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

True double bifurcation lesions: new application of the self-expandable Axxess stent and review of literature with dedicated bifurcation devices

Complex coronary artery bifurcation lesions occurred in hard clinical scenarios, such as acute coronary syndromes, may represent a challenge for interventional cardiologists, with not-defined general consensus on treatment. Even if provisional stenting is the most common option used to restore rapidly the coronary branches flow, improvements in industrial technologies and design of new dedicated bifurcation devices might open new modalities of treatment in these complex cases. The Axxess stent (Biosensors Europe SA, Morges, Switzerland) is a self-expanding biolimus-eluting conical V-shape stent, specifically designed to treat "easily" coronary artery bifurcation lesions, with reported favorable long-term clinical results in stable patients compared to a provisional technique. We report for the first time the feasibility to use this device in a case of "true double coronary bifurcation lesion" occurred in the context of acute coronary syndrome. Moreover, we reviewed studies with bifurcation dedicated devices and available cases of "true double bifurcation lesions", underlying advantages/disadvantages of using one device over the others during acute coronary syndrome.

Impact of Percutaneous Coronary Revascularization of Severe Coronary Lesions on Secondary Branches

INTRODUCTION AND OBJECTIVES

To analyze the percutaneous revascularization strategy for severe lesions in the secondary branches (SB) (diameter ≥ 2mm) of major epicardial arteries compared with conservative treatment.

METHODS

This study analyzed patients with severe SB lesions who underwent percutaneous revascularization treatment compared with patients who received pharmacological treatment. The study examined the percentage of branch-related events (cardiovascular death, myocardial infarction attributable to SB, or the need for revascularization of the SB).

RESULTS

We analyzed 679 SB lesions (662 patients). After a mean follow-up of 22.2±10.5 months, there were no significant differences between the 2 treatment groups regarding the percentage of death from cardiovascular causes (1.7% vs 0.4%; P=.14), nonfatal acute myocardial infarction (AMI) (1.7% vs 1.7%; P=.96), the need for SB revascularization (4.1% vs 5.4%; P=.45) or in the total percentage of events (5.1% vs 6.3%; P=.54). The variables showing an association with event occurrence on multivariate analysis were diabetes (SHR, 2.87; 95%CI, 1.37-5.47; P=.004), prior AMI (SHR, 3.54; 95%CI, 1.77-7.30; P<.0001), SB reference diameter (SHR, 0.16; 95%CI, 0.03-0.97; P=.047), and lesion length (SHR, 3.77; 95%CI, 1.03-1.13; P<.0001). These results remained the same after the propensity score analysis.

CONCLUSIONS

The percentage of SB-related events during follow-up is low, with no significant differences between the 2 treatment strategies. The variables associated with event occurrence in the multivariate analysis were the presence of diabetes mellitus, prior AMI, and greater lesion length.

Tryton dedicated bifurcation stent in treatment of unprotected distal left main bifurcation disease

Percutaneous coronary interventions involving coronary bifurcation lesions are more complex and associated with adverse outcomes (both angiographic and clinical) compared to non-bifurcation lesions. Tryton, a dedicated bifurcation stent, has been introduced with the aim to simplify treatment of bifurcation lesions. Tryton stent in combination with conventional drug eluting stent is safe and associated with reduced stenosis and bail-out stenting of side branch compared to provisional stenting involving a large side. However, little is known regarding safety and efficacy of Tryton stent in left main (LM) bifurcation lesion. We describe two cases of unprotected LM bifurcation stenting using Tryton stent in combination with drug eluting stent.

Treatment of coronary bifurcation lesions: current knowledge and future perspectives

Coronary lesions at bifurcation sites are frequent and still remain a challenging subset for the interventional cardiologist. Although in the last years the provisional stenting technique has shown more consistent results, coronary bifurcation interventions still share a worse procedural success rate and increased rates of mid- and long-term cardiac events. Most of the dedicated devices proposed in the last few years have failed to show improved results when compared with standard devices. The broader use of imaging techniques, such as intravascular ultrasound and optical coherence tomography, lead to a better understanding of the real anatomy of bifurcations and has shown to be a great tool for percutaneous coronary intervention optimization. Preliminary results come from drug-coated balloons and bioresorbable vascular scaffolds, especially for the 'leave nothing behind' concept, particularly interesting in this setting of lesions.

Percutaneous coronary intervention of bifurcation lesions and platelet reactivity

BACKGROUND

Although bifurcation percutaneous coronary intervention (PCI) is associated with lower procedural success rates and higher risk of complications, there are little data regarding outcomes after successful bifurcation PCI with contemporary stents and techniques. Whether residual platelet reactivity (PR) affects outcomes differently after bifurcation versus non-bifurcation PCI is also unknown. We studied the association between bifurcation PCI, PR, and clinical outcomes among patients undergoing successful PCI with drug-eluting stents.

METHODS

Patients in the prospective, multicenter ADAPT-DES study were stratified according to whether they underwent bifurcation PCI. Two-year outcomes were compared between groups using Cox proportional hazards models. Target vessel failure (TVF) was defined as the composite of all-cause death, myocardial infarction, and ischemia-driven target vessel revascularization.

RESULTS

Among the 8582 patients included in ADAPT-DES, 1276 (15%) had bifurcation PCI. Bifurcation PCI was independently associated with increased risk of TVF (adjusted hazard ratio [HR] 1.26, 95% confidence interval [CI] 1.08-1.46, p=0.003), driven by higher risk of myocardial infarction (5.9% vs. 4.6%, p=0.033) and ischemia-driven target vessel revascularization (13.0% vs. 9.2%, p<0.0001). There was no statistical interaction between PR and bifurcation PCI regarding TVF risk (adjusted p_interaction=0.87). Stenting of both bifurcation branches was associated with the highest risk of TVF (adjusted HR 1.91, 95% CI 1.48-2.46 versus non-bifurcation PCI; p_trend<0.001).

CONCLUSIONS

Bifurcation PCI is associated with a higher risk of 2-year adverse ischemic events than non-bifurcation PCI, a risk that is particularly high when both bifurcation branches are stented, and with HPR conferring similar risk for bifurcation and non-bifurcation PCI.

The Need For Dedicated Bifurcation Stents: A Critical Analysis

There is growing evidence that optimally performed two-stent techniques may provide similar or better results compared with the simple techniques for bifurcation lesions, with an observed trend towards improvements in clinical and/or angiographic outcomes with a two-stent strategy. Yet, provisional stenting remains the treatment of choice. Here, the author discusses the evidence - and controversies - concerning when and how to use complex techniques.

Fork in the road: Are all bifurcations created equal?

The TRYTON study evaluated routine side branch (SB) stenting with a novel bare metal stent (BMS) designed for true bifurcation lesions (Medina 1,1,1; 1,0,1; 0,1,1) and compared it to a strategy of balloon angioplasty with provisional stenting. It failed to meet the primary endpoint of non-inferiority in target vessel failure mainly driven by peri-procedural myocardial infarction (MI) with elevated CK-MB > 3× the upper limit of normal. In this substudy, 41% of patients who had a SB diameter > 2.25 mm were evaluated and the new stent was found to be non-inferior in the primary outcome of target vessel failure with no difference in post-procedural MI. This substudy suggests that appropriately sized SB stents with TRYTON may be useful when the SB is >2.25 mm in diameter. However, further studies could evaluate routine use of FFR for SBs; drug eluting versions of the stent as well as stents designed for vessels 2.25 mm in diameter which are frequently felt to be clinically larger when not subjected to core lab analysis.