Randomized evaluation of coronary angioplasty for early TIMI 2 flow after thrombolytic therapy for the treatment of acute myocardial infarction: a new look at an old study. The Thrombolysis and Angioplasty in Myocardial Infarction (TAMI) Study Group.

Background: Patients who have suffered acute myocardial infarction (AMI) and have been treated with intravenous thrombolytic agents resulting in early 'patent' [Thrombolysis in Myocardial Infarction (TIMI) 2-3 flow grade] arteries have been shown not to benefit from early percutaneous transluminal coronary angioplasty (PTCA). Recent data, however, suggest that the clinical outcome of patients with early TIMI 2 flow is decidedly inferior to that of patients with TIMI 3 flow, raising the question whether early PTCA might be beneficial for patients with TIMI 2 flow. The clinical utility of PTCA for this particular subset of patients has never been assessed.
Methods: We analyzed left ventricular ejection fraction (LVEF) recovery by contrast ventriculography and clinical outcome in Thrombolysis and Angioplasty in Myocardial Infarction Phase I (TAMI-I) study patients with initial TIMI 2 flow grade, determined by blinded core laboratory analysis.
Results: No differences were observed between baseline demographic data for the 49 patients randomly assigned to undergo early PTCA compared with that from the 59 patients randomly assigned to receive early medical therapy. Patients were 56 +/- 11 years of age (mean +/- SD), 80% were men, the time from onset of chest pain to catheterization was 268 +/- 71 min, 42% had anterior AMI, and 42% had multivessel disease. Ninety minute baseline LVEF to prehospital discharge LVEF was minimally better in the group randomly assigned to undergo PTCA (51 +/- 12 to 52 +/- 11% versus 55 +/- 10 to 53 +/- 12%, P = 0.06). This contrasted with findings in patients with TIMI 3 flow grade at baseline, which showed a relative benefit for patients randomly assigned to receive early medical therapy (54 +/- 10 to 54 +/- 8% for PTCA, versus 55 +/- 10 to 58 +/- 8% for medical therapy, P = 0.01). Among patients with TIMI 2 flow grade there were no differences in in-hospital death or congestive heart failure (6.1 versus 1.7%, P = 0.25 and 18.4 versus 23.7%, P = 0.50, PTCA versus medical therapy, respectively).
Conclusion: We conclude that (1) PTCA of infarct-related arteries with TIMI 2 flow grade may modestly improve recovery of left ventricular function, and (2) widespread application of PTCA in this setting should be deferred, pending demonstration that this benefit outweighs the risks of PTCA.