Multislice CT Angiography of Coronary Bifurcations and Outcomes After Intervention
Condition: Coronary Artery Disease
MeSH terms: Coronary Artery Disease
Study type: Interventional

Summary: 
      This is prospective, observational study, that will be conducted in two high-volume
      university interventional cardiology centers. Study population consists of patients with
      "true" coronary bifurcations (Medina 1.0.1; 0.1.1; 1.1.1) with >50% stenosis in both main
      (MB) and side branch (SB). Patients are scheduled to undergo percutaneous coronary
      intervention (PCI) based on clinical findings. Before PCI, patients will undergo multislice
      CT angiography (MSCTA). MSCTA before PCI for "true" non left main bifurcation lesions can
      determine atherosclerotic plaque characteristics in MB and SB and predict significant
      narrowing of SB after provisional stenting. Primary goal is to determine which plaque
      characteristics of "true" non left main bifurcation lesions in MB and SB, as assessed by
      MSCTA, can affect the occurrence of SB ostial compromise after provisional stenting. Patients
      will be seen in the office visit at 1, 3, 6 and 12 months after the procedure. Clinical
      evaluation and 12-channel ECG are mandatory at each visit. Comprehensive echocardiogram with
      2D-strain analysis will be done at 3-month visit. Repeated coronary angiography will be done
      at 6-month visit, and will include quantitative analysis of previously treated bifurcation
      lesion.
    

Detailed description: 
      This is prospective, observational study, that will be conducted in two high-volume
      university PCI centers. The centers are: Clinical Hospital Center Zemun-Belgrade, Cardiology
      Department, and Clinical Center of Serbia, Cardiology Clinic. Study population consists of
      patients with "true" coronary bifurcations (Medina 1.0.1; 0.1.1; 1.1.1) with >50% stenosis in
      both MB and SB9. Patients are scheduled to undergo PCI based on clinical findings. Before
      PCI, patients will undergo MSCTA. Study hypothesis is that MSCTA before PCI for "true" non
      left main bifurcation lesions can determine atherosclerotic plaque characteristics in MB and
      SB and predict significant narrowing of SB after provisional stenting. Primary goal is to
      determine which plaque characteristics of "true" non left main bifurcation lesions in MB and
      SB, as assessed by MSCTA, can affect the occurrence of SB ostial compromise after provisional
      stenting. Plaque characteristics that will be investigated include: angle between the
      arteries, the degree of stenosis, length of stenosis, density of the plaque, plaque volume,
      positive remodeling of the artery, and presence of spotty calcifications.

      Secondary aims are to determine whether MSCTA correctly identifies the degree of stenosis and
      atherosclerotic plaque composition in MB and SB of bifurcation lesions compared to invasive
      quantitative coronary angiography and IVUS. Also to determine correlation between endothelial
      wall shear stress, computed using mathematical model of fluid dynamic reconstruction of MSCTA
      findings, and the degree of stenosis and atherosclerotic plaque composition in MB and SB of
      bifurcation lesion. Another goal is to determine correlation between SB stenosis and coronary
      blood flow after provisional stenting and regional myocardial function assessed by myocardial
      deformation imaging echocardiography in the area of the left ventricle supplied by SB,
      immediately after intervention, and after three months. Study patients will be selected based
      on previous diagnostic coronary angiogram. They will undergo MSCTA on Toshiba Aquilion CXL
      128 slice CT scanner using predefined protocol. The procedure will include calcium scoring
      (Agatston) then CT angiography using Ultravist 370 contrast agent ((iopromide concentration
      370 mg/ml, Bayer Health Care, Germany). MSCTA angiograms will be analyzed using dedicated
      software Vital Vitrea Advanced 6.2, Vital Images, Minnetonka, Minnesota, US. The bifurcation
      lesion analyses will include: the measurement of the angle between MB and SB, measurement of
      the lesion length, reference diameter of the vessel, degree of stenosis, atherosclerotic
      plaque analysis 10 mm proximal and distal in the MB, and 5 mm from the ostium of the SB, and
      at the level of maximum stenosis (minimal lumen diameter).

