Asymptomatic hemorrhage after thrombolysis may not be benign: prognosis by hemorrhage type in the Canadian alteplase for stroke effectiveness study registry.

BACKGROUND AND PURPOSE: There is ongoing controversy about the impact of hemorrhagic transformation after thrombolysis on long-term functional outcome. We sought to study the relation between the type of hemorrhagic transformation on CT scans and functional outcome. METHODS: Data were obtained from the Canadian Alteplase for Stroke Effectiveness Study. This study was established as a registry to prospectively collect data for acute stroke patients receiving intravenous alteplase within 3 hours from stroke onset between February 1999 and June 2001. Follow-up was completed at 90 days, and good functional outcome was defined as a modified Rankin Scale score of 0 or 1. Copies of head CT scans obtained at 24 to 48 hours after starting treatment were read in consensus by a central reading panel consisting of 1 neuroradiologist and 1 stroke neurologist. According to European Cooperative Acute Stroke Study criteria, hemorrhagic transformation was classified as none, hemorrhagic infarction (HI-1 and HI-2), or parenchymal hematoma (PH-1 and PH-2). We compared outcome across groups and performed a multivariable analysis including previously determined important predictors of good outcome in acute ischemic stroke. RESULTS: From 1135 patients enrolled at 60 centers across Canada, 954 follow-up CT scans were assessable. We observed some hemorrhagic transformation in 259 of 954 (27.1%) patients (110 HI-1, 57 HI-2, 48 PH-1, and 44 PH-2). Proportions of patients with good outcome were 41% with no hemorrhagic transformation, 30% with HI-1, 17% with HI-2, 15% with PH-1, and 7% with PH-2 (P<0.0001, chi(2) test). After adjustment for age, baseline serum glucose, baseline Alberta Stroke Program Early CT score, and baseline National Institutes of Health Stroke Scale score, HI-1 was not a predictor of outcome. However, HI-2 (odds ratio=0.38, 95% CI=0.17 to 0.83), PH-1 (odds ratio=0.32, 95% CI=0.12 to 0.80), and PH-2 (odds ratio=0.14, 95% CI=0.04 to 0.48) were all negative predictors of outcome. CONCLUSIONS: The likelihood of a poor outcome after thrombolysis was proportional to the extent of hemorrhage on CT scans. HI grades of hemorrhagic transformation may not be benign.

How well does ASPECTS predict the outcome of acute stroke treated with IV tPA?

The authors measured the association of early ischemic change on CT scan, measured using the Alberta Stroke Programme Early CT score (ASPECTS), and functional outcome in 825 patients with anterior circulation stroke treated with IV thrombolysis within 3 hours of onset. ASPECTS predicted outcome in a graded fashion (linearly for ASPECTS 6 through 10; pattern ill-defined for ASPECTS 0 through 5) but discriminated individual outcomes weakly. Except perhaps when early ischemic change is extensive, clinicians should not estimate prognosis using ASPECTS alone.

ASPECTS on CTA source images versus unenhanced CT: added value in predicting final infarct extent and clinical outcome.

BACKGROUND AND PURPOSE: The Alberta Stroke Program Early CT Score (ASPECTS) is a grading system to assess ischemic changes on CT in acute ischemic stroke. CT angiography-source images (CTA-SI) predict final infarct volume. We examined whether the final infarct ASPECTS and clinical outcome were more related to acute CTA-SI ASPECTS than to the acute noncontrast CT (NCCT) ASPECTS. METHODS: ASPECTS was assigned by 2 raters on the acute NCCT, CTA-SI, and follow-up imaging. The mean baseline ASPECTS of acute NCCT and CTA-SI was compared with the follow-up ASPECTS. Rate ratios (RRs) were used to quantify the relationship between the dichotomized baseline ASPECTS (categorized as 0 to 7 versus 8 to 10) and favorable patient outcome. RESULTS: Thirty-nine patients were recruited. Proximal occlusion (internal carotid artery or middle cerebral artery) was seen in 62%, M2 occlusion in 18%, and no occlusion was seen in 20% of patients. The median time between symptom onset and imaging was 1.9 (1.2 to 2.5) hours. There was a significantly larger difference of 1.4 between the mean baseline NCCT and CTA-SI ASPECTS in patients who had more ischemic changes (follow-up ASPECTS=0 to 3) than a difference of 0.6 in patients who had near-to-normal CT scans (follow-up ASPECTS=8 to 10). The rate of favorable outcome for acute NCCT ASPECTS of 8 to 10 was 51.8% versus 25.0% for 0 to 7 (RR, 2.1, 95% CI: 0.7 to 5.9, P=0.12). For acute CTA-SI ASPECTS of 8 to 10, the rate of favorable outcome was 58.8% versus 31.8% for 0 to 7 (RR, 1.8, 95% CI: 0.9 to 3.8, P=0.09). CONCLUSIONS: CTA-SI ASPECTS provides added information in the prediction of final infarct size.

