Abstract 188: Correlation of Angiographic Capillary Index Score (CIS) with Diffusion and Perfusion MR Imaging in the DEFUSE 2 Trial

Abstract

Objective: The CIS has been shown to be a predictor of good clinical outcome following endovascular therapy for acute ischemic stroke. We undertook this study to determine the relationship between CIS and baseline diffusion-perfusion imaging as well as angiographic collaterals in DEFUSE 2 study patients. Methods: Patients undergoing endovascular therapy within 12 hours of stroke onset were prospectively enrolled. Only patients with an ICA/M1 occlusion and adequate demonstration of the anterior and posterior circulations at baseline angiography were included in this analysis. Blinded reading of the CIS was made using a 4 point scale from 0 (no capillary blush in ischemic territory) to 3 (blush throughout). Analysis was dichotomized to poor CIS (0-1) versus good (2-3). CIS was correlated with baseline DWI volume, PWI volume (Tmax > 6, Tmax>10), an angiographic collateral score (using a previously described 5 point scale) and subsequent infarct growth. Results: Forty-eight patients had ICA/M1 occlusions and adequate angiographic images to evaluate CIS. Baseline DWI lesion volume correlated with CIS (p=0.001). Median DWI volume for patients with poor CIS (0-1) was 28 (IQR, 11-54) versus 13 (3-27) for those with good CIS (2-3), p=0.011. Baseline T max > 6 volume correlated with CIS (p=0.004). Median volume of tissue at risk (T max > 6 sec) in those with poor CIS was 108 ml (IQR, 74-138) versus 69(43-108) with good CIS, p=0.009. Severe T max delay (> 10 sec) also correlated with CIS (p=0.001). CIS was also found to correlate with angiographic collaterals (p=0.006). On follow-up MRI CIS correlated with subsequent lesion growth (p=0.043). Conclusions: CIS provides a rapid angiographic assessment of capillary blush from collateral flow into the ischemic territory and correlates with angiographic collateral scores. In DEFUSE 2 the CIS score was strongly associated with baseline DWI and PWI lesion volumes and subsequent lesion growth.