Abstract 1122‐000037: LVO in the Setting of TTP

Abstract

Introduction : Thrombotic Thrombocytopenic Purpura (TTP) is a disorder of coagulation caused by a deficiency of ADAMTS13 due to either hereditary mutations or acquired autoimmune inhibitors. Low levels of ADAMTS13 metalloprotease leads to Von Willebrand Factor (VWF)‐platelet aggregation and microvascular thrombosis when patients with TTP are exposed to high shear stress in the microcirculation. [1] Hematologic disorder or coagulopathies are the major cause of 1–4% of all ischemic strokes. [2] TTP patients usually present with small vessel strokes or sometimes very distal branches of large arteries. The gold standard treatment for acute stroke in these patients is plasma exchange, however in patients presenting with LVO strokes, recanalization therapies should be considered. [3] Here we present a case of large vessel occlusion stroke in the setting of TTP. Methods : 31‐year‐old African American female with TTP and Strokes admitted to with right sided hemiparesis, and expressive aphasia within 2h of symptom onset. National Institute of Health Stroke Scale (NIHSS) of 16. Laboratory work up significant for Platelets 114k, Hemoglobin 12, PTT 24 seconds, Serum glucose 107, ADAMTS‐13 <1 IU/dL and negative COVID‐19 PCR. CTH showing ASPECTS of 9 (Picture A), CTA head and neck revealing a left MCA occlusion and intracranial vessel irregularities in the left Anterior Cerebral Artery (ACA) and bilateral Posterior Cerebral Arteries (PCA) (Picture B). CTP with 24cc core and 132 cc mismatch (Picture C). Patient was taken to the Angiogram Suite for urgent thrombectomy with a final TICI score of 3 achieved after one pass (Picture D/E). Results : Post procedure NIHSS was 1 for mild expressive aphasia. Brain MRI revealed Left MCA and right parietal territories infarct (Picture F). Transesophageal Echocardiogram was unremarkable. She underwent urgent Plasma Exchange (PLEX) for TTP flair in light of undetectable ADAMTS‐13, significant drop in platelet count and thrombotic event. After 5 PLEX sessions platelets remained stable with counts greater than 150.000. Immunotherapy with Prednisone, Caplacizumab, Atovaquone and Mycophenolate Mofetil was continued and she was discharged home on day 7 from admission. Conclusions : Our patient had severe and refractory disease presenting with LVO and underwent an unusual therapeutic approach considering the etiology of her disease. IV thrombolysis and arterial thrombectomy are well established therapies for acute strokes in the general population, but are rarely performed in patients affected by Thrombotic Microangiopathy (TMA) such as TTP. Safety and efficacy of these procedures have not been studied in this population and it is usually selected by extrapolating data from studies that used individuals without TMA. We aim to illustrate this uncommon case of LVO stroke in the setting of TTP and potentially stimulate the elaboration of studies that include these patients.