Background: Difference of neointimal formational pattern and incidence of thrombus formation between sirolimus-eluting stent (SES) and paclitaxel-eluting stent (PES) at 18 months after stent implantation has not previously been reported.
Methods: We retrospectively enrolled 35 event-free patients who received SES (15 patients, 18 stents) or PES (20 patients, 23 stents) implantation with 18-month follow-up coronary angioscopy. We divided our patients into SES or PES groups and compared neointimal coverage pattern and incidence of red mural thrombus formation between the 2 groups. Neointimal coverage grades were classified into 4 categories. Minimum neointimal coverage grade, maximum grade, and heterogeneity score were assessed in each stent. Heterogeneity score was calculated by subtracting minimum from maximum grade within one stent.
Results: Minimum neointimal coverage grade of PES was significantly lower than that of SES (0.70 +/- 0.64 vs 1.33 +/- 0.69, P = .005), whereas maximum grade was not significantly different (2.48 +/- 0.73 vs 2.22 +/- 0.73, P = .218). Heterogeneity score and incidence of red mural thrombus of PES were higher than those of SES (1.78 +/- 0.80 vs 0.89 +/- 0.76, P = .002 and 70% vs 11%, P < .001).
Conclusions: The present study revealed that PES shows more heterogeneous neointimal coverage and higher incidence of thrombus formation as compared with SES at 18 months after stent implantation.
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