with intensive medical therapy; the few that could benefit from stenting or endarterectomy can be identified by a number of approaches, the best validated of which is transcranial Doppler (TCD) embolus detection. Percutaneous closure of patent foramen ovale has been shown to be efficacious but should only be implemented in selected patients; they can be identified by clinical clues to paradoxical embolism and by TCD estimation of shunt grade. “Treating arteries instead of treating risk factors,” and recent findings related to the intestinal microbiome and atherosclerosis point the way to promising advances in future.

Patent foramen ovale and cryptogenic stroke: diagnosis and updates in secondary stroke prevention

The patent foramen ovale (PFO), given its high prevalence in the general population and especially in patients with cryptogenic stroke, has long generated investigation and debate on its propensity for stroke by paradoxical embolism and its management for stroke prevention. The pendulum has swung for percutaneous PFO closure for secondary stroke prevention in cryptogenic stroke. Based on a review of current evidence, the benefit from PFO closure relies on careful patient selection: those under the age of 60 years with few to no vascular risk factors and embolic-appearing stroke deemed cryptogenic after thorough evaluation. As these data look towards influencing guideline statements and device approvals in the future, patient selection remains the crucial ingredient for clinical decision making and future trials.

Cardioembolic stroke: everything has changed

Historically, because of the difficulty of using warfarin safely and effectively, many patients with cardioembolic stroke who should have been anticoagulated were instead given ineffective antiplatelet therapy (or no antithrombotic therapy). With the arrival of new oral anticoagulants that are not significantly more likely than aspirin to cause severe haemorrhage, everything has changed. Because antiplatelet agents are much less effective in preventing cardioembolic stroke, it is now more prudent to anticoagulate patients in whom cardioembolic stroke is strongly suspected. Recent advances include the recognition that intermittent atrial fibrillation is better detected with more prolonged monitoring of the cardiac rhythm, and that percutaneous closure of patent foramen ovale (PFO) may reduce the risk of stroke. However, because in most patients with stroke and PFO the PFO is incidental, this should be reserved for patients in whom paradoxical embolism is likely. A high shunt grade on transcranial Doppler saline studies, and clinical clues to paradoxical embolism, can help in appropriate selection of patients for percutaneous closure. For patients with atrial fibrillation who cannot be anticoagulated, ablation of the left atrial appendage is an emerging option. It is also increasingly recognised that high levels of homocysteine, often due to undiagnosed metabolic deficiency of vitamin B12, markedly increase the risk of stroke in atrial fibrillation, and that B vitamins (folic acid and B12) do prevent stroke by lowering homocysteine. However, with regard to B12, methylcobalamin should probably be used instead of cyanocobalamin. Many important considerations for judicious application of therapies to prevent cardioembolic stroke are discussed.

Patent foramen ovale closure versus medical therapy in cases with cryptogenic stroke, meta-analysis of randomized controlled trials

BACKGROUND

PFO is more common in cases with cryptogenic stroke compared to cases with no stroke or stroke of identified etiology. Several randomized controlled trials (RCTs) comparing PFO closure with medical therapy have been published with controversial findings.

METHODS

PubMed, Embase and Cochrane library databases were searched for RCT comparing PFO closure with medical therapy including antiplatelet therapy (aspirin or clopidogrel or combination) or anticoagulation. We identified 5 trials, including 3627 cases. The mean duration of follow-up was 4 years. Relative risk (RR) and 95% confidence intervals (CI) were calculated using fixed and random-effects models.

RESULTS

There was a significant reduction in the incidence of stroke among the PFO closure group compared to medical therapy group, 2.0 versus 4.2%, RR 0.48; 95% CI (0.3, 0.7), p < 0.001. The incidence of AF was higher in the PFO closure group compared to medical therapy group, 4.2 versus 0.7%, respectively, RR 5.9, 95% CI (3, 11), p < 0.001. After exclusion of oral anticoagulants cases (19%), analysis showed a lower incidence of stroke in the PFO closure group (2%) compared to antiplatelet therapy (5.2%), RR 0.4; 95% CI (0.3, 0.6), p < 0.001. There was no significant difference between both groups in the incidence of transient ischemic attacks or all-cause deaths.

CONCLUSION

PFO closure results in a significant reduction in the recurrence of ischemic stroke compared to medical therapy alone, primarily antiplatelet, among cases with PFO and cryptogenic stroke.

Atrial dyssynchrony and left atrial stiffness are risk markers for cryptogenic stroke in patients with patent foramen ovale

OBJECTIVE

The clinical and echocardiographic parameters associated with the risk predictors of cryptogenic stroke (CS) in patients with patent foramen ovale (PFO) still diverse and with a great debate. We hypothesized that left atrial stiffness (LASt) and atrial dyssynchrony may increase the risk of CS in patients with PFO.

