Reperfusion in acute myocardial infarction

Acute myocardial infarction is usually caused by occlusive coronary thrombosis initiated by rupture of an atheromatous plaque. The subendocardium infarcts early after coronary occlusion, but outward extension to affect the full thickness of the ventricular wall may take several hours. Restoration of normal coronary flow, before the transmural spread of infarction is complete, is now seen as the primary goal of hospital treatment because it allows reperfusion of the threatened myocardium with reduction of eventual infarct size. The best established method of restoring coronary flow is treatment with thrombolytic agents, but angioplasty, with or without the insertion of a stent, is fast gaining exponents. Thrombolytic therapy is the best tested and most widely used means of achieving this goal and among eligible patients produces coronary recanalisation in about 60-80% of cases,1 2 depending on the agent used. Beneficial effects on survival have been confirmed in several studies.3 4 Nevertheless, thrombolytic therapy has important limitations because normal coronary flow is achieved in only …