      Plaque analyses will include:

        1. Type of tissue based on density: lipid, fibro-lipid or calcified,

        2. Plaque volume at the level of bifurcation

        3. Positive remodeling of the artery at the level of bifurcation

        4. Presence of spotty calcification. Before PCI procedure, IVUS evaluation using iLab®
           Ultrasound Imaging System (Boston Scientific, Natick, Massachusetts, US), of the MB and,
           if possible, the SB will be performed. Automated pullback at 0.5 mm/s will be used to
           evaluate both branches before the PCI procedure.

      Initial strategy for PCI will be provisional stenting. The choice of vascular access, guiding
      catheters and coronary wires are left to the operators' discretion. Heparin in doses of
      80-100 IU/kg will be used as periprocedural anticoagulation. After placing the guidewires in
      the MB and SB lesion, the MB will be predilated. After predilation and nitroglycerin
      administration intracoronary, coronary angiogram will be performed. Based on this angiogram,
      a second generation drug eluting stent (DES) will be placed in the MB across the SB, so that
      its diameter will be chosen according to Murray's law. The stent will have to be long enough
      so that proximal margin of the stent is at least 10 mm proximal to the carina of the
      bifurcation. After stenting, proximal optimization (POT) of the stent in the MB will be
      performed using short noncompliant balloon catheter 0,5 mm larger than the diameter of the
      stent. The distal marker of the balloon catheter will be positioned at the level of carina.
      Inflation of the balloon catheter must be at least up to the nominal diameter. After POT and
      intracoronary nitroglycerin administration, coronary angiograms in two orthogonal projections
      will be done. If the SB does not have more than 75% diameter stenosis (DS) on quantitative
      coronary angiography analysis (QCA) and/or coronary blood flow less than TIMI III, the
      procedure is finished. If the SB has more than 75% DS stenosis or TIMI flow <III, procedure
      will be continued with guidewire exchange, preferably with a third guide wire inserted
      through the distal strut in the SB. After predilatation of the SB ostium, kissing inflation
      will be done using adequately sized noncompliant balloon catheters in the MB and SB, up to
      6-8 atm. After control coronary angiogram, if the SB has more than 75% DS, TIMI flow < III or
      ostial dissection, another DES will be implanted in the SB using the technique chosen by the
      operator. The preferred technique is T and protrusion (TAP).

      After the procedure, the patients who had an uneventful PCI will stay in the hospital for 24
      h. Blood samples for Troponin I, CK and CK-MB will be collected at 12 and 24 h after the
      procedure, and for C reactive protein (CRP) after 24h. Complications of the interventions
      will be documented in the patients study file.

      Patients will be seen in the office visit at 1, 3, 6 and 12 months after the procedure.
      Clinical evaluation and 12-channel ECG are mandatory at each visit. Comprehensive
      echocardiogram with 2D-strain analysis will be done at 3-month visit. Repeated coronary
      angiography will be done at 6-month visit, and will include QCA analysis of previously
      treated bifurcation lesion.
    

Intervention name(s): multislice CT angiography
Intervention type(s): Procedure
Intervention description(s): Study patients will undergo MSCTA on Toshiba Aquilion CXL 128 slice CT scanner using predefined protocol. The procedure will include calcium scoring (Agatston) then CT angiography using Ultravist 370 contrast agent ((iopromide concentration 370 mg/ml, Bayer Health Care, Germany). MSCTA angiograms will be analyzed using dedicated software Vital Vitrea Advanced 6.2, Vital Images, Minnetonka, Minnesota, US. The bifurcation lesion analyses will include: the measurement of the angle between MB and SB, measurement of the lesion length, reference diameter of the vessel, degree of stenosis, atherosclerotic plaque analysis 10 mm proximal and distal in the MB, and 5 mm from the ostium of the SB, and at the level of maximum stenosis (minimal lumen diameter).
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: angiography, bifurcation, stenting, CT