Is intra-arterial thrombolysis beneficial for M2 occlusions? Subgroup analysis of the PROACT-II trial.

BACKGROUND AND PURPOSE: The role of endovascular therapy for acute M2 trunk occlusions is debatable. Through a subgroup analysis of Prolyse in Acute Cerebral Thromboembolism-II, we compared outcomes of M2 occlusions in treatment and control arms. METHODS: Solitary M2 occlusions were identified from the Prolyse in Acute Cerebral Thromboembolism-II database. Primary endpoints were successful angiographic reperfusion (TICI 2-3) at 120 minutes and functional independence (mRS 0-2) at 90 days. RESULTS: Forty-four patients with solitary M2 occlusions, 30 in the treatment arm and 14 in the control arm, were identified. Successful reperfusion (TICI 2-3) was achieved in 53.6% and 16.7% of patients in the treatment and control arms, respectively (P=0.04). A favorable clinical outcome (mRS 0-2) was observed in 53.3% and 28.6%, respectively (P=0.19). Baseline characteristics were similar between the 2 groups. CONCLUSIONS: Intra-arterial thrombolysis may lead to a 3-fold increase in the rate of early reperfusion of solitary M2 occlusions and could potentially double the chance of a favorable functional outcome at 90 days. Clinical Trial Registration- This trial was not registered because enrollment began before July 1, 2005.

Intra-arterial iodinated radiographic contrast material injection administration in a rat middle cerebral artery occlusion and reperfusion model: possible effects on intracerebral hemorrhage.

BACKGROUND AND PURPOSE: Observations in human interventional stroke treatment led us to hypothesize that iodinated radiographic contrast material use may contribute to intracerebral hemorrhage. Effects of intra-arterial iodinated radiographic contrast material on hemorrhagic transformation after middle cerebral artery occlusion and reperfusion were studied in a placebo-controlled, blinded preclinical study in rats. METHODS: Four groups of male Sprague-Dawley rats were studied: saline group (n=8), contrast group (n=12), heparin group (n=9), and contrast+heparin group (n=9). The middle cerebral artery was occluded for 5 hours using suture placement. Heparin was infused before suture removal and reperfusion. Saline and/or contrast were infused immediately during reperfusion. Incidence, location, and size of hemorrhage were determined by brain necropsy inspection at 24 hours. RESULTS: There was a significant increase in incidence of cortical hemorrhage from control (37.5%), contrast (75.0%), heparin (77.8%) to contrast+heparin (100%; Cochran-Mantel-Haenszel correlation, P<0.01). Both pooled contrast groups (85.7%) and pooled heparin groups (88.9%) had higher rates of cortical intracerebral hemorrhage compared with the control group (P<0.05). Similar trends for increased cortical intracerebral hemorrhage were seen in the contrast-only (P=0.18) and heparin-only (P=0.18) groups. There was a trend for decreased infarct edema in rats receiving contrast versus those without (P=0.06). CONCLUSIONS: Intraarterial iodinated radiographic contrast material may increase cortical intracerebral hemorrhage, similar to heparin. Iodinated radiographic contrast material effect may be additive to heparin effect on the incidence of cortical intracerebral hemorrhage.

Microcatheter contrast injections during intra-arterial thrombolysis may increase intracranial hemorrhage risk.

BACKGROUND AND PURPOSE: During intra-arterial revascularization, either guide catheter injections of contrast in the neck or microcatheter contrast injections (MCIs) at or beyond the site of an occlusion, can be used to visualize intracranial vasculature. Neurointerventionalists vary widely in their use of MCIs for a given circumstance. We tested the hypothesis that MCIs are a risk factor for intracranial hemorrhage (ICH) in the Interventional Management of Stroke (IMS) I and II trials of combined intravenous/IA recombinant tissue plasminogen activator therapy. METHODS: All arteriograms with M1, M2, and ICA terminus occlusions were reanalyzed (n=98). The number of MCIs within or distal to the target occlusion was assigned. Postprocedure CTs were reviewed for contrast extravasation and ICH. Contrast extravasation was defined as a hyperdensity suggestive of contrast (Hounsfield unit >90) seen at 24 hours or present before 24 hours and persisting or replaced by ICH at 24 hours. RESULTS: In this IMS subset, the rate of any ICH was 58% (57 of 98). More MCIs were seen in the ICH group (median=2 versus 1; P=0.04). Increased MCIs were associated with higher ICH rates (P=0.03). MCIs remained associated with ICH in multivariable analysis (P=0.01) as did baseline CT edema/mass effect, atrial fibrillation, time to intravenous recombinant tissue plasminogen activator initiation, and Thrombolysis in Cerebral Infarction reperfusion score. MCIs were also associated with contrast extravasation in unadjusted and adjusted analyses. CONCLUSIONS: MCIs may risk ICH in the setting of combined intravenous/intra-arterial recombinant tissue plasminogen activator therapy, possibly due to contrast toxicity or pressure transmission by injections. MCIs should be minimized whenever possible. These findings will be tested prospectively in the IMS III trial.

Gene expression in blood changes rapidly in neutrophils and monocytes after ischemic stroke in humans: a microarray study.

