Abstract 148: Difference in Neointimal Coverage Pattern Between Zotarolimus Eluting Stents and Everolimus Eluting Stents Using Optical Coherence Tomography: A Meta-Analysis

Abstract

Background: Late stent thrombosis in drug eluting stents (DES) is attributed to poor endothelialization of struts. Second generation DES have shown superior safety profile and efficacy in comparison to first generation DES. We conducted a meta-analysis to compare the neointimal coverage patterns between Zotarolimus eluting stents (ZES) and Everolimus eluting stents (EES) using optical coherence tomography (OCT). Methods: We searched online databases for studies comparing the neointimal thickness (NIT), %malapposed strut per stent (MSS) or % uncovered strut per stent (USS) between ZES and EES using OCT. Studies included inte mmeta-analysis, OCT was performed >6 months after stent deployment. A calculation of weighted standardized mean difference (SMD) in NIT, MSS and USS between ZES and EES groups was calculated. Residual maximum likelihood (REML) metaregression was performed on smokers, diabetes mellitus (DM), hypertension, (HTN) dyslipidemia (DLD), and age and sex covariates. Results: A total of 6 studies enrolling 327 patients which met inclusion criteria were included in the meta-analysis. 400 stents including 184 ZES and 216 EES were analyzed by OCT. The median of mean age in years, male sex, smokers, DM, HTN and DLD in the ZES group was 60.7(59.5 - 60.9), 76.7% (71.4 - 77.3), 38.7% (18.2 - 45.8), 36.4% (23.3 - 37.5), 63.6% (60 - 66.6), 66.7% (47.9 - 68.4) versus 62.6(59.8 - 65.3), 63.9% (63.6 - 82.1), 30% (17.2 - 47.2), 31.8% (25 - 36.1), 69.4% (59.1 - 75.9), 70% (48.9 - 70.7) in the EES group respectively. The unweighted median NIT, MSS and USS in the ZES group are 127.5 μm (108.8 - 152.2), 0.7% (0.7 - 0.9), 1.8% (0.2 - 3.5) vs 117.4 μm (108.5 - 128.5), 0.3% (0.2 - 1.3), 2.3% (0.9 - 3.5) in the EES group respectively. The weighted SMD of NIT, MSS and USS in the ZES vs EES groups are -0.22 (95%CI -1.12; 0.67) P = 0.63, -0.51(95% CI -1.78; 0.77), P = 0.44, -1.26 (95%CI -2.83; 0.31). None of the above mentioned covariates accounted for statistical insignificance except age for NIT. As age increases, the SMD increases for NIT and was not significant for MSS and USS. Conclusion: No significant difference was noted in the NIT, MSS and USS between both groups. This suggests that the neointimal coverage patterns are similar in ZES and EES groups.