Background and Purpose-The relationship between reperfusion and hemorrhagic transformation (HT) remains uncertain.Therefore, we aimed to clarify the relationship between the time course of recanalization and the risk of HT in patients with cardioembolic stroke studied within 6 hours of symptom onset. Methods-Fifty-three patients with atrial fibrillation and nonlacunar stroke in the middle cerebral artery (MCA) territory admitted within the first 6 hours after symptom onset were prospectively studied. Serial TCD examinations were performed on admission and at 6, 12, 24, and 48 hours. CT was performed within 6 hours after stroke onset and again at 36 to 48 hours. Results-Proximal and distal MCA occlusions were detected in 32 patients (60.4%) and 18 patients (34%), respectively.Early spontaneous recanalization occurring within 6 hours was identified in 10 patients (18.8%). Delayed recanalization (Ͼ6 hours) occurred in 28 patients (52.8%). HT on CT scan was detected in 17 patients (32%) within the first 48 hours. Only large parenchymal hemorrhage (PH2) was significantly associated with an increase (Pϭ0.038, Kruskal-Wallis test) in the National Institutes of Health Stroke Scale (NIHSS) score compared with the other subtypes of HT. Univariate analysis revealed that an NIHSS score of Ͼ14 on baseline (Pϭ0.001), proximal MCA occlusion (Pϭ0.004), hypodensity Ͼ33% of the MCA territory (Pϭ0.012), and delayed recanalization occurring Ͼ6 hours of stroke onset (Pϭ0.003) were significantly associated with HT. With a multiple logistic regression model, delayed recanalization (OR 8.9; 95% CI 2.1 to 33.3) emerged as independent predictor of HT. Conclusions-Delayed recanalization occurring Ͼ6 hours after acute cardioembolic stroke is an independent predictor of HT.

Intravenous rtPA is associated with early recanalization, which leads to lower infarct size and better clinical outcome. Early recanalization is a powerful independent predictor of functional independence at 3 months.

Background and Purpose-The role of early and delayed recanalization after thrombolysis in the development of hemorrhagic transformation (HT) subtypes remains uncertain. We sought to explore the association between the timing of recanalization and HT risk in patients with proximal middle cerebral artery (MCA) occlusion treated with intravenous recombinant tissue plasminogen activator (rtPA) Ͻ3 hours of stroke onset and to investigate the relationship between HT subtypes, infarct volume, and outcome. Methods-Thirty-two patients with acute stroke caused by proximal MCA occlusion treated with rtPA Ͻ3 hours of symptom onset were prospectively studied. Serial transcranial Doppler examinations were performed on admission and at 6, 12, 24, and 48 hours. Presence and type of HT were assessed on CT at 36 to 48 hours. Modified Rankin scale was used to assess outcome at 3 months. Results-Early and delayed recanalization was identified in 17 patients (53.1%) and 8 patients (25%), respectively. HT was detected in 14 patients (43.7%): 4 (12.5%) with hemorrhagic infarction (HI 1 ), 5 (15.6%) with HI 2 , 3 (9.3%) with parenchymal hematoma (PH 1 ), and 2 (6.8%) with PH 2 . Distribution of HT subtypes differed significantly (Pϭ0.025), depending on the time to artery reopening. Eight of 9 (89%), 1 of 5 (20%), and 8 of 18 (44.4%) with HI 1 -HI 2 , with PH 1 -PH 2 , and without HT, respectively, recanalized in Ͻ6 hours. Delayed recanalization was observed in 1 patient with HI 1 -HI 2 (11%), 4 with PH 1 -PH 2 (80%), and 3 without HT (16.6%). Neurological improvement was significantly (PϽ0.001) more frequent in patients with HI 1 -HI 2 (88%) than in those without HT (39%

Background and Purpose-Intravenous thrombolysis in stroke achieves arterial recanalization in Ϸ50% of cases.Determining temporal profile of recanalization may address patient selection and potential benefits of further rescue reperfusion techniques. Methods-We studied 179 consecutive intravenous tissue plasminogen activator (t-PA)-treated patients with intracranial artery occlusion. Continuous transcranial Doppler assessed recanalization (none-partial-complete) at 60 minutes (early), 120 minutes (delayed) after t-PA bolus, and 6 hours (late) from symptom onset. Outcomes were determined: National Institutes of Health Stroke Scale (NIHSS; 48-hour NIHSS) and 3-month modified Rankin Scale (mRS). Results-On admission, 68% of patients presented proximal middle cerebral artery occlusion, median NIHSS 17.Early recanalization was complete for 30 patients (17%), partial for 50 (28%), and none for 99 (55%). Delayed recanalization was complete for 56 patients (31%), partial for 39 (22%), and none for 84 (47% T hrombolytic therapy with intravenous tissue plasminogen activator (t-PA) for acute ischemic stroke has shown to be effective by increasing and anticipating recanalization of the occluded brain vessels. 1,2 In the last years, different studies using multiple methods to assess cerebral flow described recanalization rates ranging from 30% to 60% in the first 6 to 24 hours after t-PA treatment. [2][3][4][5][6] However, the timing and temporal profile of recanalization in the very first hours after t-PA bolus remain uncertain. Continuous transcranial Doppler (TCD) monitoring at the bedside seems to be the best diagnostic tool to assess real-time recanalization. 7,8 The CLOTBUST study recently reported a 38% rate of complete recanalization at 2 hours after t-PA bolus in patients who received continuous ultrasound. 3 Nevertheless, detailed description of the temporal profile of partial versus complete recanalization during this time remains unknown. One hour after thrombolytic treatment initiation, information about the likelihood of complete recanalization during the following hours may help physicians identify those patients in whom intravenous t-PA will fail to induce early recanalization, making them eligible for rescue reperfusion therapies. We aim to study the probability and temporal profile of recana- Patients and MethodsFrom February 2002 to June 2005, all patients with an acute (Ͻ6 hours from symptom onset) stroke admitted to the emergency department of a university hospital were prospectively studied. A total of 928 patients were evaluated and underwent urgent extracranial and TCD ultrasound examination. Patients with an inadequate temporal bone window were excluded. A total of 179 patients had a TCD-documented intracranial occlusion and fulfilled established criteria for t-PA treatment (0.9 mg/kg). 1 None of these patients received rescue recanalization therapies. Clinical ProtocolA detailed history of vascular risk factors was obtained from each patient. To identify potential mechanism of cerebral infarction, ...

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