Coronary Heart Scans help diagnose heart disease in low-risk patients

CCTA Helps Diagnosis Heart Disease in Low-Risk Patients

By Marijke Vroomen Durning, RN | July 26, 2012

Low-risk patients presenting to the emergency department with chest pain benefit from undergoing coronary CT angiography (CCTA) as part of an initial evaluation, show findings of a study published this week in the New England Journal of Medicine.

Adding CCTA helped reduce the amount of time patients spent in the hospital without incurring additional costs. The study is significant because it showed CT as a viable alternative to the standard of care, said study author Udo Hoffmann, MD, MPH, director of the Cardiac MR PET CT program at Massachusetts General Hospital.

Researchers showed CT as appropriate for a broader setting, rather than only a specialized setting, he said in an interview. “It brings this to a bigger stage,” he said, adding “it’s an important step forward” for CT imaging.
For the study, funded by the NIH’s National Heart, Lung, and Blood Institute (NHLBI), researchers at MGH assessed 1,000 patients, between the ages of 40 to 74, who presented to the ED at nine U.S. hospitals between April 2010 and January 2012 with complaints of chest pain.
These patients had no history of cardiovascular disease and the initial tests (ECG and measurement of the biomarker troponin) did not indicate evidence of a heart attack. The researchers were looking at how long patients would stay in the hospital, as well as rates of discharge from the ED, major adverse cardiac events at 28 days, and cumulative costs.
Patients were randomly assigned to test group or control group, which received standard investigations. The test group underwent CCTA in addition to the regular exams.
Results showed that the patients who underwent CCTA spent significantly less time in the ED, being discharged within 8.6 hours (mean length of stay reduced by 7.6 hours) than did those in the control group, regardless of if they were discharged home or were admitted to the hospital. In addition, more patients in the CCTA group were discharged directly from the ED (47 percent versus 12 percent).
There were no undetected acute coronary events among the test group, nor did the researchers find any differences in major adverse events.
The researchers did acknowledge that the patients in the test group underwent more procedures than did those in the test groups, because of the level of clinical information available from the CT. The patients who underwent the CCTA also received more higher cumulative doses of radiation, but the authors noted that previous tests looking into lower dose CCTA are promising and could be used in the future. There were no significant differences between the two groups in terms of cost over the 28-day follow-up.
“It’s very important to strive for the greatest efficiency in diagnostic testing, and in this study, additional testing was primarily carried out in patients found to have coronary artery disease,” Hoffmann noted in a statement. “There also were fewer adverse clinical events in those receiving CCTA, although the study group was too small that CCTA reduced those risks.”
Hoffman added, “Showing at a variety of clinical sites that CCTA is at least as good as standard ED evaluation without increasing costs elevates the procedure from one appropriate only for specialized settings to one that can be applied in many centers.”