Current evidence does not support coronary CT angiography (CCTA) as the test of choice for the noninvasive evaluation of chest pain, says a cardiologist from California in a December 26 editorial published in JAMA Cardiology.
The two large-scale trials investigating the potential of CCTA for chest pain -- the Scottish Computed Tomography of the Heart (SCOT-HEART) trial and the Prospective Multicenter Imaging Study for Evaluation of Chest Pain (PROMISE) -- have reported contrasting outcomes, noted Dr. Sanjay Kaul of Cedars-Sinai Medical Center in Los Angeles.
The SCOT-HEART trial researchers found that patients who underwent CCTA in addition to standard care had a statistically significant decrease in heart attack or death due to coronary artery disease, compared with those who received standard care alone. Yet PROMISE showed no statistically significant difference in patient outcomes between the two groups.
Since the release of these results, the National Institute for Health and Care Excellence in the U.K. has endorsed CCTA as the ideal first-line test. Advocates of CCTA in the U.S. are now calling for the American College of Cardiology and the American Heart Association to do the same.
However, the improved outcomes described in the SCOT-HEART trial should be questioned due to the "serious design limitations" of the study, Kaul wrote. It is unlikely that the increased rate of prescribing statins for patients who underwent CCTA in this trial was solely responsible for the overall risk reduction. Rather, it is possible that ascertainment bias and misclassification also contributed to the difference in outcomes, he noted.
"At best, CCTA can be deemed an alternative to standard care (including conventional stress testing) in these patients," Kaul wrote. "Any claim to the contrary is perhaps a case of enthusiasm exceeding the evidence."
