Navigation Links
New method effective in detecting dangerous coronary plaque
Date:5/29/2008

BOSTON A significant number of patients who suffer a heart attack never have any warning signs. For many of these individuals, the source of the problem is noncalcified plaque, a buildup of soft deposits embedded deep within the walls of the hearts arteries, undetectable by angiography or cardiac stress tests and prone to rupture without warning.

Now a new noninvasive method has shown success in detecting and measuring noncalcified plaque. In a pilot clinical study led by investigators at Beth Israel Deaconess Medical Center (BIDMC), the technique -- voxel analysis used in conjunction with MDCTA (multi-detector computed tomography angiography) was shown to be equally as effective as catheter coronary angiography in identifying patients at risk for heart disease. Reported in the June 2008 issue of the American Journal of Roentgenology (AJR), the new findings may help doctors monitor the effects of medical treatment to reduce patients risk of atherosclerosis and heart disease.

The importance of quantifying plaque is critical because total plaque burden is considered the most important predictor of coronary events, explains the studys senior author Melvin Clouse, MD, PhD, Emeritus Chairman of the Department of Radiology and Director of Radiology Research at BIDMC and Deaconess Professor of Radiology at Harvard Medical School. Furthermore, the rupture of soft noncalcified plaque has been implicated as the cause of heart attack.

Exercise stress testing and coronary angiography, the standard methods for diagnosing atherosclerosis and heart attack risk, both work by visualizing the lumen, the channel through which blood flows.

However, because the lumen also increases in size as plaque progresses, coronary artery disease may go undetected until late in the disease process. And, adds Clouse, Because soft plaque buildup may not significantly narrow the lumen, conventional angiography and stress tests fail to provide a complete picture of plaque accumulation.

The investigators set out to evaluate a new method of plaque assessment using multidetector computed tomography angiography (MDCTA). Unlike coronary angiography, in which a catheter is threaded through the femoral artery and up into the heart, MDCTA is not invasive. The CT scanning method, comprised of 64 separate scans, provides a detailed cross-sectional view of the blood vessel wall based on the amount and volume of blockage present. Its ability to differentiate plaque density makes it particularly useful in distinguishing between stable plaque and unstable plaque.

The latest MDCT scanners have made it possible to detect noncalcified plaque, explains Clouse. However, due to a number of technical and physiologic factors, accurate and reproducible measurements of this plaque was difficult and time-consuming. We, therefore, developed a new technique that would overcome these obstacles.

The researchers analyzed 41 normal and eight abnormal arterial cross sections with noncalcified plaque selected from 10 patients undergoing MDCTA for percentage of stenosis and plaque volume using a voxel analysis technique, in which density values are measured to identify the boundaries between epicardial fat and the outer arterial wall and between the inner wall and the lumen.

Voxel analysis estimates the volume of plaque in a blood vessel based on a range of volumetric densities, explains Clouse. Within the selected volume, the number of voxels having a density within the range of plaque is established, from which the volume of plaque is then estimated. (In CT scans, voxel values are Hounsfield units, which give the opacity of material to X-rays.) The detailed measurements nearly 2,300 in total provided physicians with a detailed picture of the coronary arteries and surrounding areas.

By plotting a voxel histogram across the arterial wall, we were able to measure the amount of plaque, as well as the narrowing of the artery, explains Clouse. Importantly, he notes, the technique additionally defines the outer boundary of the adventitia, the connective tissue surrounding the artery. Though considered extraneous to the artery, the adventitia appears to play a critical role in the disease process.

Using this new method, we hope to be able to be able to better assess the effects of medication treatment and lifestyle interventions in treating atherosclerosis, says Clouse, who as a member of a team of clinical investigators will study the effects of lifestyle intervention (diet, exercise and omega-3 fatty acid supplement) or salsalate medication compared to placebo on coronary artery calcification as assessed by MDCTA. (See description below.)


'/>"/>

Contact: Bonnie Prescott
bprescot@bidmc.harvard.edu
617-667-7306
Beth Israel Deaconess Medical Center
Source:Eurekalert

Related medicine news :

1. New method identifies rat poison in humans
2. Local Methodists Host West African Choir, South African Leader at Historic Conference
3. Population Health Impact Institute Releases Methods Evaluation Process(TM) (MEP(TM)) Accreditation Standards for Public Comment Period
4. Invasive methods unnecessary for prostate cancer radiation therapy treatment planning
5. Population Health Impact Institute to Host First Methods Evaluation Process(TM) (MEP(TM)) Workshop at Annual CMSA Conference
6. New Method Proposed for Determining Which Patients Should Get Treatment for Colorectal Cancer
7. New method proposed for determining which patients should get treatment for colorectal cancer
8. Kresge Foundation Employs New Funding Methods in its First Quarter Grant Awards of Nearly $43 Million
9. Air Methods Corporation Confirms Fatal Accident in Wisconsin
10. Air Methods Reports 1Q2008 Results and 2Q2008 Update
11. Integrium Introduces Its Integrium Clinical Excellence (ICE) Methodology to Assure Consistent Delivery of Sponsor Clinical Trials
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:3/24/2017)... Maryland (PRWEB) , ... March 24, 2017 , ... ... is the first Certified Medical Reiki™ Master in Frederick, MD. Judy says, “I ... their caregivers during what is often a very difficult and challenging time.” , ...
(Date:3/24/2017)... ... ... “End Time GPS”: a dauntless and enlightened study of the second-coming of Christ, ... of published author, Wesley Gerboth, a World War II veteran, with a highly-regarded reputation ... age ninety-one, he shares the Wisdom God bestowed upon him in this publication. ...
(Date:3/24/2017)... ... March 24, 2017 , ... “The ... about real people of God in congregations across the United States. “The ... minister ordained in 1964 who has served congregations in seven states throughout his ...
(Date:3/23/2017)... ... March 23, 2017 , ... In 2016 the World Health ... there could be four million Zika-related cases in the Americas within the next year. ... US cases reported per year skyrocketing to an estimated 329,000. Yet, Zika, Lyme and ...
(Date:3/23/2017)... ... ... The physicians of KSF Orthopaedic Center PA are proud to announce the opening ... at 2255 E. Mossy Oaks Rd., Suite 440, Spring, Texas 77389 inside the new ... in the north Houston area (The Woodlands, Conroe, Magnolia, Kingwood, Humble) with an even ...
Breaking Medicine News(10 mins):
(Date:3/24/2017)... -- GenomeDx Biosciences today announced that six abstracts featuring Decipher ... Classifier tests will be presented at the 32 nd ... March 24 to 28, 2017 in London, ... Europe,s largest urological event showcasing the ... The abstract titled "Muscle invasive bladder cancer: ...
(Date:3/24/2017)... GENEVA , March 24, 2017 ... efforts to develop sutezolid as effective response to infectious ... TB Alliance and the Medicines Patent Pool (MPP) announced ... an antibiotic drug candidate which demonstrated encouraging results in ... sutezolid in combination with other TB drugs and follows ...
(Date:3/23/2017)... -- Research and Markets has announced the addition of ... Procedure By Technique, Repair Procedure By Technique, By Region, By Country ... ... to grow at a CAGR of 13.35% during 2016-2021 ... aging population, growth in population with heart disease and rising advances ...
Breaking Medicine Technology: