Impact of Primary Coronary Angioplasty Delay on Myocardial Salvage, Infarct Size, and Microvascular Damage in Patients With ST-Segment Elevation Myocardial Infarction : Insight From Cardiovascular Magnetic Resonance

Shorter time-to-reperfusion (group I) was associated with smaller IS and microvascular obstruction and larger salvaged myocardium. Mean IS progressively increased overtime: 8% (group I), 11.7% (group II), 12.7% (group III), and 17.9% (group IV), p 0.017; similarly, MVO was larger in patients reperfused later (0.5%, 1.5%, 3.7%, and 6.6%, respectively, p 0.047). Accordingly, salvaged myocardium markedly decreased when reperfusion occurred 90 min of coronary occlusion (8.5%, 3.2%, 2.4%, and 2.1%, respectively, p 0.004). Conclusions In patients with STEMI treated with primary percutaneous coronary intervention, time to reperfusion determines the extent of reversible and irreversible myocardial injury assessed by CMR. In particular, salvaged myocardium is markedly reduced when reperfusion occurs 90 min of coronary occlusion. (J Am Coll Cardiol 2009;54: 2145‐53) © 2009 by the American College of Cardiology Foundation