Ken Uchino
Research interests
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InterestsStroke, Stroke Thrombolysis, Stroke Imaging, Stroke epidemiology
Publications
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5.38Impact points
Treatment of risk factors to prevent stroke.
Neurotherapeutics : the journal of the American Society for Experimental NeuroTherapeutics. 06/2011; 8(3):463-74.
Much of the decline in stroke incidence and mortality for the past several decades in Western countries has been attributed to better treatment of risk factors. Many epidemiological studies and clinical trials confirmed the importance of managing hypertension. Comparative trials of anti-hypertensive... [more] Much of the decline in stroke incidence and mortality for the past several decades in Western countries has been attributed to better treatment of risk factors. Many epidemiological studies and clinical trials confirmed the importance of managing hypertension. Comparative trials of anti-hypertensive drugs or drug classes have not yielded clear results, but blood pressure variability may play an important role beyond the absolute value of blood pressure. Diabetes therapy remains a conundrum. Although diabetes is clearly a risk factor for ischemic stroke, treatment trials targeting different glycemic goals have not indicated that glucose lowering results in stroke prevention. Trials focused on insulin resistance are ongoing and they may be able to help establish the management of diabetes/impaired glucose tolerance. Evidence for treatment of dyslipidemia has contrasted science to diabetes mellitus. Dyslipidemia has not been strongly or consistently linked to ischemic stroke but the Stroke Prevention by Aggressive Reduction in Cholesterol Levels (SPARCL) trial showed the impact of statin treatment in stroke prevention. The results of clinical trials investigating dabigatran and rivaroxaban clearly indicate alternative strategies to vitamin K antagonists in stroke prevention for persons with atrial fibrillation. Evidence for stroke prevention by life style modification, treating metabolic syndrome, sleep disordered breathing, lipoprotein (a), hyperhomocysteinemia, and coagulation disorders are also discussed.
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16.23Impact points
ACP Journal Club. Immediate surgery reduced long-term risk for nonperioperative stroke in severe asymptomatic carotid artery stenosis.
Annals of internal medicine. 02/2011; 154(4):JC2-7.
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1.72Impact points
Evaluation of vertebral artery origin stenosis: a retrospective comparison of three techniques.
Journal of neuroimaging : official journal of the American Society of Neuroimaging. 12/2010; 22(1):14-6.
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Increased Cerebral Oxygen Metabolism and Ischemic Stress in Subjects with Metabolic Syndrome-Associated Risk Factors: Preliminary Observations.
Translational stroke research. 09/2010; 1(3):178-183.
Hypertension, diabetes, obesity, and dyslipidemia are risk factors that characterize metabolic syndrome (MetS), which increases the risk for stroke by 40%. In a preliminary study, our aim was to evaluate cerebrovascular reactivity and oxygen metabolism in subjects free of vascular disease but with o... [more] Hypertension, diabetes, obesity, and dyslipidemia are risk factors that characterize metabolic syndrome (MetS), which increases the risk for stroke by 40%. In a preliminary study, our aim was to evaluate cerebrovascular reactivity and oxygen metabolism in subjects free of vascular disease but with one or more of these risk factors. Volunteers (n=15) 59±15 (mean±SD)years of age clear of cerebrovascular disease by magnetic resonance angiography but with one or more risk factors were studied by quantitative positron emission tomography for measure ment of cerebral blood flow, oxygen consumption, oxygen extraction fraction (OEF), and acetazolamide cerebrovascular reactivity. Eight of ten subjects with MetS risk factors had OEF >50%. None of the five without risk factors had OEF >50%. The presence of MetS risk factors was highly correlated with OEF >50% by Fisher's exact test (p<0.007). The increase in OEF was significantly (P<0.001) correlated with cerebral metabolic rate for oxygen. Increased OEF was not associated with compromised acetazolamide cerebrovascular reactivity. Subjects with one or more MetS risk factors are characterized by increased cerebral oxygen consumption and ischemic stress, which may be related to increased risk of cerebrovascular disease and stroke.
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Endovascular treatment of basilar artery occlusion by manual aspiration thrombectomy.
Journal of neurointerventional surgery. 06/2010; 2(2):110-4.
Basilar artery occlusion remains one of the most devastating subtypes of stroke. Intravenous and intra-arterial therapy have altered the natural history of this disease; however, clinical results remain poor. Therefore, exploring more aggressive and innovative management is warranted. Six consecutiv... [more] Basilar artery occlusion remains one of the most devastating subtypes of stroke. Intravenous and intra-arterial therapy have altered the natural history of this disease; however, clinical results remain poor. Therefore, exploring more aggressive and innovative management is warranted. Six consecutive patients presenting with a basilar artery occlusion were treated with the same general algorithm of intra-arterial tissue plasminogen activator and mechanical thrombectomy with the Merci retrieval system. If complete recanalization was not achieved after two passes, manual syringe aspiration through a 4.3F catheter was employed. All interventions utilizing aspiration thrombectomy resulted in recanalization, with five out of six cases displaying TIMI3/TICI3 flow and one patient resulting in complete recanalization of the basilar artery with persistent thrombus in one P2 segment (TIMI2/TICI2B). All patients survived, with five out of six independent in activities of daily living at 3 months (mRS 0-2). Our small case series indicates that aspiration thrombectomy performed manually through a 4.3F catheter can facilitate recanalization of basilar artery occlusion with acceptable clinical outcomes.
