Is CCTA the right test for patients with stable chest pain?

Coronary CT angiography (CCTA) may not be the best noninvasive test of choice for patients who exhibit stable chest pain, according to a commentary published in JAMA Cardiology. Sanjay Kaul, MD, of the Cedars-Sinai Medical Center in Los Angeles, wrote the commentary. 

Among the dozen or so trials published in the last decade that compare CCTA with functional stress testing, only the Scottish Computed Tomography of the Heart (SCOT-HEART) and the Prospective Multicenter Imaging Study for Evaluation of Chest Pain (PROMISE) trials were large enough to evaluate clinical outcomes, Kaul explained. And the trials produced conflicting outcomes.

At present, the National Institute for Health and Care Excellence in the United Kingdom has recommended CCTA as “the test of first choice” for patients who do not have established coronary artery disease (CAD) and exhibit chest pain. Supporters of CCTA have also advocated for the American College of Cardiology/American Heart Association guidelines to be updated so that they are similar to those in the U.K.

The SCOT-HEART trial showed that at five years, CCTA in addition to standard care in patients with stable chest pain lowered death rates from CAD or nonfatal myocardial infarction compared to patients who only received standard care alone. Conversely, at two years, “no difference in clinical outcomes was observed" in the PROMISE trial. 

“Arguably there is only one trial with favorable, albeit not robust, outcome data; however, the quality and quantity of evidence is not sufficient to justify the imprimatur of Class I recommendation of the ACC/AHA guidelines,” Kaul wrote.

A five-year follow-up of the SCOT-HEART trial showed similar results and the principal investigator called for CCTA to be the “noninvasive test of choice.” Is this justified?

“It is important to reconcile why the findings from SCOT-HEART with its serious design limitations (a trial of functional plus anatomic testing versus functional testing alone; 10 percent use of imaging tests; and no formal event adjudication), differ from PROMISE with its credible design (a trial of functional versus anatomic testing strategy; 68 percent use of imaging tests and formal event adjudication),” Kaul wrote.

Kaul also noted that evidence does not support CCTA being the noninvasive test of choice when evaluating patient who have stable chest pain. 

“At best, CCTA can be deemed an alternative to standard care (including conventional stress testing) in these patients,” Kaul concluded. “Any claim to the contrary is perhaps a case of enthusiasm exceeding the evidence.”