Beyond TIMI III flow.

The Western Washington Intracoronary Streptokinase randomized trial1 first demonstrated that intracoronary thrombolytic therapy improved survival for patients presenting within 12 hours of symptom onset of acute myocardial infarction (MI). Perhaps equally important, this invasive study demonstrated that in-hospital and long-term survival was greatly improved in patients with patent infarctrelated arteries.2 These observations ushered in the modern era of reperfusion therapy, and they also firmly established the concept that achieving arterial patency was the predominant mechanism for the prognostic benefit of thrombolytic agents. Numerous trials since then have validated this open-artery hypothesis.3–5 In the early 1990s, Ross et al6 definitively established the relationship between prompt reinstitution of flow, improved myocardial salvage, and survival. Anderson et al7 clearly demonstrated that antegrade flow, as defined by