Background and Objectives In PCI of chronic total occlusion (CTO) lesions, we agree that drug-eluting stents (DES) is superior to bare-metal stents (BMS) in reducing repeat revascularization. But we don���t know whether there is a difference among the DES. The aim of the present study is compare the long term clinical outcomes between 1st and 2nd generation DES in CTO lesions.
Subjects and Methods For the Korea Multicenter CTO registry, 26 centers enrolled 3221 patients in whom PCI was attempted to open CTO lesions form January 2007 to December 2009. We classified the implanted DES into a 1st generation (sirolimus (SES) or paclitaxel (PES)) versus 2nd generation (everolimus (EES) or zotarolimus (ZES)). Primary end point was major adverse cardiovascular events (MACE) defined as a composite of cardiac death, nonfatal myocardial infarction (MI), and target vessel revascularization (TVR). Patients were followed up for clinical events and evaluated for development of MACE using medical record.
Results PCI was failed in 580 of these CTO patients, therefore, we analyzed 2641 patients who were successfully revascularized in this study. Among them, 1016 patients were excluded from the final analysis because of these reasons; [1] treated with BMS or a combination of BMS and DES (n=125), [2] a combination of different generation of DES (n=48), [3] no information about implanted stents (n=636), [4] no follow-up information (n=207). Finally 1625 patients were included and classified into a 1st generation DES (n=1120) or 2nd generation DES (n=505) group. At baseline characteristics, no significant differences existed between the 2 groups, including age, gender, diabetes mellitus and previous history of MI. During mean follow-up of 557 days, MACE of 2nd generation DES group was not different from that of 1st generation (8.7% vs. 7.9%, p=0.56). Also, there were no significant differences in cardiac death (1.8% vs. 1.6%, p=0.80), nonfatal MI (0.4% vs. 0.5%, p=0.71), TVR (6.5% vs. 5.7%, p=0.52) between the 2 groups. In the subgroup analysis, there were no significant differences not only in MACE but in cardiac death, nonfatal MI and TVR among the 4 DES groups.
Conclusions Midterm clinical outcomes after CTO intervention with DES are satisfactory (2Y MACE less than 10%). Comparable MACE between 1st and 2nd generation DES suggests that mild differences among stents are not easily extrapolated to the differences in clinical outcomes which are dependent not only stent per se but also various clinical factors of individual patient.