Inherited thrombophilic conditions, patent foramen ovale and juvenile ischaemic Stroke

Patent Foramen Ovale in Fetal Life, Infancy and Childhood

A patent foramen ovale (PFO) is a common, incidental echocardiographic finding in otherwise healthy and asymptomatic infants and children. However, a variety of clinical conditions have been ascribed to the presence of a PFO in childhood, such as cryptogenic stroke, platypnea-orthodeoxia syndrome, decompression sickness and migraine, although the data on these are controversial and sometimes contradictory. This review discusses embryology and correlation with post-natal anatomy, anatomical variations of the atrial septum, diagnostic modalities in special circumstances of PFO associated clinical syndromes, and the role of PFO in congenital heart disease, pulmonary hypertension, dilated cardiomyopathy and heart failure in children who require an extracorporeal membrane oxygenator or ventricular assist device as life support.

Patent foramen ovale and stroke in childhood: A systematic review of the literature

BACKGROUND

Stroke in association with a patent foramen ovale (PFO) may be due to paradoxical embolization via a right to left intracardiac shunt but the exact contribution of PFO to stroke or stroke recurrence in childhood remains unclear.

METHODS

To review the relationship of a PFO with stroke, and evaluate associated co-morbidities. An electronic database literature search of Pubmed, Cochrane and EMBASE was performed from January 2000-December 2014.

RESULTS

149 articles were retrieved, with overlap for diagnosis, management, treatment and outcome. 65 reports were utilized for the comprehensive review. Majority of childhood arterial ischemic stroke and transient ischemic attacks are associated with prothrombotic disorders or arteriopathy. Transthoracic echocardiography with a Valsalva maneuver is highly sensitive as a screening tool but may be falsely positive. Transthoracic echocardiography with color Doppler and a concurrent bubble contrast study are excellent for visualizing the atrial septum and PFO and identifying a right to left shunt. Current literature does not support PFO closure for cryptogenic stroke in young adults without an associated risk of thromboembolism.

CONCLUSIONS

High quality research in the pediatric population is lacking and most of the data is extrapolated from adults. Paradoxical embolism from a PFO as a cause of transient ischemic attack or stroke is a diagnosis of exclusion. PFO closure should be individualized based on significant shunting and risk factors such that maximum benefit is derived from the procedure. A young person with a PFO and stroke should be thoroughly investigated to rule out other etiologies.

Hematologic ramifications of patent foramen ovale--role of hypercoagulable state

This article discusses the ramifications of a hypercoagulable state in patients with a patent foramen ovale.

Prothrombin G20210A mutation, but not factor V Leiden, is a risk factor in patients with persistent foramen ovale and otherwise unexplained cerebral ischemia

BACKGROUND

Paradoxical embolism via persistent foramen ovale (PFO) is suspected to be a frequent cause of stroke in younger patients. We investigated whether the prevalence of the risk factors for venous thrombosis factor V Leiden (FVL) and prothrombin G20210A mutation (PT G20210A) is increased in this group of patients.

METHODS

We examined FVL and PT G20210A mutation in 220 patients (group 1) with cerebral ischemia associated with a PFO and without other etiology, in 196 patients with cerebral ischemia of an etiology other than PFO (group 2), and in 362 healthy subjects (group 3) from the same region in Germany.

RESULTS

Heterozygosity for the PT G20210A mutation was more common in group 1 (5.0%) than in group 3 (1.4%; sex- and age-adjusted odds ratio 3.66; 95% CI 1.25-10.75; p = 0.01). By contrast, the mutation was not more common in group 2 (2.6%; odds ratio 1.50; 95% CI 0.42-5.41; p = 0.5). Prevalences of FVL were not different between groups.

CONCLUSIONS

We identified PT G20210A but not FVL - the strongest genetic risk factor for deep venous thrombosis - to be significantly associated with stroke attributed to PFO. These findings rise doubts about the concept of paradoxical brain embolism as the dominating mechanism in stroke associated with PFO.

Inherited thrombophilic disorders in young adults with ischemic stroke and patent foramen ovale

BACKGROUND AND PURPOSE

The pathogenic link between patent foramen ovale (PFO) and stroke remains unknown in most cases. We investigated the association between inherited thrombophilic disorders and PFO-related strokes in a series of young adults in the setting of a case-control study.

