Safety of Intravenous Fibrinolysis in Imaging-Confirmed Single Penetrator Artery Infarcts

Abstract

Hemorrhagic transformation (HT) after fibrinolytic therapy may be less common in patients with acute cerebral ischemia confined to single penetrator artery (SPA) territories than in patients with large artery ischemia. Previous investigations of HT diagnosed small vessel ischemia based on lacunar clinical syndromes, an approach known to yield misdiagnosis in one-third to one-half of cases. Consecutive intravenous tissue plasminogen activator-treated patients in a prospectively maintained hospital registry were analyzed. Patients were classified as having SPA ischemia if they had imaging evidence of: (1) deep location; (2) diameter ≤ 1.5 cm; and (3) distribution in a single penetrator territory, regardless of presenting clinical syndrome. Lacunar clinical syndrome was defined according to the Oxfordshire Community Stroke Project classification. Among 93 intravenous tissue plasminogen activator-treated patients, mean age was 71.5, 62.4% were female, and median pretreatment National Institutes of Health Stroke Scale score was 14. Single penetrator artery ischemia was imaged in 13 (14.0%) and large artery ischemia was imaged in 75 (80.6%), with no visualized ischemic injury in 5 (5.4%). Lacunar clinical syndromes were present in 23 (24.7%), including 10 with SPA ischemia and 9 with large artery ischemia. No patient with imaging-confirmed SPA infarcts experienced any hemorrhagic transformation, whereas any radiological HT occurred in 29.3% of large artery infarcts (P=0.03). Symptomatic intracerebral hemorrhage occurred in 0% of SPA infarcts vs 4.0% of large artery infarcts. HT after lytic therapy in imaging-confirmed SPA infarcts is uncommon. Imaging demonstration of ischemia confined to SPA territory better-identifies this population at low risk for hemorrhagic complications than clinical lacunar syndromes.