Abstract WP96: Computed Tomography Identifies Patients At High Risk For Stroke After Transient Ischemic Attack Or Non Disabling Stroke. A Prospective, Multicenter Validation Study

Abstract

Background and Objectives: CT findings of acute and chronic ischemia are associated with stroke risk. We sought to validate these associations in a large prospective cohort of patients with TIA or minor stroke. Methods: We included prospectively enrolled emergency department patients from 13 centers with a final ED diagnosis of TIA or non-disabling stroke who had a computed tomography (CT) within 24 hours. Primary outcome was stroke within 90 days. Secondary outcomes were stroke within 2 or 7 days. CT findings were abstracted from the radiology report and classified for the presence of acute ischemia, chronic ischemia or microangiopathy. Multivariable logistic regression was used to test associations with primary and secondary endpoints. Results: In total 8,670 patients were enrolled between May 2010 to May 2017 and 8,382 had a CT within 24 hours. 4,547 patients had evidence of acute ischemia, chronic ischemia, or microangiopathy on CT imaging, of whom 175 had a subsequent stroke within 90 days (3.8% subsequent stroke rate; OR, 2.33; 95% CI, 1.62-3.36; P<0.001). Findings associated with an increased risk of stroke at 90 days were acute ischemia alone (6.0%; OR, 2.42; 95% CI, 1.03-5.66; P=0.04), acute ischemia with microangiopathy (10.7%; OR, 3.34; 95% CI, 1.57-7.14; P=0.002), chronic ischemia with microangiopathy (5.2%; OR, 1.83; 95% CI, 1.34-2.50; P<0.001), and acute ischemia with chronic ischemia and microangiopathy (10.9%; OR; 3.49; 95% CI, 1.54-7.91; P=0.003). ). Acute ischemia with chronic ischemia and microangiopathy were most strongly associated with increased risk of subsequent stroke within 2 days (OR, 4.36; 95% CI 1.31-14.54), and 7 days (OR, 4.50; 95%CI, 1.73-11.69). Conclusion: In patients with TIA or non-disabling stroke, CT evidence of acute ischemia with chronic ischemia and/or microangiopathy significantly increases the risk of subsequent stroke within 90 days of index visit. The combination of all 3 findings results in the greatest early risk.