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.