Efficacy and safety of polymer-free stent versus polymer-permanent drug-eluting stent in patients with acute coronary syndrome: a meta-analysis of randomized control trials

BACKGROUND The efficacy and safety of polymer-free stent (PFS) versus permanent polymer drug-eluting stent (PPDES) in patients undergoing percutaneous coronary intervention (PCI) remain controversial. Our meta-analysis was undertaken to evaluate and compare the efficacy and safety of PFS with those of PPDES in patients undergoing PCI. METHODS We searched PubMed, Cochrane Library, EMBASE, and Clinical Trials.gov databases for randomized controlled trials (RCTs). The primary endpoints were incidence of stent thrombosis (ST) and target-lesion revascularization (TLR). The secondary endpoints included the incidence of major adverse cardiovascular events (MACE), myocardial infarction (MI), cardiac death (CD), late lumen loss (LLL), and diameter stenosis (DS). Subgroup analyses were also conducted based on the follow-up time. RESULTS Eleven RCTs met the including criteria, and 8616 patients were included in the study. No significant differences were observed between PFS and PPDES treatments in the incidence of ST (RR 0.90; 95% CI: 0.62-1.31; P = 0.58; I 2  = 0), TLR (RR 0.87; 95% CI: 0.76-1.00; P = 0.05; I 2  = 37%), CD (RR 0.89; 95% CI: 0.72-1.10; P = 0.28; I 2  = 0), MI (RR 0.87; 95% CI: 0.71-1.05; P = 0.15; I 2  = 0), LLL (SMD 0.01; 95% CI: -0.29-0.30; P = 0.96; I2 = 90%), and DS (SMD -0.01; 95% CI: - 0.25 to 0.23; P = 0.93; I2 = 83%). Meanwhile, the patients with PFS had a lower incidence of MACE (RR 0.87; 95% CI: 0.78-0.97; P = 0.01; I 2  = 0) than those with PPDES. CONCLUSION In the overall analysis, patients with PFS presented a lower risk of MACE versus PPDES, but no significant difference were obtained in the risk of ST, TLR, MI, CD, DDD and DS. In the Short term follow up, patients with PSF presented a lower risk of TLR compared with PPDES.