Z-SEA-SIDE: Sirolimus Versus Everolimus Versus Zotarolimus-eluting Stent Assessment in Bifurcated Lesions and Clinical SIgnificance of Residual siDE-branch Stenosis

Bifurcated lesions are challenging target lesions in percutaneous coronary interventions (PCI) which may specifically benefit from the usage of drug-eluting stents (DES). However, the selection of the type of DES and the technique for DES implantation have not been clarified. In spite of the technique adopted, the side-branch (SB) is emerging as critical point, accounting for more than a third of the significant restenosis in the DES era. A series of data supports the adoption of a conservative strategy: stenting the main vessel (MV) only and reserving a conservative approach on the SB as this is not associated with worse outcome compared to more complex stenting strategies. Yet, the clinical relevance in terms of inducible ischemia of sub-optimal angiographic result has not been clarified.

AIMS OF THE STUDY:

The aims of the present study are:

• to compare in a prospective study the acute 3D angiographic results (as a measure of the impact of stent design) and the late clinical outcome of Sirolimus-eluting (SES) vs Everolimus-eluting (EES) vs Zotarolimus-eluting stent (ZES) obtained using a provisional T-and-small-protruding (TAP) approach to treat bifurcated lesions.
• to prospectively assess the clinical relevance (in terms of inducible ischemia) of suboptimal angiographic result in the SB of bifurcated lesions treated by stenting.

METHODS TO BE APPLIED:

75 consecutive patients with bifurcated lesions undergoing PCI with the provisional TAP-stenting technique with ZES implantation will be enrolled. Procedural details, post-PCI cardiac enzyme release, clinical outcome up to 1 year will be prospectively recorded. After the procedure, the subgroup of patients in which complete revascularization has been achieved (no untreated stenosis >50% in any other vessel, no residual stenosis >50% in any other treated vessel), will enter a systematic assessment of inducible ischemia by early (<8 days) and late (6-month) exercise tests.

Off line 3D quantitative coronary angiography (QCA) assessment will be performed and used to divide the study population in 2 groups according to the SB residual stenosis: Group O (optimal SB angiographic result): post-PCI SB area stenosis<50% and Group S (sub-optimal SB angiographic result): post-PCI SB area stenosis>50%.

For the comparison among SES and EES, data will be obtained from the randomized trial SEA-SIDE (NCT00697372).

PRIMARY STUDY END-POINTS.

1.

COMPARISON BETWEEN ZES, SES AND EES:

• "SB acute angiographic result": comparison of the 3DQCA-estimated MLD and MLA in the SB.
• "SB trouble": composite of: 1. occurrence of SB TIMI flow <3 after MV stenting throughout the procedure; 2. need of guidewire(s) different from BMW to re-wire SB after MV stenting; 3. failure to re-wire the SB after MV stenting; 4. failure to dilate the SB after MV stenting and SB re-wiring.
• target bifurcation failure (TBF) defined as target bifurcation-related major adverse coronary events (MACE) or target bifurcation angiographic failure.

• SB-RELATED ISCHAEMIA of Group O vs Group S in patients with complete revascularization: inducible ischemia (diagnostic ST-segment changes) at the early (<8 days) exercise test or occurrence of early (<12 weeks) spontaneous ischemia related to the SB (any ischemic episode requiring unplanned coronary angiography with documentation of main vessel patency).

Inclusion criteria

• de novo bifurcated lesions
• lesions >50% located in a major bifurcation point
• TIMI >2 on both main vessel and side branch
• main vessel visual diameter >2.5 mm
• side branch visual diameter >2.0 mm
• >18 years of age
• signed the informed consent to enter the study

Exclusion criteria

• known hypersensitivity to Sirolimus, Everolimus, cobalt, chromium, nickel, tungsten acrylic and fluoro-polymers
• contraindications to double antiplatelet therapy acute (within 48 hours) ST-elevation acute myocardial infarction