Efficacy of primary PCI: the microvessel perspective

The outcome of patients with acute myocardial infarction (AMI) is critically dependent on adequate reperfusion at the tissue level. Primary percutaneous coronary intervention (PCI) achieves full patency of the infarct-related vessel in >90% of the patients with AMI. Despite the restoration of large-vessel flow, tissue perfusion in area at risk frequently continues to be compromised. To optimize microvascular reperfusion and clinical outcomes, additional measures are needed. Thus far, mechanical approaches to improve distal perfusion, such as the use of distal protection devices, have not been shown beneficial. Among the pharmacological approaches, high-dose adenosine infusion holds promise but has to be proved by further clinical studies. Glycoprotein IIb/IIIa receptor blockade with abciximab has a documented efficacy in improving microvascular flow, contractile recovery, and patient survival after primary PCI in AMI. In addition to the inhibition of platelet aggregation, prevention of pro-inflammatory heterotypic platelet interactions may contribute to the beneficial effect of this drug.