CCTA races past treadmill ECG for cost, performance

Coronary CT angiography (CCTA) saves time and money compared with exercise treadmill tests for assessing low- to intermediate-risk patients who present with chest pain. In a randomized trial, CCTA also performed better diagnostically.

Physicians in emergency departments often choose exercise treadmill electrocardiography (ECG) to stratify patients who they consider at intermediate risk of acute coronary syndrome (ACS). Exercise ECG has low cost and availability in its favor but it may have limited diagnostic value. CCTA offers another option.

Christian Hamilton-Craig, MBBS, PhD, of the Heart and Lung Institute at Prince Charles Hospital in Brisbane, Australia, and colleagues designed a randomized prospective trial to compare the two approaches with a focus on cost and diagnostic performance. They published the results online Oct. 22 in the International Journal of Cardiology.

CT-COMPARE (CT Coronary Angiography Compared to Exercise ECG) enrolled 562 low-intermediate patients who presented at the emergency department with acute chest pain in 2010 and 2011. They were randomized to the CCTA group (332 patients) or standard exercise ECG (240 patients) after receiving a negative serum troponin test result.

Overall, 4.2 percent of patients had ACS. In the standard care group, 26 percent of the exercise ECG studies were positive, for sensitivity and specificity of 83 percent and 91 percent, respectively. The CCTA group had 34 positive studies, for sensitivity and specificity of 100 percent and 94 percent, respectively, with stenosis greater than 50 percent; and 94 percent and 99 percent, respectively, with stenosis greater than 70 percent. CCTA was better in a receiver operator characteristic analysis, too.

Costs, calculated in 2012 Australian dollars and from a hospital perspective, included direct costs of inpatient and outpatient care for the index admission for 30 days after the admission. Admission rates were similar for both groups.

CCTA costs less, at $2,193 vs. $2,704 for standard care. Length of stay was shorter with CCTA (13.5 hours vs. 19.7 hours) while downstream cardiac testing was higher (13.4 percent vs. 7.5 percent). No patients in either group experienced major coronary events or died within 30 days. At 12 months, 12.7 percent of the CCTA patients and 10 percent of the standard care patients presented again with chest pain.

“Our data showed that CCTA-based evaluation is 35% faster and 20% less expensive than ExECG [exercise ECG] in patients at low-intermediate risk of acute coronary syndrome,” Hamilton-Craig et al wrote. “These results suggest that CCTA appears to be a useful initial testing strategy for patients at low to intermediate risk for ACS.”