PROMISE Trial: CTA or Stress Test?

The PROMISE Trial (PROspective Multicenter Imaging Study for Evaluation of chest pain) showed no improvement in clinical outcomes when using Anatomic CT over functional testing for screening for coronary artery disease. However, it did find an overall increase in radiation exposure.

Data from the trial was presented Saturday, March 14 at the 2015 American College of Cardiology annual meeting in San Diego, CA and simultaneously printed online in the New England Journal of Medicine.

PROMISE enrolled a symptomatic, intermediate risk population of 10,003 subjects for whom testing is currently recommended — with a low event rate in this contemporary population. The minimal follow-up was 12 months, with a median of 25.2 months.

Pamela Douglas, MD, Duke University Medical Center, Durham, NC, and colleagues reported the composite risk of death, myocardial infarction (MI), hospitalization for unstable angina, or major procedural complications during a median 25 months of follow-up was 3.3% when administered initial CT angiography (CTA) compared with the 3.0% resulting from exercise or stress testing.

The team found that an initial CTA strategy was associated with a lower rate of invasive catheterization without obstructive CAD.

Radiation exposure was higher in CTA arm overall but lower in those patients for whom a nuclear test was specified at randomization as the initial functional test did not receive radiation.

According to Christopher Kramer, MD, of the University of Virginia Health System in Charlottesville, VA, “Certainly any concern that radiation doses would be higher with CTA than with functional testing was alleviated by the trial results.”

Several medical professionals supporting CTA believed it allow precision care — only the patients who need revascularization would actually go to the catheter lab and the rest would avoid it – invasive testing, unnecessary revascularization, and false positives would be reduced.

Debunking the merits of CTA, other healthcare professionals have commented CTA would increase and many findings would be ambiguous, which would lead to more radiation exposure, since doctors would conduct more tests.

Researchers also conducted a comparative economic analysis of PROMISE to investigate the initial test technical costs, hospital-based facility costs, and physicians’ professional fees for testing and hospital services.

Their data indicated that functional testing was approximately $279 less expensive in the first 90 days and by nearly $694 by 3 years.

“Noninvasive ability to directly visualize the coronary arteries of patients with chest pain has long been on cardiology’s wish list,” said Daniel Mark, MD, MPH.

According to Athena Poppas, MD, the added radiation and unnecessary use of heart catheters and stents — which did nothing to improve the outcome – quickly put to bed the idea of completely replacing functional testing.

Mark said, “Coronary CTA may not be the “holy grail” of diagnostic testing once hoped for, but its more liberal use following PROMISE standards will improve some aspects of care without causing a major new economic burden on the health care system.”

Experts concluded that functional testing, with stress echo or stress nuclear, is still the best first step in patients who you are wondering if they have coronary disease.