Thrombus resolution with tirofiban in the conservative management of patients presenting with plaque erosion

OBJECTIVE: Recent studies suggest that conservative management with antithrombotic therapy without stenting may be an option in selected patients with acute coronary syndrome (ACS). We evaluated whether a glycoprotein IIb/IIIa inhibitor, tirofiban, would offer additional benefit in patients with plaque erosion presenting with ACS who were treated with antiplatelet therapy without stenting. PATIENTS AND METHODS: Forty-nine patients who completed 1-year follow-up optical coherence tomography imaging in the EROSION study were divided into two groups: tirofiban (n=32) versus no tirofiban (n=17). Thrombus volume, thrombus burden, and the incidence of major adverse cardiovascular events were evaluated. RESULTS: At baseline, the tirofiban group had similar thrombus volume [3.73 (1.27-12.49) vs. 3.51 (1.70-8.65) mm, P=0.983] and marginally greater thrombus burden [17.9 (10.1-26.1) vs. 10.6 (6.8-19.0)%, P=0.097]. At 1 month, the tirofiban group had smaller residual thrombus volume [0.00 (0.00-1.78) vs. 0.94 (0.07-4.20) mm, P=0.054], thrombus burden [0.0 (0.0-6.4) vs. 7.0 (1.8-14.8)%, P=0.024], and greater reduction of thrombus volume (85.4±24.6 vs. 67.1±27.1%, P=0.021). These differences were maintained up to 1 year. Complete resolution of thrombus at 1 month was more frequent in the tirofiban group (53.1 vs. 17.6%, P=0.031). None of the patients experienced major bleeding during the initial hospitalization. The 1-year major adverse cardiovascular events rate was not different (5.6 vs. 15.0%, P=0.336). CONCLUSION: In patients with ACS caused by plaque erosion who were managed conservatively without stenting, tirofiban provided additional benefit in reducing residual thrombus without an increased risk for bleeding.