The advancement of imaging technology is invariably followed by a host of related challenges. Many of these challenges are questions raised by payors and answered by various medical associations in an effort to ensure a seamless transition from research and development to practical use. Coronary CT angiography (CCTA) has followed this well-worn path.
As one may expect, physicians were pleased with CCTA as another arrow in their treatment quivers, while payors were concerned about overutilization, specifically the use of CCTA as a screening tool for patients without symptoms or risk, or at low risk, for coronary-artery disease (CAD).
Appropriately, some medical organizations, including the American College of Cardiology, the ACR, and the Society of Cardiovascular Computed Tomography, have developed appropriateness criteria for CCTA that establish guidelines for proper use of this technology.
Selecting the Ideal Candidates
William Shea, MD, is the vice president and director of the 3D imaging lab and cardiac imaging for NightHawk Radiology, Couer d’Alene, Idaho. Shea has been involved in furthering the use of CCTA within appropriate guidelines. Shea recognizes that one of the important points in a higher-profile CCTA program is clearly identifying those patients who are candidates for the study.
“At this point in time, everyone in the medical community agrees that CCTA should be performed on patients who are either symptomatic with angina or chest pain that is unclear in its origin or are at high risk for CAD who will be undergoing surgical procedures,” Shea says. “For instance, a candidate for aortic-valve surgery or abdominal aortic aneurysm surgery who fits the profile of high risk of possible periarterial disease is a candidate for cardiac CT preoperatively.”
He continues, “Another large group includes those who have chest pain and an equivocal ECG or an equivocal stress test, or patients who have had atypical chest pain—in other words, symptomatic individuals or patients who have a high indication that they will be undergoing surgical procedures.”
CCTA, however, is not just for the more familiar cases. According to Shea, there are smaller niche groups that must be considered. “Other candidates are patients who have congenital heart disease, especially those who have undergone surgical procedures as children and are now approaching adulthood. Another niche group is those patients who have had coronary bypass surgery who are going to undergo reoperation. The last niche group would be those with suspected coronary anomalies,” he says.
CCTA as a Tool in the ED
Shea’s criteria clearly indicate that a large group of patients can benefit from this test, but is there a place for CCTA in the emergency department (ED) for patients who present with chest pain? Despite the cost-containment concerns of payors, will it ever be appropriate to screen a population for CAD using CCTA?
“Each year, there are 4 to 6 million ED visits for chest pain in the United States,” Shea says. “Somewhere between 5% and 10% of these patients don’t need a scan; those patients can go right to the cath lab or right into therapy, whatever that therapy is. They don’t need anything extra. We’re still left, though, with 80% to 90% of the patients presenting with chest pain. CT fits because what we do today is observe those patients, get serial ECGs and serial biomarkers, and wait at least 12 hours to see if there’s any significant change in the ECG or biomarkers. If they’re still within the normal range, the patient has a stress test; if that’s OK, then they discharge the patient.”
Shea continues, “We’re talking 18 to 24 hours for a great majority of these patients. This incurs a large expense for the hospital. In that patient population, if you could do a CT scan and the results were normal, then all these people could be discharged, and there could be a great savings to the system and a great benefit to the ED.”
In real time, Shea reports a remarkable difference in care. “A CT scan could be ordered by the ED physician, and even if the nurses and technologists have to be called in, we’re still talking only a couple of hours—and you gain so much information with a CT scan. When it is normal, the patient can be discharged with confidence,” he says.
Studying the Potential Benefits
As is often the case, costs and benefits enter the picture. For Shea, there is a clear difference not only in the quality of patient care, but in the quantity.