Segmental comparison between a dedicated bifurcation stent and balloon angioplasty using intravascular ultrasound and three-dimensional quantitative coronary angiography: A subgroup analysis of the Tryton IDE randomized trial

Objective: Randomized comparison between the Tryton Side Branch Stent (Tryton Medical, Durham, NC), used in combination with a main branch drug-eluting stent (DES), and side branch balloon angioplasty (SBBA, in combination with a main branch DES) using intravascular ultrasound (IVUS), and three-dimensional quantitative coronary angiography (3D-QCA). Background: The Tryton stent has been developed to improve clinical outcomes after percutaneous coronary intervention (PCI) of bifurcation lesions. Methods: We present the pre-specified IVUS (n = 159) and 3D-QCA (n = 190) sub-group analyses of the Tryton coronary bifurcation trial (randomizing Tryton vs. SBBA). Results: There were no differences in the main branch with regard to minimal lumen area (MLA) (5.33 ± 1.37 in Tryton vs. 5.69 ± 1.72 mm² in SBBA, P = 0.235) with low neo-intima area in both groups. In the side branch, there were also no statistical significant differences between both groups (3.04 ± 1.02 in Tryton vs. 3.46 ± 1.15 mm² in SBBA, P = 0.072). On 3D-QCA, no differences in minimal lumen diameter (MLD) and percentage diameter stenosis (%DS) were observed in the proximal and distal main branches. In the side branch, there were also no differences found in %DS and MLD (MLD: 1.34 ± 0.043 mm [Tryton] vs. 1.45 ± 0.31 mm [SBBA], P = 0.090). Conclusions: There were no differences in 9-month luminal dimensions of the side branch between the Tryton Stent and Side Branch Balloon Angioplasty, as assessed with IVUS (MLA) and 3D QCA (MLD). Angiographic and ultrasound results of the main branch were not negatively influenced by the Tryton stent.