Teruyuki Hirano

Publications (3)14.39 Total impact

• Article: Residual vessel length on magnetic resonance angiography identifies poor responders to alteplase in acute middle cerebral artery occlusion patients: exploratory analysis of the Japan Alteplase Clinical Trial II.

  Teruyuki Hirano, Makoto Sasaki, Etsuro Mori, Kazuo Minematsu, Jyoji Nakagawara, Takenori Yamaguchi
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  ABSTRACT: It remains unknown whether the effects of 0.6 mg/kg alteplase differ with occlusion site of the middle cerebral artery (MCA). We therefore evaluated the effects of 0.6 mg/kg intravenous alteplase in patients with different sites of MCA occlusion. An exploratory analysis was made of 57 patients enrolled in the Japan Alteplase Clinical Trial II (J-ACT II), originally designed to evaluate 0.6 mg/kg alteplase in Japanese patients with unilateral occlusion of the MCA (M1 or M2 portion). The residual vessel length (in mm), determined by pretreatment magnetic resonance angiography, was used to reflect the occluded site. The proportions of patients with valid recanalization (modified Mori grade 2 to 3) at 6 and 24 hours and a modified Rankin Scale (mRS) score of 0 to 1 and of 0 to 2 at 3 months were compared between the groups dichotomized according to length of the residual vessel. Multiple logistic-regression models were generated to elucidate the predictors of valid recanalization, mRS 0 to 1, and mRS 0 to 2. Receiver operating characteristics analysis revealed that 5 mm was the practical cutoff length for dichotomization. In patients with an M1 length < 5 mm (n = 12), the frequencies of valid recanalization at 6 and 24 hours (16.7% and 25.0%) were significantly lower compared with those (62.1% and 82.8%, respectively) of the 45 patients with a residual M1 length ≥ 5 mm and an M2 occlusion (P = 0.008 for 6 hours, P < 0.001 for 24 hours). The proportions of patients who achieved an mRS of 0 to 1 and an mRS of 0 to 2 were also lower for those with an M1 length < 5 mm (8.3% and 16.7%, respectively) compared with the other group (57.8% and 68.9%, respectively; P = 0.003 for mRS 0 to 1, P = 0.002 for mRS 0 to 2). In logistic-regression models, the site of MCA occlusion (< 5 mm) was a significant predictor of valid recanalization at 6 and 24 hours and of an mRS of 0 to 1 and of mRS of 0 to 2. In patients with acute MCA occlusion, a residual vessel length < 5 mm on magnetic resonance angiography can identify poor responders to 0.6 mg/kg alteplase. Clinical Trial Registration-URL: http://www.clinicaltrials.gov. Unique identifier: NCT00412867.
  Stroke 10/2010; 41(12):2828-33. · 5.73 Impact Factor
• Article: Effects of 0.6 mg/kg intravenous alteplase on vascular and clinical outcomes in middle cerebral artery occlusion: Japan Alteplase Clinical Trial II (J-ACT II).

  Etsuro Mori, Kazuo Minematsu, Jyoji Nakagawara, Takenori Yamaguchi, Makoto Sasaki, Teruyuki Hirano
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  ABSTRACT: The purpose of this study was to evaluate further the efficacy of 0.6 mg/kg intravenous alteplase on vascular and clinical outcomes in patients with middle cerebral artery occlusion in a postmarketing Phase IV trial of prospective cohort study design. Alteplase was given intravenously at 0.6 mg/kg to patients with ischemic stroke within 3 hours of onset with MR angiography-documented middle cerebral artery occlusion. Vascular outcome was evaluated by MR angiography at 6 and 24 hours after symptom onset based on the modified Mori grade. The primary end points also included a favorable outcome (modified Rankin Scale 0 to 1 at 3 months after onset) and incidence of symptomatic intracranial hemorrhage within 36 hours after treatment. The impact of recanalization on clinical outcome was assessed by stepwise logistic regression analysis. Fifty-eight patients were enrolled. Recanalization was noted in 51.7% on 6-hour MR angiography and 69.0% on 24-hour MR angiography. A favorable clinical outcome was achieved in 46.6%. None had symptomatic intracranial hemorrhage. In logistic regression models, recanalization on either 6-hour or 24-hour MR angiography was an independent predictor for clinical outcome as well as the baseline National Institutes of Health Stroke Scale score. Early recanalization of an occluded middle cerebral artery can be provoked by 0.6 mg/kg intravenous alteplase and may induce a favorable clinical outcome. The rates of recanalization and favorable outcome are comparable to that previously reported with the 0.9-mg/kg dose.
  Stroke 03/2010; 41(3):461-5. · 5.73 Impact Factor
• Source

  Available from: ajnr.org

  Article: Topographic distribution of misery perfusion in relation to internal and superficial borderzones.

  Shuji Arakawa, Kazuo Minematsu, Teruyuki Hirano, Yutaka Tanaka, Yasuhiro Hasegawa, Kohei Hayashida, Takenori Yamaguchi
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  ABSTRACT: Whether misery perfusion (MP) commonly accompanies brain borderzones (BZs) in patients with major cerebral artery occlusion remains unclear. We elucidated topographic patterns of chronic hemodynamic failure in such patients. Twenty-four patients with unilateral occlusion or severe stenosis (>75% in diameter) of the internal carotid artery (ICA) or middle cerebral arterial (MCA) trunk with minimal or no infarct underwent PET with (15)O-labeled gas inhalation. Mean cerebral blood flow (CBF), cerebral blood volume (CBV), cerebral metabolic rate of oxygen, oxygen extraction fraction (OEF), and CBV/CBF ratio were determined in the superficial BZs, internal BZ, and MCA territory excluding BZs. Values in BZs were standardized and compared with those in controls. Topographic distributions of regions with OEF greater than that in controls were determined. Values in patients and controls were not significantly different. Topographic distributions included matched perfusion in 10 patients, MP in only the ipsilateral internal BZ in four, MP in both ipsilateral internal and superficial BZs in two, MP in the ipsilateral MCA territory including BZs in one, MP in the ipsilateral MCA territory including BZs and contralateral BZs in two, and MP in the ipsilateral MCA territories including BZs in five. Only 25% of the patients had MP localized in affected BZs Although localized MP more frequently accompanied the internal BZ than other regions, no patient had elevated OEF in the superficial BZ alone. These results are inconsistent with clinical observations that 80% of BZ infarctions develop superficially. Thus, hemodynamic mechanisms may not cause most superficial BZ infarctions.
  American Journal of Neuroradiology 03/2003; 24(3):427-35. · 2.93 Impact Factor