Results of percutaneous transluminal coronary angioplasty in unstable angina and non-Q-wave myocardial infarction. Observations from the TIMI IIIB Trial.

BACKGROUND

This report describes the results of percutaneous transluminal coronary angioplasty (PTCA) in the Thrombolysis in Myocardial Ischemia (TIMI) IIIB Investigation.

METHODS AND RESULTS

PTCA was performed before hospital discharge in 444 of 1473 patients with either unstable angina pectoris or non-Q-wave myocardial infarction (NQWMI) enrolled in TIMI IIIB. Angiographic success was observed in 96.1% of patients. For the entire cohort, the cumulative incidences of death and infarction at 1 year were 2.0% and 8.2%, respectively. The periprocedural incidence of myocardial infarction was 2.7%; emergency coronary bypass surgery, 1.4%; and death, 0.5%. By 1 year of follow-up, 122 patients (28.0%, Kaplan-Meier) had an additional revascularization procedure, 75 (61.5%) had PTCA only, 30 (24.6%) had coronary bypass surgery only, and 17 (13.9%) had both procedures. The results of PTCA were not improved by routine pretreatment with intravenous tissue plasminogen activator (TPA). Periprocedural myocardial infarction was more common among patients receiving TPA than placebo (odds ratio [OR], 2.19; P = .03) and among those with unstable angina than those with NQWMI (OR, 15.5; P = .007). No difference in outcome was observed when patients were analyzed according to age (OR, 1.06; P = .092) or sex (OR, 1.54; P = .51). Variables predictive of poor outcome were PTCA within the first 24 hours of enrollment, PTCA site being the left anterior descending coronary artery, and unsuccessful angiography.

CONCLUSIONS

In TIMI IIIB, PTCA was performed for patients with unstable angina and NQWMI with a very high rate of angiographic success and a low incidence of complications. By 1 year, repeat revascularization was performed in 28.0% of patients. Routine pretreatment with thrombolysis did not enhance outcome.