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3.54Impact points
Does current oral antiplatelet agent or subtherapeutic anticoagulation use have an effect on tissue-plasminogen-activator-mediated recanalization rate in patients with acute ischemic stroke?
Cerebrovascular diseases (Basel, Switzerland). 01/2010; 30(5):508-13.
Our goal is to assess if current antiplatelet (AP) use has an effect on recanalization rate and outcome in acute stroke patients. We conducted a retrospective analysis of acute stroke patients who received intravenous (IV) recombinant tissue plasminogen activator (rt-PA) and had transcranial Doppler... [more] Our goal is to assess if current antiplatelet (AP) use has an effect on recanalization rate and outcome in acute stroke patients. We conducted a retrospective analysis of acute stroke patients who received intravenous (IV) recombinant tissue plasminogen activator (rt-PA) and had transcranial Doppler examination within 3 h of symptom onset. The TCD findings were interpreted using the Thrombolysis in Brain Ischemia flow grading system as persistent arterial occlusion, reocclusion or complete recanalization. Complete recanalization was defined as established Thrombolysis in Brain Ischemia 4 or 5 within 2 h of IV rt-PA. The patients were divided based on their current use of AP agents. Comparisons were made between the different groups based on recanalziation rate, reocclusion and good long-term outcome (mRS ≤ 2) using χ(2) test. Multiple regression analysis was used to identify AP use as a predictor for recanalization and outcome including symptomatic intracranial hemorrhage after controlling for age, baseline NIHSS score, time to treatment, previous vascular event, hypertension and diabetes mellitus. Two hundred and eighty-four patients were included; 154 (54%) males, 130 (46%) females, with a mean age of 69.5 ± 13 years. The median baseline NIHSS score was 16 ± 5. The median time to TCD examination was 131 ± 38 min from symptom onset. The median time to IV rt-PA was 140 ± 34 min. One hundred eighty patients were not on AP prior to their stroke, 76 were on aspirin, 15 were on clopidogrel, 2 were on aspirin-dipyridamole combination, 2 were on both aspirin and clopidogrel, and 9 patients on subtherapeutic coumadin. In patients who were naïve to AP, 68/178 (38.2%) had complete recanalization, whereas in the AP group, 25/91 (28%) had complete recanalization. Patients on aspirin alone had a lower recanalization rate (16/72) as compared to those not on AP (22 vs. 39%) (p = 0.017), while those on clopidogrel had higher rates of complete recanalization (9/19, 60%). There was no difference in the rate of symptomatic intracranial hemorrhages in patients on AP agents as compared to those not on AP (9/180, 5% vs. 9/95, 9.5%) (p = 0.13). A good long-term outcome (mRS ≤2) was achieved in 85/160 (53%) of the patients naïve to AP and in 33/84 (39%) of the patients on AP (p = 0.035). In multiple regression, AP use was not a predictor of either recanalization rate (p = 0.057) or good outcome (p = 0.27). No correlation was found between AP use and recanalization rate and good outcome in patients with acute stroke who received IV rt-PA treatment. Prior AP use should not defer patients from receiving IV rt-PA treatment in an acute stroke setting.
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3.54Impact points
Transient Ischemic Attack after Tissue Plasminogen Activator: Aborted Stroke or Unnecessary Stroke Therapy?
Cerebrovascular diseases (Basel, Switzerland). 11/2009; 29(1):57-61.
Background: The frequency with which intravenous thrombolysis for acute ischemic stroke results in normal clinical and radiographic status is currently unknown. Methods: Patients who received intravenous thrombolysis at community hospitals and a stroke center were retrospectively analyzed for occurr... [more] Background: The frequency with which intravenous thrombolysis for acute ischemic stroke results in normal clinical and radiographic status is currently unknown. Methods: Patients who received intravenous thrombolysis at community hospitals and a stroke center were retrospectively analyzed for occurrence of normal imaging after tissue plasminogen activator (tPA) treatment. The cases were classified as nonischemic process (stroke mimic), transient ischemic attack (TIA) or ischemic stroke. The occurrence rate and predictors of each condition were sought. Results: Of 254 patients who received tPA, 9 (3.5%) had a nonischemic process, 23 (9.1%) had TIA, and 222 (87%) were diagnosed with ischemic stroke. Nonischemic process patients were younger and were more likely to have received tPA at a community hospital than those with TIA or stroke. TIA was associated with lower pretreatment serum glucose, prevalence of coronary artery disease and stroke severity but not to time to treatment. Conclusion: Over 10% of patients who receive tPA for cerebral ischemia do not develop ischemic injury. tPA use for a nonischemic process is infrequent but is associated with community hospital use.
