First Multicenter Trial Confirms Effectiveness of Combined CT Angiography and Myocardial Perfusion Imaging Using 320-Detector Row CT

Combined noninvasive computed tomography coronary angiography (CTA) and myocardial perfusion (CTP) with 320-detector row CT allows accurate identification of flow-limiting lesions requiring revascularization. These are the key findings of the first worldwide multicenter trial evaluating the diagnostic performance of combined CTA and CTP as compared to the conventional evaluation of flow-limiting stenosis by means of single photon emission computed tomography-myocardial perfusion imaging (SPECT-MPI) and invasive coronary angiography (ICA).

The trial’s findings, CORE320, sponsored by Toshiba Medical Systems Corp. (Tokyo, Japan), were presented in Munich (Germany) August 25-29, 2012, during an European Society of Cardiology (ESC) Hotline Session by Dr. João A. C. Lima, MD, senior author of the study and professor of medicine and radiology at the Johns Hopkins University School of Medicine (Baltimore, MD, USA).

“The CORE 320 study 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. 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” said Dr. Lima.

Three hundred eighty-one patients completed all imaging and were included in the primary analysis. The patient-based diagnostic accuracy (AUC) of combined CTA and CTP for detecting or excluding flow-limiting cornary artery disease (CAD) without history of CAD was 0.93 when the ICA stenosis reference standard was 50%. CTP increased the diagnostic accuracy of CTA alone to delineate flow-limiting disease (AUC: 0.87 vs. 0.81, respectively, p < 0.001). The combination of CTA and CTP had similar diagnostic power to the combination of ICA and SPECT-MPI in identifying revascularized patients at 30 days.

The researchers say the two modalities combined--CTA and CTP--still generate less radiation than a cardiac scan with the 64-slice CT scanner in widespread use today. Dr. Lima stated, “In our study, the amount of radiation exposure to patients from the two 320-slice CT scanner tests was half the amount they received as a result of the traditional evaluation methods--the angiogram and nuclear medicine stress test combined.”

The unique ability of Aquilion One, the dynamic volume CT system used in CORE320, which acquires the entire heart in a single temporally uniform volume, permits accurate myocardial perfusion analysis. The perfusion technique developed for Aquilion One provides perfusion images at the lowest possible radiation dose when AIDR (adaptive iterative dose reduction three-dimensional [3D]) reconstruction, is applied.

“One of Toshiba’s core missions is to validate its technology through clinical trials by leaders in the medical field,” explained Satoshi Tsunakawa, president of Toshiba Medical Systems Corp. “CORE320 has shown that it is now possible to perform a comprehensive cardiac functional and morphological analysis in just one, low-dose examination using Aquilion One. This technology can reduce the need to perform multiple examinations using different modalities, a true economical advantage and valuable contribution in cardiac healthcare,” said Mr. Tsunakawa.

The Aquilion Onesystem, in conjunction with myocardial perfusion software available on the VitreafX and Vitrea Enterprise Suite, includes all the features used for CORE 320 data acquisition and analysis, allowing physicians to perform myocardial perfusion imaging in their institution today.

“Training is another essential part of Toshiba’s myocardial perfusion solution,” said Tsunakawa. To assist physicians in implementing myocardial perfusion into their clinical practice, Toshiba is sponsoring the Myocardial Perfusion CT Workshops held at Rigshospitalet in Copenhagen (Denmark). Dr Klaus Kofoed, the co-program director, participated in CORE320 and brings a wealth of experience from the trial to all attendees.

Related Links:
Toshiba Medical Systems
Johns Hopkins University School of Medicine