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‘Good news’ for endovascular revascularization for CLI
WASHINGTON — A multidimensional approach to endovascular revascularization along with new therapies will improve treatment of patients with critical limb ischemia, according to a speaker at the American College of Cardiology Scientific Session.
During his presentation, Subhash Banerjee, MD, FACC, professor of medicine at UT Southwestern Medical Center and chief of the division of cardiology at the VA North Texas in Dallas, said methods and systems of care are critical for the treatment of patients with CLI.
The first question in CLI is whether a patient should be treated with endovascular therapy first or surgery, Banerjee said. According to results from the CRITISCH registry, in which 54% of patients received endovascular therapy and 24% underwent bypass, researchers found no difference between treatment groups in amputation-free survival, and treatment strategy did not affect time to death, amputation or re-intervention.
“The good news is that from study to study and registry to registry — real live data — the proportion of patients representing CLI is increasing, meaning we will get more data, more evidence and, hopefully, we’ll be able to energize the community and form coalitions,” Banerjee said.
Emerging evidence
Although the currently enrolling randomized BEST-CLI trials comparing the best endovascular treatment available with the best available surgical treatment are garnering attention, several other ongoing clinical trials also warrant discussion, including BASIL-2 and BASIL-3, according to Banerjee.
BASIL-2 is comparing vein bypass first with best endovascular treatment first in patients with infrapopliteal severe ischemia of the leg, whereas BASIL-3 is comparing three modalities of endovascular treatment: primary balloon angioplasty with or without a bare-metal stent; drug-coated balloon angioplasty with or without a BMS; and treatment with a drug-eluting stent. Outcomes include amputation-free survival, overall survival and other clinical endpoints, as well as quality of revascularization, quality of life, functional status and economic ramifications.
Additionally, Banerjee discussed encouraging evidence from the WIFI trial, which showed that patients classified as high risk had poor outcomes after endovascular therapy.
“This is good news to me because it shows we are heading toward creating algorithms that can help us identify which patients we should treat and how using established classification schemes,” he said.
‘Tools, technologies and tricks’
Banerjee said it is important for physicians to have knowledge of various modes of CLI treatment.
“An endovascular specialist treating patients with CLI should be well-equipped with tools, technologies and tricks in their bag to attempt to treat and revascularize these lesions in multiple ways,” he said.
Data show that if patients with CLI have femoropopliteal disease, overall outcomes of using DCBs are favorable, although the representation of patients with CLI in these studies was relatively low, Banerjee said.
In contrast, dedicated studies such as IN.PACT DEEP indicate that DCB angioplasty was not as effective for below-the-knee treatment. However, this may be attributable to the technology of the balloon used, lack of involvement of a wound care specialist, the severity of peripheral artery disease and chosen endpoints that did not reflect care. Nevertheless, there are more studies in the works evaluating different devices for below-the-knee arteries, which will be insightful, Banerjee said.
Atherectomy has also shown promise, he noted, citing data from DEFINITIVE-LE — a large, rigorously adjudicated study that was, however, not a randomized controlled trial. After 12 months, freedom from amputation was 95% and primary patency was 71%. Additionally, results from the DEFINITIVE-AR pilot study indicated that combining atherectomy with DCB angioplasty was beneficial.
Banerjee also said the use of a bioresorbable vascular scaffold in below-the-knee arteries is “exciting,” noting that a recent single-arm study indicates the device resulted in improved outcomes in all sorts of lesions across a limited number of patients.
New techniques
For patients who cannot be revascularized, gene and cell therapy, including the use of hepatocyte growth factor, fibroblast growth factor and hypoxia-inducible factor-1 alpha, all delivered through intramuscular injections. Banerjee said, however, that despite recent research favoring these treatments, half of the studies are not interpretable in terms of their benefit.
Another area of improvement is perfusion imaging, according to Banerjee.
“We are emphasizing a lot on perfusion, including laser Doppler techniques, indocyanine green fluorescent angiography, among others, and a whole slew of methodologies that not only assess skin perfusion but muscle perfusion is coming down the pike,” he said.
Several readily adoptable methods of perfusion imaging that can help optimize endovascular therapy include the “wound blush” score; processing algorithms that can divide the regional interest and evaluate perfusion imaging from a patient’s angiography; traditional contrast-enhanced ultrasound using time-intensity curves for assessing muscle perfusion; and injectable microsensors, which are potentially the most exciting, according to Banerjee.
“Phosphorescence and decay are exposed to oxygen and leave a signal that can be captured through electric materials and help assess balloon inflation and deflation,” he said. “For endovascular specialists, this is going to be a dramatic new development.”
Ultimately, even with these novel techniques, the multidimensional approach in CLI is essential.
“Simply putting in balloons and stents is not very good. We need better forms and methods and systems of care,” Banerjee said. “We need better detection, treatment and data on how to sustain our successes gained with initial endovascular therapy.” – by Melissa Foster
Reference:
Banerjee S. Clinical assessment and revascularization for critical limb ischemia. Presented at: American College of Cardiology Scientific Session; March 17-19, 2017; Washington, D.C.
Disclosure: Banerjee reports receiving consultant fees or honoraria and research grants from Boston Scientific, having ownership, partnership or principal interest in Mdcare Global and being on the speakers’ bureau for SCI and Medtronic.