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7.04Impact points
Mechanical Approaches Combined With Intra-Arterial Pharmacological Therapy Are Associated With Higher Recanalization Rates Than Either Intervention Alone in Revascularization of Acute Carotid Terminus Occlusion.
Stroke; a journal of cerebral circulation. 05/2009;
BACKGROUND AND PURPOSE: Acute stroke attributable to internal carotid artery terminus occlusion carries a poor prognosis. Vessel recanalization is crucial to improve clinical outcome. Historically, pharmacological thrombolysis alone has low recanalization rates. We sought to determine whether adjunc... [more] BACKGROUND AND PURPOSE: Acute stroke attributable to internal carotid artery terminus occlusion carries a poor prognosis. Vessel recanalization is crucial to improve clinical outcome. Historically, pharmacological thrombolysis alone has low recanalization rates. We sought to determine whether adjunctive mechanical approaches achieve better vessel recanalization and functional outcome. METHODS: We retrospectively reviewed 75 consecutive endovascular cases of acute internal carotid artery terminus occlusions treated at our center between 1998 and 2008. Mechanical approaches (MERCI retrieval/angioplasty/stent) with and without adjunctive intra-arterial pharmacological therapy (urokinase or tissue plasminogen activator) was compared to intra-arterial lytics alone. Univariate and multivariate analyses were performed to determine predictors of recanalization (thrombolysis in myocardial infarction grades 2 to 3) and favorable functional outcome (modified Rankin score </=2) at 3 months. RESULTS: Lowest recanalization rates were observed with intra-arterial lytics alone (3/17, 17.6%). MERCI embolectomy combined with intra-arterial lytics was associated with the highest recanalization rates (18/21, 85.7%; P<0.0001). MERCI embolectomy alone achieved 46.2% recanalization rates (6/13; P=0.23). Angioplasty or stenting and intra-arterial lytics achieved 25% (2/8; P=0.65) and 40% (4/10; P=0.085) recanalization, respectively. In multivariate analysis, combination of MERCI embolectomy with intra-arterial lytics (OR, 16.2; CI, 4.6-77.6), or any mechanical technique with intra-arterial lytics (OR, 6.7; CI, 2.5-19.5) independently predicted thrombolysis in myocardial infarction 2 to 3 recanalization. Clinically significant parenchymal hemorrhage rates were 7.5% with combination (3/38) and 12.5% with pharmacological therapies (2/16; P=0.46). Using stepwise logistic regression, age (OR, 0.95; CI, 0.90-0.995), baseline NIHSS (OR, 0.82; CI, 0.70-0.96), and thrombolysis in myocardial infarction 2 to 3 recanalization (OR, 4.0; CI, 1.1-14.4) were associated with favorable functional outcome. CONCLUSIONS: Combined mechanical and intra-arterial pharmacological therapy is associated with higher recanalization rates than either intervention alone in acute internal carotid artery terminus occlusion revascularization.
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2.86Impact points
Lower pretreatment cerebral blood volume affects hemorrhagic risks after intra-arterial revascularization in acute stroke.
Neurosurgery. 12/2008; 63(5):874-8; discussion 878-9.
OBJECTIVE: Intra-arterial therapies are being used more frequently in patients presenting with acute cerebral occlusions, but they have been limited by the potential for hemorrhage. We sought to determine whether pretreatment computed tomography perfusion parameters might help to identify patients a... [more] OBJECTIVE: Intra-arterial therapies are being used more frequently in patients presenting with acute cerebral occlusions, but they have been limited by the potential for hemorrhage. We sought to determine whether pretreatment computed tomography perfusion parameters might help to identify patients at a higher risk of developing intracranial hemorrhage after intra-arterial stroke revascularization treatment. METHODS: We retrospectively reviewed all patients at the University of Pittsburgh Medical Center and Michigan State University who underwent computed tomography perfusion imaging of the brain before intra-arterial thrombolysis between January 2006 and June 2007. Demographic information, angiographic variables, and types of endovascular interventions were recorded. The mean transit time and cerebral blood volumes were recorded for the ipsilateral and contralateral middle cerebral artery territories. A binary logistic regression model was constructed to determine the independent predictors of developing intracranial hemorrhage. RESULTS: A total of 57 patients (33 from the University of Pittsburgh and 24 from Michigan State University) with a mean age of 66 +/- 13 years and mean National Institutes of Health Stroke Scale scores of 16 +/- 5 were studied. The overall recanalization (Thrombolysis in Myocardial Infarction Trial scale 2 or 3 flow) was 72% for the cohort, and the overall rate of parenchymal hemorrhage was 5 of 57 (9%) patients. The overall hemorrhage rate was 19 of 57 (33%) patients. The only variable found to be predictive of the development of hemorrhage after intervention was reduced pretreatment cerebral blood volume (odds ratio, 0.49; 95% confidence interval, 0.35-0.91; P < 0.022). CONCLUSION: A reduced pretreatment ipsilateral cerebral blood volume value before endovascular revascularization of an acute middle cerebral artery or internal carotid artery occlusion significantly increases the risk of an intracranial hemorrhage.