METHODS

A total of 129 consecutive patients presented without clinical reasoning of stroke were recruited. Transesophageal echocardiographic assessment was performed to investigate the presence of PFO. PFO was identified in 52% (group I) and absent in 48% (group II). Utilizing speckle-tracking imaging LASt and atrial dyssynchrony was evaluated among patients with PFO (group I) vs those without PFO (group II).

RESULTS

LASt was significantly increased in group I patients compared with group II (P < .001). Likewise patients with PFO had a significant LA dyssynchrony compared with those in group II (P < .001). Interatrial dyssynchrony and left atrial dyssynchrony were correlated with LASt (r = .47 and 0.51, respectively; P < .001). Cardiac arrhythmias were significantly encountered in group I patients (at presentation and with Holter monitoring) P < .001. Besides significantly increase in atrial dyssynchrony and in LASt in patients with arrhythmias compared with those without (P < .001). ROC analysis revealed that LASt index ≥ 0.61 and LA dyssynchrony ≥ 23.5 predicts cardiac arrhythmias in CS patients with PFO with (AUC: 0.85 and 0.87, respectively, P < .001).

CONCLUSION

In conclusion, we demonstrated that LASt and atrial dyssynchrony might be risk markers of cryptogenic stroke in patients with PFO.

Surgical Treatment for Thrombus Straddling a Patent Foramen Ovale

We present a case of a 41-year-old female with deep vein thrombosis after abdominal surgery. The patient quickly developed severe pulmonary embolism and stroke representative of paradoxical embolism. Echocardiography showed a thrombus straddling a patent foramen ovale, which was confirmed intraoperatively. An accurate diagnosis and rapid treatment decisions are crucial for preventing patient deterioration in the form of new pulmonary embolisms or stroke.

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.

Association of Left Atrial Enlargement with Cortical Infarction in Subjects with Patent Foramen Ovale

Background and Purpose

Left atrial dysfunction has been reported in patients with patent foramen ovale (PFO). Here we investigated the role of left atrial dysfunction in the development of embolic stroke in patients with PFO.

Methods

We identified consecutive patients with embolic stroke of undetermined sources except for PFO (PFO+ESUS). Healthy subjects with PFO served as controls (PFO+control). A stratified analysis by 10-year age group and an age- and sex- matching analysis were performed to compare echocardiographic markers between groups. In the PFO+ESUS group, infarct patterns of PFO-related stroke were determined (cortical vs. cortico-subcortical) and analyzed in correlation with left atrial function parameters.

Results

A total of 118 patients and 231 controls were included. The left atrial volume indices (LAVIs) of the PFO+ESUS patients were higher than those of the PFO+controls in age groups of 40–49, 50–59, and 60–69 years (P<0.001, P=0.003, and P=0.027, respectively), and in the age- and sex-matched analysis (P=0.001). In the PFO+ESUS patients, a higher (>28 mL/m²) LAVI was more associated with the cortical infarct pattern (P=0.043 for an acute infarction and P=0.024 for a chronic infarction, both adjusted for age and shunt amount). The degree of right-to-left shunting was not associated with infarct patterns, but with the posterior location of acute infarcts (P=0.028).

Conclusions

Left atrial enlargement was associated with embolic stroke in subjects with PFO. Left atrial physiology might contribute to the development of PFO-related stroke and need to be taken into consideration for optimal prevention of PFO-related stroke.

Association of multiple ischemic strokes with mortality in incident hemodialysis patients: an application of multistate model to determine transition probabilities in a retrospective observational cohort

Background

Little is known about the effect of multiple, or subsequent, ischemic strokes in patients receiving hemodialysis.

Methods

We undertook a retrospective cohort study of incident hemodialysis patients with Medicare coverage who had experienced a first ischemic stroke. Factors associated with either a subsequent ischemic stroke or death following a first new stroke were modeled. A multistate model with Cox proportional hazards was used to predict transition probabilities from first ischemic stroke to either subsequent stroke or to death, and the demographic and clinical factors associated with the respective transition probabilities were determined. Effect of a subsequent ischemic stroke on survival was quantified.

Results

Overall, 12,054 individuals (mean age 69.7 years, 41.3 % male, 53.0 % Caucasian and 34.0 % African-American) experienced a first new ischemic stroke. Female sex was associated with an increased risk of having a subsequent ischemic stroke (adjusted hazard ratio 1.37, 95 % confidence intervals 1.20 – 1.56, P < 0.0001); African-Americans, as compared to Caucasians, had lower likelihood of dying after a first new ischemic stroke (0.81, 0.77 – 0.85, P < 0.0001). A subsequent stroke trended towards having a higher likelihood of transitioning to death compared to a first new ischemic stroke on dialysis (1.72, 0.96 – 3.09, P = 0.071). When a subsequent ischemic stroke occurs at 24 months, probability of survival dropped >15 %, in absolute terms, from 0.254 to 0.096, with substantial drops observed at subsequent time points such that the probability of survival was more than halved.

