CT Better Than MRI for Ruling Out Coronary Disease


Last Updated: 2010-02-01 17:46:15 -0400 (Reuters Health)

NEW YORK (Reuters Health) - When a noninvasive test for ruling out coronary artery disease is appropriate, computed tomography (CT)-based angiography is more sensitive and specific than magnetic resonance imaging (MRI)-based angiography, a new meta-analysis shows.

Noninvasive angiography is most useful for patients with a low or intermediate risk of coronary disease, as a first step in determining whether invasive assessment is needed, according to senior author Dr. Marc Dewey, from Charite Medical School, Berlin, and his colleagues. Whatever test is chosen should produce few false-negative results and thus have a relatively high sensitivity.

In searching MEDLINE and other sources, Dr. Dewey and his group identified prospective studies that compared conventional angiography either to CT (89 studies; 7516 patients) or MRI (20 studies; 989 patients).

In the February 2nd Annals of Internal Medicine, the researchers report that on pooled analysis, CT was 97.2% sensitive and 87.4% specific in detecting clinically significant coronary disease. The sensitivity and specificity of MRI were lower: 87.1% and 70.3%, respectively.

When the analysis was confined to the 45 studies of patients with suspected coronary disease, the sensitivity and specificity of CT were even higher, 97.6% and 89.2%, respectively.

Further analysis showed that CT scanners with more then 16 rows were significantly more sensitive than scanners with fewer rows: 98.1% vs. 95.6% (p < 0.05). Also, CT was more sensitive with heart rates less than 60 beats/min (p < 0.001).

"Our analysis indicates that CT should be considered the foremost noninvasive alternative to conventional angiography for detecting and ruling out coronary artery stenoses in selected patient populations," the authors conclude.

They add, "Randomized studies are clearly needed to address the potential of coronary CT angiography for use in triage as a means of positively altering management and outcomes in patients with suspected coronary artery disease."

Ann Intern Med 2010;152:167-177.

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