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7.04Impact points
Platelet C4d Is Associated With Acute Ischemic Stroke and Stroke Severity.
Stroke; a journal of cerebral circulation. 10/2008;
BACKGROUND AND PURPOSE: Platelets bearing complement C4d were recently reported to be 99% specific for a diagnosis of systemic lupus erythematosus (SLE) and associated with neuropsychiatric lupus. We compared the prevalence of platelet C4d and investigated the clinical associations of platelet C4d i... [more] BACKGROUND AND PURPOSE: Platelets bearing complement C4d were recently reported to be 99% specific for a diagnosis of systemic lupus erythematosus (SLE) and associated with neuropsychiatric lupus. We compared the prevalence of platelet C4d and investigated the clinical associations of platelet C4d in patients with acute ischemic stroke. METHODS: We recruited 80 patients hospitalized for acute ischemic stroke. Stroke severity was measured by the National Institutes of Health Stroke Scale (NIH-SS). Infarct volume was determined by MRI. Platelet C4d was measured by flow cytometry. RESULTS: Mean age was 57.9 years (range: 24.6 to 86.8 years), 58% were male, and 91% were white. Eight patients (10%) with acute ischemic stroke were platelet C4d-positive, which was significantly higher in prevalence compared to healthy controls (0%, P<0.0001) and non-SLE patients with immune/inflammatory disease (2%, P=0.004). The median NIH-SS score and infarct volume for acute stroke patients were 6 (interquartile range [IQR]: 2 to 13) and 3.4 cc (IQR: 1.1 to 16.6), respectively. Platelet C4d-positive patients were more likely to have a severe stroke compared to those with negative platelet C4d (NIH-SS median: 17.5 versus 5, P=0.003). Positive platelet C4d was independently associated with stroke severity (P=0.03) after controlling for age, anticardiolipin antibody (aCL) status, and total anterior circulation of stroke involvement, and also with infarct volume (P=0.005) after controlling for age, aCL status, and old stroke by MRI. CONCLUSIONS: Platelet C4d is associated with severe acute ischemic stroke. Platelet C4d may be a biomarker as well as pathogenic clue that links cerebrovascular inflammation and thrombosis.
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8.17Impact points
Better late than never?: the story of arterial recanalization in acute ischemic stroke.
Neurology. 05/2007; 68(17):1335-6.
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7.04Impact points
Site of arterial occlusion identified by transcranial Doppler predicts the response to intravenous thrombolysis for stroke.
Stroke; a journal of cerebral circulation. 04/2007; 38(3):948-54.
BACKGROUND AND PURPOSE: The objective of this study was to examine clinical outcomes and recanalization rates in a multicenter cohort of stroke patients receiving intravenous tissue plasminogen activator by site of occlusion localized with bedside transcranial Doppler. Angiographic studies with intr... [more] BACKGROUND AND PURPOSE: The objective of this study was to examine clinical outcomes and recanalization rates in a multicenter cohort of stroke patients receiving intravenous tissue plasminogen activator by site of occlusion localized with bedside transcranial Doppler. Angiographic studies with intraarterial thrombolysis suggest more proximal occlusions carry greater thrombus burden and benefit less from local therapy. METHODS: Using validated transcranial Doppler criteria for specific arterial occlusion (Thrombolysis in Brain Ischemia flow grades), we compared the rate of dramatic recovery (National Institutes of Health Stroke Scale score < or =2 at 24 hours) and favorable outcomes at 3 months (modified Rankin Scale < or =1) for each occlusion site. We determined the likelihood of recanalization at various occlusion sites and its predictors. Then, stepwise logistic regression was used to determine predictors of complete recanalization. RESULTS: Three hundred thirty-five patients had a mean age 69+/-13 years and 48.5% were women (median baseline National Institutes of Health Stroke Scale score 16 [range, 3 to 32], mean time to transcranial Doppler 140+/-84 minutes, and mean time to intravenous tissue plasminogen activator 145+/-68 minutes). Distal middle cerebral artery occlusion had an OR of 2 for complete recanalization (50 of 113 [44.2%], 95% CI: 1.1 to 3.1, P=0.005), proximal middle cerebral artery 0.7 (49 of 163 [30%], 95% CI: 0.4 to 1.1, P=0.13), terminal internal carotid artery 0.1 (one of 17 [5.9%], 95% CI: 0.015 to 0.8, P=0.015), tandem cervical internal carotid artery/middle cerebral artery 0.7 (6 of 22 [27%], 95% CI: 0.3 to 1.9, P=0.5), and basilar artery 0.96 (3 of 10 [30%], 95% CI: 0.2 to 4, P=0.9). Prerecombinant tissue plasminogen activator National Institutes of Health Stroke Scale