WHAT: Patients with symptoms suggesting undiagnosed coronary artery disease had similar long-term health outcomes regardless of whether doctors initially used a computed tomographic angiography (CTA) or a stress test to assess the health of their cardiac arteries, according to research supported by the National Heart, Lung, and Blood Institute (NHLBI) at National Institutes of Health. The finding comes from the first randomized study that compared the two types of diagnostic testing and should help inform doctors’ choice as to which test to use.
The study, published in the New England Journal of Medicine, will be presented Saturday at the American College of Cardiology 2015 Annual Scientific Session in San Diego. Roughly 10,000 patients participated in the study, known as the PROspective Multicenter Imaging Study for Evaluation of chest pain (PROMISE). The subjects were assigned randomly to receive either a CTA or a stress test. For a CTA, which involves patients receiving an intravenous injection of a contrast agent (a dye), a scanner takes a series of X-rays to generate a three-dimensional image of the heart and the arteries that supply it. Doctors then review the image to determine the degree to which the arteries are clogged with plaque and whether follow-up testing and treatments are needed.
Unlike CTA, a stress test involves one of several methods; in the case of this study, patients received either an exercise electrocardiogram, a stress echocardiography, or a nuclear stress test. Approximately 67 percent of those who received a stress test received a nuclear stress test, which involves intravenous injection of a radioactive substance and generates images that doctors can then interpret to assess blood flow to the heart, but without the detailed anatomical imaging of CTA.
Although research has suggested that CTA is more accurate than stress testing at diagnosing coronary artery disease, researchers have called for randomized studies on whether use of CTA results in better health outcomes than stress testing. The PROMISE study found that when comparing those individuals who had a CTA and those who had a stress test, there was no significant difference in the rate of cardiovascular events, such as heart attacks, over an average period of 25 months after the testing.
WHO: Lawton Cooper, M.D., M.P.H., Medical Officer, Clinical Applications and Prevention Branch, Prevention and Population Sciences Program, Division of Cardiovascular Sciences, is available to comment on the findings and implications of this research.
CONTACT: For more information or to schedule an interview, please contact the NHLBI Communications Office at 301-496-4236 or email@example.com(link sends e-mail).