Coronary bifurcation lesions pose therapeutic problems during percutaneous coronary interventions (PCI) and are associated with higher rates of periprocedural complications as well as higher rates of in-stent restenosis and stent thrombosis. Therefore the optimal approach to coronary bifurcations treatment is still a subject of debate, especially when the side branch is large, not easily accessible and narrowed by a long lesion. One of the proposed alternatives are dedicated bifurcation stents (DBS). However, there is large scarcity of randomized trials with DBS.

The aim of POLBOS I (POLish Bifurcation Optimal Stenting) study was to compare two intervention strategies for bifurcation treatment: provisional T-stenting (PTS) with any regular drug-eluting stent (rDES), the best treatment strategy at the moment, with stenting of bifurcation lesions with dedicated bifurcation paclitaxel-eluting stent BiOSS Expert® (Balton, PL).

Inclusion Criteria:

• Subject able to verbally confirm understandings of risks, benefits of receiving PCI for true bifurcation lesions, and he/she or his/her legally authorized representative provides written informed consent prior to any study related procedure.
• Target main branch lesion(s) located in a native coronary artery with diameter of ≥ 2.5 mm and ≤ 4.5 mm. Target side branch lesion(s) located in a native coronary artery with diameter of ≥ 2.0 mm.
• Target lesion(s) amenable for PCI with balloon angioplasty of the side branch.

Exclusion Criteria:

• STEMI
• Non-cardiac co-morbid conditions are present with life expectancy <1 year or that may result in protocol non-compliance (per site investigator's medical judgment).
• Subjects who refuse to give informed consent.
• Subjects with LVEF<30%
• Subjects with moderate or severe degree valvular heart disease or primary cardiomyopathy