A Randomized Comparison of a Provisional One-Stent Versus a Dedicated Two-Stent Strategy for True Bifurcation Lesions - TRYTON Bifurcation
The goal of the trial was to evaluate treatment with a 2-stent strategy compared with a 1-stent strategy for bifurcation lesions.
Contribution to the Literature: This study on bifurcation stenting, shows that a 1-stent strategy with provisional stenting of the side-branch remains the treatment of choice for bifurcation lesions.
- Patients with objective evidence of myocardial ischemia due to a bifurcation lesion
- Main vessel required to be between 2.5 and 4.0 mm with lesion ≤28 mm
- Side-branch required to be between 2.5 and 3.5 mm with lesion ≤5 mm
Number of enrollees: 704
Duration of follow-up: 1 year
Mean patient age: 65 years
Percentage female: 27%
Ejection fraction: 58%
- ST-segment elevation myocardial infarction (STEMI) within 72 hours
- Non-STEMI within 7 days
- Hemodynamic instability
- Creatinine >2.5 mg/dl
- Bleeding abnormality
- Left ventricular ejection fraction <30%
- Left main lesion
- Trifurcation lesion
- Complex lesion including chronic total occlusion, heavy calcium, thrombus, TIMI 0/1 flow, or severe tortuosity
- Target vessel at 9 months defined as cardiac death, target vessel MI, or target vessel revascularization
- Percent diameter stenosis of the side-branch
Patients with a bifurcation lesion were randomized to a dedicated side-branch bare-metal stent (Tryton) and a drug-eluting stent in the main vessel (2-stent strategy; n = 355) vs. a drug-eluting stent in the main vessel, plus a provisional stent in the side-branch (1-stent strategy; n = 349).
In the 2-stent strategy, the main-branch and side-branch was pre-dilated, followed by implantation of the dedicated side-branch bare-metal stent from the main-branch into the side-branch, followed by implantation of a drug-eluting stent in the main-branch. Kissing balloon dilatation was the final step.
In the 1-stent strategy, a drug-eluting stent was implanted in the main-branch and the side-branch was intervened upon (balloon or stent) only if poor flow, dissection, or severe residual stenosis. Kissing balloon dilatation was the final final step.
Overall, 704 patients were randomized. The mean age was 65 years, 27% were women, 28% had diabetes, 75% presented as stable angina, vessel location was left anterior descending artery in 75%, main vessel reference diameter was 2.9 mm, and side branch reference vessel diameter was 2.2 mm.
In the 2-stent group, an additional side-branch stent was required in 8% of patients; three patients (0.9%) proximally within the side-branch and in seven patients (2.0%) distally within the side-branch. In the 1-stent group, an additional side-branch stent was required in 28 patients (8.0%, p = 0.02 between groups). Procedure time: 70.5 minutes vs. 56.9 minutes (p < 0.001) and contrast volume: 261 vs. 223 cc (p < 0.001), respectively for 2-stent vs. 1-stent strategy.
The primary outcome of target vessel failure occurred in 17.4% of the 2-stent group vs. 12.8% of the 1-stent group (p = 0.11). This exceeded the prespecified margin of noninferiority (p for noninferiority = 0.42). Subjects with a small side-branch (<2.25 mm) did not have benefit from a 2-stent strategy (21.7% vs. 10.3%), while those with larger side-branches (≥2.25 mm) had potential benefit from this approach (11.3% vs. 15.6%, respectively for 2-stent vs. 1-stent; p for interaction = 0.006).
- Cardiac death: 0 vs. 0, respectively, for 2-stent vs. 1-stent
- Target vessel MI: 15.1% vs. 10.1% (p = 0.11), respectively
- In 92% of periprocedural MIs, the creatine kinase-myocardial band was <10 x the upper limit of normal
- Target vessel revascularization: 4.7% vs. 3.6% (p = 0.56), respectively
- Stent thrombosis (definite/probable): 0.6% vs. 0.3% (p = 1.0), respectively
- Side-branch percent diameter stenosis: 31.6% vs. 38.6% (p = 0.002), respectively
Among patients with a bifurcation lesion, a 2-stent strategy failed to demonstrate noninferiority compared with a 1-stent strategy with provisional treatment of the side-branch. This was due to a higher frequency of periprocedural MI and target vessel revascularization in the 2-stent group vs. the 1-stent group. Angiographic side-branch percent diameter stenosis was lower in the 2-stent group; however, this did not translate into clinical benefit. Bifurcation lesions remain a challenging lesion subset and at the present time, provision stenting of a side-branch remains the preferred treatment strategy. The post-hoc finding of possible benefit from a 2-stent strategy with larger side-branches deserves further study, especially in light of the fact that only 41% of enrolled subjects met the inclusion criteria for side-branch diameter size.
Généreux P, Kumsars I, Lesiak M, et al. A Randomized Trial of a Dedicated Bifurcation Stent Versus Provisional Stenting in the Treatment of Coronary Bifurcation Lesions. J Am Coll Cardiol 2015;65:533-543.
Presented by Dr. Martin B. Leon at the Transcatheter Cardiovascular Therapeutics meeting (TCT 2013), San Francisco, CA, October 30, 2013.
Keywords: Myocardial Infarction, Follow-Up Studies, Angina, Stable, Thrombosis, Drug-Eluting Stents, Creatine Kinase, MB Form, Dilatation, Constriction, Pathologic, Diabetes Mellitus
< Back to Listings