Inherited Thrombophilic Disorders in Young Adults With Ischemic Stroke and Patent Foramen Ovale

Abstract

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 TT 677 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.