Conclusions

Likelihood of subsequent ischemic stroke and of survival in hemodialysis patients appears to vary by sex and race: females are more likely than males to experience a subsequent ischemic stroke, and Caucasians are more likely than African-Americans to die after a first new ischemic stroke. The risk of a transitioning to a subsequent stroke (after having had a first) increases until about 1 year, then decreases. Subsequent strokes are associated with decreased probability of survival, an effect which increases as time since first stroke elapses. This information may be of assistance to clinicians when counseling hemodialysis patients about the implications of recurrent ischemic stroke.

An Approach to Working Up Cases of Embolic Stroke of Undetermined Source

Background

From a therapeutic viewpoint, it is important to differentiate the underlying causes of embolism in patients with cryptogenic stroke, such as aortic arch atheroma, patent foramen ovale, and paroxysmal atrial fibrillation. We investigated the clinical and radiological characteristics of these 3 common causes of cryptogenic embolism to develop models for decision making in etiologic workups.

Methods and Results

A total of 321 consecutive patients with acute infarcts from cryptogenic embolism were included. Patients were divided into 3 groups—aortic arch atheroma (n=40), patent foramen ovale (n=153), and paroxysmal atrial fibrillation (n=128)—based on extensive cardiologic workups. We used a multinomial logistic regression analysis to detect the clinical and diffusion‐weighted imaging factors associated with the probability of aortic arch atheroma, patent foramen ovale, and paroxysmal atrial fibrillation. Clinical and radiological features differed among the groups. The patent foramen ovale group had a healthy vascular risk factor profile and showed posterior circulation involvement compared with other groups (P<0.01). In contrast, paroxysmal atrial fibrillation–related strokes had higher initial National Institutes of Health Stroke Scale (NIHSS) scores and larger lesions than the other groups (P<0.001). The aortic arch atheroma group had clinical features similar to those of the paroxysmal atrial fibrillation group but showed small lesions scattered in multiple vascular territories (P<0.001). Multivariate regression analysis revealed that age, initial NIHSS score, lesion size (≥20 mm), multiple (≥3) lesions, and involvement of posterior circulation or multiple vascular territories differentiated the 3 groups (pseudo, R²=0.656). The prediction ability of this model was validated in the external validation cohort (n=117, area under the curve 0.78).

Conclusions

Our data indicate that patients with cryptogenic embolic stroke show distinct clinical and radiological features depending on the underlying causes.

PFO: Button me up, but wait … Comprehensive evaluation of the patient

Patent foramen ovale (PFO) is a slit or tunnel-like communication in the atrial septum occurring in approximately 25% of the population. A wide number of pathological conditions have been linked to its presence, most notably, cryptogenic stroke (CS) and migraine. However, in the setting of a neurological event, it is not often clear whether the PFO is pathogenically related to the index event or an incidental finding. Therefore, a detailed analysis of several clues is needed for understanding PFO's clinical significance, with a frequent case-by-case decision about destination therapy. Indeed, the controversy about PFO's pathogenicity prompted a paradigm shift of research interest from medical therapy with antiplatelets or anticoagulants to percutaneous transcatheter closure, in secondary prevention. Observational data and meta-analysis of observational studies had previously suggested that PFO closure with a device was a safe procedure with a low recurrence rate of stroke. To date, however, recent randomized controlled trials have not shown the superiority of PFO closure over medical therapy. Thus, the optimal strategy for secondary prevention of paradoxical embolism in patients with a PFO remains unclear. Moreover, the latest guidelines for the prevention on stroke restricted indications for PFO closure to patients with deep vein thrombosis and high-risk of its recurrence. Given these recent data, in the present review, we critically discuss current treatment options, pointing out the role of a comprehensive patient evaluation in overcoming PFO closure restrictions and planning the best management for each patient.

Transcranial Doppler is Complementary to Echocardiography for Detection and Risk Stratification of Patent Foramen Ovale

BACKGROUND

In patients with patent foramen ovale (PFO), strategies are needed to identify patients at higher risk, who might benefit from PFO closure.

METHODS

We studied the frequency of detection of a right-to-left shunt (RLS) using transesophageal echocardiography (TEE) among patients with cryptogenic stroke and transcranial Doppler (TCD) to detect RLS, and analyzed the prediction of recurrent stroke according to TCD shunt grade, by detection of RLS on TEE, and by atrial septal aneurysm or mobility.

