We hypothesized that blood flow in noninfarct arteries would improve after percutaneous coronary intervention of the culprit artery in the setting of ST-elevation myocardial infarction (STEMI). The corrected Thrombolysis In Myocardial Infarction (TIMI) frame count was measured in 94 patients (102 arteries) enrolled in the INTEGRITI, ENTIRE, and FASTER trials of reduced dose fibrinolytic and glycoprotein IIb/IIIa inhibition. The corrected TIMI frame count in nonculprit arteries improved by 3.4 +/- 13.4 frames after percutaneous coronary intervention but remained significantly slower than flow in normal arteries.