Tryton Post Approval Study (PAS) for the Tryton Side Branch Stent

Inclusion Criteria: General Inclusion Criteria 1. The patient must be ≥18 and ≤ 90 years of age; 2. Acceptable candidate for CABG; 3. The intention to treat the side branch of the target bifurcation based on angiographic evaluation 4. The patient is willing to comply with specified follow-up evaluations; 5. The patient or legally authorized representative has been informed of the nature of the study, agrees to its provisions and has been provided written informed consent, approved by the appropriate Institutional Review Board (IRB). 6. Planned use of FDA approved and commercially available drug-eluting stents (DES) for subject's index procedure Angiographic Inclusion Criteria 7. a) Single de novo lesion in a bifurcation involving both the main branch and the side branch b) The bifurcation: main branch and side branch with a visual diameter stenosis ≥ 50% (Medina classification 1.1.1; 0.1.1; 1.0.1) by visual assessment; 8. Target lesion located in a native coronary artery; 9. a) Bifurcation lesion main branch reference vessel diameter must be ≥2.5 mm to ≤ 4.0 mm, and b) Side branch reference vessel diameter must be ≥2.5mm by visual estimate (≥2.25mm by QCA) and \<3.5 mm by visual estimate (\<3.25 mm by QCA); 10. a) Bifurcation lesion main branch lesion length ≤ 28 mm and b) Side branch lesion length ≤ 5.0 mm (the ability to be treated with a single stent for both main and side branch); 11. Target lesion ≥50% and \<100% stenosed by visual estimate in both the main branch and side branch; - Exclusion Criteria: General Exclusion Criteria 1. Pregnant or nursing patients and those who plan pregnancy in the period up to 1 year following index procedure. Female patients of child-bearing potential must have a negative pregnancy test done within 7 days prior to the index procedure per site standard test; 2. Impaired renal function (serum creatinine \>2. mg/dL or 150 μmol/l); 3. Platelet count \<100,000 cells/mm3 or \>700,000 cells/mm3 or a WBC \<3,000 cells/mm3, or documented or suspected liver disease (including laboratory evidence of hepatitis); 4. Presence of a heart transplant 5. Known allergy to cobalt chromium 6. Hypersensitivity or contraindication to cobalt-chromium or structurally-related compounds, cobalt, chromium, nickel, or tungsten 7. Anticipated use of rotational artherectomy 8. Patient in whom the use of a drug eluting stent is contraindicted, e.g., who cannot receive the recommended dual anti-platelet (aspirin and an approved P2Y12 inhibitor) and/or anticoagulant therapy Angiographic Exclusion Criteria: 9. Left main coronary artery disease (protected and unprotected); 10. Trifurcation lesion; 11. Totally occluded target vessels (TIMI flow 0 or 1); 12. Moderate to Severely calcified target lesion(s); 13. Highly calcified target lesion(s) requiring rotational atherectomy; 14. Target lesion has excessive tortuosity unsuitable for stent delivery and deployment; 15. Angiographic evidence of thrombus in the target lesion(s); 16. Tryton Stent placement without angioplasty pre-dilatation of the main branch and side branch (i.e., direct stenting is contraindicated) 17. Tryton Stent placement alone, without implantation of a main branch stent 18. An untreated significant (\>50%) stenosis proximal or distal in either the side branch or main branch; 19. Impaired runoff in the treatment vessel with diffuse distal disease; 20. Left ventricular ejection fraction (LVEF) 30% (LVEF must be obtained within 6 months prior to the index procedure); -