RIMARY PERCUTANEOUS REPERfusion for patients with acute ST-segmentelevationmyocardial infarction (STEMI) has been shown to reduce mortality and is consideredthestandardofcarewhenavailable. 1,2he benchmarked standards for time to reperfusion have shortened over time; despite significant reductions in door-toballoon times over the past few years in theUnitedStates,theSTEMImortalityrate has not significantly improved. 3,4atients with acute STEMI, representing 30% to 45% of approximately 1.5 million hospitalizations for acute coronary syndromes annually in the United States, 5 are still at substantial acute mortality risk with 1-year mortality estimated to be between 6% and 15%. 2,5This may be related to microvascular obstruction resulting in no reflow at the time of mechanical reperfusion and infarct expansion over time. 6,7Additionally, this increase in infarctsizeisassociatedwithadverseremodeling and decreased left ventricular (LV) function leading to heart failure and longterm morbidity following STEMI. 8,

Intra-aortic Balloon Counterpulsation and Infarct Size in Patients With Acute Anterior Myocardial Infarction Without Shock