Background: The best treatment strategy for coronary bifurcation stenosis is still unknown. Dedicated bifurcation stents are the most promising solution.
Aim: To evaluate the safety and short-term efficacy of a new stent dedicated for coronary bifurcation stenosis.
Methods: A new bifurcation optimisation stent system (BiOSS, Balton, Poland) is made of 316L stainless steel and is coated with a mixture of biodegradable lactate polymer and paclitaxel (1 μg/mm(2)). The stent consists of two parts, with different diameters according to Murray law connected by two 1.5 mm long bridges. BiOSS is mounted on a dedicated bifurcation balloon (Bottle, Balton, Poland) with markers of the proximal and the distal stent edge, and a third marker at the mid part showing the proximal end of its smaller distal part. The stent delivery is a rapid exchange system. Provisional T-stenting is the obligatory strategy. In order to optimise the result, Bottle balloon (nominal pressure: 10 atm) is inflated with mid marker positioned at the side branch ostium. Double antiplatelet therapy was planned for 12 months. Forty five patients with non-left main bifurcation stenosis (the n-LMB group), as well as 15 patients with left main (LM) bifurcation stenosis (the LMB group), were included in the prospective, feasibility and safety assessment registry. An intravascular ultrasound control is obligatory for all LM patients and strongly recommended for the remaining patients. Patients with ST-elevation myocardial infarction (STEMI) and Medina type 001 bifurcation lesions were excluded from the registry. The primary end-points of the study were: death, MI, in-stent thrombosis and target lesion revascularisation (in-hospital and one, three, six, and 12 months after the intervention). An angiographic control is planned at nine months in all patients. Here, we present the results of a three-month follow-up.
Results: The average age of the enrolled patients (63% males) was 67 ± 11 years. Thirty five (58%) patients had hypertension, and 16 (27%) were diabetic (five on insulin treatment). Almost half of the patients (29, 48%) had previous non-ST- -elevation acute coronary syndrome treated with percutaneous coronary intervention. Six (10%) patients had previous coronary artery bypass grafting. In the LMB group (n = 15), there were: six with Medina type 111; five with type 010; three with type 110; and one with type 011 bifurcation lesions. In the n-LMB group (n = 45), the dominant vessel was left anterior descending (n = 26, 58%), followed by left circumflex (n = 15, 33%) and right coronary artery (n = 4, 9%). Medina type 111 lesions were present in 48% of patients. Intravascular ultrasound was performed in 37 (62%) cases. All BiOSS stents were implanted successfully (avg. pressure 12 atm), without any periprocedural complications. There were only seven (14%) cases with a second stent implanted within a side branch. There were four periprocedural increases of troponin interpreted as MI. At one month and at three months, all patients were uneventful (out-of hospital MACE rate 0%).
Conclusions: The BiOSS bifurcation dedicated stent is a feasible device, with promising safety and short-term clinical effectiveness/profile.