score, systolic blood pressure, glucose, and Thrombolysis in Brain Ischemia flow grade at the occlusion site were the negative independent predictors for complete recanalization in the final model. There were no associations among time to treatment, stroke mechanisms, or recanalization rate. Patients with no flow (Thrombolysis in Brain Ischemia 0) at the occlusion site had less probability of complete recanalization than patients with dampened flow (Thrombolysis in Brain Ischemia 3) (OR(adj): 0.256, 95% CI: 0.11 to 0.595, P=0.002). Continuous transcranial Doppler monitoring (exposure to ultrasound) was a positive predictor for complete recanalization (OR(adj): 3.02, 95% CI: 1.396 to 6.514, P=0.005). National Institutes of Health Stroke Scale score < or =2 at 24 hours was achieved in 66 of 305 patients (22%): distal middle cerebral artery 33% (35 of 107), tandem cervical internal carotid artery/middle cerebral artery 24% (5 of 21), proximal middle cerebral artery 16% (24 of 155), basilar artery 25% (2 of 8), and none of the patients with terminal internal carotid artery had dramatic recovery (0%, n=14; P=0.003). Modified Rankin Scale score < or =1 was achieved in 90 of 260 patients (35%): distal middle cerebral artery 52% (50 of 96), proximal middle cerebral artery 25% (33 of 131), tandem cervical internal carotid artery/middle cerebral artery 21% (3 of 14), terminal internal carotid artery 18% (2 of 11), and basilar artery 25% (2 of 8) (P<0.001). Patients with distal middle cerebral artery occlusion were twice as likely to have a good long-term outcome as patients with proximal middle cerebral artery (OR: 2.1, 95% CI: 1.1 to 4, P=0.025). CONCLUSIONS: Clinical response to thrombolysis is influenced by the site of occlusion. Patients with no detectable residual flow signals as well as those with terminal internal carotid artery occlusions are least likely to respond early or long term.
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7.04Impact points
Quantitative perihematomal blood flow in spontaneous intracerebral hemorrhage predicts in-hospital functional outcome.
Stroke; a journal of cerebral circulation. 03/2007; 38(2):319-24.
BACKGROUND AND PURPOSE: Few data on xenon computed tomography-based quantitative cerebral blood flow (CBF) in spontaneous intracerebral hemorrhage have been reported. We correlated perihematomal CBF in a retrospective series of 42 subacute spontaneous intracerebral hemorrhage patients undergoing xen... [more] BACKGROUND AND PURPOSE: Few data on xenon computed tomography-based quantitative cerebral blood flow (CBF) in spontaneous intracerebral hemorrhage have been reported. We correlated perihematomal CBF in a retrospective series of 42 subacute spontaneous intracerebral hemorrhage patients undergoing xenon computed tomography with in-hospital discharge status and mortality. METHODS: We calculated 3 area-weighted mean CBF values: (1) within the computed tomography-visible rim of perihematomal edema, (2) within a 1-cm marginal radius around the hematoma, and (3) all cortical regions of interest immediately adjacent to the hematoma. Primary outcomes were in-hospital mortality and discharge status (ordinally as 0=home, 1=acute rehabilitation, 2=nursing home, 3=death). Discharge status was used as a surrogate for in-hospital functional outcome. RESULTS: Median hematoma volume was 14.4 cm(3) (range, 2 to 70). Median perihematomal (low-attenuation rim) CBF was 21.9 cm(3).100 g(-1).min(-1) (range, 6.1 to 81.1), and the median 1-cm marginal radius CBF was 26.8 cm(3).100 g(-1).min(-1) (range, 10.8 to 72.8). The median regional cortical CBF was 26.7 cm(3).100 g(-1).min(-1) (range, 6.9 to 72.6). Eight patients had 1-cm marginal radius or regional cortical CBF values <20 cm(3).100 g(-1).min(-1). Hematoma volume (odds ratio [OR], 1.68 per 10-cm(3) volume; P=0.036) and intraventricular hemorrhage (OR, 1.88 per grade of intraventricular hemorrhage; P=0.036) predicted mortality. Two CBF measures, hydrocephalus, and IVH predicted poor in-hospital functional outcome in bivariate analysis. Each CBF measure (OR, 0.34 to 0.43; P<0.001 to 0.003) and intraventricular hemorrhage (OR, 3.42; P<0.001) predicted in-hospital functional outcome in multivariable analyses. CONCLUSIONS: Most spontaneous intracerebral hemorrhage patients lack perihematomal penumbra. Perihematomal CBF independently predicts in-hospital discharge status but not in-hospital mortality. Further studies are warranted to determine whether perihematomal CBF predicts long-term functional outcomes.
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7.04Impact points
Clinical deterioration after intravenous recombinant tissue plasminogen activator treatment: a multicenter transcranial Doppler study.
Stroke; a journal of cerebral circulation. 01/2007; 38(1):69-74.
