The routine implementation of fractional flow reserve computed tomography (FFR-CT) in cardiac evaluations represents a paradigm shift in cardiovascular medicine and it is now being used more widely in community hospital settings. The quest for noninvasive, yet precise methods to evaluate coronary artery disease (CAD) has enabled FFR-CT to emerge as a groundbreaking tool because it combines anatomical and physiological data that provide valuable insights into the hemodynamic significance of plaques without the need for other tests or invasive angiography.
"What we do is any patient undergoing cardiac CT, if we think it's clinically appropriate, we send for FFR HeartFlow analysis. The idea behind that is, we are trying to find actionable intelligence about whether the patient needs to undergo any kind of invasive procedure, or if they can be easily managed medically. The idea to understand the severity of disease is based on combining the coronary CT data, which is anatomical information with the physiological information," explained Himanshu Gupta, MD, the director of cardiac imaging at the Heart and Vascular Clinic of Valley Health System in New Jersey. He shared his center's experience of route FFR-CT implementation in an interview with Cardiovascular Business at the Society of Cardiovascular CT (SCCT) 2023 meeting.
He said the integration of FFR-CT not only informs medical decisions, but also profoundly impacts patient care. Gupta said the images can be shown to patients to help explain their condition to empower them with a deeper comprehension of their condition. Sharing FFR-CT results and images with referring providers and patients also fosters a collaborative approach, ensuring everyone involved comprehends the nuances of the diagnosis and treatment strategy.
Selective patient stratification for FFR-CT
Valley Health System sends about 25-29% of patients undergoing coronary CT exams to also undergo a HeartFlow analysis. Rather than employing FFR-CT universally, Gupta's team judiciously selects patients falling within the intermediate category, typically encompassing those with coronary disease that appears to block from 40% to 90% of a vessel. This selective approach allows for a nuanced assessment of patients who stand to benefit most from FFR information. It is not merely about determining who needs a catheterization procedure, but understanding the physiology of the disease for appropriate decision-making.
"We make sure that the referring providers, who are many times interventionalists, understand what the disease is, the severity of disease and if the patient is going to benefit form an invasive procedure. Alternatively, we would do FFR and we will find disease, which in some cases may not necessarily need invasive angiogram, despite knowing that there is significant disease. This is partly because we know from medical literature that medical management is equally good if not better, especially in a lower risk population. So we are trying to stratify the patient population. Thirdly, I think it provides a peace of mind to the patients, because they understand their disease better," Gupta explained.
Streamlined FFR-CT workflow and timely results
Efficiency is paramount in cardiac care, and Gupta underscored the fast turnaround times for FFR-CT results. Reports are usually available within a day, he said, and it can be even quicker in emergency cases.
Redefined cath lab utilization with FFR-CT
Implementing FFR-CT as a gatekeeper has impacted cath lab utilization. While diagnostic catheterizations may see a reduction, the precision of FFR-CT aids interventionalists in planning procedures more efficiently. Guta said this can help reduce radiation exposure and optimize contrast use. Also, the 3D FFR-CT images can serve as a clear roadmap for interventions, contributing to enhanced patient safety and procedural efficacy.
"I believe that it is actually helping the interventionalist plan the procedure in which we are finding frequently, at least at our center, they would either take very limited pictures of the coronary arteries or use special kinds of catheters where they can directly go for intervention based on what the study results shows on the CT and the FFR. They also know upfront exactly what to fix and what not to fix," Gupta explained.
Encouraging radiologists and cardiologists to work together
One unique factor about Valley Health System is it uses a collaborative model for reading cardiac exams, combining the expertise of both radiologists and cardiologists. Gupta said their joint efforts, coupled with robust quality control processes, ensure the optimal integration of FFR-CT into clinical practice.
"We basically thrive on each other's strength. So we have a couple of very high-quality radiologists working with a couple of high-quality cardiologists and we are continually expanding our team," Gupta said.
Exploring new frontiers for FFR-CT
Beyond its conventional use in coronary artery stenosis, Gupta's team is exploring other novel applications of FFR-CT. This includes evaluating anomalous coronary artery physiology, studying gender-based differences in chest pain presentations and evaluating patients during transcatheter aortic valve replacement (TAVR) pre-procedural workups.
"We are able to do a CT angiogram at the same time of a TAVR evaluation for the coronary arteries. We combine it with FFR data to try to risk prognosticate what is the risk of any event during the TAVR procedure and determine if they need an invasive angiogram or any kind of interventional procedure. So it really helps optimize high-risk, frail patients in terms of more optimal outcome," Gupta said.
FFR-CT was included as a recommendation in the 2021 ACC/AHA chest pain guidelines to evaluate chest pain. It was the first clinical artificial intelligence (AI) algorithm to be included in any U.S. cardiology guidelines.
Dave Fornell has covered healthcare for more than 17 years, with a focus in cardiology and radiology. Fornell is a 5-time winner of a Jesse H. Neal Award, the most prestigious editorial honors in the field of specialized journalism. The wins included best technical content, best use of social media and best COVID-19 coverage. Fornell was also a three-time Neal finalist for best range of work by a single author. He produces more than 100 editorial videos each year, most of them interviews with key opinion leaders in medicine. He also writes technical articles, covers key trends, conducts video hospital site visits, and is very involved with social media. E-mail: dfornell@innovatehealthcare.com