Background: The persistence of polymer may be related to late and very late stent thrombosis. Recently, biodegradable polymer (BD) and polymer-free (PF) stents have become a focus for prevention of detrimental clinical events. However, the long-term efficacy of these types of stent compared to that of permanent polymer (PP) stents is unclear.
Methods and results: A total of 989 consecutive coronary heart disease (CHD) patients from five centres who required the implantation of drug-eluting stents (DES) were randomly divided into the PP (n = 321), PF (n = 327) and BD groups (n = 341). The primary endpoint was major adverse cardiac events (MACE). The secondary endpoints were stent thrombosis events, all-cause death and rehospitalisation. The study was designed to test the noninferiority of the PF and BD stents compared with that of the PP stent with respect to two-year MACE, using a noninferiority margin of 0.05. After clinical follow-up for 26.96 ± 12.99 months, the 2-year MACE rates were 6.17% in the PF group, 6.58% in the BD group and 7.24% in the PP group. The noninferiority testing produced lower limits of the one-sided 95% confidence interval of -0.0435 (P = 0.024) for the PF group and -0.0401 (P = 0.017) for the BD group. There were no significant differences in stent thrombosis events, all-cause death and rehospitalisation among the three groups (all P>0.05).
Conclusion: In this multicentre, randomised, controlled clinical trial, PF paclitaxel-eluting stents and BD rapamycin-eluting stents were shown to be noninferior to PP rapamycin-eluting stents in two-year clinical outcomes for the treatment for CHD.
Keywords: Coronary heart disease; Drug-eluting stents; Major adverse cardiovascular events; Paclitaxel; Polymer; Rapamycin.
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