BACKGROUND AND PURPOSE: Patients may experience clinical deterioration (CD) after treatment with intravenous recombinant tissue plasminogen activator (rt-PA). We evaluated the ability of flow findings on transcranial Doppler to predict CD and outcomes on modified Rankin Scale. METHODS: Patients with... [more] BACKGROUND AND PURPOSE: Patients may experience clinical deterioration (CD) after treatment with intravenous recombinant tissue plasminogen activator (rt-PA). We evaluated the ability of flow findings on transcranial Doppler to predict CD and outcomes on modified Rankin Scale. METHODS: Patients with acute stroke received intravenous rt-PA within 3 hours of symptom onset at four academic centers. CD was defined as an increase in the National Institutes of Health Stroke Scale (NIHSS) score by 4 points or more within 24 hours. Poor long-term outcome was defined by modified Rankin Scale > or =2 at 3 months. Transcranial Doppler findings were interpreted using the Thrombolysis in Brain Ischemia flow grading system as persistent arterial occlusion, reocclusion, or complete recanalization. Multiple regression analysis was used to identify transcranial Doppler flow as a predictor for CD after controlling for age, sex, baseline NIHSS, hypertension, and glucose. RESULTS: A total of 374 patients received intravenous rt-PA at 142+/-60 minutes (median pretreatment NIHSS score 16 points). At the end of intravenous rt-PA infusion, transcranial Doppler showed persistent arterial occlusion in 219 patients (59%), arterial reocclusion in 54 patients (14%), and complete recanalization in 101 patients (27%). CD occurred in 44 patients: 36 had persistent arterial occlusion or reocclusion (82%), 13 symptomatic intracerebral hemorrhage (29%), and both persistent occlusion/reocclusion and symptomatic intracerebral hemorrhage in 10 patients (23%). After adjustment, patient risk for CD with persistent occlusion was OR 1.7 (95% CI: 0.7 to 4) and with arterial reocclusion 4.9 (95% CI: 1.7 to 13) (P=0.002). Patient risk for poor long-term outcomes with persistent occlusion, partial recanalization, or reocclusion was OR 5.2 (95% CI: 2.7 to 9, P=0.001). CONCLUSIONS: Inability to achieve or sustain vessel patency at the end of rt-PA infusion correlates with the likelihood of clinical deterioration and poor long-term outcome. Early arterial reocclusion on transcranial Doppler is highly predictive of CD and poor outcome.
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7.04Impact points
Safety, feasibility, and short-term follow-up of drug-eluting stent placement in the intracranial and extracranial circulation.
Stroke; a journal of cerebral circulation. 11/2006; 37(10):2562-6.
BACKGROUND AND PURPOSE: The use of bare metal stents to treat symptomatic intracranial stenosis may be associated with significant restenosis rates. The advent of drug-eluting stents (DESs) in the coronary circulation has resulted in a reduction of restenosis rates. We report our technical success r... [more] BACKGROUND AND PURPOSE: The use of bare metal stents to treat symptomatic intracranial stenosis may be associated with significant restenosis rates. The advent of drug-eluting stents (DESs) in the coronary circulation has resulted in a reduction of restenosis rates. We report our technical success rate and short-term restenosis rates after stenting with DESs in the intracranial and extracranial circulation. METHODS: This study was a retrospective review of the period between April 1, 2004, and April 15, 2006, of 59 patients with 62 symptomatic intracranial or extracranial atherosclerotic lesions at 2 medical centers (University of Pittsburgh and Borgess Medical Center). RESULTS: The mean age of our cohort was 61+/-12 years. The location of the 62 lesions was as follows: extracranial vertebral artery 31 (50%), intracranial vertebral artery or basilar artery 18 (29%), extracranial internal carotid artery (ICA) near the petrous bone 5 (8%), and intracranial ICA 8 (13%). There were 2 (3%) periprocedural complications: 1 non-flow-limiting dissection and 1 disabling stroke. Fifty vessels were available for follow-up angiography or computed tomography angiography at a median time of 4.0+/-2 months. A total of 2 of 36 extracranial stents (7%) and 1 of 26 intracranial stents (5%) were found to have restenosis > or = 50% at follow-up. CONCLUSIONS: This report demonstrates that DES delivery in the intracranial and extracranial circulation is technically feasible. A small percentage of patients developed short-term in-stent restenosis. Longer-term follow-up is required in the setting of a prospective study to determine the late restenosis rates for DESs in comparison with bare metal stents.
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7.04Impact points
Reduced pretreatment ipsilateral middle cerebral artery cerebral blood flow is predictive of symptomatic hemorrhage post-intra-arterial thrombolysis in patients with middle cerebral artery occlusion.
Stroke; a journal of cerebral circulation. 11/2006; 37(10):2526-30.
