Randomized study on provisional stenting with sirolimus-eluting stent vs. bare metal stent for the treatment of true coronary bifurcations: The PROSUMER (PROvisional with sirolimus-eluting vs. bare metal stents in truE bifuRcations) study

⁎ Corresponding author. Via Tommaso Inghirami 85, 00179 Rome, Italy. Tel.: +39 348 3392006; fax: +39 06 330 62516. E-mail address: f.pelliccia@mclink.it (F. Pelliccia). Percutaneous treatment of coronary bifurcations with stent implantation is still a matter of debate [1]. Despite the implementation of numerous techniques to stent both branches, none has shown clinical and angiographic superiority to the main branch (MB) stent technique with provisional T-stenting of the side branch (SB) in case of dissection or residual severe disease [2]. In addition, concerns have been raised about safety of drug-eluting stents (DES) because of the greater late and very late [3] stent thrombosis and mortality as compared to bare metal stents (BMS). Also, technical characteristics of stents (i.e. high radial force, favorable vessel wall covering percentage and larger patency of SBs) seem to be crucial factors in case of provisional T-stenting strategy [2,4]. To address these issues, we designed the PROSUMER (PROvisional with sirolimus-eluting vs. bare metal stents in truE bifuRcations) study in order to prospectively and randomly compare the safety and efficacy of sirolimus-eluting stent (SES) vs. a BMS in case of treatment of true coronary bifurcation lesions with provisional T-stenting. The studywasdesigned as a prospective, single-center pilot trial, and included consecutive angina patients with a de novo true coronary arterybifurcation lesion (Medina classifications1,1,1 or 1,0,1 or0,1,1)[5] who were allocated to SES (CypherTM, Johnson & Johnson, Miami Lakes, Fla) or a novel BMS (Horus S, International Biomedical Systems, Trieste, Italy). The BMS under investigation is made from 316 LVM stainless steel. The stent is a cylindrical helix with sinusoidal loops, consisting of medical-grade stainless-steel continuouswire, that has high radial force (1.5% diameter reduction at 200 mm Hg) with good scaffolding and favorable vesselwall coveragewith patency of SBs (covering percentage in the expanding state ranging between 19.1%—2.5 mm and 16.2%— 3.5 mm).All patientswere followedup to9 months. Theprimary clinical end point of the study was the occurrence of major adverse cardiac events (MACE), defined as the composite of cardiac or noncardiac death, Q-wave or non-Q-wave myocardial infarction, or target vessel revascularization. The primary angiographic end point of the study was the insegment per cent diameter stenosis of the SB at 9 month follow-up. Coronary angiograms were analyzed off-line with the use of an automated edge-detection system (Cardiovascular Medical System, MEDIS Imaging Systems, Leiden). Sixty consecutive patients (age: 62±12 years) were randomized to a SES (N=30) or a BMS (N=30) in the MB. The two study groups did not show any significant difference in baseline clinical and angiographic characteristics. Procedural success after stenting the MB was similar in the two groups (97%), with 2 cases of periprocedural non-Q-wave myocardial infarction (1 in the SES group and in 1 in the BMS group) caused by periprocedural occlusion of the nonstented SB because of dissection. The primary clinical endpoint of the study, cumulative MACE at 9month follow-up, occurred in 6 patients of the SES group and in 4 patients of the BMS group (20 vs. 17%; P=1.00) (Table 1). During follow-up, no patient died, but one patient of the SES group had stent thrombosis. No significant differences in the rate of target lesion revascularization and target vessel revascularization occurred between the two groups (Table 1). The primary study angiographic endpoint did not differ significantly between the SES and BMS groups (20% vs. 34%, P=0.38). When restenosis rates were analyzed by restenosis site, the two groups showed similar rates of binary restenosis occurring in both MB and SB, in MB only and in SB only (Table 1). Quantitative data at follow-up angiography (Table 2) revealed that, as compared with the BMS group, the SES group had significantly larger minimal lumen diameter and percent diameter restenosis as well as lower late loss at MB. Conversely, no significant difference was found between the two study groups in any angiographic variable at SB. The PROSUMER study shows that good long-term results when treating coronary bifurcations can be achieved with a strategy of provisional stenting with BMS as compared with SES, provided that a stent with favorable technical characteristics for bifurcations coupled with an optimal delivery technique are adopted. The results of PROSUMER show that binary restenosis rate at 9-month control angiography did not differ significantly between the SES and BMS