A Randomized Trial of a Dedicated Bifurcation Stent Versus Provisional Stenting in the Treatment of Coronary Bifurcation Lesions
Philippe GénéreuxIndulis KumsārsMaciej LesiakAnnapoorna KiniGéza FontosTon SlagboomImre UngiD. Christopher MetzgerJoanna J. WykrzykowskaPieter R. StellaAntonio L. BartorelliWilliam F. FearonThierry LefèvreRobert L. FeldmanLaura LaSalleDominic P. FranceseYoshinobu OnumaMaik J. GrundekenHéctor M. García‐GarcíaLinda L. LaakDonald E. CutlipAaron V. KaplanPatrick W. SerruysMartin B. Leon
Key result
Dedicated bifurcation stenting fails noninferiority vs. provisional stenting for target vessel failure.
- Difference +4.6%
- 95% CI -1.0 to 10.3
- P=0.42 for noninferiority
- n=704
Why the study?
Bifurcation lesions are common in symptomatic coronary disease treated by PCI, and current evidence recommends a conservative provisional approach for side branch treatment.
Does a dedicated bifurcation stent reduce target vessel failure compared to provisional stenting in patients with true coronary bifurcation lesions?
Key Points
- To compare the safety and effectiveness of a dedicated side branch bifurcation stent against standard provisional stenting in patients with de novo true coronary bifurcation lesions.
- Single-blind randomized trial conducted across 58 centers in Europe and the United States enrolling 704 patients with true bifurcation lesions (NCT01258972).
- Patients were randomized to receive either a dedicated side branch stent with a main vessel drug-eluting stent or provisional side branch balloon angioplasty with main vessel stenting.
- The primary endpoint was 9-month target vessel failure (cardiac death, target vessel myocardial infarction, and target vessel revascularization), powered for noninferiority with a 5.5% margin.
- Target vessel failure occurred in 17.4% of the bifurcation stent group versus 12.8% of the provisional group (difference +4.6%, 2-sided 95% CI -1.0% to 10.3%, P=0.42 for noninferiority), failing the noninferiority threshold.
- Periprocedural myocardial infarction rates were 13.6% in the bifurcation stent arm versus 10.1% in the provisional arm (P=0.19).
- Side branch in-segment diameter stenosis was significantly lower with the bifurcation stent (31.6% vs. 38.6%, P=0.002 for superiority), but 9-month binary restenosis rates did not differ significantly (22.6% vs. 26.8%, P=0.44).
Study Design
Type
RCT (n=704)
Blinding
Single-blind
Randomization
randomly assigned
Multicenter
Yes
Structured PICO
Does a dedicated bifurcation stent reduce target vessel failure compared to provisional stenting in patients with true coronary bifurcation lesions?
P
Population
704 patients with de novo true bifurcation coronary lesions, followed for 9 months.
I
Intervention
Dedicated bifurcation stent (Tryton Side Branch Stent used with DES)
C
Comparator
Main vessel stent plus provisional stenting (side branch balloon angioplasty)
O
Outcome
Target vessel failure (TVF) (composite of cardiac death, target vessel myocardial infarction, and target vessel revascularization) at 9 monthscomposite
Main Result
Effect estimate: Difference +4.6% (95% CI -1.0 to 10.3)
Absolute Event Rate: 17.4% vs 12.8%
p-value: p=0.42 for noninferiority
Key expert perspectives
Captured external expert commentary on this paper, strongest first. Original sources are linked where available.
“The post hoc analysis strongly supports a benefit for the Tryton Stent in the intended population. The results are hypothesis generating, to be supported by further analysis.”
“Treatment of complex lesions at the site of a bifurcation has historically been inconsistent, with results varying depending on the procedure and the experience of the interventionist. A predictable bifurcation solution helps alleviate some of the stress in these procedures by limiting variability and reducing the need for bailout stenting. This important FDA decision could have a profound impact on treatment protocols and guidelines for significant bifurcation lesions in the years ahead.”
“The Tryton Pivotal IDE trial is a first of its kind, landmark study that has provided high-quality data and will inform the treatment of bifurcation disease worldwide for years to come. Tryton represents an important option when treating complex bifurcations.”
Implication
A dedicated bifurcation stent failed to demonstrate noninferiority to provisional stenting for target vessel failure at 9 months in patients with true coronary bifurcation lesions.
Abstract
BACKGROUND: Bifurcation lesions are frequent among patients with symptomatic coronary disease treated by percutaneous coronary intervention. Current evidence recommends a conservative (provisional) approach when treating the side branch (SB). OBJECTIVES: The TRYTON (Prospective, Single Blind, Randomized Controlled Study to Evaluate the Safety & Effectiveness of the Tryton Side Branch Stent Used With DES in Treatment of de Novo Bifurcation Lesions in the Main Branch & Side Branch in Native Coronaries) bifurcation trial sought to compare treatment of de novo true bifurcation lesions using a dedicated bifurcation stent or SB balloon angioplasty. METHODS: We randomly assigned patients with true bifurcation lesions to a main vessel stent plus provisional stenting or the bifurcation stent. The primary endpoint (powered for noninferiority) was target vessel failure (TVF) (cardiac death, target vessel myocardial infarction, and target vessel revascularization). The secondary angiographic endpoint (powered for superiority) was in-segment percent diameter stenosis of the SB at 9 months. RESULTS: We randomized 704 patients with bifurcation coronary lesions at 58 centers (30 from Europe and 28 from the United States). At 9 months, TVF was 17.4% in the bifurcation stent group compared with 12.8% in the provisional group (p=0.11), mainly because of a higher periprocedural myocardial infarction rate (13.6% vs. 10.1%, p=0.19). The TVF difference of +4.6% (2-sided 95% confidence interval: -1.0 to 10.3; upper limit of the 1-sided 95% confidence interval: 10.3) was not within the pre-specified noninferiority margin of 5.5% (p=0.42 for noninferiority). The SB in-segment diameter stenosis among the angiographic cohort was lower in the bifurcation stent group compared with the provisional group (31.6% vs. 38.6%, p=0.002 for superiority), with no difference in binary restenosis rates (diameter stenosis≥50%) at 9 months follow-up (22.6% vs. 26.8%, p=0.44). CONCLUSIONS: Provisional stenting should remain the preferred strategy for treatment of non-left main true coronary bifurcation lesions. (Prospective, Single Blind, Randomized Controlled Study to Evaluate the Safety & Effectiveness of the Tryton Side Branch Stent Used With DES in Treatment of de Novo Bifurcation Lesions in the Main Branch & Side Branch in Native Coronaries [TRYTON]; NCT01258972).
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Cite This Study
Généreux et al. (2015) conducted an RCT in De novo true bifurcation coronary lesions (n=704). Dedicated bifurcation stent (Tryton Side Branch Stent) vs. Main vessel stent plus provisional stenting (side branch balloon angioplasty) was evaluated on Target vessel failure (cardiac death, target vessel myocardial infarction, and target vessel revascularization) (Difference +4.6%, 95% CI -1.0 to 10.3, p=0.42 for noninferiority). A dedicated bifurcation stent was not noninferior to provisional stenting for target vessel failure at 9 months (17.4% vs 12.8%; difference +4.6%, 95% CI -1.0 to 10.3; P=0.42 for noninferiority).