RESULTS

Among 334 patients with TCD, 69.8% were female, with a mean (SD) age of 53 (14) years, with a median follow-up of 420 days. There were 284 cases with TCD and TEE; 54 (19%) had atrial septal aneurysm or mobility. Echocardiography failed to show a RLS in 43 (15.1%) of the patients who had TCD and TEE, even in some patients with high-grade shunts on TCD: 18 (42%) were grade 3 or higher on TCD. Survival free of stroke or transient ischemic attack was predicted significantly by TCD shunt grade < 2 (P = 0.028), shunt grade < 3 (P = 0.03), and shunt grade < 4 (P < 0.0001); this was attenuated by adjustment for risk factors in Cox regression (P = 0.08). Neither RLS on TEE (P = 0.47), or atrial septal aneurysm or mobility (P = 0.08), predicted events.

CONCLUSIONS

Our findings suggest that TCD might be more sensitive than TEE for detection of RLS, which misses some cases with substantial RLS, and might be valuable for prediction of recurrent stroke or transient ischemic attack in patients with PFO. TCD complements TEE for management of suspected paradoxical embolism.

Patent Foramen Ovale and Stroke-Current Status

Patent foramen ovale (PFO) is growing in clinical interest because of a renewed focus on embolic stroke of undetermined source (ESUS), the PFO attributable fraction (the 10-point Risk of Paradoxical Embolism score), technical advances in PFO diagnosis, and the emergence of endovascular device closure as a treatment option. However, recent randomized controlled trials of the management of patients with ESUS and PFO failed to demonstrate the superiority of closure over medical treatment. The mechanisms of stroke other than paradoxical embolism may be important in patients with ESUS and PFO. This paper reviews the current understanding of the pathophysiology of stroke and therapeutic options in patients with PFO and ESUS.

Hypercoagulability and the risk of myocardial infarction and ischemic stroke in young women

BACKGROUND

Myocardial infarction (MI) and ischemic stroke (IS) are acute forms of arterial thrombosis and share some, but not all, risk factors, indicating different pathophysiological mechanisms.

OBJECTIVE

This study aims to determine if hypercoagulability has a differential effect on the risk of MI and IS.

PATIENTS AND METHODS

We reviewed the results from the Risk of Arterial Thrombosis in Relation to Oral Contraceptives study, a population-based case-control study involving young women (< 50 years) with MI, non-cardioembolic IS and healthy controls. From these data, relative odds ratios (ORIS /ORMI ) and their corresponding confidence intervals for all prothrombotic factors that were studied in both subgroups were calculated.

RESULTS

Twenty-nine prothrombotic risk factors were identified as measures of hypercoagulability. Twenty-two of these risk factors (21/29, 72%) had a relative odds ratios > 1; for 12 (41%), it was > 2; and for 5 (17%), it was > 2.75. The five risk factors with the largest differences in associations were high levels of activated factor XI (FXI) and FXII, kallikrein, the presence of lupus anticoagulans, and a genetic variation in the FXIII gene.

CONCLUSION

In young women, prothrombotic factors are associated more with the risk of IS than with MI risk, suggesting a different role of hypercoagulability in the mechanism leading to these two diseases.

The RoPE Score and Right-to-Left Shunt Severity by Transcranial Doppler in the CODICIA Study

BACKGROUND

For patients with cryptogenic stroke (CS) and patent foramen ovale (PFO), it is unknown whether the magnitude of right-to-left shunt (RLSh) measured by contrast transcranial Doppler (c-TCD) is correlated with the likelihood an identified PFO is related to CS as determined by the Risk of Paradoxical Embolism (RoPE) score. Additionally, for patients with CS, it is unknown whether PFO assessment by c-TCD is more sensitive for identifying RLSh compared with transesophageal echocardiography (TEE). Our aim was to determine the significance of RLSh grade by c-TCD in patients with PFO and CS.

METHODS

We evaluated patients with CS who had RLSh quantified by c-TCD in the Multicenter Study into RLSh in Cryptogenic Stroke (CODICIA) to determine whether there is an association between c-TCD shunt grade and the RoPE Score. For patients who underwent c-TCD and TEE, we determined whether there is agreement in identifying and grading RLSh between these two modalities.

RESULTS

The RoPE score predicted the presence versus the absence of RLSh documented by c-TCD (c-statistic = 0.66). For patients with documented RLSh by c-TCD, shunt severity was correlated with increasing RoPE score (rank correlation (r) = 0.15, p = 0.01). Among 293 patients who had both c-TCD and TEE performed, c-TCD was more sensitive (98.7%) for detecting RLSh. Of the 97 patients with no PFO identified on TEE, 28 (29%) had a large amount of RLSh seen on c-TCD.