BACKGROUND AND PURPOSE: Intracerebral hemorrhage (ICH) can be a devastating complication associated with thrombolytic therapy for acute ischemic stroke. We hypothesized that patients with lower prethrombolysis cerebral blood flow (CBF) were at a higher risk of symptomatic ICH (sICH). METHODS: Twenty... [more] BACKGROUND AND PURPOSE: Intracerebral hemorrhage (ICH) can be a devastating complication associated with thrombolytic therapy for acute ischemic stroke. We hypothesized that patients with lower prethrombolysis cerebral blood flow (CBF) were at a higher risk of symptomatic ICH (sICH). METHODS: Twenty-three patients who underwent quantitative CBF assessment with Xenon CT studies for acute stroke before intra-arterial (IA) thrombolysis for a middle cerebral artery (MCA) or internal carotid artery terminus occlusion within 6 hours of symptom onset were studied. Univariate and multivariate analysis were carried out to determine predictors of sICH post-IA thrombolysis. Receiver operating characteristic curves were generated to determine the association between mean ipsilateral CBF and the occurrence of sICH. RESULTS: The mean age of our cohort was 68+/-12 years and a mean National Institutes of Health Stroke Scale (NIHSS) score of 18+/-3. In univariate analysis, patients with higher percent of core infarct, hyperglycemia, and reduced mean ipsilateral CBF were at risk of sICH. In multivariate analysis only mean ipsilateral CBF was associated with higher rates of sICH (odds ratio 1.58; 95% CI, 1.01 to 2.51; P<0.04). The area under the receiver operating characteristic curve was 0.87 (95% CI, 0.76 to 0.97; P<0.005). CONCLUSIONS: Patients with lower pre-IA thrombolysis mean ipsilateral MCA CBF are at significantly higher risk for sICH in the setting of a MCA or carotid terminus occlusion. The threshold identified in this study may be useful for selection of patients with acute MCA occlusions for acute stroke thrombolysis.
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6.31Impact points
Argatroban tPA stroke study: study design and results in the first treated cohort.
Archives of neurology. 09/2006; 63(8):1057-62.
BACKGROUND: The benefit of intravenous recombinant tissue plasminogen activator (rtPA) in acute stroke is linked to clot lysis and artery recanalization. Argatroban is a direct thrombin inhibitor that safely augments the benefit of rtPA in animal stroke models. There are no human data on this combin... [more] BACKGROUND: The benefit of intravenous recombinant tissue plasminogen activator (rtPA) in acute stroke is linked to clot lysis and artery recanalization. Argatroban is a direct thrombin inhibitor that safely augments the benefit of rtPA in animal stroke models. There are no human data on this combination. DESIGN: We report the first phase of the Argatroban tPA Stroke Study, an ongoing prospective, open-label, dose-escalation, safety and activity study of argatroban and rtPA in patients with ischemic stroke. The primary outcome was incidence of intracerebral hemorrhage; secondary outcome, complete recanalization at 2 hours. After standard-dose intravenous rtPA administration, a 100-mug/kg bolus of argatroban followed by infusion of 1 mug/kg per minute for 48 hours was adjusted to a target partial thromboplastin time of 1.75 times that of the control group. RESULTS: Fifteen patients (including 10 men) were enrolled, with a mean +/- SD age of 61 +/- 13 years. All patients had middle cerebral artery occlusions. Baseline median National Institute of Health Stroke Scale score was 14 (range, 4-25). The mean +/- SD time from symptom onset to argatroban bolus administration was 172 +/- 53 minutes. Symptomatic intracerebral hemorrhage occurred in 2 patients, including 1 with parenchymal hemorrhage type 2. Asymptomatic bleeding occurred in 1 patient and there was 1 death. Recanalization was complete in 6 patients and partial in another 4, and reocclusion occurred in 3 within 2 hours of rtPA bolus administration. CONCLUSION: The safety of low-dose argatroban combined with intravenous rtPA may be within acceptable limits, and its efficacy for producing fast and complete recanalization is promising, but a larger cohort of patients is required to confirm these preliminary observations.
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7.04Impact points
Multimodal reperfusion therapy for acute ischemic stroke: factors predicting vessel recanalization.
Stroke; a journal of cerebral circulation. 05/2006; 37(4):986-90.
BACKGROUND AND PURPOSE: Endovascular therapies using mechanical and pharmacological modalities for large vessel occlusions in acute stroke are rapidly evolving. Our aim was to determine whether one modality is associated with higher recanalization rates. METHODS: We retrospectively reviewed 168 cons... [more] BACKGROUND AND PURPOSE: Endovascular therapies using mechanical and pharmacological modalities for large vessel occlusions in acute stroke are rapidly evolving. Our aim was to determine whether one modality is associated with higher recanalization rates. METHODS: We retrospectively reviewed 168 consecutive patients treated with intra-arterial (IA) therapy for acute ischemic stroke between May 1999 and November 15, 2005. Demographic, clinical, radiographic, angiographic, and procedural notes were reviewed. Recanalization was defined as achieving thrombolysis in myocardial infarction 2 or 3 flow after intervention. A logistic regression model was constructed to determine independent predictors of successful recanalization. RESULTS: A total of 168 patients were reviewed with a mean age of 64+/-13 years and mean National Institutes of Health Stroke Scale score of 17+/-4. Recanalization was achieved in 106 (63%) patients. Independent predictors of recanalization include: the combination of IA thrombolytics and glycoprotein IIb/IIIa inhibitors (odds ratio [OR], 2.9 [95% CI, 1.04 to 6.7]; P<0.048), intracranial stent placement with angioplasty (OR, 4.8 [95% CI, 1.8 to 10.0]; P<0.001), or extracranial stent placement with angioplasty (OR, 4.2 [95% CI, 1.4 to 9.8]; P<0.014). Lesions at the terminus of the internal carotid artery were recalcitrant to revascularization (OR, 0.34 [95% CI, 0.16 to 0.73]; P value 0.006). CONCLUSIONS: Intracranial or extracranial stenting or combination therapy with IA thrombolytics and glycoprotein IIb/IIIa inhibitors in the setting of multimodal therapy is associated with successful recanalization in patients treated with multimodal endovascular reperfusion therapy for acute ischemic stroke.
