To optimize outcomes for PCI procedures, new technologies have emerged to assist interventionalists with clinical decision making and patient selection. With fractional flow reserve (FFR) gaining more adoption since the release of the FAME trial in 2009, physicians are now exploring newer complimentary intravascular imaging technologies, such as optical coherence tomography (OCT). To assess the impact in U.S. cath labs, five interventional cardiologists discussed the practice management considerations.
Why & when to use?
FFR is a physiological index that determines the severity of blood flow blockages in the coronary arteries through a pressure wire technology measurement, and intravascular OCT provides high-resolution, cross sectional images of tissue in situ.
"There are distinct roles for these technologies," says Thomas Tu, MD, from Baptist Medical Associates in Louisville, Ky. "FFR is a hemodynamic assessment, and gathers information on the physiology of the coronary artery, whereas OCT is an anatomic assessment. As angiographers, we need both sets of information to understand lesions; the structural problems along with their functional significance."
FAME's Principal Investigator William F. Fearon, MD, from Stanford University Medical Center in Calif., says that the use of the pressure wire to measure FFR is the first step to determine whether or not a lesion is causing ischemia and therefore warrants PCI. "Then, I use anatomical techniques like OCT to optimize PCI: to guide decisions about stent length, vessel size, whether or not to use other techniques and to ensure that the stent is optimally well deployed, expanded and apposed without any edge dissection," he says.
OCT might find its largest niche in post-stent deployment. "You get excellent post-deployment data, and that's where the clinical data will probably lead us. OCT also provides a great deal of information on vulnerable plaque, which is intriguing, but we still need a better understanding of what to do with the information obtained," states Mark A. Turco, MD, from Washington Adventist Hospital in Takoma Park, Md.
Also, PCI has expanded to certain complex patient subsets, such as those with left main disease, in whom FFR may have a role. "It is vital to get a hemodynamic assessment for patients with left main disease. We also have excellent evidence now suggesting that in patients with left main disease that have FFRs greater than 0.75, they do not need to move forward with bypass surgery as these are hemodynamicaly insignificant despite what angiography might suggest," Turco says.
Likewise, Michael J. Rinaldi, MD, of Sanger Heart & Vascular Institute in Charlotte, N.C., says he employs OCT or other imaging technologies in at-risk patients, specifically where he perceives "higher risk factors for stent thrombosis or where the stenting results aren't perfect; overall about 30 percent of the time."
Others touted the image quality of OCT, but suggested its final role is yet to be determined. "Having better visual assessment is fantastic, and OCT is like high-definition compared with IVUS [intravascular ultrasound]," says Tu. "What we do with that information, the clinical significance, decision making based on that will come with experience.
Appropriate use: a driver of use
With the proliferation of FFR and otherintravascular imaging technologies, ACC President David R. Holmes, MD, from the Mayo Clinic questioned what would drive higher adoption. While there has been a "dramatic increase" in FFR utilization, he questions whether the increasing need for transparency will foster greater adoption.
"We are going to see an increase in the use of FFR due to the mounting oversight over our procedures," Turco points out. "Increased scrutiny on physicians performing appropriate procedures, and not over-stenting or over-intervening. While good clinical judgment is important, we are going to need a document with regards to FFR assessment to show we have legitimate evidence that a lesion is hemodynamically significant."
In particular, Maryland and Louisiana have undergone a fair amount of scrutiny due to alleged physician over-stenting. "It's going to be incumbent upon us to be fully transparent and follow the appropriate use criteria as proposed by the American College of Cardiology (ACC). We are going to need to prove how on board we are with guideline-driven medicine. These types of technologies will allow us to have the transparency that is needed," Turco says.
Cardiologists at Washington Adventist are required to document additional FFR or IVUS assessment if treatment is performed in a lesion that is 70 percent angiographically stenotic or less. "Usually, we prefer hemodynamic assessment with FFR for this evaluation, so we can ensure transparency and guideline-driven care is being given," he says.
However, some query the control that increased data reporting could have on clinical practice. "The word 'transparency' represents all the positive aspects about sharing knowledge and greater understanding about the medical decision making," Tu adds. "While I fully support giving physicians more tools to make better decisions, if that information is used to control clinical decision making, it could be problematic."
Holmes responds, "This is the important point about appropriate use criteria because under the criteria. Procedures designated as one, two or three should not be performed, while six, seven and eight should be." Yet, he also acknowledges that there are "a group of patients in the middle about whom we are not entirely sure of the best treatment path." This group requires discussions with the patient, family and referring physician about his or her individualized care.
"We need to approach each of our patients individually," Turco suggests. "But we are going to need to prove to governmental agencies and others that we are doing the right thing at a time when Medicare costs are rising, and they are looking for every avenue to reduce expenses. As a profession, we are under fire for implanting stents or at least for implanting stents inappropriately and we need to use decision making technologies to defend our actions."
With healthcare reform cost-restructuring scheduled to take effect in 2014, along with potential forthcoming transformations regarding the implementation accountable care organizations and bundling payments, providers are very focused on the bottom line.
"Healthcare costs are in silos," Rinaldi explains. "Costs to the overall U.S. healthcare system or the government are probably lower if you are a heavy adopter of FFR because you are going to prevent treatments that are unnecessary."
In fact, data have emerged from the FAME cost-effectiveness study, which showed that the procedure saved more than $2,000 per patient. "From a societal perspective, it was a cost-saving approach," says Fearon. "It also may be cost-saving in the hospital perspective setting. In the same trial, patients in the angiographic-guided arm received about three stents per patient and about two on average in the FFR-guided arm. The hospital gets reimbursed for the procedure, so by using fewer stents, the hospital may save money."
Holmes adds that converting patients from bypass surgery to PCI, which can result from employing FFR, may have "enormous implications in terms of improving the cost to the healthcare system."
Fearon says that he and his FAME investigators are exploring this cost-saving possibility. "We have assessed the creation of a functional SYNTAX score where you don't count lesions that are not significant based on the FFR, even if they are more than 50 percent narrowed." They found that in more than 30 percent of cases where the patient was classified to a lower SYNTAX score, the treatment strategy was converted. "In the end, we hypothesized that this strategy will save money."
To justify the cost of an OCT system at Sanger, the physicians calculated the cost of stent thrombosis to its healthcare system. "As we publicly report our outcomes, providers want to minimize the number of adverse events. The right thing is to do what's right for the patient. But, there also could be a fiscal argument."
FFR and OCT are projected to continue adoption growth, and while additional clinical validation is ongoing, many are already utilizing them to reduce overall cost and ensure patient treatment is warranted.