Coronary CTA bested MPI in patients with acute chest pain

Goldstein J. J Am Coll Cardiol. 2011;58:1414-1422.

Issue: November 2011

The use of coronary CTA resulted in a more rapid, cost-efficient diagnosis than rest-stress myocardial perfusion imaging in ED acute, in low-risk patients with chest pains, according to study results.

From June 2007 to November 2008, patients with acute chest pain admitted to the ED were randomly assigned to a coronary CTA group or a myocardial perfusion imaging (MPI) group. According to researchers, patients included in the study had chest pain suspicious for angina; were aged 25 years or older; had a time from onset of chest pain to presentation of 12 hours or less; had a time from ED presentation to randomization of 12 hours or less; had normal or nondiagnostic rest electrocardiogram evidence of ischemia; and had a thrombolysis in MI risk score of 4 or less for unstable angina or non-STEMI. Researchers defined the primary outcome as diagnostic efficiency starting when patients were randomly assigned into coronary CTA or MPI groups and ending when test results were called to ED physicians; secondary outcomes were defined as ED cost of care and safety.

Researchers reported a 54% reduction in time to diagnosis when using the coronary CTA diagnostic strategy demonstrating a more rapid diagnosis vs. MPI (P<.0001). In secondary outcomes, there was a 38.2% reduction in total ED costs of care in the coronary CTA diagnostic strategy vs. MPI (P<.0001), and the safety endpoint showed that both strategies had similar low number of cases with adjudicated major adverse cardiac events (P=.29) and that there were no deaths in either group.

Overall, 361 patients were enrolled in the coronary CTA group. More than minimal CAD was ruled out in 82.2% of coronary CTA patients, more than 70% stenosis was detected in 3.6% of patients, intermediate stenosis was found in 10.2% of patients, and 3.9% of cases had scans that were not fully interpretable, according to researchers. Of the 37 coronary CTA patients who had rest-stress MPI performed, 23 had either intermediate lesions or nondiagnostic scans, 10 had normal CCTA, and four showed more than 50% narrowing. Index testing among 338 MPI patients was normal or probably normal in 89.9%, and 89.1% were discharged within 6 hours. Invasive coronary angiography was performed in 24 coronary CTA cases vs. 21 MPI cases.

Disclosure: Dr. Goldstein reports no relevant financial disclosures.

This is an extremely important trial that provides evidence supporting coronary CTA as an efficient and highly accurate diagnostic tool in the ED. This will be an invaluable modality for assessment of non-ACS patients in the ED.

– Leslie Shaw, PhD, FASNC, FACC, FAHA
Professor of Medicine, Emory University School of Medicine, Georgia

Disclosure: Dr. Shaw received grants from Bracco Diagnostics and Astellas Healthcare.

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