The role of Computed Tomography (CT) of the coronary arteries in the diagnosis and treatment of coronary artery disease remains is in evolution. Yet in several areas of the world, this technique is already in widespread use, and it is not yet known what effect this has had on other areas of the diagnosis and management of coronary artery disease. This study looked at the impact of the utlization of coronary CT on other diagnostic modalities in the same centre.

1053 consecutive patients underwent coronary CT after the installation of a new 64-slice Siemens Somatom in Columbus, Ohio. The yearly procedural volumes in cardiac catheterization and noninvasive stress testing were reviewed both before and after the introduction of the CT machine. Overall, only 91 patients (8.6%) of the 1053 patients scanned went on to have invasive diagnostic catheterization, and of these, 48% required percutaneous or surgical intervention. This did not represent an increase in procedures over previous years. However, a 30% decrease was noted in patients referred for non-invasive stress testing.

As very few patients who underwent coronary CT went on to cardiac catheterization, the study highlights the high negative predictive value of coronary CT. However, current guidelines recommend noninvasive stress testing to confirm myocardial ischaemia before percutaneous coronary intervention. This small study also reminds cardiologists that even if coronary disease is detected using CT, other non-invasive stress testing must still be used when appropriate.

· Alex J. Auseon, DO, Sunil S. Advani, MD, Charles A. Bush, MD, Subha V. Raman, MD, MSEE. Impact of 64-Slice Multidetector Computed Tomography on Other Diagnostic Studies for Coronary Artery Disease. Am J Med 122(4);388-391.