選択的冠動脈内血栓溶解療法におけるウロキナーゼ急速静注併用の意義

The beneficial effects of intravenous bolus injection of urokinase followed by conventional selective intracoronary thrombolysis

　虚血による心筋壊死を可能な限りくいとめ，心機能を確保する目的で，近年急性心筋梗塞（以下AMI）の発症早期に，冠動脈内血栓溶解療法（以下ICT），あるいは経皮的冠動脈形成術（以下PTCA）が広く行われるようになった。しかし，患者自身の意志決定時間や救急搬送体制，第一次診療機関における判断，さらに急性期におけるinterventionの可能な施設が限られること，またそのような施設においても緊急時における医師・看護婦・放射線技師等の人員の確保，CatheterizationLaboratoryの使用状況，患者来院時刻などの種々の点から必ずしもGolden Time内に行われているとは限らない。今回我々は，できるだけ早期に血栓溶解を計り，梗塞巣を最小限にとどめる目的で，AMI患者来院後直ちに，すなわちICTの準備中にウロキナーゼ（以下UK）の急速静注をICTに先立って行った症例と，従来のICT症例を比較検討し，若干の知見を得たのでここに報告する。

In order to recanalize the occluded coronary ar-teries in patients with acute myocardial infarction (AMI) as soon as possible and limit the infarct size. we evaluated the effects of intravenous bolus injec-tion of urokinase (UK) followed by intracoronary thrombolysis (ICT). Eighty-seven patients were divided into two groups ; one group with intravenous injection of UK (the IV group, 34 cases) and another group without (the IC group, 53 cases). They were also subdivided into three groups each ; recanaliza-tion before ICT (group A, 21 vs 20 cases), recanaliza-tion after ICT (group B, 10 vs 27 cases), recanaliza-tion not achieved (group C, 3 vs 6 cases). The amount of UK injected during ICT was not significantly different between N and IC groups (67.8±30.5 vs 68.3±34.0×10⁴ units). Intravenous UK in IV group was 24.9×10⁴ units. Total recanalization rate after ICT was equivalent between the two groups (N : 88.2%, IC: 88.7%), but recanalization rate before ICT was significantly higher in the N group (61. 8 vs 37.7%, p<0.05). No significant differences were observed in the maximum values of CK-MB and CK, the elapsed time from the onset of AMI to the maximum values of these enzymes, the global left ventricular ejection fraction and the regional wallmotion. Interestingly, cardiac death was most infre-quent in the N-A group, who received the intra-venous UK before ICT and recanalization was achieved before ICT (4.8% at 1 month after the onset, 0% at 1 year, 4.8% in the overall estimation). The serious complications including hematoma of the puncture site was not observed. These favorable effects were attributed to the intravenous admini-stration of 24.9×10⁴ units of UK because the higher recanalization rate before ICT was also observed even modifying the recanalization criteria, the blood coagulation parameters show the marked dominancy of fibrinopeptide Bβ_15-42 over fibrinopeptide An in-dicating the exaggerated fibrinolysis, and the two groups (N and IC) were equivalent in terms of characteristics of the cases, the cares given, the elap-sed time from the onset of AMI, to ICT etc. Thus relatively small amount of UK injected intravenously early in AMI led to the higher recanalization rate before ICT and this was associated with the better prognosis.