Intravascular ultrasound findings in patients with restenosis of sirolimus- and paclitaxel-eluting stents

Objective We used intravascular ultrasound (IVUS) to compare restenotic sirolimus-eluting (SES) vs paclitaxel-eluting (PES) stents. Background Little is known about the IVUS pattern and mechanisms of restenosis, in the two widely available drug-eluting stent (DES) platforms. Methods Volumetric IVUS analysis was performed in patients with clinical restenosis in DES (n = 29 SES and 11 PES respectively). Results Despite similar vessel volumes (347.5 ± 155.6 vs 356.5 ± 164.1 mm3, p = 0.84) and stent volumes (175.6 ± 74.57 vs 179.7 ± 84.24 mm3, p = 1.0), IVUS analysis showed that neointimal hyperplasia volume was significantly greater in PES restenoses than in SES restenoses (40.0 ± 44.2 vs 19.3 ± 11.4 mm3, p = 0.02) without any significant difference in distribution over the stent length. This leads to a higher percent of volume obstruction (intimal hyperplasia volume divided by stent volume: 18.5 ± 13.7% vs 11.8 ± 7.7%, p = 0.045). Minimal stent area was smaller in SES than in PES (4.3 ± 1.2 vs 5.6 ± 1.2 mm2, p = 0.06) and stent underexpansion was more frequently observed in SES stents: minimal stent area < 4.5 mm2 (65% in SES vs 27% in PES, p = 0.04). Stent edge restenosis occured in 1/29 SES (3%) vs 3/11 PES (27%) stents, p = 0.056. Conclusion The magnitude of neointimal hyperplasia was greater in PES than in SES while stent underexpansion appeared to be more common in SES.