SNOWMASS, COLO. — CT angiography has rapidly emerged as the most cost-effective imaging technique to exclude acute coronary syndrome in the emergency department.
The overall diagnostic accuracy of CT angiography is essentially equivalent to that of SPECT myocardial perfusion imaging, its main competition. But CT angiography is the winner in terms of time to diagnosis and cost, Dr. Christopher M. Kramer said at a conference sponsored by the American College of Cardiology.
“CT angiography is a very exciting new technology. There are still some issues in terms of insurance coverage, but in terms of the science it's clearly a very useful technique in the ED,” said Dr. Kramer, professor of medicine and radiology and director of the cardiovascular imaging center at the University of Virginia, Charlottesville.
Chest pain accounts for more than 6 million ED visits annually, resulting in 1.24 million admissions for unstable angina/non–ST-elevation MI and another 330,000 for ST-elevation MI. Emergency physicians are eager for new ways to rapidly and reliably rule out acute coronary syndrome—and CT angiography has a lot to offer in this regard, according to the cardiologist.
In the 16-center CT-STAT trial, now in press, 701 low-risk patients with chest pain and a nondiagnostic ECG in the ED were randomized to CT angiography or the standard protocol, which typically included serial biomarkers along with SPECT myocardial perfusion imaging (MPI).
Time to diagnosis averaged 6.3 hours in the group who received the standard work-up compared to 2.9 hours with CT angiography, a 53% reduction. Median costs to obtain a diagnosis were $3,158 with the standard protocol and $2,137 with CT angiography, a 38% reduction.
Acute coronary syndrome was diagnosed in roughly 3% of patients in each study arm, and invasive coronary angiography was performed in 5%.
Dr. Kramer serves as a consultant to Siemens Medical Solutions and is the recipient of research grants from Astellas and GlaxoSmithKline.