AI-based coronary IT helps comprehensively treat patients with just one test
At the Prairie Heart Institute in Springfield, Illinois, cardiovascular stress testing, predominantly myocardial perfusion imaging, has been the primary screening tool for patients presenting with symptoms suspicious for coronary artery disease.
If a patient were to have a positive result, cardiac catheterization was almost always the gold standard next step in the work-up. Even patients with suggestive chest pain but with equivocal myocardial perfusion imaging were bound for the cath lab.
Unfortunately, there is a significant number of patients who, despite clinical symptoms that are supportive of coronary artery disease and evidence of ischemia based on their MPI stress test, have angiographically normal coronary arteries.
“We are constantly tracking the number of patients who have normal cardiac caths at Prairie Heart,” said Kristin Doster, executive vice president of cardiovascular services, HSHS central Illinois division, Prairie Heart Institute at HSHS St. John’s Hospital.
"For the right patient, this one-stop evaluation has helped to reduce unnecessary testing, reduced radiation exposure and helped to provide a more standardized pathway to appropriate revascularization."
Kristin Doster, Prairie Heart Institute
“Although our numbers are lower than national averages, we still see anywhere from 20-30% of patients who receive a cardiac cath have normal coronary arteries or non-obstructive coronary disease. As a group, we felt we could do better than one in three patients, so we began to explore other opportunities.”
Although the team was well versed with CT angiography for structural heart evaluations and electrophysiology procedural planning, it was doing a relatively low volume for evaluation of coronary artery disease.
“It is useful for non-invasive imaging of the coronary arteries and gives good information about stenosis, but it still isn’t ideal as a standalone modality,” Doster said. “It provides high sensitivity results but not the specificity we needed to impact what we were trying to accomplish. That’s when we made the decision to introduce the HeartFlow FFRct technology to our toolkit.”
HeartFlow is a digital health company focusing on applying artificial intelligence to diagnosing and treating heart disease.
“The HeartFlow FFRct technology provides both an anatomical and functional assessment of the coronary arteries,” she continued. “FFRct provides computational fluid dynamics modeling that is applied to a CT coronary angiography dataset and provides lesion-specific functional information of a coronary stenosis.”
This offers greater specificity and positive predictive value for detecting hemodynamically significant coronary artery disease compared with anatomic imaging alone, she said.
MEETING THE CHALLENGE
“Having this accurate assessment of coronary flow physiology through non-invasive means has helped us to reduce unnecessary catheterizations,” Doster explained. “Additionally, with our current CT technology, coronary CT with FFRct can be performed with a much lower radiation dose than a typical nuclear stress test.”
When the team was considering the addition of the FFRct technology at the organization, the team knew it was important to ensure that it had stakeholder buy-in from the beginning.
“We invited administrative leadership, several IT leaders, and cardiologists and radiologists alongside their service-line leads to the table for our early discussions,” Doster recalled. “At Prairie Heart, cardiology and radiology have worked collaboratively for some time, having built a strong partnership with the introduction of our structural heart program in 2011.”
Building on the existing synergies allowed the team to perfect the workflows across the continuum. Cardiology is responsible for ordering the coronary CTA, instructing the patient procedural expectations and ensuring that the patient receives the pre-procedural beta blocker for heart rate management during the CT.
“The radiology team worked extensively with the team from HeartFlow to verify that all of the imaging protocols were in place,” Doster explained. “They met with both the radiologists and the CT technicians. We participated in a multi-study quality validation prior to sending our first study for FFRct assessment.”
Since the FFRct interpretations are only as good as the baseline coronary CTA, the entire team spent about four months in initial strategic planning as well as operational planning to ensure it could build a high-quality program with reproducible results, she added.
Once Prairie Heart Institute was live with the FFRct technology, the provider organization underwent an internal validation of its first 100 patients.
“We also developed our own internal algorithm around patient selection,” Doster said. “We offer coronary CTA to patients at moderate risk of heart disease. Organizationally, this was defined as patients who present with stable angina but have significant risk factors for coronary artery disease.”
If patients have a normal coronary CTA, the team can stop there as there are no lesions to analyze through FFRct. The best opportunity comes when patients have lesions that indicate a 50% to 69% stenosis, Doster said.
“Before FFRct technology, the treatment path was not always certain,” she said. “Now we can just send the study on for FFRct analysis, and if the value is less than 0.8, we consider this to be a significant blockage. The results from a coronary CTA with FFRct allow us to facilitate a more customized approach to the care and management of our patients.”
With the development of a robust coronary CTA program and the addition of FFR technology, the institute has seen a 15% reduction in myocardial perfusion imaging volume. It also has seen an approximate 10% reduction in ad-hoc percutaneous coronary interventions, which has resulted in improved operational efficiencies within the cath lab.
“We have experienced significant growth in our coronary CTA volumes with an annualized increase of about 1,500 scans,” Doster explained. “Our FFRct volume averages around 25 to 30 cases per month.”
ADVICE FOR OTHERS
“Operationalizing CTA-FFRct within the Prairie Heart Institute has helped to support our goals of offering patients a comprehensive evaluation of coronary anatomy and functional evaluation of stenosis in a single test,” Doster said. “For the right patient, this one-stop evaluation has helped to reduce unnecessary testing, reduced radiation exposure and helped to provide a more standardized pathway to appropriate revascularization.”
The key to the successful implementation was having stakeholder buy-in at the beginning, she advised. Ensuring all of the team members had an equity seat at the table allowed the team to build a comprehensive CTA-FFRct program, she concluded.