Coronary CTA really works, but why isn't its use soaring?

November 4, 2010

Coronary CT angiography came of age in the last decade. This occurred because CT technology moved into the 16- and 64- detector era.

Coronary CT angiography came of age in the last decade. This occurred because CT technology moved into the 16- and 64- detector era. These technical advances, together with refinements in technique, made the procedure possible on a routine basis for the vast majority of patients at sites that had the multislice technology and properly trained technologists and physicians.

Enthusiasm for a noninvasive method of examining the coronary arteries was so great that it spawned a cottage industry: coronary CT angiography (CCTA) education, with courses popping up out of nowhere. We were one of the first. In 2006-2007, more than 1000 radiologists were trained in our private office alone. Thousands of others were taught at remote, destination-style courses we hosted. This produced gross revenue in the millions of dollars. Multiply this by the numerous sites at major academic institutions, for both cardiologists and radiologists, and you get a feel for how quickly CCTA came to be viewed as a major breakthrough in medical imaging.

The medical literature has been clear that CCTA stacks up very favorably against stress tests as an initial exam and against catheter coronary angiography for examining the coronary arteries for obstructive coronary artery disease. The cost savings of using a protocol that incorporates early use of CCTA in emergency and nonemergency settings for low- to intermediate-risk coronary artery disease patients has been well documented. The Rule Out Myocardial Infarction/Ischemia Using Computer Assisted Tomography (ROMICAT-II) and CT for Systematic Triage of Acute Chest Pain Patients to Treatment (CT-STAT) trial results will soon document the advantages of CCTA in the emergency department. The Coronary CT Angiography Evaluation for Clinical Outcomes (CONFIRM) registry, encompassing more than 10,000 patients, will reveal that CCTA has prognostic value in patients without known coronary artery disease.

Paradoxically, despite all these achievements, CCTA has had a very difficult time gaining traction in routine clinical care protocols and in the reimbursement world. Utilization of CCTA is actually down from 2005 levels. The number of physicians seeking training in the procedure has diminished greatly, and it is harder than ever to obtain reimbursement for it. A confluence of unfortunate events, some medical and some economic, are the cause.


The furor over radiation exposure from medical imaging tests began in the U.S. at the 2007 RSNA meeting. A study documenting radiation exposure from CT scans used in the trauma setting1 made its way into the national spotlight and there is no going back. This led to increased awareness of radiation dose, technical improvements to reduce dose, and increased awareness of self-referral and inappropriate utilization of CT. This, in turn, has led to a decline in CT utilization of anywhere from 10% to 20% in the outpatient imaging centers with which I have close contact.

Unfortunately, CCTA has suffered more from the radiation dose scare than other CT exams for reasons that are less than true. When CCTA burst on the scene, it was done using retrospective gating. Effective doses using retrospectively gated CCTA were in the range of 10 to 30 mSv, depending mostly on the patient’s body mass index. This dose level exceeded that commonly quoted for catheter coronary angiography, which ranged from 3 to 10 mSv for noncongenital work.

In addition to this, radiation dose became a political football at local, national, and international levels and was used to scare people away from CCTA by those who wished to maintain the treatment status quo for coronary artery disease: nuclear stress tests leading to catheter coronary angiography. What was conveniently hidden by this crowd was the radiation dose of SPECT nuclear stress tests. Using a sestamibi-sestamibi protocol,2 radiation doses range from 12 to 25 mSv. When thallium is incorporated into the protocol, as either a single or dual isotope, radiation doses can easily exceed 22 to 30 mSv per test. Prospectively gated CCTA with adaptive iterative reconstruction is now performed with a dose range of 0.4 to 10 mSv, which is well below the SPECT stress test range.

So where are the radiation dose police regarding the use of SPECT stress exams, utilization of which (according to Medicare data) has seen exponential growth since the mid-1990s? Why wasn’t CCTA trumpeted as a low-dose, low-cost first-line alternative to SPECT stress tests? Some will argue that the answer is the need for functional imaging and myocardial perfusion. But my personal experience is that if a patient has a CCTA showing no stenosis greater than 50%, that patient will eventually get an echocardiogram to document wall motion and valve function and, if it’s negative, will have no cardiac events at six months follow-up. It is my strong opinion that the radiation dose of CCTA was used to delay its clinical adoption and to preserve the income stream of those who provide SPECT stress tests.


The explosion of medical imaging utilization as a leading cause of increasing healthcare costs has been well documented. The causes of this are many and include the increased ability of medical imaging to contribute to the diagnosis of patients’ problems, the speed at which it can achieve this, the increased availability of high-end imaging equipment, medicolegal concerns about missed diagnoses, and self-referral.

These factors have put medical imaging smack in the center of the insurance industry’s radar screen. Initial “soft” attempts to decrease utilization were tried in the form of patient and referring physician education, but the approach was quickly abandoned. Insurance companies began contracting with radiology business management companies (RBMs) in an effort to stem the tide of high-end medical imaging. RBMs, in turn, created “hard stops” and roadblocks in the imaging referral process by a variety of means. In their favor, RBMs heavily research their positions for what can be approved or disapproved in medical imaging. They defend their positions aggressively and have been able to reduce inappropriate utilization. However, the buck never stops there.

I have presented at meetings of RBM medical directors and spoken with executives of RBMs numerous times about how the use of CCTA, with its 100% negative predictive value, could virtually eliminate the elective negative diagnostic coronary catheterization. I have documented that this is the number one reason for referrals to me from cardiologists. I have produced literature on the safety and cost-effectiveness of this approach. I have explained how this would break up any abuse of self-referral resulting from the echo cardiogram to stress test to cath referral pattern so common with both equivocal and negative stress tests.

