CORE320: Noninvasive imaging strategy helped identify flow-limiting CAD

Issue: October 2012

MUNICH — Adding CT myocardial perfusion to CTA was associated with robust diagnostic accuracy for the identification of patients with flow-limiting CAD in need of myocardial revascularization, according to new results from the CORE320 trial.

The prospective, multicenter, international trial evaluated the diagnostic accuracy of combined noninvasive CTA and CT myocardial perfusion imaging (CTP) as compared with invasive angiography (ICA) and single-photon CT myocardial perfusion imaging (SPECT-MPI). The primary objective was whether combined CTA and CTP could reliably determine the presence or absence of flow-limiting coronary stenoses as defined by the combination of ICA and SPECT-MPI, according to a press release.

Joao A.C. Lima, MD, presented data on 381 patients aged 45 to 85 years with suspected or known CAD who were clinically referred for ICA and successfully completed all imaging. Images were evaluated in double masked core laboratories. Area under the receiver operating curve (AUC) was used as the primary diagnostic parameter.

“We found that adding CTP to CTA allows clinicians to distinguish between anatomic and flow-limiting stenoses,” said Lima, who is a Cardiology Today Editorial Board member.

Prevalence of obstructive CAD defined by combined ICA/SPECT-MPI was 38% and for ICA alone was 59%. The patient-based diagnostic accuracy (AUC) of combined CTA and CTP for detecting or excluding flow-limiting CAD was 0.87 (95% CI, 0.83-0.91) and 0.89 (95% CI, 0.86-0.93) when the ICA stenosis reference standards were 50% or greater and 70% or greater. CTP increased the diagnostic accuracy of CTA alone to delineate flow-limiting disease (AUC 0.87; 95% CI, 0.83-0.91 vs. AUC 0.81; 95% CI, 0.77-0.86), respectively. Combining CTA and CTP had similar diagnostic power to the combination of ICA and SPECT-MPI in the identification of revascularized patients at 30 days, according to the release.

“CT perfusion adds significantly to the diagnostic power of CT angiography alone,” Lima, professor of medicine and director of CV imaging in the division of cardiology at Johns Hopkins University School of Medicine, said at a press conference. “The combination of CTA and CTP in one noninvasive exam is useful in identifying the patients who will benefit most from revascularization and to guide the management of CAD.”

The CORE320 study was conducted at 16 centers in the United States, Canada, Brazil, Germany, Denmark, Japan, Singapore and the Netherlands. Sixty-six percent of the patients were men; the median age was 62 years; the mean BMI was 27; and the mean Agatston calcium score was 162. Additionally, 34% of patients had diabetes, 26% had a history of previous MI, 29% had prior PCI, 78% had hypertension, 68% had dyslipidemia and 45% had a family history of CAD. – by Katie Kalvaitis

For more information:
Lima JAC. Hot line III: Late breaking trials on arrhythmias and CAD. Presented at: the European Society of Cardiology Congress; Aug. 25-29, 2012; Munich.

Disclosure: The study was sponsored by Toshiba Medical Systems. Dr. Lima has received grant/research support from Bracco Diagnostics and Toshiba Medical Systems and federal grant support from NHLBI, NIA and NIDDK.