Abstract W P46: Specific Infarct Locations Define Troponin Elevation in Acute Ischemic Stroke

Introduction: Myocardial injury is often encountered in acute ischemic stroke (AIS). Specific infarct locations have been considered as involved in its pathophysiology but there has been no systematic study involving MRI volumetric analyses. We aimed to define the imaging factors related to elevated troponin levels in AIS. Hypothesis: Specific infarct locations would be associated with AIS-related myocardial injury. Methods: We analyzed prospectively collected stroke registry data of patients with AIS admitted in one calendar year and included all patients with clinical and diffusion-weighted imaging (DWI) proven diagnosis of AIS, serum troponin measured within 24 hours of onset, and DWI studies of sufficient quality to permit analyses. Serum troponin ≥ 0.04 was considered elevated. A brain atlas was co-registered to each DWI volume by affine transform with 12 parameters representing pre-specified brain regions, including temporal, parietal, frontal, occipital lobes, insula and brainstem. Lesion volumes were calculated and the percent of total lesion volume within each region was computed. The relationship between troponin status (elevated vs. normal) and presence of ischemic lesion in a brain region was assessed using χ2 test. Multivariate logistic regression models with stepwise selection were done to determine which combination of brain regions were associated with elevated troponin levels. Results: We included 266 patients; 138 (52%) were men, mean age was 66(±14) years. Elevated troponin level was found in 72 (27%) and normal in 194 (73%) patients. There was no age difference between the two groups. Patients with elevated troponin levels had larger infarct volumes than those with normal levels [21,446(±35,414) mm3 vs. 13,058 (±38,100) mm3, p=0.001). Patients with elevated troponin levels were more likely to have left parietal (OR=2.74, 95%CI=1.48 to 5.07, p=0.001) and right frontal (OR=2.05, 95%CI=1.06 to 3.94, p=0.032) infarct location. Conclusions: Myocardial injury is often encountered in AIS, especially in patients with larger infarct volumes. Left parietal and right frontal infarct locations are independent predictors of myocardial injury. Further study will help define the clinical and prognostic significance of our findings.