Dedicated Bifurcation Stent for the Treatment of Bifurcation Lesions Involving Large Side Branches: Outcomes From the Tryton Confirmatory Study.

OBJECTIVES: The aim of this study was to prospectively study and confirm the safety and efficacy of the Tryton Side Branch Stent in the treatment of coronary artery bifurcations involving large side branches (SBs). BACKGROUND: The TRYTON Pivotal randomized controlled trial (RCT) was designed to compare the Tryton stent with standard provisional SB stenting in large vessels. The trial inadvertently enrolled patients with too small SBs (<2.25 mm). The overall trial did not meet its primary endpoint, because of an increased rate of periprocedural myocardial infarction in the Tryton stent arm. A post hoc analysis restricted to the intended population showed that the trial would have met its endpoint if only patients with SBs ≥2.25 mm in diameter (by core laboratory quantitative coronary angiography) had been enrolled. METHODS: The Tryton Confirmatory Study was a prospective, single-arm extension of the TRYTON Pivotal RCT that enrolled an additional 133 patients treated with the Tryton Side Branch Stent. It was designed to confirm the results of the post hoc analysis and emphasized the inclusion of appropriately sized SBs. The primary endpoint was noninferiority with regard to periprocedural myocardial infarction (creatine kinase myocardial band 3 times the upper limit of normal) compared with a performance goal based on the TRYTON Pivotal RCT. RESULTS: Among the 133 enrolled patients, 132 (99.2%) had SBs ≥2.25 mm. Baseline clinical and angiographic parameters were similar in this study and the RCT. Periprocedural myocardial infarction occurred in 10.5% of patients, which was numerically lower than the provisional group in the TRYTON Pivotal RCT (11.9%). The 95% confidence bounds did not extend beyond the pre-defined performance goal of 17.9%, meeting the noninferiority primary endpoint. CONCLUSIONS: The Tryton Confirmatory Study, in conjunction with the post hoc analysis of the intended population in the TRYTON Pivotal RCT, supports the safety and efficacy of the Tryton Side Branch Stent for treatment of bifurcation lesions involving large SBs.

Prospective Assessment of the Diagnostic Accuracy of Instantaneous Wave-Free Ratio to Assess Coronary Stenosis Relevance: Results of ADVISE II International, Multicenter Study (ADenosine Vasodilator Independent Stenosis Evaluation II).

OBJECTIVES: The purpose of this study was to assess the diagnostic accuracy of the instantaneous wave-free ratio (iFR) to characterize, outside of a pre-specified range of values, stenosis severity, as defined by fractional flow reserve (FFR) ≤0.80, in a prospective, independent, controlled, core laboratory-based environment. BACKGROUND: Studies with methodological heterogeneity have reported some discrepancies in the classification agreement between iFR and FFR. The ADVISE II (ADenosine Vasodilator Independent Stenosis Evaluation II) study was designed to overcome limitations of previous iFR versus FFR comparisons. METHODS: A total of 919 intermediate coronary stenoses were investigated during baseline and hyperemia. From these, 690 pressure recordings (n = 598 patients) met core laboratory physiology criteria and are included in this report. RESULTS: The pre-specified iFR cut-off of 0.89 was optimal for the study and correctly classified 82.5% of the stenoses, with a sensitivity of 73.0% and specificity of 87.8% (C statistic: 0.90 [95% confidence interval (CI): 0.88 to 0.92, p < 0.001]). The proportion of stenoses properly classified by iFR outside of the pre-specified treatment (≤0.85) and deferral (≥0.94) values was 91.6% (95% CI: 88.8% to 93.9%). When combined with FFR use within these cut-offs, the percent of stenoses properly classified by such a pre-specified hybrid iFR-FFR approach was 94.2% (95% CI: 92.2% to 95.8%). The hybrid iFR-FFR approach obviated vasodilators from 65.1% (95% CI: 61.1% to 68.9%) of patients and 69.1% (95% CI: 65.5% to 72.6%) of stenoses. CONCLUSIONS: The ADVISE II study supports, on the basis rigorous methodology, the diagnostic value of iFR in establishing the functional significance of coronary stenoses, and highlights its complementariness with FFR when used in a hybrid iFR-FFR approach. (ADenosine Vasodilator Independent Stenosis Evaluation II-ADVISE II; NCT01740895).

