Prediction of late restenosis after sirolimus-eluting stent implantation using serial quantitative angiographic and intravascular ultrasound analysis

Although sirolimus-eluting stents (SESs) have shown to significantly reduce the incidence of restenosis, it remains unclear when the follow-up angiography should be performed after SES implantation. A total of 868 patients with 1,574 lesions were treated with SES. Of the 71 patients with 87 lesions were performed serial angiographic and intravascular ultrasound (IVUS) analysis (pre, post, 1st and 2nd-follow-up). The first follow-up period was 7.9 +/- 3.5 months and the second follow-up was 18.9 +/- 7.7 months. Late restenosis (LR) was defined as diameter stenosis >= 50% at second follow-up, which was < 50% at first follow-up. A total of restenosis was documented in 69 patients with 89 lesions (5.7%) overall, 13 lesions (3.2%) led to LR. Angiographic pattern of LR was predominately focal pattern. In LR group, late lumen loss by angiography was increased between 1st-follow-up and 2nd-follow-up (0.69 +/- 0.41 mm in first follow-up and 1.98 +/- 0.44 mm in second follow-up, p < 0.0001). Minimum lumen area (MLA) by IVUS had slightly decreased already in 1st-follow-up (6.07 +/- 2.31 mm(2) in post procedure and 4.71 +/- 2.05 mm(2) in 1st-follow-up, p = 0.098) and significantly decreased in 2nd-follow-up (6.07 +/- 2.31 mm 2 in post procedure and 1.71 +/- 0.93 mm(2) in 2ndfollow-up, p < 0.0001). However, in each period, there were no significant difference in both late lumen loss and MLA in non-LR group. Neointima growth prolonged gradually over 1 year in LR group. These findings suggest that if neointimal proliferation is recognized in short-termfollow-up period, long-follow-up should be needed.