Polymer‐free versus permanent polymer drug eluting stents in coronary artery disease: A meta‐analysis of 10 RCTs with 6575 patients

Background Permanent polymer drug eluting stents (PP‐DES) may induce inflammation of the vessel wall due to the existence of the polymer, which may delay intimal healing. Polymer‐free DES (PF‐DES) that eliminate the polymeric carrier may potentially lead to safer DES. However, the safety and efficacy of PF‐DES remains controversial. Methods Randomized controlled trials comparing PF‐DES with PP‐DES were searched in online database including MEDLINE, Excerpta Medica Database (EMBASE) and Cochrane Library. Studies reporting late lumen loss (LLL), all‐cause death, myocardial infarction (MI), target lesion revascularization (TLR) and late stent thrombosis (LST) were enrolled and quantitatively analyzed. Results Ten studies enrolling 6575 patients were included in this meta‐analysis. The PF‐DES showed a benefit in reducing all‐cause death ( OR = 0.77, 95% CI : 0.61 to 0.98, P = 0.03) and long‐term LLL (weighted mean difference (WMD) −0.16 mm, 95% CI : −0.22 to −0.11 mm, P < 0.001), while no superiority was found in reducing short‐term LLL (WMD 0.03 mm, 95% CI : −0.07–0.13 mm, P = 0.57), MI ( OR = 1.12, 95% CI : 0.19 to 23.18, P = 0.39), TLR ( OR = 1.19, 95% CI : 0.42 to 3.38, P = 0.83) and LST ( OR = 0.92, 95% CI : 0.05 to 5.71, P = 0.74). Conclusion PF‐DES showed benefits in reducing long‐term LLL and mortality compared with PP‐DES, but no superiority was found in short‐term LLL, MI, TLR and LST. These findings provide a sound basis for the wide application of PF‐DES in the future.