To See or Not to See: Beyond the Open Artery in Myocardial Reperfusion

Acute ST-elevation myocardial infarction (STEMI) is the major cause of mortality and morbidity in industrialised countries. The pathogenesis of STEMI is well know in the present: after plaque rupture and intracoronary thrombus formation, ischemia causes damage to myocytes and coronary microcirculation, soon after occlusion. Thus, the goal of therapy in patients with STEMI is to re-establish a pa-tent infarct-related epicardial artery as soon as possible.
Primary percutaneous coronary intervention (PCI) has now emerged as the optimal mode of reperfusion therapy, if performed by an experienced team within 90 minutes after the onset of symptoms [1]. The Thrombolysis In Myocardial Infarction (TIMI) group has categorized epicardial coronary flow into four grades (0–3) to standardize the angiographic characterization of reperfusion. Primary PCI results in patency of the occluded artery in almost all patients and in restoration of TIMI flow grade 3 (normal epicardial flow) in more than 90% of patients [2].
The restoration of TIMI-3 coronary flow in patients with STEMI is associated with improved survival and enhanced recovery of left ventricular function. This observation has led to the ‘Open artery theory’ explaning that restoration of TIMI-3 flow has been used as the gold standard for reperfusion success [3]. [More]