Coronary CTA proves cost-effective for low-risk acute chest pain patients

August 5, 2008

Massachusetts General Hospital researchers have added to the roll of preliminary evidence suggesting that 64-slice coronary CT angiography can serve as a useful adjunct for emergency department patients who present with acute chest pain.

Massachusetts General Hospital researchers have added to the roll of preliminary evidence suggesting that 64-slice coronary CT angiography can serve as a useful adjunct for emergency department patients who present with acute chest pain.

Guided by senior researcher Dr. G. Scott Gazelle, director of the MGH Institute for Technology Assessment, researchers assessed the cost-effectiveness of 64-slice CTA on patients at low risk for acute coronary syndrome.

Results were published in August issue of the American Journal of Roentgenology (2008;191:455-463).

Based on the findings, principal investigator Joseph A. Ladapo suggested that coronary CTA could lead to shorter ED waits, potential cost benefits, and more accurate diagnoses for patients with possible heart attack or unstable angina.

"Our study cautiously reinforces the potential for this technology to play a role in care," said Ladapo, a Harvard medical and public policy student, in an interview with Diagnostic Imaging.

The standard of care protocol calls for a patient with acute chest pain, negative initial biomarkers, a normal or nondiagnostic ECG, and no history of heart disease to undergo cardiac enzyme measurements.

If troponin is normal, the patient is discharged. If it's elevated, the patient has a stress test. A negative stress test leads to discharge, while a positive result indicates the cath lab. With CTA, the patient is imaged and discharged with no further testing if the arteries are normal. Those with mild atherosclerosis or significant stenosis undergo the standard of care protocol.

When CTA was used to triage 55-year-old men with acute chest pain, emergency room and hospital costs increased by $110 and total healthcare costs by $200. In 55-year-old women, ED and hospital costs decreased $410, and total healthcare costs decreased $380.

Though CTA raised overall costs in men, it was more likely to identify patients with cornonary artery disease. As a result, the health risks for these patients were lowered.

Compared with the standard of care, CTA-based triage extended life expectancy by 10 days in men and six days in women.

A 2007 randomized controlled trial (Goldstein et al) assessed the health outcomes of CTA. The current study is the first to focus on the economics as well, Ladapo said.

"The big risk with routine use of the exam is that it has historically exposed patients to pretty high doses of radiation, but physicians have developed protocols that reduce the radiation load significantly," he said. "My hunch is the exposure may be low enough now to routinely use the test to triage low to intermediate-risk patients who would otherwise end up receiving many more tests and spending much more time in the ED."

Researchers also accounted for several parameters, including the rate at which these patients returned to the emergency department, the test characteristics of CTA, and the cost of CTA.

"Nonetheless, 64-MDCT coronary angiography-based triage was generally still associated with improved health benefits in both sexes and cost savings in women when compared with the standard of care," they said.

For more information from the Diagnostic Imaging archives:

Coronary CT speed, resolution eduge out catheter angiography

CTA seeks niche triage role in unstable angina patients

Massive trial uses imaging to assess myocardial, stroke risk