CONCLUSIONS

For patients with CS, severity of RLSh by c-TCD is positively correlated with the RoPE score, indicating that this technique for shunt grading identifies patients more likely to have pathogenic rather than incidental PFOs. c-TCD is also more sensitive in detecting RLSh than TEE. These findings suggest an important role for c-TCD in the evaluation of PFO in the setting of CS.

Current status of percutaneous PFO closure

The clinical significance of persistent patent foramen ovale (PFO) is not well defined. Empirically, PFO has been associated with many clinical conditions. In cryptogenic stroke, migraine, and orthodeoxia/platypnea, a plausible biologic mechanism exists to support PFO closure as a possible treatment. Although transcatheter closure of PFO has been available for over 2 decades, it has remained controversial due to a paucity of evidence to guide patient and device selection. Contemporary studies investigating PFO closure as treatment for patients with these conditions have been published recently and longitudinal data regarding the safety and efficacy of the devices is now available. In this review, we aim to describe the potential clinical significance of a patent foramen in the adult, appraise the newest additions to the body of evidence, and discuss the safety, benefit, patient selection, and future of transcatheter treatment of PFO.

"Migraine side effect" and stroke recurrence in late follow-up after transcatheter patent foramen ovale closure as secondary prevention of cryptogenic thromboembolism

INTRODUCTION

Patent foramen ovale (PFO) is associated with cryptogenic strokes, recurrent transient neurologic deficits, sleep apnea, decompression illness and migraines with aura.

AIM

We verify cryptogenic embolism recurrence after transcatheter PFO closure in patients younger than 55 years old, and determine the prevalence of migraine with aura before and after PFO closure.

MATERIAL AND METHODS

We sent a questionnaire concerning the recurrence of stroke or transient ischemic attack (TIA) and the presence of migraine symptoms before and after PFO closure to 224 consecutive patients (mean age 40.9 ±9 years; 103 men; 108 patients < 40 years old, 116 patients 40-55 years old) after successful PFO transcatheter closure as secondary prevention of cryptogenic embolism.

RESULTS

The mean follow-up period was 37.8 ±32.5 (median 27) months. Stroke or TIA recurred in 6 patients (2.6%), all of whom were over 40 years old at the time of closure. The median time of recurrence was 24 months. Two patients (0.89%) died, but the deaths were not related to the device nor to thromboembolism. Migraine occurred in the study group before closure in 68 (30.4%) patients. After the procedure 55 (80.9%) reported improvement or disappearance of migraine symptoms.

CONCLUSIONS

Recurrent strokes after PFO closure are rare, and they occur more often in patients over 40 years old at the time of closure. The PFO closure results in migraine subsiding or symptoms noticeably ameliorating.

Selection bias in rheumatic disease research

The identification of modifiable risk factors for the development of rheumatic conditions and their sequelae is crucial for reducing the substantial worldwide burden of these diseases. However, the validity of such research can be threatened by sources of bias, including confounding, measurement and selection biases. In this Review, we discuss potentially major issues of selection bias--a type of bias frequently overshadowed by other bias and feasibility issues, despite being equally or more problematic--in key areas of rheumatic disease research. We present index event bias (a type of selection bias) as one of the potentially unifying reasons behind some unexpected findings, such as the 'risk factor paradox'--a phenomenon exemplified by the discrepant effects of certain risk factors on the development versus the progression of osteoarthritis (OA) or rheumatoid arthritis (RA). We also discuss potential selection biases owing to differential loss to follow-up in RA and OA research, as well as those due to the depletion of susceptibles (prevalent user bias) and immortal time bias. The lesson remains that selection bias can be ubiquitous and, therefore, has the potential to lead the field astray. Thus, we conclude with suggestions to help investigators avoid such issues and limit the impact on future rheumatology research.

Cardiac right-to-left shunt subtypes in Chinese patients with cryptogenic strokes: a multicenter case-control study

BACKGROUND AND PURPOSE

Data on the possible association between cardiac right-to-left shunt (RLS) and cryptogenic stroke are lacking in Asians. RLS and its subtypes in Chinese cryptogenic stroke patients were investigated.

METHODS

Patients (n = 153, mean age 42 ± 10 years, 81 male) with cryptogenic stroke from four medical centers in China and 135 healthy volunteers (mean age 34 ± 8 years, 54 male) were recruited. Contrast transcranial Doppler was used to assess the prevalence of RLS. A three-level RLS categorization was applied as follows: none, 0 microbubbles (MBs); small, 1-25 MBs; and large, >25 MBs. RLS was considered latent if it occurred only after the Valsalva maneuver or permanent when it occurred also during normal respiration.