METHODS

We investigated 125 consecutive subjects (age, 34.7+/-7.3 years) with ischemic stroke and 149 age- and sex-matched control subjects. PFO was assessed in all patients with transcranial Doppler sonography with intravenous injection of agitated saline according to a standardized protocol. Genetic analyses for the factor V (FV)(G1691A) mutation, the prothrombin (PT)(G20210A) variant, and the TT677 genotype of methylenetetrahydrofolate reductase (MTHFR) were performed in all subjects.

RESULTS

A pathogenic role of PFO was presumed in 36 patients (PFO+). Interatrial right-to-left shunt either was not detected or was considered unrelated to stroke occurrence in the remaining 89 patients (PFO-). The PT(G20210A) variant was more frequent in the PFO+ group compared with control subjects and the PFO- group (PFO+ versus control subjects, 11% versus 2%; 95% CI, 0.04 to 0.94; PFO+ versus PFO-, 11% versus 1.1%; 95% CI, 1.09 to 109; P=0.047). A similar distribution was observed for subjects carrying either the PT(G20210A) variant or the FV(G1691A) mutation (PFO+ versus control subjects, 19.4% versus 5.3%; 95% CI, 0.08 to 0.75; PFO+ versus PFO-, 19.4% versus 3.3%; 95% CI, 1.45 to 26.1; P=0.021). Combined thrombophilic defects were observed in 3 subjects of the PFO+ group, in 2 control subjects (8.3% versus 1.3%; 95% CI, 0.01 to 0.66; P=0.015), and in 0 subjects in the PFO- group. A trend toward a difference in the frequency of the FV(G1691A) mutation between PFO+ and control subjects was found after bivariate analysis (11% versus 3.3%; P=0.068) but not after multinomial logistic regression analysis. No significant association was found in the distribution of the TT MTHFR genotype in the 3 groups.

CONCLUSIONS

In young adults, the PT(G20210A) variant and, to a lesser extent, the FV(G1691A) mutation may represent risk factors for PFO-related cerebral infarcts. A role of systemic thrombophilic disorders in the pathogenesis of this specific subtype of stroke may be hypothesized.

Transoesophageal echocardiography in patients without arterial and major cardiac sources of embolism: difference between stroke subtypes

We studied the records of 175 consecutive patients referred to our neurologic ward between January 1994 and February 2000 with a diagnosis of ischaemic cerebrovascular disease (ICVD) (stroke or transient ischaemic attack - TIA) who underwent transoesophageal echocardiography (TEE). We excluded patients with large vessel disease, high-risk embolic cardiopathies and other rare causes of stroke. According to clinical and neuroimaging findings, patients were divided into two groups. The lacunar (LAC) group (69/175 (39.4%)) and the nonlacunar (N-LAC) one (106/175 (60.6%)). The control population consisted of 78 consecutive patients, referred to the echocardiography laboratory for TEE without history of ICVD and known heart disorders. Patent foramen ovale (PFO) frequency was significantly higher in case patients than in control subjects (55/175 (31.4%) vs. 13/78 (16.6%); p = 0.02). Among case patients, PFO was more prevalent in the N-LAC group than in the LAC one (43/106 (40.6%) vs. 12/69 (17.4%); p = 0.0005). A large degree of shunt occurred in 53.5% of N-LAC patients and in 16.7% of LAC ones (p = 0.04). Atrial septal aneurysm (ASA) was detected in 12% of case patients and 1.3% of control subjects (p = 0.003) and was more frequent in the N-LAC group than in the LAC one (16 vs. 5.8%; p = 0.05). Mitral prolapse (MP) was present in 6/175 (3.4%) ICVD patients (vs. 1/78 among controls) in most cases associated with myxomatous valve redundancy. Aortic arch atheromas (AA) were detected in 12% of ICVD patients and in 10.2% of controls. The frequency was 9.4% in N-LAC and 15.9 in LAC. No complicated AA (plaque thickness >4 mm, ulcerated atheroma, superimposed thrombus) were detected. After multivariate analysis, PFO (OR = 3.8; 95% CI = 2.7-7.9) and ASA (OR = 8.01; 95% CI = 3.0-16.1) appeared to be independent predictors of ICVD. PFO (OR = 2.24; 95% CI = 1.24-4.92) was also independently associated with N-LAC stroke subtype and its importance was even higher in younger patients. Our study provides further evidence that TEE is a helpful diagnostic tool in stroke patients without arterial and major cardiac sources of embolism. However, its utility differs according to type and localization of the ischaemic lesion being more relevant in patient with N-LAC infarctions.