Ischemic brain and peripheral white blood cells release cytokines, chemokines and other molecules that activate the peripheral white blood cells after stroke. To assess gene expression in these peripheral white blood cells, whole blood was examined using oligonucleotide microarrays in 15 patients at 2.4+/-0.5, 5 and 24 h after onset of ischemic stroke and compared with control blood samples. The 2.4-h blood samples were drawn before patients were treated either with tissue-type plasminogen activator (tPA) alone or with tPA plus Eptifibatide (the Combination approach to Lysis utilizing Eptifibatide And Recombinant tPA trial). Most genes induced in whole blood at 2 to 3 h were also induced at 5 and 24 h. Separate studies showed that the genes induced at 2 to 24 h after stroke were expressed mainly by polymorphonuclear leukocytes and to a lesser degree by monocytes. These genes included: matrix metalloproteinase 9; S100 calcium-binding proteins P, A12 and A9; coagulation factor V; arginase I; carbonic anhydrase IV; lymphocyte antigen 96 (cluster of differentiation (CD)96); monocarboxylic acid transporter (6); ets-2 (erythroblastosis virus E26 oncogene homolog 2); homeobox gene Hox 1.11; cytoskeleton-associated protein 4; N-formylpeptide receptor; ribonuclease-2; N-acetylneuraminate pyruvate lyase; BCL6; glycogen phosphorylase. The fold change of these genes varied from 1.6 to 6.8 and these 18 genes correctly classified 10/15 patients at 2.4 h, 13/15 patients at 5 h and 15/15 patients at 24 h after stroke. These data provide insights into the inflammatory responses after stroke in humans, and should be helpful in diagnosis, understanding etiology and pathogenesis, and guiding acute treatment and development of new treatments for stroke.

Genetic and environmental risk factors for intracerebral hemorrhage: preliminary results of a population-based study.

BACKGROUND AND PURPOSE: Intracerebral hemorrhage (ICH) has a 30-day mortality rate of 40% to 50% and lacks a proven treatment. We report a preplanned, midpoint analysis of the first population-based, case-control study that examines both genetic and environmental risk factors of ICH. METHODS: We prospectively identified cases of hemorrhagic stroke at all 16 hospitals in the Greater Cincinnati/Northern Kentucky region. All cases underwent medical record and neuroimaging review. Cases enrolled in the direct interview and genetic sampling arm of the study were matched to population-based control subjects by age, race, and sex. Multivariable logistic regression was performed to identify significant independent risk factors. RESULTS: We enrolled 188 cases of ICH (67 lobar, 121 nonlobar) and 366 control subjects in the direct interview arm of the study. Significant independent risk factors for lobar ICH included the presence of an apolipoprotein E2 or E4 allele, frequent alcohol use, prior stroke, and first-degree relative with ICH. Significant independent risk factors for nonlobar ICH were hypertension, prior stroke, and first-degree relative with ICH. An increasing level of education was associated with a decreased risk of nonlobar ICH. The attributable risk of apolipoprotein E2 or E4 for lobar ICH was 29%, and the attributable risk of hypertension for nonlobar ICH was 54%. CONCLUSIONS: There is significant epidemiological evidence that the pathophysiology of ICH varies by location. We estimate that a third of all cases of lobar ICH are attributable to possession of an apolipoprotein E4 or E2 allele and that half of all cases of nonlobar ICH are attributable to hypertension.

Methodology of the Interventional Management of Stroke III Trial.

RATIONALE: The Interventional Management of Stroke (IMS) I and II pilot trials demonstrated that the combined intravenous (i.v.) and intraarterial (i.a.) approach to recanalization may be more effective than standard i.v. rt-PA (Activase) alone for moderate-to-large National Institutes of Health Stroke Scale (NIHSS>or=10) strokes, and with a similar safety profile. AIMS: The primary objective of this NIH-funded, Phase III, randomized, multicenter, open-label clinical trial is to determine whether a combined i.v./i.a. approach to recanalization is superior to standard i.v. rt-PA alone when initiated within 3 h of acute ischemic stroke onset. The IMS III trial will develop and maintain a network of interventional centers to test the safety, feasibility, and potential efficacy of new FDA-approved catheter devices as part of a combined i.v./i.a. approach to recanalization as the IMS III study progresses. A secondary objective of the IMS III trial is to determine the cost-effectiveness of the combined i.v./i.a. approach as compared with standard i.v. rt-PA. Trial enrollment began in July of 2006. DESIGN: A projected 900 subjects with moderate-to-large (NIHSS>or=10) ischemic strokes between ages 18 and 80 will be enrolled over the next 5 years at 40-plus centers in the United States and Canada. Patients must have i.v. treatment initiated within 3 h of stroke onset in both arms. Subjects will be randomized in a 2 : 1 ratio with more subjects enrolled in the combined i.v./i.a. group. The i.v. rt-PA alone group will receive the standard full dose [0.9 mg/kg, 90 mg maximum (10% as bolus)] of rt-PA intravenously over an hour. The combined i.v./i.a. group will receive a lower dose of i.v. rt-PA ( approximately 0.6 mg/kg, 60 mg maximum) over 40 min, followed by immediate angiography. If a treatable thrombus is not demonstrated, no i.a. therapy will be administered. If an appropriate thrombus is identified, treatment will continue with either the Concentric Merci thrombus-removal device, infusion of rt-PA and delivery of low-intensity ultrasound at the site of the occlusion via the EKOS Micro-Infusion Catheter, or infusion of rt-PA via a standard microcatheter. If i.a. rt-Pa therapy is the chosen strategy, a maximum of 22 mg of i.a. rt-PA may be given. The choice of i.a. strategy will be made by the treating neurointerventionalist. The i.a. treatment must begin within 5 h and be completed within 7 h of stroke onset. STUDY OUTCOMES: The primary outcome measure is a favorable clinical outcome, defined as a modified Rankin Scale Score of 0-2 at 3 months. The primary safety measure is mortality at 3 months and symptomatic ICH within the 24 h of randomization.