Polymer-free drug-eluting stents versus permanent polymer drug-eluting stents: An updated meta-analysis

BACKGROUND: Polymer-free drug-eluting stents (PF-DES) have been demonstrated comparable to permanent polymer drug-eluting stents (PP-DES) during long-term follow-up. As a critical component of drug-eluting stents, antiproliferative drugs may be a confounding factor for the results. Thus, we sought to compare the outcomes of these stents during long-term follow-up, especially in consideration of different stent platforms with the same drugs. METHODS: A systemic search was performed to identify the related randomized controlled trials comparing PF-DES with PP-DES. Primary outcomes included short (≤1 year) and long-term (>1 year) target lesion revascularization (TLR), short-term in-stent late luminal loss (LLL) and diameter stenosis (DS). Subgroup analyses stratified by the different platforms with the same proliferative drugs were conducted in TLR, LLL, and DS. Standardized mean differences (SMDs) and risk ratios (RRs) were estimated using fixed /random effects models RESULTS: A total of 6927 patients extracted from 12 RCTs were enrolled in the meta-analysis. No differences were observed in clinical outcomes of short-term and long-term overall mortality, myocardial infarction and stent thrombosis and angiographic outcomes of short-term in-stent LLL and DS between PF-DES and PP-DES for patients with coronary artery lesions. Nevertheless, compared with PP-DES coated with the same proliferative drugs, PF-DES had significantly increased risks of in-stent LLL (SMD, 0.49; 95% confidence interval [CI], 0.25–0.72) and DS (SMD, 0.67; 95% CI, 0.27–1.07), and long-term TLR (RR, 1.64; 95% CI 1.13–2.39). There were no significant differences in other outcomes. CONCLUSIONS: Under the condition of using same antiproliferative drugs (paclitaxel or sirolimus) in different stent systems, PF-DES are associated with the increased risk of restenosis compared to PP-DES.