Outcomes of a dedicated stent in coronary bifurcations with large side branches: A subanalysis of the randomized TRYTON bifurcation study

Abstract

Objectives: To examine the benefit of the Tryton dedicated side branch (SB) stent compared with provisional stenting in the treatment of complex bifurcation lesions involving large SBs. Background: The TRYTON Trial was designed to evaluate the utility of a dedicated SB stent to treat true bifurcation lesions involving large (≥2.5 mm by visual estimation) SBs. Patient enrolled in the trial had smaller SB diameters than intended (59% SB ≤2.25 mm by Core Lab QCA). The TRYTON Trial did not meet its primary endpoint due to an increased rate of peri-procedural myocardial infarctions (MIs). Methods: The TRYTON Trial randomized 704 patients to the Tryton SB stent with main vessel DES versus provisional SB treatment with main vessel DES. The rates of the primary end point of target vessel failure and the secondary powered end point of angiographic percent diameter stenosis in the SB at 9 months were assessed and compared between the two treatment strategies among patients with a SB ≥2.25 mm diameter at baseline determined by Core Lab QCA. Results: Among the 704 patients enrolled in the TRYTON Trial, 289 patients (143 provisional and 146 Tryton stent; 41% of entire cohort) had a SB ≥2.25 mm. The primary end point of TVF was numerically lower in the Tryton group compared with the provisional group (11.3% vs. 15.6%, P = 0.38), and was within the non-inferiority margin. No difference among the rates of clinically driven target vessel revascularization (3.5% vs. 4.3% P = 0.77) or cardiac death (0% both groups) were seen. In-segment percent diameter stenosis of the SB was significantly lower in the Tryton group compared with the provisional group (30.4% vs. 40.6%, P = 0.004). Conclusions: Analysis of the TRYTON Trial cohort of SB ≥2.25 mm supports the safety and efficacy of the Tryton SB stent compared with a provisional stenting strategy in the treatment of bifurcation lesions involving large SBs.