PET/CT for the Quantification of Atherosclerotic Plaque Inflammation

Summary

This is a single-centre prospective trial with 140 patients employing \[18F\]-fluorodeoxyglucose positron emission computed tomography (FDG PET/CT) and advance motion correction and image fusion algorithms to create motion frozen displays and quantify FDG-uptake and thus inflammatory activity in atherosclerotic plaques in the coronary tree. Four groups of patients, two with stable coronary artery disease and two with acute coronary syndrome will be compared and the results of FDG PET/CT will be correlated to results of invasive coronary angiography, intravascular ultrasound / virtual histology, patient risk profile and serum markers of inflammation.

The investigators hypothesize that increased FDG accumulation in atherosclerotic plaques shows a positive correlation with inflammatory activity in coronary plaques and markers of plaque vulnerability as well as the risk profile of the patients and serum markers of inflammation. The investigators furthermore hypothesize that FDG PET/CT is able to detect high risk patients and provide an important means for risk stratification and optimization of patient management.

Conditions

• Coronary Artery Disease
• Acute Coronary Syndrome

Interventions

OTHER

[18F]-FDG positron emission computed tomography

Patients will receive 20 mg furosemide and 20 mg butylscopolamine together with 370 MBq FDG. 120 minutes after the FDG application a ECG- and respiratory gated cardial PET acquisition will be performed, followed by a CT calcium scan, which will also be used for attenuation correction. This will be followed by CT-angiography with the application of 80 ml contrast medium. Patients without betablocker and a heart rate of more than 70 / min will be treated with 50 - 100 mg metoprolol as long as there are no contraindications. Subsequently, a 3D-mode whole body PET scan will be acquired followed by a low-dose CT transmission scan from the base of the scull to the iliac crest.

PROCEDURE

Invasive coronary angiography

ICA is performed via the femoral artery in three projections (RAO 30°, RAO 15° and LAO 45°) and, if necessary, also in further projections. All angiograms are recorded digitally and assessed quantitatively by two experienced readers, who are blinded to the PET/CT results (Quant-Cor, QCA, Siemens Medical Systems, Forchheim, Germany or Digital Cardiac Imaging Systems, Philips, Eindhoven, Netherlands). The mean stenosis of the vessel is assessed in two projections and the percentage of stenosis is calculated for each single segment. Stenoses are localized by means of the AHA (American Heart Association) classification. Occlusions of the vessels are documented and revascularization is performed immediately in patients with acute coronary syndrome (STEMI, NSTEMI).

PROCEDURE

Intravascular ultrasound and virtual histology

During the procedure an intravascular ultrasound will be recorded in grayscale. Radiofrequency raw-data will be collected at the peak of the R-wave and a VH-IVUS data recorder is used to reconstruct a color-coded map. Acquired data will be evaluated with a dedicated software. The grayscale IVUS images will be analyzed frame by frame and used to measure the diameter of the vessel lumen, of the external elastic membrane (EEM) as well as plaque and media thickness (defined as EEM minus lumen). The plaque burden will be calculated. A VH-IVUS analysis will be performed for each frame. Four plaque components will be color-coded: dense calcium white, the necrotic core red, fatty tissue light green and scar tissue dark green. color fractions are expressed as percentage of the plaque area and percentage of plaque volume. Lesions will be classified: pathologic intima thickening, fibroatheroma with thin cap, fibroatheroma with thick cap, fibrotic plaque and fibro-calcified plaque.

OTHER

Serum biomarkers

A 20 ml blood sample will be obtained from each patient. The following biomarkers will be assessed: glucose level, HBA1C, cholesterol levels, LDL cholesterol, HDL cholesterol, triglycerides, fibrinogen, factor XIII, plasminogen, complement C3, TNF-alpha, IL-6, CRP, resistin, adiponectin, CD40, 5-lipoxygenase, MMP-9, MMP-1, osteopontin, osteoprotegerin, fetuin, FGF21. ELISA and/or calorimetric assays will be used for the biochemical analyses of the serum markers.

Sponsors & Collaborators

• Ludwig-Maximilians - University of Munich

  lead OTHER

Principal Investigators

• Marcus Hacker, MD · LMU Munich

Eligibility

Min Age

50 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2012-06-30

Primary Completion

2014-06-30

Completion

2014-12-31

Countries

• Germany

Study Locations