RESULTS

Overall, RLS (P = 0.02), large RLS (P < 0.001) and permanent RLS (P = 0.02) were more frequently detected in patients with cryptogenic stroke than in healthy volunteers. The prevalences of small RLS and latent RLS in the two groups were similar (22% vs. 21% and 11% vs. 10%, respectively). The proportion of large RLSs amongst the subjects with RLS was much higher in the patient group than in healthy volunteers (45% vs. 18%, P < 0.001), whilst the proportion of permanent RLS was similar (72% vs. 64%, P = 0.11). Most large RLSs in the patient group (22/27, 81%) were permanent RLSs.

CONCLUSIONS

Cardiac RLS is associated with cryptogenic stroke in Chinese. However, the higher prevalence of overall RLS in the patient group was mainly due to the increased proportion of large RLSs. The results only support large RLSs as a pathological condition.

Stroke and Cancer- A Complicated Relationship

The interrelationship between stroke and cancer is complex. Cancer and stroke may occur independently in a given patient, or cancer may directly or indirectly lead to stroke via: hypercoaguability, non-bacterial thrombotic endocarditis (NBTE), direct tumor compression of blood vessels, or treatment-related effects which potentiate stroke. Patients with cryptogenic stroke are relatively common, and under the right circumstances, may provide an opportunity to screen for occult malignancy. In this review, we discuss relevant data linking stroke and cancer as well as propose a testable algorithm for cancer screening in the patient with cryptogenic stroke. Future directions should focus on validating patient-care algorithms in prospective clinical trials to provide an evidence base for this important issue.

Neurologic aspects of multiple organ transplantation

Complex multiorgan failure may require simultaneous transplantation of several organs, including heart-lung, kidney-pancreas, or multivisceral transplantation. Solid organ transplantation can also be combined with hematopoietic stem cell transplantation to modulate immunologic response to a solid organ allograft. Combined multiorgan transplantation may offer a lower rate of allograft rejection and lower immunosuppression needs. In recent years, intestinal and multivisceral transplantations became viable as a rescue treatment for patients with irreversible intestinal failure who can no longer tolerate total parenteral nutrition with 70% survival after 5 years which is comparable to other types of solid organ allografts. Post-transplant neurologic complications were reported in up to 86% of allograft recipients and greatly overlap in intestinal and multivisceral allograft recipients, without a significant effect on the outcome of transplantation. Other common organ combinations in multiorgan transplantation include kidney-pancreas, which is mostly used for patients with renal failure and uncontrolled diabetes, and heart-lung for patients with congenital heart disease and idiopathic pulmonary arterial hypertension. Kidney-pancreas transplantation frequently results in an improvement of diabetic complications, including diabetic neuropathy. Heart-lung allograft recipients have very similar clinical course and spectrum of neurologic complications to lung transplant recipients. At this time there are no reports of an increased risk of graft-versus-host disease with combined transplantation of solid organ allograft and hematopoietic stem cells. Chronic immunosuppression and complex toxic-metabolic disturbances after multiorgan transplantation create a permissive environment for development of a wide spectrum of neurologic complications which largely resemble complications after transplantations of individual components of complex multiorgan allografts.

Ultrasound-based imaging in neurocritical care patients: a review of clinical applications

OBJECTIVE

To analyze the diagnostic, monitoring, and procedural applications of ultrasound (US) imaging in neurocritical care (NCC) patients.

METHOD

US imaging has been extensively validated in various subset of critically ill patients, but not specifically in the NCC population. We reviewed the clinical applications of US imaging for heart, vascular, brain, and lung evaluation and for possible procedural uses in NCC patients. Major neurosurgical books, journals, testimonials, authors' personal experience, and scientific databases were analyzed.

RESULTS

Cardiac US imaging provides accurate information at NCC arrival to stratify risk factors, including presence of atrial septal defect/patent formen ovale, abnormal ventricular function, or pericardial effusion, and to monitor cardiac anatomy and function during the NCC stay for guiding goal-directed therapy. Vascular US in NCC patients has three especially relevant indications: to screen anatomy and flow in extracranial supra-aortic arteries, to diagnose deep vein thrombosis, and to optimize the safety of central venous catheterization. Brain US has important clinical applications in the NCC, including transcranial Doppler and emerging techniques for cerebral blood flow evaluation with contrast-enhanced US imaging. Lung US, as demonstrated in other intensive care unit patients, provides accurate diagnosis of anatomical and functional abnormalities and enables diagnosis of pleural effusion, pneumothorax, lung consolidation, pulmonary abscess and interstitial-alveolar syndrome, and lung recruitment/derecruitment. US imaging can effectively guide percutaneous tracheostomy.

CONCLUSION

In conclusion, US imaging is an important diagnostic tool that provides real-time information at the bedside to stratify risk, monitor for complications, and guide invasive procedures in NCC patients.

