Study Name

Double Kissing and Double Crush versus Provisional T Stenting Using Everolimus-Eluting Cobalt Chromium Stent for the Treatment of Unprotected Distal Left Main True Bifurcation Lesions: A Randomized, International, Multi-center Clinical Trial

Purpose

Compare essential functional, angiographic variables and clinical outcomes in patients with unprotected distal left main true bifurcation  (LMb) lesions, treated by DK crush versus provisional T stenting using drug-eluting stent (DES)

Study Design

A Randomized, International, Multi-center Clinical Trial

Patient
Enrollment

A total of 544 patients will be included in the study.

Patient Follow-up

All patients will be seen at the outpatient clinic of the participating centers after 1-, 6- , 12- and 24-month. The outpatient visit may be substituted with a telephone contact and subsequent investigational documentation forms.
Angiographic follow-up would be undergone at 13-month after index procedure

Primary Endpoint

Rate of TLR at 12-month

Secondary endpoint

Combined endpoint of all-cause death, MI, TVR at 1- and 2-year
Individual endpoints of all-cause death, cardiac death, MI, TLR,TVR at 1- and 2-year
Definite and probable stent thrombosis
NYHA functional class
Angina CCS class
Braunwald class
ISR
Net gain of lumen diameter
Fractional flow reserve (FFR)

Other registered outcome parameters

Procedure related biomarker release
Stroke
Outer diameter of guiding catheter
Devices consumed during indexed procedure
Contrast volume
Procedural time
X-ray exposure time
X-ray dose, DAP-total, DAP-record, DAP-fluoro

Inclusion Criteria

Patient must be at least ≥18, ≤80 years of age.
Patient (or patient’s legally-authorized representative) understands the trial requirements and treatment procedures and provides written informed consent before any trial-specific tests or procedures are performed.
Patient is eligible for percutaneous coronary intervention (PCI).
Patient has stable/unstable angina or NSTEMI.
Patient has STEMI>24-hour from the onset of chest pain to admission.
Patient is an acceptable candidate for coronary artery bypass grafting (CABG).
Patient is willing to comply with all protocol-required follow-up evaluations.
LMb (Medina 0,1,1/1,1,1 ) with/without ostial/shaft lesions.
Downstream lesions in LAD or LCX could be covered by two stents.
LMb with CTO lesion in LAD, or LCX or RCA after recanalization.
Diameter stenosis in LAD/LM and LCX ≥50% by visual estimation.

Exclusion Criteria

Patient with STEMI (within 24-hour from the onset of chest pain to admission).
Patient has known allergy to the study stent system (everolimus) or protocol-required concomitant medications.
Patient has intolerable to dual anti-platelet therapy.
Patient has any other serious medical illness that may reduce life expectancy to less than 12 months.
Patient is a woman who is pregnant or nursing .
Patient has a planned procedure that may cause non-compliance with the protocol or confound data interpretation. Patient is participating in another clinical trial that has not reached its primary endpoint within 24 months after the index procedure.
CTO lesion in either LAD, or LCX or RCA not re-canalized.
Severe calcification needing rotational athrectomy.
Distal left main coronary restenosis.

Safety

For safety reason, stent thrombosis after one month(late stent thrombosis) will be monitored continuously. A 1-year rate of definite very late stent thrombosis exceeding 5% in the any group will necessitate premature termination of the study.

Randomization Procedure

The patients will be randomized after angiography to either DK or T group. The randomization serial number for patients will be performed by Interactive Web Randomization System (IWRS). The randomization serial number for each participating center will be undergone by the same system.

Sample Size Calculation

The study is planned as a superiority study, where an experimental treatment of a disease (E, here DK) is compared to a standard treatment (S, here T). Calculations are based on the following:
All event curves are exponential
Randomization into two equally sized groups
α=0.05(two-sided)
β=0.20
1-β (Power)=0.20
The difference in TLR between two groups is 0.08 (0.15 in T group minus 0.07 in DK group), with smaller value of 0.07 in DK group. The above preconditions and assumptions result in a necessary number of patients in each randomization group of 237. Because of the uncertainty and dropout during follow-up, additional 15% patients are required, leading to a total number of 544 patients, with 272 patients in each group.