In TIMI IIIB, a total of 1,473 patients seen within 24 hours of ischemic chest pain at rest, considered to represent unstable angina or non-Q-wave myocardial infarction (NQMI), were randomized using a 2 x 2 factorial design to compare t-PA versus placebo as initial therapy and an early invasive strategy consisting of early coronary arteriography followed by revascularization when the anatomy was suitable versus an early conservative strategy consisting of coronary arteriography followed by revascularization if initial medical therapy failed. All patients were treated with bed rest, anti-ischemic medications, aspirin, and heparin. The primary endpoint for the t-PA placebo comparison was death, myocardial infarction, or failure of initial therapy at six weeks. Randomization began in October 1989 and concluded in June 1992. The primary endpoint for the early invasive and early conservative strategies was death, post randomization myocardial infarction or an unsatisfactory exercise tolerance test (ETT) at six weeks.