The probability of middle cerebral artery MRA flow signal abnormality with quantified CT ischaemic change: targets for future therapeutic studies.

OBJECTIVES: In this study we define the probability of vascular abnormality in the middle cerebral artery (MCA) territory according to the extent of ischaemic change seen using computed tomography (CT). We assessed the sensitivity and specificity of the hyperdense middle cerebral artery (HMCA) and the "dot" sign using magnetic resonance angiography (MRA). METHODS: Patients presenting with ischaemic stroke had a CT scan (<6 h) prior to MRI (<7 h). A quantitative CT scoring system (ASPECTS) was applied to CT and diffusion weighted images (DWI) at baseline and follow up (24 h) by five independent observers. The presence of HMCA and the MCA "dot" sign was also evaluated. An expert reader assessed the 3D time of flight (TOF) MRA in the anterior circulation for areas of decreased vascular signal in the MCA territory, with an absent signal taken to represent severely reduced or absent flow. RESULTS: A total of 100 consecutive patients had baseline CT and MR scans. The median NIHSS was 9. The median CT ASPECTS was 8 and equalled the median DWI ASPECTS. There were a total of 10 HMCA and 19 MCA "dot" signs, with four patients having both HMCA and "dot" signs. A total of 47 MRA flow signal abnormalities were observed in the anterior circulation. CONCLUSIONS: In the absence of accessible neurovascular imaging, the extent of CT ischaemia (ASPECTS) is a strong predictor of vascular occlusion. The CT hyperdense artery signs have a high positive predictive value but low negative predictive value.

Is intravenous recombinant tissue plasminogen activator (rt-PA) safe for use in patients over 80 years old with acute ischaemic stroke? - The Calgary experience.

BACKGROUND: Acute ischaemic stroke is common in older people. There is one licensed acute treatment, intravenous recombinant tissue plasminogen activator, but little information is available on its safety in over 80 year olds. DESIGN: Review of prospectively collected data on 62 consecutive patients, aged 80 years and over, treated with recombinant tissue plasminogen activator in a tertiary centre. METHODS: Admission demographic data, clinical and CT stroke severity, symptomatic haemorrhage rate and other complications were compared between patients who were dead at 3 months and those who survived. Discharge location and functional scores outcome were reviewed. The results were compared to those of other studies. RESULTS: The in-hospital death rate was 24.2% and 3 month mortality 32.8%. Patients that died had higher stroke severity scores at presentation (NIHSS 20 versus 16, P = 0.04). Six patients (9.7%) suffered symptomatic intracranial haemorrhage (SICH), three were classified as fatal (4.8%). SICH was significantly associated with death by 3 months (P = 0.02). There were no other serious bleeding complications. The SICH rate is similar to that from other thrombolytic studies and the mortality rate is similar to the natural history of stroke in older populations. CONCLUSION: Older patients have high mortality and morbidity from stroke. Older patients should not be excluded from recombinant tissue plasminogen activator treatment on the basis of age alone.

Mild neurological symptoms despite middle cerebral artery occlusion.

BACKGROUND AND PURPOSE: Only a small percentage of stroke patients are treated with thrombolytic therapy. We sought to determine whether vessel occlusion in mild strokes represented a new target population for interventional therapy. METHODS: We imaged 106 acute stroke patients with MRI. Patients were identified with evidence of middle cerebral artery (MCA) occlusion and mild or no stroke signs (National Institutes of Health Stroke Scale [NIHSS] 3, and MCA occlusion. RESULTS: We identified 5 patients with absent flow on MRA in the MCA and mild or no stroke signs (NIHSS