Cardiac coronary computed tomography angiography (CCTA) exam showing different views of the myocardium and the coronary arteries. This was scanned on a Canon Aquilion Prime CT scanner.
October 6, 2021 – A new study published in Radiology: Cardiothoracic Imaging on cardiac imaging trends over a decade reports that the rate of coronary computed tomography angiography (CCTA) exams by radiologists in hospital outpatient departments increased markedly from 2010 to 2019. This suggests a bright future for the technology. The study also found that reimbursement cuts and advances in technology have helped shift much of the imaging done by cardiologists from the office to hospital outpatient department.
Since 2010, the combined rates of transthoracic echocardiography (TTE), stress echo (SE) and transesophageal echocardiography (TEE) have decreased by 3% (23,911 to 23,188), and nuclear myocardial perfusion imaging (MPI) decreased by 36% (7,817 to 4,996). However, cardiac positron emission computed tomography (PET, or cPET) has risen by 146% (202 to 496), CCTA has risen by 84% (169 to 312), and cardiac magnetic resonance imaging (MRI) has risen by 125% (53 to 119).
Researchers pulled this data from 2010–2019 Physician/Supplier Procedure Summary (PSPS) files obtained from the Centers for Medicare and Medicaid Services (CMS) website. The PSPS files contain yearly summaries of the Medicare Part B carrier fee-for-service claims. Healthcare Common Procedure Coding System codes were used to identify imaging studies related to cardiac imaging.
DRA Changed Self-referral Patterns in Cardiology and Opened Door for CCTA
Imaging has long played a critical role in the diagnosis of cardiovascular disease, the leading killer in the world. Both radiologists and cardiologists perform noninvasive cardiac imaging, but over time two of the most common cardiac imaging methods, echocardiography and nuclear myocardial perfusion imaging, became almost exclusively the domain of cardiologists.
The dominance was partly due to a cardiologist’s unique position as a provider who both orders and performs diagnostic cardiac imaging. However, reimbursement cuts from the Deficit Reduction Act (DRA) of 2005 had a major impact on in-office cardiac imaging. The DRA aimed to reduce providers self-referring tests and imaging exams by cutting reimbursements.
“In the early 2000s, cardiology office imaging utilization was skyrocketing,” said study lead author Russell A. Reeves, M.D., from the Center for Research on Utilization of Imaging Service (CRUISE) and diagnostic radiology resident in the Department of Radiology at Thomas Jefferson University in Philadelphia. “The changes brought by DRA reversed that trend to where it no longer was lucrative or even feasible for a lot of cardiologists to do imaging in their offices.”
Cardiac CT Use Rose as In-office Cardiac Imaging Dropped
During that same period, technological advances made competing imaging exams traditionally performed by radiologists, such as CCTA, appealing options. This led to an increase in cardiac CT exams at hospitals.
Reeves and colleagues studied data from the 2010-2019 Physician Supplier Procedure Summary files to assess the impact of these developments on utilization of different types of cardiac imaging. They found that cardiologist in-office myocardial perfusion imaging rates per 100,000 Medicare beneficiaries dropped by 52%, from 4,426 to 2,119, over the 10-year period. Correspondingly, imaging rates per 100,000 beneficiaries at hospital outpatient departments rose 71%, from 935 to 1,598.
“Cardiologists are not performing nearly as many myocardial perfusion scans as they were, and most are now being done at hospital outpatient imaging departments,” Reeves explained.
Over the same period, the rates of CCTA by radiologists in hospital outpatient departments increased by 355%.
Overall rates, however, remained low compared to nuclear myocardial perfusion imaging, despite the fact that some studies have shown CCTA to be more accurate. The technology’s uptake may also be limited, Reeves said, by its complexity and the cost of equipment, in addition to the fact that it requires a dedicated CT technologist.
CCTA is Giving Rise to Closer Collaboration Between Radiologists and Cardiologists
But the increasing rate of CCTAs performed by radiologists represents a growing opportunity for collaboration in cardiac imaging. Recently at Thomas Jefferson, cardiologists have shown interest in reading CCTA exams side-by-side with radiologists to enhance patient care.
