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.