CT Angiograms Outperform Ergometrics for Detecting Blocked Arteries

A new study shows that noninvasive computerized tomography (CT) scanning of cardiac vessels is far better at spotting coronary artery disease (CAD) than commonly prescribed exercise stress tests.

Researchers at Johns Hopkins University (JHU; Baltimore, MD, USA), St. Luke’s International Hospital (Tokyo, Japan), and other institutions conducted a study to compare the accuracy of single-photon emission computed tomography (CT)–acquired myocardial perfusion imaging (SPECT-MPI)and coronary CT angiography (CTA) for the diagnosis of CAD in 391 symptomatic patients who were prospectively enrolled in 16 hospitals in eight countries, after clinical referral for cardiac catheterization.

All the patients (ages 45–85) underwent noninvasive SPECT-MPI angiograms, followed by traditional CTA; within two months, each patient also underwent an exercise stress test. The results showed that sensitivity to identify CAD was greater for CTA than SPECT-MPI; the results were similar in patients without previous history of CAD. Noninvasive CTA accurately detected or ruled out artery blockages in 91% of the patients, compared with 69% for stress testing. The study was published online on October 14, 2015, in Circulation: Cardiovascular Imaging.

“Results of the new study should help settle lingering doubts among physicians and the nearly 15 million Americans who seek medical attention each year for symptoms that signal a clogged artery, including chest pain, shortness of breath, and extreme fatigue,” said lead author Armin Zadeh, MD, PhD, MPH, associate professor of medicine at the JHU School of Medicine. “We hope our findings will settle any residual uncertainty about the effectiveness of these two common noninvasive heart tests.”

Current guidelines from the American Heart Association (AHA; Dallas, TX, USA) and the American College Cardiology (ACC) call for a stress tests in all patients who show signs of CAD to confirm the diagnosis and define the severity of the blockage. CT angiograms are generally reserved only for patients with borderline stress test results. However, according to the researchers, the much higher accuracy of CTA may be a better first-line test in people with symptoms suggestive of a blocked artery.

Related Links:
Johns Hopkins University
St. Luke’s International Hospital
American Heart Association