Clinical outcomes of new-generation drug-eluting stents in patients with coronary artery disease: meta-analyses of randomised controlled trials

Abstract

Advances in coronary stent technology have revolutionised the treatment of coronary artery disease (CAD) in current clinical practice. Novel stent platforms, such as biodegradable polymer drug-eluting stents (BP-DES) and polymer-free drug-eluting stents (PF-DES), have been developed in recent years to improve on patient outcomes of preceding generations of devices. These new-generation drug-eluting stents (DES) utilise a biocompatible or bioresorbable polymer coating to theoretically eliminate the risk of very late stent thrombosis (ST) associated with the current gold standard durable polymer drug-eluting stents (DP-DES). The permanent polymer coating of DP-DES has been shown to induce a chronic inflammatory response in the vessel wall leading to ST. The performance of new-generation DES compared with DP-DES has not been well appraised in the literature. To summarise the latest clinical evidence, the present thesis included meta-analyses of randomised controlled trials (RCTs) comparing the safety and efficacy profiles of new-generation DES, namely BP-DES and PF-DES, with DP-DES. Subgroup analyses based on anti-proliferative drug, duration of dual antiplatelet therapy (DAPT), and length of follow-up were performed to ascertain if these variables might affect patient outcomes. Landmark analyses were also performed to evaluate late outcomes beyond 1 year. The overall rationale for the present thesis was to provide both qualitative and quantitative assessments of the clinical outcomes of new-generation DES to better inform the ongoing development of clinical practice guidelines for the use of coronary stents in patients with CAD. In summary, new-generation DES and DP-DES conferred equivocal safety and efficacy profiles, with comparable risks of definite or probable ST, myocardial infarction (MI), cardiac death, all-cause death, target lesion revascularisation (TLR), and target vessel revascularisation (TVR). The theoretical advantages of BP-DES and PF-DES over DP-DES were not realised in the meta-analyses. Further RCTs with greater length of follow-up and larger patient population are warranted to determine the purported benefits of these novel stent platforms.