Abstract WP52: Defining and Predicting Fast Progression of Infarct Growth in Large Vessel Occlusion Strokes
Background and Purpose: Identification of patients with failing collaterals and rapid progression of infarct growth (fast progressors) is crucial when assessing patients for potential transfer from primary to comprehensive stroke centers endovascular therapy (ET). Methods: Review of a prospectively collected database of endovascular patients with anterior circulation Large vessel occlusion strokes from 09/2010-11/2018. Patients with adequate CTP maps and follow-up final infarct volume (FIV) measurements who achieved full reperfusion (mTICI 2c-3) were included.Infarct growth rate was calculated as the difference between FIV and the acute CTP core volume, divided by time from CTP to reperfusion in hours. Receiver operating characteristic analysis was used to identify the optimal infarct growth rate that better discriminated 90-day good outcome(mRS 0-2). Fast progression was defined as having an infarct growth rate above the identified threshold. Results: 461 patients qualified for the study. The optimal infarct growth rate threshold to predict good outcome was 3.9 ml/h (sensitivity 79%, specificity 47%). 286 (62%) were subsequently categorized as fast progressors. There were no differences in baseline characteristics between fast and slow progressors except for higher NIHSS(16[12-21]vs16[11-21],p=0.02), longer Last known normal to CT times (367 mins [219-679]vs 269.5[111.5-570],p<0.001) and smaller CTP core volumes (3.8cc[0-20] vs 8[0-25.5],p=0.02). Fast progressors had larger FIV (36.7[18.6-66.9] vs 7[3.5-16],p<0.001), lower rates of good outcome (52.8% vs 77.4%, p<0.001), higher mortality rates (17.5% vs 6%,p=0.02). There was a trend toward higher rates of parenchymal hematomas in fast progressors (5.1% vs 1.7%,p=0.07). On multivariate analysis, only ASPECTS was an independent predictor of fast progression (aOR 0.7 95%CI[0.54-0.91,p=0.007) while CTP parameters did not reach statistical significance. Conclusions: Fast progression of infarct growth is associated with poorer clinical outcomes. ASPECTS may help triage transfers when assessing patients for ET. Larger studies are warranted.