Abstract 27: Unique ASPECTS of Conditioning? Prior TIA or Atrial Fibrillation and Early CT Findings in FAST-MAG
Background: Ischemic conditioning, or endogenous protection of brain tissue, may be elicited by prior TIA or absent due to sudden cardioembolic occlusion in atrial fibrillation (AF). We hypothesized that such specific co-morbidities may be manifest by the extent of early ischemic changes, or ASPECTS score, on CT in the prehospital NINDS FAST-MAG trial.
Methods: All FAST-MAG subjects with a final diagnosis of cerebral ischemia were included in these analyses of baseline clinical variables and ASPECTS, scored on the initial non-contrast CT acquired at ED arrival. The relationship between prior medical conditions and total ASPECTS score was determined by bivariate analyses, Mann-Whitney U, and Kruskal-Wallis tests.
Results: 1,240 patients (mean age 69 SD 13; 45% women) had ASPECTS scored on initial imaging, CT in 1227 (97%), MRI in 42. ASPECTS (median 10, range 1-10) was notably higher, signifying less ischemic changes in those with history of prior TIA, median 10 (IQR 10-10) vs. 10 (8-10), p=0.012 by Mann-Whitney, whereas prior history of stroke revealed no difference. Conversely, substantially lower ASPECTS or greater ischemic changes were noted in those with history of AF, median 10 (7-10) vs. 10 (8-10), p=0.010) and presence of AF on EKG in ED, median 10 (6-10) vs. 10 (8-10), p=0.041. Interestingly, other cardiac history and all other co-morbidities demonstrated no relationship with ASPECTS. Elevated prehospital systolic blood pressure was linked with higher ASPECTS (r=0.098, p=0.001), as was the change in blood pressure from field to ED (ANOVA, p=0.049). Initial ASPECTS was linked with 90-day mRS outcomes (r=-.259, p<0.001).
Conclusions: Prior TIA and AF exhibit striking, yet opposite relationships with the extent of early CT findings in this large cohort of patients enrolled in a prehospital stroke trial. These findings suggest that patient-specific factors, such as conditioning, may be pivotal in the course of cerebral ischemia.
Author Disclosures: D.S. Liebeskind: Consultant/Advisory Board; Modest; Stryker, Covidien. Research Grant; Significant; NIH-NINDS. N. Sanossian: None. S. Starkman: None. P. Villablanca: None. A.M. Burgos: None. F. Scalzo: None. M.S. Johnson: None. M. Eckstein: None. S. Stratton: None. F. Pratt: None. R. Conwit: None. S. Hamilton: None. J.L. Saver: None.
- © 2015 by American Heart Association, Inc.