Background: Despite great advances in coronary intervention by drug-eluting stent (DES), long term outcome is still limited by the occurrence of DES restenosis. This study is to assess the preliminary information of detailed angiographic restenosis patterns of DES compared with bare metal stent (BMS) at 6-month from Korea University Medical Center (KUMC) DES registry.
Methods: A total 112 pts (Male 86, mean age, 61.2 ± 8.6 years) with 149 lesions were treated with Sirolimus-eluting stent (SES, Cypher™; C, n=55), Paclitaxel-eluting stent (Taxus™; T, n=65) or Bare metal stent (BMS; B, n=29) were enrolled and entered into the dedicated data base for detailed 6-month angiographic analysis.
Results: Baseline characteristics were similar among three groups. Small stent (≤2.75mm) was implanted in 30.2% (45/149) and long stent (>20mm) in 65.1% (97/149). The mean stent diameter was similar among 3 groups (C; 2.98±0.3mm, T; 2.92±0.3mm, B; 3.40mm±0.6, p=NS) but the mean stent length of BMS was shorter than DES (C; 25.1±6.3, T; 21.3±3.3, B; 20.1±5.0, p=0.03). Binary restenosis was less in DES compared to BMS (C; 7.7%, T; 5.8%, B; 9.6%, P=0.03). Mean % Restenosis was lowest at the Cypher group among 3 groups (C; 22.3±19.6%, T; 45.9±29.6%, B; 42.9±18.7%, p=0.009). Mean restenosis lesion lengths (C; 8.3±6.1mm, T; 6.8±4.6mm, B; 12.8±5.9mm, p=0.25) and follow up minimal luminal diameter (MLD) were not different (C; 2.4±0.8, T; 2.0±1.2, B; 1.9±1.0, P=0.80). Late loss was significantly lower in Cypher and higher in BMS (C; 0.48±0.7, T; 0.98±1.1, B; 1.29±0.8, p=0.01). The DES restenosis patterns are; Mehran Type Ia 2.8%, Ib 15.5%, Ic 54.2%, Id 5.6%, II 12.0%, III 5.6% and IV 4.2% (Focal 78.2% and Diffuse 21.8%). Edge restenosis patterns are not different (C; 53.3%, T; 20.0%, B; 20.0%, p=0.29).
Conclusion: Although routine DES implantation is highly effective in reducing in-stent restenosis (ISR), DES failure by intimal regrowth at 6 months is still occurs in 5-7% of KUMC DES registry. Most common DES failure type was Ic for focal ISR and II for diffuse ISR. Mean % restenosis and late loss was lowest after Cypher implantation compared with Taxus or BMS implantation.
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