急性期脳梗塞に対する経静脈的組織プラスミノーゲンアクチベーター(t-PA)投与例の検討

Intravenous Tissue Plasminogen Activator (t-PA) for Acute Ischemic Stroke in a Local University Hospital

要旨　急性期脳梗塞に対し，当科で過去5年間（1999年4月～2004年3月）に経静脈的に組織プラスミノーゲンアクチベーター（t-PA）を使用した20症例（平均年齢73.6±10.9歳，男15例，女5例）につき検討した。使用したt-PAは18例はアルテプラーゼ，2例はモンテプラーゼであった。t-PA投与前のNIH stroke scaleは17.5（中央値）であり，90日後のmodified Rankin Scale 3以下の割合は40％であった。症候性出血性梗塞は1例認めた。過去の米国における成績と比較すると，90日後の機能予後良好の割合が少なかったが，われわれの投与症例では進行性脳梗塞に関しては，発症3時間以上経過した症例にも投与していたこと，投与前の重症度や平均年齢が高かったこと，アルテプラーゼの投与量が14例で0.4mg/kg以下と低用量であったことがその原因と考えられた。

Thrombolytic therapy for ischemic stroke has not been approved in Japan yet. However, we have used intravenous t-PA for acute ischemic stroke patients. We reviewed the clinical data on patients who were treated with intravenous t-PA and entered in the stroke registry of our hospital between April 1999 and March 2004. Of 408 acute ischemic stroke patients, 20 patients （mean age 73.6±10.9, male 15, female 5） were given intravenous t-PA （alteplase in 18 patients and monteplase in two patients）. The baseline NIH Stroke Scale （NIHSS） and Japan Stroke Scale （JSS） scores were 17.5 （median） and 13.3±7.6 （mean）, respectively. The NIHSS and JSS at discharge were 12.5 and 12.1±11.8, respectively. Symptomatic intracerebral hemorrhage occurred in one patient. The rate of favorable outcome （mRS 0-3） at 90 days was 40％.

　The rate of favorable outcome at 90 days in our study was lower than that in reported randomized trials of intravenous t-PA, such as the NINDS study or the ATLANTIS trial, perhaps because age and baseline severity were higher in our patients than in the subjects in these trials. Another reason may be the dose of t-PA. As we concerned about the occurrence of symptomatic intracranial hemorrhage and there are no data on appropriate dose of t-PA for Japanese patients, the dose of t-PA that we used was 0.4mg/kg in most patients. Although five patients died in our study, the cause of death in four patients was not hemorrhagic transformation but deteriorating ischemic infraction. The dose of t-PA that we used may have been safe but a little low for thrombolysis.

（Received : January 19, 2005）