The honeymoon has ended for coronary CT angiography (CCTA) and the seven-year itch has commenced for some radiologists and cardiologists. They do not advocate replacing the technique though. Rather, they are asking if the requirements in training guidelines need a makeover to reduce variability and better maximize CCTA’s potential to improve patients’ clinical care and outcomes.
The multicenter ACCURACY trial helped to ease concerns that the accuracy of 16-slice CCTA occurred only in academic settings by enrolling 83 percent of its patients from non-academic sites (J Am Coll Cardiol 2008;52:1724-1732). The study showed that CCTA was both a highly accurate diagnostic tool for detecting stenosis at the 50 percent and 70 percent thresholds in patients with chest pains and no known coronary artery disease, and it effectively ruled out obstructive coronary artery stenosis. The authors noted that “with adequate training, any imaging center can perform CCTA procedures with high quality” and that accuracy was achieved with a variety of readers.
However, centers and operators involved in trials tend to be a special breed, notes John R. Lesser, MD, director of cardiovascular CT and MRI at the Minneapolis Heart Institute and president of the Society of Cardiovascular Computed Tomography (SCCT). Physicians often are recruited because they are meticulous; centers often work in high volumes; and the trials themselves are designed to control against the vagaries of real-world settings.
“Physicians need to be trained well to read [a CT exam] properly,” Lesser says. Good training is not just teaching radiologists and cardiologists how to interpret a scan but also how to understand its clinical context and then effectively communicate that information to the referring physician or emergency room personnel. “Oftentimes it is not completely straightforward.”
And then there is the scenario of a good technology in less competent hands. If trained radiologists and cardiologists infrequently use CCTA, then they and their patients may not reap its full benefits. This may be especially exacerbated in cases where physicians met minimal standards during their training.
In late 2012, Lesser floated a question to his peers in a letter in the Journal of Cardiovascular Computed Tomography. Was it time to revisit the CCTA training standards developed in the mid-2000s at a period when the technology was still in its infancy and the medical community and public both were infatuated with its possibilities? Anecdotally, radiologists and cardiologists at the vanguard of CCTA were now detecting variability in the quality of both the scans and their interpretation in clinical practice.
Lesser tossed out the gauntlet: Perhaps current training standards were not vigorous enough, resulting in variable competencies. “The technique has great potential, but if you don’t do it properly, it will not live up to anywhere near that potential,” he says. “It will look like it is not any good.”
U. Joseph Schoepf, MD, director of cardiovascular imaging at the Medical University of South Carolina in Charleston and a co-author of the American College of Radiology’s (ACR) practice guidelines, shares this concern. If too many practitioners apply CCTA poorly, it will diminish the gains that would manifest as improved outcomes. “If there is no improvement in patient outcomes with the addition of cardiac CT to our diagnostic and therapeutic algorithms, people will wonder if it is worthwhile to approve any kind of reimbursement for this particular test,” he says.
CCTA is a poster child for progress in medical imaging, according to Schoepf. As a noninvasive alternative to conventional angiography, it appealed to providers and patients both for assessing coronary arteries and evaluating cardiac function. The National Heart and Blood Institute, for instance, characterizes it as “a painless test that uses an x-ray machine to take clear, detailed pictures of the heart” to patients. The birth of 64-slice cardiac CT, with its improved performance and reduced effective dose, attracted even more attention and proponents.
But the credentialing criteria for interpreting CCTA set the bar too low, according to Schoepf. “It is too simple to become ‘certified’ to interpret cardiac CT,” he argues. “Yet there are people who feel entitled to interpret such studies.”
The American College of Cardiology Foundation (ACCF), the American Heart Association (AHA)