Abstract TMP13: Baseline DWMRI Characteristics In Patients With Cryptogenic Stroke And Patent Foramen Ovale: Results From The Closure I Trial

Abstract

Background: Cryptogenic stroke may have several etiologies including paradoxical embolism through a patent foramen ovale (PFO). A cardiac source of embolism may be suggested by multiple infarcts, sometimes hemorrhagic, in different vascular distributions or a cortical wedge shaped infarct. We report the baseline diffusion weighted MRI (DWMRI) characteristics in patients with cryptogenic stroke and a patent foramen ovale (PFO) from the CLOSURE I trial. Methods: CLOSURE I compared device closure versus medical therapy for secondary prevention in patients with cryptogenic TIA or stroke and a PFO. Of 909 patients randomized, 562 patients demonstrated acute infarcts on baseline DWMRI and are included in this analysis. Multivariate proportional hazard Cox regression compared imaging subgroups with remaining randomized patients Results: Single infarcts were found in 62% of patients. Of these, 61% were anterior circulation, 30% posterior, and 8.5% were of uncertain territory. Of the anterior circulation infarcts, 40% were cortical, 36% subcortical, and 24% affected both the cortical and subcortical regions. Of the posterior circulation infarcts, 45% were thalamic or cerebellar. Of 562 patients, 18.5% had a single subcortical lesion <1.5cm in diameter and met the radiological definition of an acute lacunar infarct. Multiple infarcts were found in 38%. Infarcts in a single vascular territory were found in 23%, often in the anterior circulation (66%). Infarcts in multiple vascular territories were found in 15%. Hemorrhagic infarction was present in 9%. Adjusting for patient characteristics, no significant difference in 2 year rate of TIA, stroke or death was found compared to remaining randomized patients. Discussion: The specificity of infarct patterns for embolism in patients with cryptogenic stroke and a PFO is uncertain. We found no significant relationship between lacunar or subcortical infarction and the risk of recurrent TIA or stroke. Baseline infarct patterns on DWMRI in patients with cryptogenic stroke and PFO may not be useful in predicting recurrent stroke risk or determining best prevention therapy.