The Impending Paradigm Shift in FFR and What the Future Holds

In recent years, physicians have increasingly recognized the measurement of flow physiology as a gold standard to determine whether stenting—as opposed to medical management or bypass surgery—is required to treat narrowed coronary vessels. Traditionally, these measurements, which occur in catheterization labs, are taken by threading a pressure wire into individual vessels to measure the fractional flow reserve (FFR). In 2018, approximately 20% of all PCIs in the US were guided by diagnostic FFR measurements beforehand.

While numerous completed and ongoing clinical trials have shown the benefits of coronary physiology assessment with FFR in both patient outcomes and long-term hospital cost savings (see FAME and FAME II), the technique is not without its drawbacks. Though accurate, this method exposes patients to the same risks involved in other cardiac catheterization procedures, such as uncontrolled bleeding at the catheter insertion site and the potential to dislodge coronary deposits that can themselves cause myocardial infarctions; moreover, this procedure is time consuming and can be highly uncomfortable for patients, with the additional pressure wires—which, per DRG’s PriceTrack tool, cost around 600$ USD—further inflating procedural costs.

As a result, a number of companies have been developing solutions to increase patient safety and comfort and decrease procedural costs while continuing to provide precise flow physiology data. For example, Medis Medical Imaging Systems and CathWorks have developed angiography-based alternatives to traditional FFR. The companies have developed algorithms that create 3-D reconstructions of patients’ vessels from angiograms, allowing for immediately available and simultaneous FFR measurements for a large number of vessels, thus saving procedural time and minimizing patient discomfort.

Recent results in the FAVOR and FAST-FFR trials demonstrate a high degree of concordance between these angiography-based FFR technologies and direct measurements with pressure wires, further supporting the viability of the former’s implementation into the catheterization lab workflow. With that said, however, although this method mitigates the need for inserting pressure wires into each vessel, it nevertheless involves similar drawbacks to traditional FFR, namely the requirement for catheterization.

Nonetheless, there are companies that have managed to provide a truly noninvasive alternative to traditional FFR; HeartFlow and Canon, for instance, have been developing software that can calculate FFR from high-resolution computed tomography (CT) scans, and clinical data has, similar to angiography-based FFR, shown a high level of concordance between CT-based FFR and pressure–wire-based FFR (see here and here). This technology allows for unprecedented and accurate diagnosis of coronary flow physiology without needing invasive cardiac catheterization, thus reducing patient burden in catheterization labs, decreasing overall patient radiation exposure, and saving costs for patients and payers alike.

These alternatives to traditional FFR continue to gain traction. CT-based FFR, such as that offered by HeartFlow, was issued CPT codes by the American Medical Association (AMA) in July 2017 after receiving FDA clearance in 2014; moreover, the technique experienced tremendous success in 2018, having received expanded insurer coverage and gained approval for reimbursement in Japan. More recently, CathWorks’ angiography-based FFR technique was issued a CPT code in July 2018 and received FDA clearance in December 2018.

Increased investment in such technologies signals a shift away from invasive FFR methods; the ramifications of this shift, however, remain somewhat unclear. While such disruptive technologies may ultimately bolster percutaneous coronary intervention (PCI) volumes by making diagnostic tools more affordable and less invasive—thereby potentially leading to more procedures performed among patients who would have otherwise remained undiagnosed—they may also reveal that many patients who would have traditionally received PCIs do not actually need them, thus reducing procedure volumes. Regardless, these innovations will likely diminish the cost burden on health care systems by avoiding unnecessary procedures and decreasing the use of expensive pressure wires.

What is perhaps most compelling about these developments is the fact that they do not represent innovations within interventional cardiology, but are rather a manifestation of an ongoing paradigm shift wherein diagnostic imaging is becoming an increasingly substantial component of interventional cardiology practices. Moreover, these improved techniques are almost entirely software-based and do not rely on radical innovations to existing hardware or on the development of brand new medical devices.

This is, of course, representative of a larger trend in medtech markets, where new software technologies, such as improved algorithms, artificial intelligence, and telemedicine, continue to open new avenues for practitioners, providing novel alternatives to existing treatment pathways. Going forward, interventional cardiology practices will continue to be improved by enhanced software capabilities, which will dictate future interventional guidelines and determine the rate of procedural expansion.

 

For more information on DRG’s insights into interventional cardiology, please see our Medtech Solutions. Visit PriceTrack’s homepage to learn more about our SKU-level pricing and analytics tool. For any questions, please contact us at questions@teamdrg.com.

Follow @MikeT_DRG and @DRGMedtech on Twitter for more insights on interventional cardiology.


Contributors: Michael Tian - Senior Analyst, Medtech Insights and Zaid Al-Nassir - Analyst, Product Support
Published on: 18 January, 2019