Coronary CT angiography (CTA) can rapidly identify a subset of low- to moderate-risk patients presenting to the emergency department with symptoms suggesting acute coronary syndrome (ACS) who can be discharged without adverse clinical outcomes.
This conclusion comes from research presented at the 2008 RSNA meeting in Chicago. "Our findings suggest that patients with normal coronaries or mild disease can be safely discharged to home. Patients with moderate or severe disease should be referred for further testing," said Dr. Ethan Halpern, associate professor of radiology at Jefferson Medical College in Philadelphia.
"No patient with a normal coronary CT angiography exam or only mild disease died or developed ACS by 30-day follow-up," he added. "Only one of 148 patients with a negative initial CT reading developed significant coronary artery disease, and that was due to operator error."
The single-center, prospective-cohort study involved 201 patients with acute chest pain but normal initial troponin and myotropin levels, and no evidence of myocardial ischemia on initial electrocardiogram. The mean age of the patients was 47.5 years, and 43% were male.
All patients underwent 64-slice, contrast-enhanced coronary CTA (Brilliance Pro, Philips Healthcare, Andover, MA) during administration of 95 cc of intravenous contrast material. Four patients were excluded because of technical problems.
Of the remaining 197 patients, 10 patients had severe disease, defined as greater than 70% stenosis, and 12 had moderate disease, defined as 50% to 70% stenosis. A total of 46 patients (23%) had mild disease, with less than 50% stenosis, and 129 (65%) had no coronary disease on CT.
Clinically significant noncoronary artery disease findings were noted in 49 patients (25%). In 22 patients (11%), a new diagnosis that explained the presenting symptoms was established based on the noncoronary findings. "These would not have been found on stress testing," Halpern said.
No further diagnostic testing was performed in 133 of the 175 (76%) patients with no coronary disease or mild coronary disease. No patient with a normal coronary CTA exam or who had only mild disease died or developed ACS at 30 days.
"At 30-day follow-up, the absence of significant coronary artery disease on CT accurately predicted the absence of ACS, with a negative predictive value of 99.4%," Halpern concluded. "Our one false negative was related to observer error."
By Charlene Laino
AuntMinnie.com contributing writer
December 9, 2008
Related Reading
Scientists doubt utility of CT scan as heart test, November 30, 2008
CT not ready to replace conventional coronary angiography, November 26, 2008
Coronary CT effective for triage of patients with acute chest pain, November 11, 2008
CT angiography aids risk stratification in patients with chest pain, November 3, 2008
Copyright © 2008 AuntMinnie.com
