Feature | November 22, 2013

Advanced CT Proves as Accurate as Invasive Tests to Assess Heart Blockages

ct systems angiography clinical trial study CTA 320 anio core

November 22, 2013 — A 320-detector computed tomography (CT) scanner that shows both anatomy within coronary arteries and blood flow can accurately sort out which people need an invasive procedure to identify coronary blockages, according to an international study. The researchers say their findings could potentially save millions of people worldwide from having an unnecessary cardiac catheterization. The study, known as CORE 320, involved 381 patients at 16 hospitals in eight countries. The European Heart Journal published an article on the results online Nov. 19.

In the study, participants were evaluated with a 320-detector CT and conventional tests that are widely used today. The researchers say 91 percent of those in whom the CT scan ruled out blockages would not have required invasive treatment such as stenting or bypass surgery. So those patients, none of whom had a history of coronary artery disease (CAD), could have avoided invasive tests because for them the CT scan was just as accurate in determining who would be a good candidate for revascularization as the conventional tests.

"Ours is the first prospective, multicenter study to examine the diagnostic accuracy of CT for assessing blockages in blood vessels and determining which of those blockages may be preventing the heart from getting adequate blood flow," said Joao Lima, M.D., professor of medicine and radiology, Johns Hopkins University School of Medicine and senior author of the study. "We found an excellent correlation in results when we compared the 320-detector CT testing with the traditional means of assessment using a stress test with imaging and cardiac catheterization."

The study findings, says Lima, would apply to people who have chest pain but not a heart attack based on electrocardiograms (ECGs) and other evidence. Many people in that situation are sent to a cardiac catheterization laboratory for further evaluation with angiography. About 30 percent of people who have such catheterization are found to have minimal disease or no blockage requiring an intervention to open the vessel with a stent or bypass the vessel through surgery.

The 381 patients who completed the study had traditional single-photon emission computed tomorgraphy (SPECT) tests and invasive angiography. Lima says SPECT shows reduced blood flow to the heart without indicating the number or specific location of blockages.

Study participants also had two types of tests with a noninvasive 320-detector CT scanner. In the first CT test, the scanner was used to see the anatomy of vessels to assess whether and where there were blockages — a computed tomography angiography (CTA). Then, in a second CT test with the same machine, patients were given a medication that dilates blood vessels and increases blood flow to the heart in ways similar to what happens during a stress test — a computed tomography perfusion (CTP).

"We found that the 320-detector CT scanner allowed us to see the anatomy of the blockages and determine whether the blockages were causing a lack of perfusion to the heart," said Carlos Rochitte, M.D., cardiologist, Heart Institute (InCor), University of São Paulo Medical School, Brazil and lead author of the study. "We were therefore able to correctly identify the patients who needed revascularization within 30 days of their evaluation."

"Many patients are sent for an angioplasty when they may not need it. Our ultimate goal is to have more certainty about which patients having chest pain — without evidence of a heart attack — need an invasive procedure to open an arterial blockage," said Richard George, M.D., cardiologist, associate professor of medicine, Johns Hopkins University School of Medicine and a co-author of the study.

George developed the CTP method with Lima. "The CTP test added significant information about the patients' conditions and boosted our ability to identify those whose blockages were severe enough to reduce blood flow to the heart," added George.

The 320-detector CT provides a complete picture of the heart by making just one revolution around the body. The researchers say the two tests combined (CTA and CTP) still produce less radiation than a scan with the 64-detector CT scanner in widespread use.

"In our study, the amount of radiation exposure to patients from the two 320-detector CT tests was half the amount they received as a result of the traditional evaluation methods — the angiogram and nuclear medicine stress test combined," said Lima.

The researchers say they will continue to follow the patients in the study for five years, looking for any heart-related events such as heart attacks, as well as hospital admissions, procedures or operations.

"CORE320 confirms the results of numerous single center studies performed by investigators throughout the world that myocardial CT perfusion imaging, when added to the coronary CT angiogram, provides incremental improvement in the diagnosis of flow limiting coronary artery disease," said George. "This study demonstrates that cardiac CT is a comprehensive diagnostic tool that can define coronary plaque, plaque burden, anatomic stenosis and the hemodynamic significance of coronary artery disease."

George also said this should affect the practice of cardiac CT.

"We now have evidence from numerous single center studies and now two multicenter studies that myocardial CTP accurately diagnosis myocardial ischemia," added George. "In the setting of an abnormal coronary CTA, myocardial perfusion imaging may be added to assess the hemodynamic significance of stenosis".

With regards to CT perfusion, these next steps will be considered for the future:

  • Training physicians in the acquisition and interpretation of CTP.
  • Evaluating its ability to assist in treatment decisions.
  • Evaluating its prognostic significance.

For more information: www.hopkinsmedicine.org, eurheartj.oxfordjournals.org

Related Content

Beaumont Hospital Royal Oak, first in Michigan, FFR-CT, HeartFlow Inc., heart failure

Image courtesy of HeartFlow Inc.

News | FFR Catheters| October 05, 2015
Beaumont Hospital - Royal Oak is the first in Michigan and one of just a handful in the United States to offer...
News | Heart Failure| October 02, 2015
Cyberonics Inc. announced results from the extension of the ANTHEM-HF clinical study (ENCORE Study). Results of the...
Tryton Side Branch Stent, clinical trial results, Catheterization and Cardiovascular Interventions

Tryton Side Branch Stent image courtesy of Tryton Medical

News | Stents Bifurcation| October 02, 2015
October 2, 2015 — Tryton Medical Inc.
Intact Vascular, TOBA II study, Tack Endovascular System

Image courtesy of Intact Vascular

News | Peripheral Arterial Disease (PAD)| October 01, 2015
Intact Vascular Inc. announced the U.S. Food and Drug Administration has granted conditional approval for a U.S. and...
Johns Hopkins, sticky gel, stem cells, rat hearts, heart attacks

Hydrogel applied to beating rat hearts improves stem cell uptake by the heart muscle and speeds up tissue healing after heart attack. Image courtesy of Johns Hopkins Medicine.

News | Stem Cell Therapies| September 29, 2015
A sticky, protein-rich gel created by Johns Hopkins researchers appears to help stem cells stay on or in rat hearts and...
News | Cath Lab| September 29, 2015
The Innovation Institute announced that Boston Scientific has signed an agreement to become the founding medical device...
Eluvia drug-eluting vascular stent system, 12-month primary patency, Boston Scientific, MAJESTIC trial, CIRSE

Image courtesy of Boston Scientific

News | Stents Peripheral| September 28, 2015
New 12-month clinical trial outcomes assessing the safety and performance of the Boston Scientific Eluvia drug-eluting...
predicting arrhythmias, mcgill university, alternans patterns
News | EP Lab| September 28, 2015
Researchers have discovered how to predict some cardiac arrhythmias several steps before they even occur. It’s a...
News | Antiplatelet and Anticoagulation Therapies| September 25, 2015
The Icahn School of Medicine at Mount Sinai has launched the international TWILIGHT clinical trial to test the safety...
Medisafe, medication management, mHealth platform, blood pressure study, hypertension, adherence
News | Hypertension| September 25, 2015
Medisafe, an mHealth platform for medication management, announced the results of its blood pressure study, which...
Overlay Init