Thrombolysis and percutaneous transluminal coronary angioplasty in patients with acute myocardial infarction

Acute myocardial infarction (AMI) remains a leading cause of morbidity and mortality in the developed countries. Thrombotic occlusion of a coronary ar tery has been shown to cause acute myocardial infarction in over 90 % of th e cases. Early and complete restoration of bloodflow in the infarct-related coronary artery is the principal mechanism by which reperfusion therapy im proves outcomes in patients with acute myocardial infarction. Thrombolytic therapy has been shown to reduce mortality when given early after symptom o nset. However, even the most effective, approved thrombolytic regimens achi eve normal (so-called TIMI 3) flow in the infarct vessel at 60-90 minutes o nly in about half of the patients and reocclusion occurrs in 5-10 %. Bleedi ng events, especially intracranial bleedings, observed in up to 1 % of the patients, are the most severe complication of thrombolysis. Primary percuta neous transluminal coronary angioplasty (PTCA) is associated with somewhat higher patency rates and significantly fewer strokes than thrombolysis, but confers a reocclusion rate of about 5-10 % and it is not universally avail able. While smaller randomized studies suggested a significant advantage of PTCA over thrombolysis, these results could not be confirmed in the larger GUSTO IIb angioplasty study in over 1000 patients and in non-randomized co mparisons in large registries. Therefore, a general mortality advantage of PTCA over thrombolysis could not be demonstrated. Primary PTCA should be pr eferred in patients with contraindications against thrombolysis, patients w ith a high risk for intracranial bleedings (age > 75 and high blood pressur e on admission) and hemodynamically unstable patients. There are several approaches to improve outcome of patients with acute myoc ardial infarction: new fibrinolytic agents may improve early infarct relate d patency, single bolus administration of thrombolytics may reduce time-to- treatment, stent implantation may improve direct PTCA, enhanced thrombin an d platelet inhibition may facilitate both, thrombolysis and primary PTCA, e nhance reperfusion on the cellular level and reduce reocclusions and ultima tively improve prognosis of patients with acute myocardial infarction.