Transesophageal echocardiography in cryptogenic stroke and patent foramen ovale: analysis of putative high-risk features from the risk of paradoxical embolism database

BACKGROUND

Patent foramen ovale (PFO) is associated with cryptogenic stroke (CS), although the pathogenicity of a discovered PFO in the setting of CS is typically unclear. Transesophageal echocardiography features such as PFO size, associated hypermobile septum, and presence of a right-to-left shunt at rest have all been proposed as markers of risk. The association of these transesophageal echocardiography features with other markers of pathogenicity has not been examined.

METHODS AND RESULTS

We used a recently derived score based on clinical and neuroimaging features to stratify patients with PFO and CS by the probability that their stroke is PFO-attributable. We examined whether high-risk transesophageal echocardiography features are seen more frequently in patients more likely to have had a PFO-attributable stroke (n=637) compared with those less likely to have a PFO-attributable stroke (n=657). Large physiologic shunt size was not more frequently seen among those with probable PFO-attributable strokes (odds ratio [OR], 0.92; P=0.53). The presence of neither a hypermobile septum nor a right-to-left shunt at rest was detected more often in those with a probable PFO-attributable stroke (OR, 0.80; P=0.45; OR, 1.15; P=0.11, respectively).

CONCLUSIONS

We found no evidence that the proposed transesophageal echocardiography risk markers of large PFO size, hypermobile septum, and presence of right-to-left shunt at rest are associated with clinical features suggesting that a CS is PFO-attributable. Additional tools to describe PFOs may be useful in helping to determine whether an observed PFO is incidental or pathogenically related to CS.

Risk of a recurrent cardiovascular event in individuals with type 2 diabetes or intermediate hyperglycemia: the Hoorn Study

OBJECTIVE

To investigate risk of a recurrent cardiovascular event and its predictors in a population-based cohort.

RESEARCH DESIGN AND METHODS

Participants of the Hoorn Study who had experienced a first cardiovascular event after baseline (n = 336) were followed with respect to a recurrent event. Absolute risk of a recurrent event was calculated for individuals with normal glucose metabolism, intermediate hyperglycemia, and type 2 diabetes. Cox regression models were used to investigate which variables, measured before the first vascular event, predicted a recurrent event using the stepwise backward procedure.

RESULTS

During a median follow-up of 4.1 years, 44% (n = 148) of the population developed a recurrent vascular event. The rate of recurrent events per 100 person-years was 7.2 (95% CI 5.8-8.7) in individuals with normal glucose metabolism, compared with 9.8 (6.6-14.0) in individuals with intermediate hyperglycemia and 12.5 (8.5-17.6) in individuals with type 2 diabetes. Higher age (hazard ratio 1.02 [95% CI 1.00-1.04]), male sex (1.56 [1.08-2.25]), waist circumference (1.02 [1.02-1.03]), higher systolic blood pressure (1.01 [1.01-1.02]), higher HbA1c (%, 1.13 [0.97-1.31]/ mmol/mol, 1.01 [1.00-1.03]), and family history of myocardial infarction (1.38 [0.96-2.00]) predicted a recurrent cardiovascular event.

CONCLUSIONS

Individuals with type 2 diabetes, but not individuals with intermediate hyperglycemia, are at increased risk for a recurrent vascular event compared with individuals with normal glucose metabolism. In people with a history of cardiovascular disease, people at increased risk of a recurrent event can be identified based on the patient's risk profile before the first event.

An index to identify stroke-related vs incidental patent foramen ovale in cryptogenic stroke

OBJECTIVE

We aimed to create an index to stratify cryptogenic stroke (CS) patients with patent foramen ovale (PFO) by their likelihood that the stroke was related to their PFO.

METHODS

Using data from 12 component studies, we used generalized linear mixed models to predict the presence of PFO among patients with CS, and derive a simple index to stratify patients with CS. We estimated the stratum-specific PFO-attributable fraction and stratum-specific stroke/TIA recurrence rates.

RESULTS

Variables associated with a PFO in CS patients included younger age, the presence of a cortical stroke on neuroimaging, and the absence of these factors: diabetes, hypertension, smoking, and prior stroke or TIA. The 10-point Risk of Paradoxical Embolism score is calculated from these variables so that the youngest patients with superficial strokes and without vascular risk factors have the highest score. PFO prevalence increased from 23% (95% confidence interval [CI]: 19%-26%) in those with 0 to 3 points to 73% (95% CI: 66%-79%) in those with 9 or 10 points, corresponding to attributable fraction estimates of approximately 0% to 90%. Kaplan-Meier estimated stroke/TIA 2-year recurrence rates decreased from 20% (95% CI: 12%-28%) in the lowest Risk of Paradoxical Embolism score stratum to 2% (95% CI: 0%-4%) in the highest.

