Trial finds 64-slice CTA capable of ruling out significant coronary artery disease

Results from a widely anticipated multicenter trial led by researchers at Johns Hopkins University Medical Center showed that 64-slice CT angiography of the heart and its surrounding arteries is nearly as reliable and accurate as more invasive diagnostic tests for coronary artery disease.

The Coronary Artery Evaluation using 64-Row Multidetector Computed Tomography (CORE-64) study also showed that early detection with 64-slice CT reliably predicts who will need angioplasty or coronary bypass surgery.

The final results suggest that 64-slice CTA will not replace cardiac catheterization, but the noninvasive scans will help cardiologists more quickly rule the presence of coronary artery disease, thereby sparing some patients from more invasive procedures. Studies suggest that as many as 25% of the 1.3 million cardiac catheterizations performed each year in the U.S. may be unnecessary.

"This study is the first step to realizing the full potential of CT imaging in predicting coronary artery disease, and these scans complement the arsenal of diagnostic tests available to physicians to prevent heart attacks," said chief investigator Dr. Julie M. Miller, an assistant professor of medicine in interventional cardiology at Johns Hopkins.

Results showed that on average 91% of patients with significant stenoses were detected by 64-slice CT and that the scans could rule out the presence of disease for 83% of patients. Researchers say this reliability allows them to accurately identify patients who need angioplasty or bypass surgery.

Investigators selected 291 men and women over the age of 40 who were already scheduled to have cardiac catheterization to check for blocked arteries. Radiologists and cardiologists who joined with John Hopkins University in the trial came from Beth Israel Hospital in Boston, Iwate Medical University in Japan, Charité University Medical Center in Berlin, Leiden University in the Netherlands, Mount Elizabeth Medical Center in Singapore, University of São Paolo, and the University of Toronto.

Toshiba Aquilion 64 CFX multislice CT scanners were used for imaging. Toshiba provided funding for the research.

Subjects underwent a 64-slice CT scan prior to catheterization and were then monitored through regular checkups to identify who developed or did not develop coronary artery disease and who required subsequent bypass surgery or did not need surgery. After a year of monitoring, researchers found 90% correlation between the 64-slice CT scans and invasive catheterization for the presence of significant stenosis.

The new study also suggests that 64-slice CTA may be a good alternative to cardiac stress testing, which evaluates heart function by measuring the effects of hard exercising. Exercise stress testing generally cannot be performed safely on weak and elderly patients. It is often used a preliminary test before cardiac catheterization for patients with a low or intermediate risk of myocardial infarction.

"Use of 64-slice CT scans will dramatically improve our ability to detect and treat people with suspected coronary disease and chest pain much earlier in their disease," said cardiologist Dr. João Lima, a senior investigator on the Core 64 research team.

For more information from the Diagnostic Imaging archives:

Coronary CT angiography saves lives and money: 20,000-plus cases prove it

Plaque distribution proves that men are from Mars, women from Venus

Coronary CT angiography finally finds itself an affordable home

JAMA study raises public awareness of radiation risk from cardiac CT

Report from SCCT: low-dose 64-slice cardiac CTA vies with catheter angiography