Thrombolysis in Myocardial Infarction (TIMI)

BACKGROUND:

Coronary artery disease is the leading cause of death in the United States, accounting for almost 500,000 deaths each year. Studies have confirmed that myocardial infarction is related to an occlusive coronary thrombus in up to 80 percent of patients. First and second-generation thrombolytic agents (including streptokinase and rt-PA) have been successfully used to restore myocardial blood flow where thrombus has occluded an infarct-related coronary artery. However, further clinical investigation was necessary to determine the most suitable thrombolytic agent dose and method of administration, the risk of subsequent reocclusion, restenosis, and/or myocardial infarction, the need for additional therapies, and the likelihood of benefit or hemorrhagic complications.

In 1983 the National Heart, Lung, and Blood Institute established the TIMI Study Group. The group consisted of 13 clinical centers (later expanded to 24), a Radiographic Core Laboratory, Radionuclide Core Laboratory, and a Data Coordinating Center.

DESIGN NARRATIVE:

The TIMI trial was conducted in two stages. In Phase I or TIMI I, eligible patients were randomized to receive either 80 mg of recombinant tissue-type plasminogen activator (rt-PA) or 1.5 million units of streptokinase intravenously to determine relative safety and efficacy. Following randomization, patients found to have angiographically documented stenosis greater than 50 percent in the infarct-related artery received thrombolytic therapy in a double-blind fashion, full anticoagulation, and conventional care. Patients subsequently underwent repeat catheterization, radionuclide ventriculogram, and pre-discharge, six-week and six-month cardiovascular examination.