ABSTRACT
Epicardial coronary artery patency has been the primary outcome measure of coronary angiography and intervention in patients with ST-segment acute myocardial infarction (STEMI). Strategies to improve the effectiveness of both fibrinolytic and percutaneous interventional therapies have relied on this angiographic measure to assess treatment efficacy and outcome. Despite the reliance on epicardial patency, there is still significant variability in morbidity and mortality among patients with full restoration of coronary artery blood flow or Thrombolysis in Myocardial Infarction (TIMI) grade 3 flow. The realization that restoration of epicardial flow is necessary, but not sufficient, has led to the evaluation of the myocardial vasculature and reperfusion downstream at the level of the capillary bed as a more accurate predictor of clinical outcome and treatment efficacy (1-8). The goal of this chapter is to review the methods used to evaluate myocardial perfusion and their association with clinical outcomes.
