Implications of upstream glycoprotein IIb/IIIa inhibition and coronary artery stenting in the invasive management of unstable angina/non-ST-elevation myocardial infarction: a comparison of the Thrombolysis In Myocardial Infarction (TIMI) IIIB trial and the Treat angina with Aggrastat and determine Cost of Therapy with Invasive or Conservative Strategy (TACTICS)-TIMI 18 trial

Abstract

Background: TIMI IIIB and TACTICS-TIMI 18 were 2 trials of an early invasive strategy in unstable angina (UA)/non-ST-elevation myocardial infarction (NSTEMI) that were conducted nearly a decade apart but with virtually identical enrollment criteria and designs, except that upstream glycoprotein IIb/IIIa inhibition was mandated and coronary artery stenting was routinely used in TACTICS-TIMI 18. We sought to examine the effect of these advances on clinical outcomes and the benefits of an early invasive strategy in UA/NSTEMI.

Methods and results: Patients were stratified on the basis of their TIMI risk score into low-, intermediate-, and high-risk categories. Within each risk category, the rates of clinical outcomes and the benefit of an early invasive strategy were compared. Compared with patients in TIMI IIIB and adjusting for baseline risk, patients in TACTICS-TIMI 18 had lower rates of death, MI, or rehospitalization for acute coronary syndromes (OR, 0.62; P<0.0001). Across both trials, the benefit of an early invasive strategy was significantly greater with increasing baseline risk: OR, 1.39 in low-risk, 0.80 in intermediate-risk, and 0.57 in high-risk patients (P< or =0.004 for interactions). After adjustment for baseline risk, an early invasive strategy tended toward a more favorable result in TACTICS-TIMI 18 than in TIMI IIIB (OR, 0.79; 95% CI, 0.56 to 1.11).

Conclusions: Advances in the care of patients with UA/NSTEMI, including glycoprotein IIb/IIIa inhibition and stenting, were associated with lower rates of death, MI, and rehospitalization for acute coronary syndromes and a trend toward a greater benefit of an early invasive strategy.