[The era of myocardial reperfusion].

Myocardial reperfusion is the single most useful therapeutic approach in patients with acute myocardial infarction. The thousands of lives saved each year by this treatment are the result of scientific progress in very different areas, including the biopathology of myocardial ischemia and reperfusion, the mechanisms of coronary occlusion, the pharmacology of the fibrinolytic system, and clinical research. The 30% reduction in mortality achieved by fibrinolytic treatment in patients with acute myocardial infarction does not fit, apparently, with the short time-window during which restoration of blood flow results in significant myocardial salvage in animal models with few collaterals. This discrepancy could be due to the protective effect of intermittent coronary occlusions immediately preceding stable occlusive thrombosis (ischemic preconditioning), or to other possible beneficial effects of reperfusion independent of myocardial salvage, as limitation of ventricular remodelling or reduction of the risk of cardiac rupture or severe arrhythmias. Clearly, the best approach to increase the beneficial effects of reperfusion therapy is to perform it as early as possible; the cost-effectiveness of pre-hospital treatment strategies is now under investigation. In the other hand, current reperfusion therapy cannot be considered optimal. Thrombolytic agents fail to achieve recanalization of the infarct related vessel in 20-30% of patients, and 10-15% of the successfully opened arteries present early reocclusion. In certain subgroups of patients, such in those with cardiogenic shock, failure rate is higher. Mechanical recanalization by "direct" angioplasty represent an alternative reperfusion method, which utility has been established in certain circumstances only. So, well in the "reperfusion era", many questions remain open.(ABSTRACT TRUNCATED AT 250 WORDS)