Abstract WP38: Early Progressive Ischemia Predicts Worse Clinical Outcome In Acute Ischemic Stroke and Is Decreased With tPA Treatment
Background: While some ischemic stroke patients improve rapidly after onset, many show no improvement or even worsening in the first days after stroke. We hypothesized that development of brain regions with “progressive ischemia” within hours of stroke onset may predict poor clinical outcome.
Methods: Acute ischemic stroke patients underwent two MR scans: within 4.5 hrs (tp1) and at 6 hrs (tp2) after onset. Mean transit time (MTT) maps measured tp1 and tp2 perfusion deficits. “Perfusion deficit” was defined as MTT > 6 s longer than the contralateral median. Volume of progressive ischemia (VPR) was defined by regions of normal perfusion (MTT<6) at tp1 which became abnormal (MTT>6) at tp2. Bivariate analyses between VPR and ΔNIHSS from admission to 1 month, VPR and 1 month mRS, and VPR and 1 month mortality were performed. Multivariable regression identified if VPR predicted ΔNIHSS, mRS, and mortality after adjusting for admission NIHSS, volume of reperfusion (Vrep), and volume of tp1 perfusion deficit (Vtp1). Regression analysis determined if tPA treatment predicted VPR after adjusting for admission NIHSS and Vtp1.
Results: Fifty patients were scanned at 2.9 (tp1) and 6.4 hrs (tp2) after onset. Mean NIHSS=14; 74% received IV tPA. Progressive ischemia was found in 34 (68%) patients (Fig. shows patient example). Mean Vtp1, Vrep, and VPR were 50, 14.4, and 6.4ml, respectively. VPR correlated with ΔNIHSS (r=-.25, p=0.096), mRS (r=.44, p=0.002), and mortality (r=.31, p=0.034). In multivariable analysis, VPR predicted less improvement in ΔNIHSS (β=-.19, p=0.019) and greater disability on mRS (β=0.06, p=0.016). In multivariable analysis, tPA treatment negatively predicted VPR (β=-3.6, p=0.050).
Conclusion: Progressive ischemia, identified in 2/3 of our cohort, predicted worse outcomes. As tPA treatment predicted less progressive ischemia, therapies aimed at preventing progressive ischemia in acute ischemic stroke may be considered in addition to promoting reperfusion.
- © 2012 by American Heart Association, Inc.