Drug-eluting stent (DES) thrombosis (ST) can be devastating. The study aim was to evaluate intravascular ultrasound (IVUS) predictors for DES thrombosis by comparing IVUS studies after implantation in 13 patients with 14 DES thrombosis lesions with a group of controls (30 lesions in 27 patients) matched for history of chronic renal failure and type of DES. Five patients (38%) discontinued dual antiplatelet therapy at the time of ST. There were 3 in-stent restenosis lesions (21%) treated using DESs in the ST group compared with 0 in the control group (p <0.05). Compared with the control group, IVUS studies in the ST group showed a smaller minimum stent area (4.6 +/- 1.1 vs 5.6 +/- 1.7 mm(2), p = 0.0489). In the ST group, 11 of 14 stents had a minimum stent area < or =5.0 mm(2) compared with 12 of 30 in the control group (p = 0.0392). Minimum stent area in patients who stopped clopidogrel therapy and developed ST (5.30 +/- 1.15 mm(2)) tended to be larger compared with that in patients who developed ST while using clopidogrel (4.24 +/- 0.96 mm(2), p = 0.091). Within the 5-mm-long proximal and distal reference segments analyzed, the ST group had larger proximal reference maximum plaque burdens and smaller minimum lumen areas, along with a tendency toward similar findings in the distal reference segments. In conclusion, IVUS findings at the time of DES implantation in patients who subsequently developed ST showed a smaller minimum stent area (especially in patients who developed ST while using clopidogrel) and more residual disease at the stent edges.