Risk factors of symptomatic intracerebral hemorrhage after tPA therapy for acute stroke

Abstract

Background: Studies evaluating predictors of tPA-associated symptomatic intracerebral hemorrhage (SICH) have typically focused on clinical and CT-based variables. MRI-based variables have generally not been included in predictive models, and little is known about the influence of reperfusion on SICH risk.

Methods: Seventy-four patients were prospectively enrolled in an open-label study of intravenous tPA administered between 3 and 6 hours after symptom onset. An MRI was obtained before and 3 to 6 hours after tPA administration. The association between several clinical and MRI-based variables and tPA-associated SICH was determined using multivariate logistic regression analysis. SICH was defined as a > or = 2 point change in National Institutes of Health Stroke Scale Score (NIHSSS) associated with any degree of hemorrhage on CT or MRI. Reperfusion was defined as a decrease in PWI lesion volume of at least 30% between baseline and the early follow-up MRI.

Results: SICH occurred in 7 of 74 (9.5%) patients. In univariate analysis, NIHSSS, DWI lesion volume, PWI lesion volume, and reperfusion status were associated with an increased risk of SICH (P<0.05). In multivariate analysis, DWI lesion volume was the single independent baseline predictor of SICH (odds ratio 1.42; 95% CI 1.13 to 1.78 per 10 mL increase in DWI lesion volume). When early reperfusion status was included in the predictive model, the interaction between DWI lesion volume and reperfusion status was the only independent predictor of SICH (odds ratio 1.77; 95% CI 1.25 to 2.50 per 10 mL increase in DWI lesion volume).

Conclusions: Patients with large baseline DWI lesion volumes who achieve early reperfusion appear to be at greatest risk of SICH after tPA therapy.

Figure

This scatterplot displays the baseline DWI lesion volumes for 4 groups of patients: (1) patients with SICH and reperfusion (top row), (2) patients with SICH but without reperfusion (second row), (3) patients without SICH with reperfusion (third row), and (4) patients without SICH and without reperfusion (bottom row). Patients with reperfusion are marked with open circles (●), and patients without reperfusion are marked with closed circles (○). The bars indicate the mean±SEM for each group. Patients with SICH are characterized by reperfusion in the setting of large baseline DWI lesion volumes. The 2 patients with SICH who do not follow this pattern are numbered in the figure. Patient 1 had evidence of reperfusion on his follow-up scan without signs of hemorrhage. He developed an SICH during carotid endarterectomy performed the day after his stroke. Patient 2 had evidence of minor hemorrhagic transformation of his acute ischemic lesion on his follow-up MRI (4.5 hours after tPA therapy) associated with a 2 point increase in NIHSSS.