Optical coherence tomography evaluation of intermediate-term healing of different stent types: systemic review and meta-analysis.

Aims: The intermediate-term incidence of strut malapposition (SM) and uncovered struts (US), and the degree of neointimal thickness (NIT) according to stent type have not been characterized.
Methods and Results: All studies of >50 patients in which optical coherence tomography was performed between 6 and 12 months after stent implantation were included. The incidences of SM and US were the co-primary end points, while NIT was the secondary end point. A total of 458 citations were initially appraised at the abstract level, and 11 full-text studies (280 652 analysed struts, 921 patients) were assessed. The 6-12 months incidences of SM and US were 5.0 and 7.8%, respectively, and the mean NIT was 206 μm. Biolimus-eluting stents (BES) and bioresorbable vascular scaffolds (BVS) had the highest SM rates (2.7 and 3.8%, respectively), while everolimus-eluting stents (EES) and fast-release zotarolimus-eluting stents (ZES) had the lowest SM rates (0.9 and 0.1%, respectively). BES and sirolimus-eluting stents (SES) had the highest US rates (7.7 and 8.8%, respectively), while bare metal stents (BMS) and ZES had the lowest US rates (0.3 and 0.3%, respectively). BMS had the greatest NIT (340 μm), while SES, EES, and BES had the least NIT.
Conclusion: Second-generation drug-eluting stents (DES) have better intermediate-term strut apposition and coverage than first-generation DES, BVS, and BMS. EES demonstrate the overall best combination of healing with suppression of neointimal hyperplasia at 6-12 months. Further studies with clinical correlation are warranted to determine the implications of these findings.
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