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2.95Impact points
Stroke burden in Mexican Americans: the impact of mortality following stroke.
Annals of epidemiology. 02/2006; 16(1):33-40.
PURPOSE: To estimate ethnic-specific all-cause mortality risk following ischemic stroke and to compare mortality risk by ethnicity. METHODS: DATA from the Brain Attack Surveillance in Corpus Christi Project, a population-based stroke surveillance study, were used. Stroke cases between January 1, 200... [more] PURPOSE: To estimate ethnic-specific all-cause mortality risk following ischemic stroke and to compare mortality risk by ethnicity. METHODS: DATA from the Brain Attack Surveillance in Corpus Christi Project, a population-based stroke surveillance study, were used. Stroke cases between January 1, 2000 and December 31, 2002 were identified from emergency department (ED) and hospital sources (n = 1,234). Deaths for the same period were identified from the surveillance of stroke cases, the Texas Department of Health, the coroner, and the Social Security Death Index. Ethnic-specific all-cause cumulative mortality risk was estimated at 28 days and 36 months using Kaplan Meier analysis. Cox proportional hazards regression was used to compare mortality risk by ethnicity. RESULTS: Cumulative 28-day all-cause mortality risk for Mexican Americans (MAs) was 7.8% and for non-Hispanic whites (NHWs) was 13.5%. Cumulative 36-month all-cause mortality risk was 31.3% in MAs and 47.2% in NHWs. MAs had lower 28-day (RR = 0.58; 95% CI: 0.41, 0.84) and 36-month all-cause mortality risk (RR = 0.79, 95% CI: 0.64, 0.98) compared with NHWs, adjusted for confounders. CONCLUSIONS: Better survival after stroke in MAs is surprising considering their similar stroke subtype and severity compared with NHWs. Social or psychological factors, which may explain this difference, should be explored.
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7.04Impact points
Emergent stenting of extracranial internal carotid artery occlusion in acute stroke has a high revascularization rate.
Stroke; a journal of cerebral circulation. 12/2005; 36(11):2426-30.
BACKGROUND AND PURPOSE: Acute ischemic stroke attributable to extracranial internal carotid artery (ICA) occlusion is frequently associated with severe disability or death. In selected cases, revascularization with carotid artery stenting has been reported, but the safety, recanalization rate, and c... [more] BACKGROUND AND PURPOSE: Acute ischemic stroke attributable to extracranial internal carotid artery (ICA) occlusion is frequently associated with severe disability or death. In selected cases, revascularization with carotid artery stenting has been reported, but the safety, recanalization rate, and clinical outcomes in consecutive case series are not known. METHODS: We retrospectively reviewed all of the cases of ICA occlusions that underwent cerebral angiography with the intent to revascularize over a 38-month period. Two groups were identified: (1) patients who presented with an acute clinical presentation within 6 hours of symptom onset (n=15); and (2) patients who presented subacutely with neurologic fluctuations because of the ICA occlusion (n=10). RESULTS: Twenty-five patients with a mean age of 62+/-11 years and median National Institutes of Health Stroke Scale (NIHSS) of 14 were identified. Twenty-three of the 25 patients (92%) were successfully revascularized with carotid artery stenting. Patients in group 1 were younger and more likely to have a tandem occlusion and higher baseline NIHSS when compared with group 2. Patients in group 2 were more likely to show early clinical improvement defined as a reduction of their NIHSS by > or =4 points and a modified Rankin Score of < or =2 at 30-day follow-up. Two clinically insignificant adverse events were noted: 1 asymptomatic hemorrhage and 1 nonflow-limiting dissection. CONCLUSIONS: Endovascular treatment of acute ICA occlusion appears to have a high-recanalization rate and be relatively safe in our cohort of patients with acute ICA occlusion. Future prospective studies are necessary to determine which patients are most likely to benefit from this form of therapy.
Following (3)
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Adrian V Hernandez
Cleveland Clinic -
Moises Auron
Cleveland Clinic -
Lawrence R Wechsler
University of Pittsburgh Medical Center
