Background: Acute myocardial infarction (AMI) associated with significant left ventricular dysfunction (LVD) indicates a poor prognosis. Previous studies suggested that revascularization improves survival of patients with AMI complicated by cardiogenic shock. However, other studies that suggested that revascularization improves survival of stable patients with significant LVD did not specifically address patients who had recently had an AMI. Objectives: Our purpose was to determine whether patients with thrombolysis-treated AMI associated with significant LVD are likely to incur a survival advantage from catheterization and coronary revascularization performed within 30 days after AMI. Methods: The study population was drawn from the Argatroban in Acute Myocardial Infarction-2 (ARGAMI-2) trial, which included 1200 patients with AMI, all of whom received thrombolytic therapy. Our analysis included 737 patients for whom LV function was estimated by echocardiography. Two hundred two patients had significant LVD; of them, 117 (58%) underwent cardiac catheterization and 85 were treated noninvasively. Among 535 patients without significant LVD, 291 (54%) underwent cardiac catheterization and 244 were treated noninvasively. Results: Compared with a noninvasive approach, an invasive approach resulted in reduced 30-day and 6-month mortality rates in patients with significant LVD: 4.3% versus 10.6%, adjusted odds ratio (OR) 0.26, 95% confidence interval (CI) 0.04 to 1.18, and 6.1% versus 15.5%, OR 0.27, 95% Cl 0.06 to 0.98, respectively. A similar comparison in patients without significant LVD resulted in comparable 30-day and 6-month mortality rates for both patient groups: invasively versus noninvasively treated, 0.7% versus 0.8%, OR 1.04, 95% Cl 0.04 to 12.7, and 1.4% versus 1.7%, adjusted OR 1.60, 95% Cl 0.20 to 9.87. Conclusions: The current study suggests that AMI patients with significant LVD may benefit from cardiac catheterization and revascularization performed early after AMI, whereas in patients without significant LVD the outcome of those treated invasively or conservatively was similar.