Patterns of restenosis after drug-eluting stent implantation: insights from a contemporary and comparative analysis of sirolimus- and paclitaxel-eluting stents

Aim To evaluate patterns of restenosis following implantation of sirolimus-eluting stent (SES) and paclitaxel-eluting stent (PES) in comparable unselected lesions. Methods and results We have identified all episodes of restenosis after SES or PES implantation in our institutions between March 2003 and March 2005. Restenosis pattern was classified as focal, diffuse, proliferative, or occlusive. The position of focal restenosis was also categorized as proximal, in-stent, distal, or multi-focal. We have characterized 150 and 149 restenotic lesions in SES and PES groups, respectively. The incidence of diffuse and occlusive restenosis was significantly higher in PES than in SES (47.6 vs. 27.0%, P < 0.001). Multivariable (OR 2.693, 95% CI 1.425-5.089, P=0.002) and propensity (OR 3.00, 95% CI 1.584-5.672, P < 0.001) analyses confirmed the positive association of PES with non-focal restenosis. For both stents, focal-edge restenosis was significantly more likely to occur proximally than distally (61.0 vs. 16.9%, P < 0.001 for PES and 45.8 vs. 16.8%, P < 0.001 for SES). Conclusion Focal restenosis remains the most common pattern with SES. In contrast, just under half of restenosis in PES is the more severe non-focal pattern. Paradoxically, the majority of focal restenosis occurs at the proximal stent margin for both platforms.