Late stent malapposition risk is higher after drug-eluting stent compared with bare-metal stent implantation and associates with late stent thrombosis

Late stent malapposition (LSM) may be acquired (LASM) or persistent. LSM may play a role in patients who develop late stent thrombosis (ST). Our objective was to compare the risk of LASM in bare metal stents (BMS) with drug-eluting stents (DES) and to investigate the possible association of both acquired and persistent LSM with (very) late ST. We searched PubMed and relevant sources from January 2002 to December 2007. Inclusion criteria were: (a) intra-vascular ultrasonography (IVUS) at both post-stent implantation and follow-up; (b) 6-9-month-follow-up IVUS; (c) implantation of either BMS or the following DES: sirolimus, paclitaxel, everolimus, or zotarolimus; and (d) follow-up for LSM. Of 33 articles retrieved for detailed evaluation, 17 met the inclusion criteria. The risk of LASM in patients with DES was four times higher compared with BMS (OR = 4.36, CI 95% 1.74-10.94) in randomized clinical trials. The risk of (very) late ST in patients with LSM (five studies) was higher compared with those without LSM (OR = 6.51, CI 95% 1.34-34.91). In our meta-analysis, the risk of LASM is strongly increased after DES implantation compared with BMS. Furthermore, LSM seems to be associated with late and very late ST.