Abstract NS 2: Antiphospholipid Associated Hypercoagulability and Subclinical White Matter Lesions in Patent Foramen Ovale Related Stroke - Searching for Footprints of Paradoxical Embolism

Background: Patent foramen ovale (PFO) related stroke has been reported to have higher frequency of hypercoagulable state and “non-specific” subclinical white matter lesions on MRI. While it is interesting to hypothesize that paradoxical embolic events may trigger subclinical infarcts in the setting of prothrombotic state, the associations are unclear. We examined antiphospholipid antibody status, one of the hypercoagulable conditions, with respect to white matter lesions (WMLs) in PFO related stroke to better understand this relationship. Methods: 79 consecutive prospectively recruited non-migrainous PFO-related stroke patients (adjudicated by two vascular neurologists) underwent FLAIR sequence MRI and anticardiolipin antibody IgG, IgM and lupus anticoagulant measurement. Subclinical (or clinically “silent”) white matter lesions (WMLs) were inspected by investigators blind to clinical information using two scales (Fazekas and Scheltens) to insure inter-rater reliability and accuracy. Results: Patients with elevated anticardiolipin titer (n=6; 7.6%; 50% men) had similar age (mean = 53 vs 48) to those with normal titers (n= 73; 92.4%). Of the patients with positive anticardiolipin antibody, mean IgG was 27 GPL (range 21.4-38.6; normal range 0-15); mean IgM was 32.7 MPL (range 22.2-36.6; normal range 0-15), and none had lupus anticoagulant. WMLs were found in both periventricular regions (PV-WML) and in deep white matter (D-WML). Overall, global WML burden is statistically significantly increased in PFO stroke patients with positive anticardiolipin antibody compared to those with negative titers (Fazekas scale - 2.333 vs 1.35 , p Conclusions: In non-migraineur PFO-related stroke patients with antiphospholipid-associated hypercoagulability, there is greater global WMLs burden than those without any hypercoagulable states. Antiphospholipid antibody positivity may contribute to global burden of WMLs in patients with PFO related stroke, independent of conventional risk factors for WML. WMLs found on MRI FLAIR maybe “footprints” of subclinical embolic events which can potentially be used to follow disease progression and triage more aggressive stroke prevention strategy in this patient population. Further study with a larger disease cohort and other hypercoagulable states are needed to validate these preliminary findings.