Comparison of Early Strut Coverage Between Zotarolimus- and Everolimus-Eluting Stents Using Optical Coherence Tomography

There have been no optical coherence tomographic (OCT) data directly comparing the pattern of strut coverage between the 2 second-generation drug-eluting stents in the early period. The aim of this prospective study was to evaluate early strut coverage using optical coherence tomography 3 months after Resolute zotarolimus-eluting stent (ZES-R) or everolimus-eluting stent (EES) implantation in de novo coronary artery lesions. A total of 40 patients who were suitable for the OCT procedure and consented to the study protocol were randomized 1:1 to receive either ZES-R or EES. Among these patients, 35 stented lesions (18 ZES-R, 17 EES) in 34 patients were evaluated by optical coherence tomography immediately and 3 months after stent implantation. Neointimal hyperplasia thickness, percentage of uncovered struts, and the proportion of malapposed struts were measured at 1-mm intervals. An uncovered strut was defined as having a neointimal hyperplasia thickness of 0 μm. At the 3-month OCT evaluation, mean neointimal hyperplasia thickness (ZES-R vs EES 74 ± 41 vs 75 ± 35 μm, p = 0.89) and mean percentage of uncovered struts (ZES-R vs EES 6.2 ± 6.9 vs 4.7 ± 5.1%, p = 0.62) were not significantly different between the groups. The percentage of malapposed struts was also similar between the groups (0.7 ± 2.2% for ZES-R and 0.7 ± 1.7% for EES, p = 0.64). Thrombi were documented in 3 stents (1 [5.6%] in a ZES-R vs 2 [11.8%] in EES, p = 0.60). In conclusion, early stent strut coverage on the basis of serial OCT evaluation was comparable between ZES-R and EES 3 months after stent implantation.