Safety And Efficacy Of Polymer-Free Versus Polymer-based Drug Eluting Stent: Evidence From A Meta-analysis Of Randomized Controlled Trials

Purpose: Despite the higher efficacy compared to bare-metal stents(BMS), concerns remain regarding the long-term safety of DES, includinglocalized hypersensitivity and late stent thrombosis. New generation stentswith free polymers have recently been developed. The aim of this study wasto perform a meta-analysis of randomized controlled trials (RCTs)comparing the safety and efficacy profile of polymer-free versuspolymer-based DES.Methods: Major electronic information sources were explored forrandomized controlled trials comparing polymer-free with polymer-basedDES among patients undergoing PCI during at least9months follow-up.Safety endpoints were mortality, myocardial infarction (MI), and stentthrombosis (ST). Efficacy endpoint was target lesion revascularization(TLR).Results: The meta-analysis included five clinical trials (n=5098).At afollow-up of at least nine months, as compared to polymer-based DES, polymer-free DES use did not increase mortality (RR [95%CI]=0.81[0.58,1.10], p=0.17) or MI (RR [95%CI]=1.14[0.84,1.57],p=0.39). Rates of STand TLR were comparable between polymer-free and polymer-based DES.Conclusion: Polymer-free DES are at least as safe as polymer-basedDES with regard to survival, MI, ST and TLR. For this study powered forclinical end points, the polymer-free DES was noninferior to thepolymer-based DES. Further large RCTs with long-term follow-up arewarranted to definitively confirm the potential benefits of polymer-freeDES.