Regular drug eluting stent versus dedicated bifurcation paclitaxel-eluting stent in coronary bifurcation treatment: interim analysis of randomized POLBOS study

Abstract

Aims: The POLBOS study (POLish Bifurcation Optimization Strategy) was designed to compare two intervention strategies for bifurcation treatment: provisional T‐stenting (PTS) with any regular drug‐eluting stent (DES) and dedicated bifurcation paclitaxel‐eluting stent BiOSS Expert (Balton, Poland). Methods and results: In POLBOS study patients with stable CAD or NSTE‐ACS who signed informed consent were randomised to the group where BiOSS Expert was implanted or to the group where regular DES was used. In the second group another randomisation concerning final kissing balloon technique was performed. The enrollment was performed between September 2010 and November 2012 in four invasive cardiology centres in Poland (Warsaw, Olsztyn, Bydgoszcz and Bialystok). Patients with STEMI or Medina type 0,0,1 bifurcation lesions were excluded from the registry. Provisional T‐stenting was obligatory strategy. Double antiplatelet therapy was planned for 12 months. An angiographic control was planned at 9‐12 months in all patients. The primary end‐point of the study is the rate of death, myocardial infarction, in‐stent thrombosis and target lesion revascularisation after 12 months. Here are presented complete results of 3‐month follow‐up. However at the time of EuroPCR 2013 complete clinical 6‐month followup will be available as well as angiographic controls will be performed in 75% of enrolled patients. BiOSS Expert was implanted in 119 patients (49.4%) and regular DES was implanted in 122 patients (50.6%). 1/3 were females. The average age of patients did not differ significantly between groups (BiOSS vs. DES: 66.5 vs. 66.8 yrs). In the BiOSS group there were significantly more patients with NSTE‐ACS (9.6% vs. 3.5%), diabetes (32.2% vs. 16.8%), prior MI (45.2% vs. 32.7%), prior CABG (8.7% vs. 3.5%) and with chronic kidney disease (15.7% vs. 7.1%). In the DES group there were more patients addicted to smoking (13% vs. 22.1%). The dominant vessel was LAD (BiOSS vs. DES: 52.1% vs. 70.5%) followed by LMS (22,7% vs. 13,9%, respectively). According to the Medina classification true bifurcations were present in 70%. In the DES group 35.4% of stents eluted paclitaxel. There were the following nominal stent parameters in the BiOSS group: 3.69+0.36 mmx2.99+0.36 mmx16.96+1.44 mm and in the DES group: 3.27+0.49 mmx20.6+6.96 mm. Except for 2 (1.64%) cases in DES group and 1 (0.84%) in BiOSS group all stents were implanted successfully (avg. pressure 14 atm), without any serious periprocedural complications. There were 16% and 11.2% cases with second stent implanted within the side branch, respectively in BiOSS group and DES group. There was also trend to shorter radiation time and smaller contrast media volume in BiOSS group. At one and three months all patients were uneventful (out‐of hospital MACE rate 0%). Up to now control angiography was performed in 54.6% of patients in BiOSS group and in 46% of patients in DES group. TLR in BiOSS group was 12.3%, whereas in regular paclitaxel‐eluting stents subgroup ‐ 8% (p=0.06). Conclusions: So far collected data have shown similar clinical results for both groups studied, however BiOSS Expert enabled to procedure completion in a shorter time with reduced volume of contrast media and radiation time.