Despite all this I have found no clear acceptance of CCTA. Why? Because there are often underlying competing economic motives. RBMs may be reimbursed by how well they decrease utilization. RBMs have also taken on risk-sharing contracts with insurance companies whereby they are reimbursed a flat fee for medical imaging expenses and are allowed to keep whatever they can by further squeezing down the costs of imaging.

Recently, I have come across an additional disincentive, this one put on the backs of patients in need of CT, MRI, or PET/CT scans. Copays have been shifting from employers to employees. Traditionally, the copay is based on the encounter and is the same whether it is for an x-ray or a CT. It has never depended on the type of exam the patient is receiving. A local self-funded PPO, however, has announced plans to increase its copay based on the type of imaging exam performed. The patient copay may be $10 for a mammogram but could be $300-out of pocket-for a CT or MRI. This undoubtedly discourages patients from having unnecessary exams, but may also cause them to shun any exam to avoid a severe financial burden. I regard this as unethical and I hope it will be met with rigorous opposition.

Long-term thinking takes a back seat to financial performance in the current economic climate. My efforts to convince RBM and insurance executives of the great value CCTA has to offer their patients and their bottom line are greeted with courteous yawns and thank-yous, and the game remains unchanged.


Opinions on the appropriate utilization of CCTA coming out of the cardiology community could hardly be classified as unified. Cardiologists, appropriately, are seen as the most qualified physicians to speak on the topic of coronary artery disease and how it is imaged.

Their views about CCTA are strong and very divergent. This is best illustrated by an interaction that occurred after the appearance of a paper in the New England Journal of Medicine. Titled “Pay now, benefits may follow-the case of cardiac computed tomographic angiography”3 by lead author Dr. Rita Redberg, this paper attacked the view that CCTA has immediate benefit to patients. In defense of Dr. Redberg, she is an outspoken opponent of inappropriate utilization of many tests, not just CCTA.

Nonetheless, many cardiologists and radiologists disagreed with her opinions. Dr. Tony DeFrance, a highly respected cardiologist, responded, “I am a cardiologist, but there is a heavy vested interest against [CCTA] succeeding because of people’s revenue streams. It is no secret that cardiologists make the majority of their money from nuclear scans-or a large percentage of it-and invasive catheter angiography. So some people don’t want the status quo to change.”4 It is this internal conflict, which mixes both medical and economic considerations, that is seized upon by the insurance/RBM industry as a reason for not approving any utilization of CCTA. They have a “call us when you can agree” attitude.

There is a good side of RBMs though. In New Jersey, a nationally prominent RBM has made it extremely difficult for nonradiologists to use CT, MRI, and PET/CT scanners in their offices through the in-office ancillary service loophole in the Stark II law. The negative ramifications of self-referral have been known for decades and recently documented in a series of articles in the Journal of the American College of Radiology by Drs. Levin and Rao.

The insurance industry is beginning to act on self-referral. This will eliminate many unnecessary exams and their costs from the healthcare system; they simply will not be done at all. Although these exams will not shift to radiology, there will be a benefit for radiology because the specialty’s most uncontrollable source of competition, self-referral, will be diminished.

What will be the affect on CCTA? As long as it competes with a stress test as a first-line test, probably not much, but the use of stress tests has significantly decreased. Many RBMs are taking the decision of which test to use out of the hands of cardiologists. Over the long term, I suspect that the declining reimbursement for stress tests will make it unattractive to do them and therefore open the door for CCTA. And if RBMs prohibit nonradiologists from owning CT scanners, CCTA utilization could take off.


Radiologists were very quick to recognize how important CCTA could become to patients and to their own practices. They were eager to become trained in the procedure; thousands now meet the American College of Radiology and Level II American College of Cardiology criteria for performing CCTA.

Radiologists have been leaders in the development of cardiac imaging for decades. Echocardiography, SPECT nuclear stress tests, and catheter angiography have all had their beginnings in radiology only to be lost to cardiology in subsequent turf wars. CCTA was seen by radiologists as an opportunity to get back into cardiac imaging and they jumped on this opportunity with fervor.

Add in the Medicare/insurance industry/RBM alignment against selfreferral and you have a major advantage for radiology in grabbing CCTA market share. There will always be turf wars within hospitals, which cardiologists traditionally win. But there may be an advantage held by radiologists in the ability to provide 24/7/365 coverage. Radiologists are responsible, either by themselves or through the use of a teleradiology service, for this level of coverage. Adding another exam to the mix is logical and easier for them than it is for cardiologists. But there is a caveat: teleradiology has softened the underbelly of radiology. Nobody wants more after-hours work. Groups fear the effect increasing after-hours work will have on their ability to recruit new radiologists. There is a sense of entitlement that exists among some, though not all, radiology recruits that they will never work the graveyard shift. Certainly many established radiologists do not want to expand after-hours work and deal with the negative effects on their lifestyles, even if that attitude undermines a major advantage they hold in getting into CCTA.

But they say that “fat cats don’t hunt.” The cure for that condition is decreasing reimbursement, which, unfortunately is occurring now and will continue for the foreseeable future.

So what is wrong with CCTA?

Essentially nothing, if you look at the exam itself and how it is relevant to patient care. It is the politics and economics of healthcare that have gotten in the way of a truly remarkable test that could save the lives of many (Figures 1 and 2). I don’t see that situation improving anytime soon, but stay tuned…