This trend has been confirmed in recent years at the annual meetings of the Society of Cardiovascular Computed Tomography (SCCT). Its attendees are split about 50/50 between radiologists and cardiologists working on the same goal of improving care with the use of CCTA.
“Coronary CTA is a useful screening tool for coronary artery disease that obviates the need for invasive coronary angiography,” Reeves said. “I think the future is looking favorably on it.”
PET Perfusion Imaging Increases 193%
Rates of PET nuclear imaging in cardiologist offices increased by 193% over the 10-year period, but cardiac PET performed by radiologists in offices and hospital outpatient departments saw little change. The increase in the in-office cPET is likely due to a combination of technological advances, interpretation familiarity and financial incentives, according to Reeves.
PET enabled clearer imaging of defects in the heart muscle, and the exam is much faster than the old standard single photon emission computed tomography (SPECT) nuclear imaging technology. PET exams take about 75 seconds to perform, as opposed to more than a hour with SPECT technology. PET also uses a small on-demand isotope generator in the imaging room, rather than requiring access to a cyclotron, as is the case with SPECT.
Echocardiography Sees In-office Exams Drop
From 2010 to 2019, the rate of TTE performed by cardiologists decreased in the office (8,299 to 6,365 per 100,000 beneficiaries), a drop of about 23%. This corresponds to the growth in hospital outpatient department (HOPD) imaging (2,869 to 5,944), which increased by 107%.
Cardiologist TTE rates fell slightly in the inpatient setting (7,249 to 6,863) by 5%. In the emergency department (ED), TTE rates grew for both cardiologists (94 to 128; 36%) and other nonradiologist providers (34 to 131; 284%). Of the TTE performed in 2019, cardiologists performed 89% (6,365 of 7,163). However, by 2019, cardiologists performed only 49% (128 of 261) of TTE in the ED, with 50% (131 of 261) being performed by other nonradiologist providers. Radiologists performed less than 1% of all TTE in all settings, according to the study.
Stress echocardiography performed by cardiologists decreased in the office (723 to 406), a decrease of 44%. From 2010 to 2014, there was a small increase in SE performed by cardiologists in the HOPD (365 to 454, an increase of 24%), but by 2019, the rates fell to nearly 2010 levels. Radiologists performed less than 1% of SE in all four imaging locations.
TEE rates remained relatively low in comparison with those of TTE and SE, but cardiologist rates doubled in the HOPD during this time (201 to 402), increasing 100%.
Cardiac MRI Sees Growth
Cardiac MRI grew in the HOPD for both cardiologists (15 to 48 per 100,000 beneficiaries; 209%) and radiologists (12 to 37; 207%). However, the rate of cMRI performed in cardiologist offices fell by half (6 to 3), while cMRI in radiology offices nearly doubled (5 to 7). However, overall office-based cardiac MRI rates remained low compared with the HOPD (10 vs. 85 in 2019).
In 2019, cardiologists performed 55% of cardiac MRI in the HOPD, with radiologists performing 42%.
Tracking Cardiac Imaging Trends Into the Future
Reeves plans to continue following the trends to study the impact of regulatory, economic and other factors on imaging utilization.
“Ultimately, we as radiologists need to be self-regulators and also do the research to support change, to help the speciality and help medical practices overall in the future,” he said.
The research is also a way of honoring the legacy of Reeves’ mentor, David Levin, M.D., professor and chairman emeritus at Thomas Jefferson University. Levin, a former fighter pilot who became a leading researcher in imaging utilization trends and founded CRUISE, died in 2020.
For more information about CCTA: RadiologyInfo.org
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1. Russel Reeves, Ethan J. Halpern and Vijay M. Rao. Cardiac Imaging Trends from 2010 to 2019 in the Medicare Population. Radiology: Cardiothoracic Imaging. Published online Sept. 30, 2021. https://doi.org/10.1148/ryct.2021210156.