CONCLUSION

Clinical characteristics identify CS patients who vary markedly in PFO prevalence, reflecting clinically important variation in the probability that a discovered PFO is likely to be stroke-related vs incidental. Patients in strata more likely to have stroke-related PFOs have lower recurrence risk.

Seizure and embolic stroke secondary to patent foramen ovale in a migrant girl

Episodes of loss-of-consciousness in school-aged children are not uncommon and include metabolic, cardiovascular, neurological, and psychiatric/psychosocial causes. This case describes a first episode of seizure in an 11-year-old migrant girl. History and language issues contributed to the diagnostic dilemma. Ongoing neurological symptoms prompted transfer to a tertiary care facility where investigation revealed patent foramen ovale (PFO) with likely paradoxical embolus. Prevalence and management of this condition is briefly reviewed in the context of the current presentation.

Modern management of a patent foramen ovale

A patent foramen ovale (PFO) has been associated with medical conditions such as cryptogenic stroke, migraine with aura, and decompression illness. Whether closure of the PFO has clinical benefit has been suggested from registry studies, but not yet confirmed in multiple randomized trials. Methods of diagnosis of a PFO and a summary of the current evidence for treatment is presented and discussed as a guide to patient-centred decision-making.

Epidemiology and risk factors

PURPOSE OF REVIEW

: This article presents current knowledge on stroke epidemiology. It covers recent data on the global burden of stroke, disparities, silent stroke, traditional and novel risk factors, and stroke triggers as well as the clinical implications of these findings.

RECENT FINDINGS

: Stroke is the third leading cause of death and the leading cause of chronic disability in the United States, and the burden of stroke worldwide is even greater. Large international and US case-control and prospective cohort studies have demonstrated disparities in stroke mortality and incidence. They have also shed light on the relative importance of several well-established, modifiable risk factors for ischemic stroke, such as hypertension, atrial fibrillation, other cardiac diseases, hyperlipidemia, diabetes, cigarette smoking, physical inactivity, alcohol consumption, abdominal obesity, diet, and TIA. Research on other putative stroke risk factors (including inflammation, infection, renal disease, depression, stress, and others) is ongoing. Identifying stroke triggers may be another way to minimize stroke incidence if high-risk time windows can be determined.

SUMMARY

: Stroke is a major global health burden. While many of the risk factors for stroke are well known and have been studied for decades, recent studies continue to shed light on the distribution and severity of these problems.

The risk of paradoxical embolism (RoPE) study: initial description of the completed database

BACKGROUND

Detecting a benefit from closure of patent foramen ovale in patients with cryptogenic stroke is hampered by low rates of stroke recurrence and uncertainty about the causal role of patent foramen ovale in the index event. A method to predict patent foramen ovale-attributable recurrence risk is needed. However, individual databases generally have too few stroke recurrences to support risk modeling. Prior studies of this population have been limited by low statistical power for examining factors related to recurrence.

AIMS

The aim of this study was to develop a database to support modeling of patent foramen ovale-attributable recurrence risk by combining extant data sets.

METHODS

We identified investigators with extant databases including subjects with cryptogenic stroke investigated for patent foramen ovale, determined the availability and characteristics of data in each database, collaboratively specified the variables to be included in the Risk of Paradoxical Embolism database, harmonized the variables across databases, and collected new primary data when necessary and feasible.

RESULTS

The Risk of Paradoxical Embolism database has individual clinical, radiologic, and echocardiographic data from 12 component databases, including subjects with cryptogenic stroke both with (n = 1925) and without (n = 1749) patent foramen ovale. In the patent foramen ovale subjects, a total of 381 outcomes (stroke, transient ischemic attack, death) occurred (median follow-up 2·2 years). While there were substantial variations in data collection between studies, there was sufficient overlap to define a common set of variables suitable for risk modeling.

CONCLUSION

While individual studies are inadequate for modeling patent foramen ovale-attributable recurrence risk, collaboration between investigators has yielded a database with sufficient power to identify those patients at highest risk for a patent foramen ovale-related stroke recurrence who may have the greatest potential benefit from patent foramen ovale closure.

Cryptogenic stroke in low-risk patients, consider a cardiac shunt at your peril

Patent foramen ovale (PFO) as a cause of cryptogenic stroke from paradoxical embolisation remains a controversial issue. The optimal care between medical and surgical management of these patients for the attending clinician remains a conundrum. We report a case of cryptogenic stroke in a woman aged 59, with a PFO, concomitant venous thrombosis and cryptogenic stroke. The case highlights the difficulty in diagnosing and managing such patients, particularly as recent evidence challenges the clinical practice of percutaneous closure and pathophysiological rationale.