COmplex BifuRcation Lesions: a Comparison Between the AXXESS Device and Culotte Stenting: an Optical Coherence Tomography (OCT) Study

Treatment of bifurcation lesions with drug-eluting stents (DES) (especially when a double stent technique is used) is associated with a higher risk for stent thrombosis. Different factors may play a role in the higher risk for stent thrombosis in bifurcation lesions. Possible mechanisms are delayed endothelialisation due to the action of the drug, coating polymers, or overlapping stent segments, incomplete stent apposition at specific sites in the bifurcation lesion and higher thrombogenicity due to turbulent flow at the bifurcation site. In human pathological data, the RUTSS (ratio of uncovered to total stent struts) appears to be the most powerful predictor of stent thrombosis.

This prospective study will assess the differences in stent strut coverage and stent strut apposition after complex bifurcation lesion treatment with the dedicated AXXESS Biolimus A9-eluting bifurcation stent at the bifurcation site and additional Biomatrix Biolimus A9-eluting stents in the distal main vessel and the side branch versus treatment with the culotte technique using the Xience Prime everolimus-eluting stents.

BACKGROUND: There is an ongoing controversy over the efficacy and safety of different bifurcation stenting techniques. Critical considerations are the rate of restenosis at the side branch ostium, and completeness of healing at sites of overlap of stent struts, which may affect the risk of stent thrombosis.

AIMS: To compare vessel healing at 9 months using OCT imaging for two different treatment techniques for treating bifurcation lesions. Quantitative assessment of OCT images will be used to assess re-endothelialisation and quality of strut apposition to the vessel wall.

METHODS: Patients with true bifurcation lesions with involvement of a significant side branch requiring a stent will be randomly assigned to one of two treatment strategies. Group A will comprise 20 patients which will be treated with the Axxess™ Drug Eluting Coronary Bifurcation Stent System (Biosensors Europe SA) where additional Biomatrix™ Drug Eluting Coronary Stent Systems (Biosensors Europe SA) are implanted into the distal main branch (MB) and the side branch (SB) as required. Group B will consist of 20 patients which will be treated with the culotte technique using Xience Prime everolimus-eluting stents (Abbott-Vascular, US). Kissing balloon dilatation using non-compliant balloons will complete the index procedure in all cases. At 9 months, control angiography for all patients (with QCA using dedicated software) and OCT (of both main vessel and side branch) will be performed.

ENROLMENT PLAN:

Start: Third quarter of 2011 Enrolment period: ± 12 months Clinical follow-up: 5 years Angiographic and OCT results expected third quarter of 2013

Eligibility Criteria:
Inclusion Criteria:

1. Patient older than 18 years
2. The subject has stable or unstable angina pectoris, or a positive functional study for ischemia.
3. The subject is eligible for PCI, and is an acceptable candidate for coronary artery bypass surgery.
4. The subject is male, or if female, has no childbearing potential or has had a negative urine or serum pregnancy test within 7 days of the index procedure and has no intention to become pregnant within a year of the procedure.
5. The subject has signed the informed consent prior to the procedure, and agrees to comply with the follow up requirements.
6. Patients with a de novo and true coronary bifurcation lesion (Medina classification (1,1,1), (1,0,1) or (0,1,1)).
7. Coronary artery with proximal parent vessel reference diameter of 2.75 - 3.75 mm and a branch vessel diameter of ≥ 2.25 mm.
8. The lesion must be at least 50% diameter stenosis within either the MB or SB.
9. Regarding lesion length: lesion should be able to be covered by 2 Xience Prime stents in a Culotte technique, or by a combination of maximally 1 AXXESS and 2 Biomatrix™ Drug Eluting Coronary Stents.
10. The side branch ostium is located at least 12 mm from the left main coronary artery.
11. The angle between the sidebranch and the parent vessel is less than 70°.

Exclusion Criteria:

1. Left ventricular ejection fraction of \< 30%
2. Impaired renal function (serum creatinine \> 2.0 mg/dl)
3. Previous and/or planned brachytherapy of target vessel
4. Lesion of the left main trunk \> 50%, unprotected
5. The target vessel contains intraluminal thrombus.
6. The target lesion shows angiographic evidence of moderate to severe calcification or tortuosity.
7. Known allergies to antiplatelet, anticoagulation therapy, contrast media, everolimus or biolimus, stainless steel, cobalt, chromium, nickel or titanium
8. Pregnant and/or breast-feeding females or females who intend to become pregnant (pregnancy test required)
9. Patients with a life expectancy of less than one year
10. Patient currently enrolled in other investigational device or drug trial
11. Patient not able or willing to adhere to follow-up visits
12. Patients who intend to have a major surgical intervention within 6 months of enrolment in the study.
13. Patients who previously participated in this study.