Morgan C D
Division of Cardiology, Sunnybrook Health Science Centre, University of Toronto, Ontario.
Can J Cardiol. 1995 May;11(5):435-40.
The efficacy, and mechanisms of benefit, of thrombolytic therapy in reducing mortality following myocardial infarction are time-dependent. Early treatment results in myocardial salvage and preservation of left ventricular function, mediated through prompt restoration of normal antegrade infarct artery perfusion. Later treatment exerts favourable effects on electrical stability of the myocardium and may attenuate progressive left ventricular dilation independent of myocardial salvage. Tissue plasminogen activator, administered using an accelerated, front loaded dosing regimen, affords early infarct artery patency which is superior to that achieved with streptokinase and is associated with a small, but significant, further reduction in mortality. The implications for choice of thrombolytic agent in a cost-contained health care system are examined, as is the importance of minimizing in-hospital delay in administering thrombolytic agents in the setting of acute myocardial infarction (AMI). Recognition of the pivotal role of patency and the shortcomings of thrombolytic agents in achieving optimal reperfusion has lead to renewed interest in percutaneous transluminal coronary angioplasty (PTCA) as primary therapy for AMI, Preliminary results are promising but must be confirmed in larger studies. Primary PTCA should be considered for patients with AMI and contraindications to thrombolytic therapy.
溶栓治疗在降低心肌梗死后死亡率方面的疗效及获益机制具有时间依赖性。早期治疗可实现心肌挽救并保留左心室功能，这是通过迅速恢复梗死相关动脉的正常前向灌注来介导的。后期治疗对心肌电稳定性产生有利影响，并可能减轻左心室进行性扩张，且与心肌挽救无关。采用加速、负荷剂量给药方案使用组织型纤溶酶原激活剂，可使梗死相关动脉早期开通，其效果优于链激酶，且与死亡率进一步小幅但显著降低相关。本文探讨了在成本受限的医疗保健系统中选择溶栓药物的意义，以及在急性心肌梗死（AMI）情况下尽量减少院内溶栓药物给药延迟的重要性。认识到血管开通的关键作用以及溶栓药物在实现最佳再灌注方面的不足，使得经皮腔内冠状动脉成形术（PTCA）作为AMI的主要治疗方法重新受到关注，初步结果很有前景，但必须在更大规模的研究中得到证实。对于有AMI且有溶栓治疗禁忌证的患者，应考虑行直接PTCA。