Unprotected left main disease managed with drug-eluting stents: long-term outcome of 100 patients with increased surgical risk.

OBJECTIVES: The purpose of this study was to determine long-term clinical outcomes in high surgical risk patients (pts) with unprotected left main (ULM) disease who were managed with drug-eluting stents (DES). BACKGROUND: The long-term efficacy of unprotected left main (ULM) stenting with DES remains uncertain. METHODS: From June 2003 to December 2005, 100 pts with increased surgical risk underwent ULM stenting with DES. Patient risk was estimated by EuroSCORE. Disease was confined to the ostium/main stem in Group A (31 pts) and involved the bifurcation in Group B (69 pts). Study endpoints were MI, TVR, and death. RESULTS: Mean age was 68 +/- 1 years, EF 52 +/- 1%. Mean EuroSCORE was 5.2 +/- 0.4, and 41% pts had a EuroSCORE of >6. In Group A, 87% of lesions were directly stented. In Group B, 61% of pts received one stent and 39% received two stents. Primary success was 95%. Follow-up data (mean 28 +/- 1 months) were obtained in all patients. Restenosis occurred at the proximal stent margin in 5/9 pts. There were 12 cardiac deaths (88% cardiac survival) and 9 noncardiac deaths (79% total survival). In Group B, 5 pts died suddenly: 3 within the first week and 2 additional pts after 1 year. Sudden death did not occur in Group A. All cause event-free survival was 65% in Group A and 67% in Group B. CONCLUSION: A substantial number of late adverse events occurred in both ostial and bifurcation groups with equal frequency. Until definitive data from randomized trials are available, ULM stenting should be performed only in patients with prohibitive surgical risk.

Technique of left main stenting is dependent on lesion location and distal branch protection.

The purpose of this study was to review our experience with left main stenting and evaluate initial results with drug-eluting stents (DESs). Drug-eluting stents delivered with contemporary techniques could change the traditional surgical approach to patients with significant left main disease. One hundred sixty-one patients underwent left main stenting (100 bare metal, 61 drug-eluting) after being excluded from surgery. In group A, disease was confined to the ostium or main stem; in group B, disease involved the bifurcation. Patients were classified as either unprotected (U) or protected (P) depending on the presence of a patent bypass graft. Study endpoints were any major adverse cardiac event (MACE). In-hospital MACE was 6% with no deaths; 74% of patients in group A underwent direct stenting, whereas 89% of the patients in group B had predilatation performed prior to stent implantation. A total of 98% of patients in BU had kissing balloon inflations after stent deployment; provisional side-branch stenting was required in one patient. V-stenting was performed in 13% of patients in group BU. The 1-year mortality in the bare metal stent group was 9% with the majority of deaths in group BU. There was one noncardiac death in the DES group at 6 months and five patients (8.2%) underwent target vessel revascularization for restenosis. Event-free survival at 6 months in group BU treated with DESs was 87%. Significant left main disease presents a spectrum of angiographic abnormalities and different interventional techniques are required depending on lesion location and distal protection. Although in-hospital complications with left main stenting were low in this single-center study, follow-up events were common in patients treated with bare metal stents. A randomized multicenter trial will be required to determine whether drug-eluting stents will improve survival in patients with left main disease.

Coronary stenting in stable patients: identification of a low-risk subgroup that may not require adjunctive antiplatelet therapy.

The present study prospectively evaluated adjunctive antiplatelet therapy in patients without insulin-requiring diabetes during elective coronary stenting. Three hundred patients were randomized to one of three treatment groups: clopidogrel pretreatment, adjunctive abciximab, or control. Stenting was successful in 98% and no deaths occurred. Thirty-day and 1-year major adverse coronary events (MACEs) was similar in all groups. A subgroup of 109 patients undergoing single-vessel stenting of type A/B1 lesions with short guidewire times had no postprocedure myocardial infarction or 30-day MACE. We conclude that patients with these characteristics may safely undergo elective coronary stenting without adjunctive antiplatelet therapy.