IVUS Guidance Associated With Improved Outcomes in Lower Extremity PVD Interventions in Medicare Data Analysis

November 8, 2021—The results of large-scale, real-world analyses of Centers for Medicare & Medicaid Services (CMS) data on the health outcomes of peripheral vascular interventions guided by intravascular ultrasound (IVUS) were presented by Eric A. Secemsky, MD, at TCT 2021 in Orlando, Florida. The studies, which were conducted independently by the Smith Center for Outcomes Research at Beth Israel Deaconess Medical Center in Boston, Massachusetts with support provided by Philips, explored the utility of IVUS during lower extremity peripheral artery disease (PAD) revascularization and iliofemoral venous stenting for chronic venous disease.

According to a Philips announcement on the data, key findings include:

• In lower extremity arterial interventions to treat PAD, there was a 32% reduction in major adverse limb events.
• In iliofemoral venous stenting to treat chronic venous disease, there was a 31% reduction in the composite outcome of repeat intervention, hospitalization, or death, together with a reduced risk of stent thrombosis, embolization, and stenosis.

Regarding the PAD study, Philips summarized that the investigators looked at Medicare beneficiaries aged ≥ 65 years who underwent lower extremity arterial interventions between January 1, 2016, and December 31, 2019. Among 697,794 interventions, they found a 32% reduction in major adverse limb events, such as amputations, over a median 425 days of follow-up. These findings were consistent across disease states, including critical limb ischemia (CLI), as well as iliac, femoropopliteal, and tibial arterial segments.

Separately, for chronic venous disease, the investigators examined Medicare beneficiary data for 20,984 chronic venous disease patients treated between January 1, 2017, and December 31, 2019, in multiple clinical settings, including hospital inpatient and hospital outpatient centers and private office-based clinics. Of these patients, 72% underwent stenting guided by IVUS. When IVUS was used, there was a 31% reduction in the composite outcome of repeat intervention, hospitalization, or death. In addition, IVUS use reduced the risk of stent thrombosis, embolization, and stenosis.

“On the arterial side, endovascular procedures have been increasing in number, yet we have plateaued somewhat in terms of our impact on clinical outcomes—on how to create durable long-term, effective interventions, said Dr. Secemsky in comments to Endovascular Today. “We’ve learned a lot from the coronary space, including that intravascular imaging is incredibly important for optimizing stent implants and understanding vessel prep, but I don’t think we’ve fully embraced that in the periphery.”

Among the findings from the PAD study shared in a poster at TCT, Dr. Secemsky highlighted that there is considerable variation in the application of IVUS in the United States. Some operators are using IVUS fairly regularly (most often when there is multilevel intervention including the tibial vessels), but there is still a large proportion of operators who do not use IVUS in any of their cases, he said.

“We know that IVUS can be critical for understanding how to size vessels, so when we have therapies like a stent implant or drug-coated devices, they’re not going to be nearly as effective if they’re not sized appropriately,” continued Dr. Secemsky. “IVUS also helps with evaluating dissections and residual disease and understanding plaque morphology in terms of need for vessel prep and when other devices such as atherectomy should be utilized.

“In our real-world study on the arterial side, we examined whether IVUS had an impact on these outcomes. In particular, amputation, arterial, thrombosis, embolism, all-cause hospitalization and death, as well as surgical revascularization. Among about 11% of procedures that were performed with IVUS out of more than 600,000 procedures, we found that there was a meaningful reduction in the presence of a major adverse limb event, the need for a major amputation, or the risk for hospitalization or death. Those are the endpoints we’re striving toward, and we saw that IVUS seemed to be associated with improvement. That improvement was notable whether this was an iliac, tibial, or SFA/popliteal intervention, as well as whether they were CLI or not chronic, so it really spanned different arterial beds and conditions.”

Similar to the findings from the arterial study, when Dr. Secemsky and colleagues looked at the outcomes after iliofemoral venous stenting, they found that there was less need for hospitalization within 6 months of the stenting procedure when IVUS was used in the index procedure. In stent-related outcomes, there were fewer long-term events of stent thrombosis, stent embolization, and restenosis.

“Intravascular imaging helps evaluate the lesion more clearly—we can size a vessel and also determine whether there needs to be additional evaluation of the venous system to extend the coverage of the stent or land in normal vessel,” said Dr. Secemsky. “There are risks of undersizing, such as stent embolization, but there are also risks of oversizing that can result in back pain and other pain syndromes. Those outcomes are hard to measure in claims or insurance-based studies, but we were able to show a meaningful reduction in hospitalizations for stent embolization or migration when IVUS was used compared to not, which I think is quite novel. With all the concerns about stent embolization with venous stents, it’s time that IVUS is more universally adopted.”

Noting the limitations in reviewing claims data, Dr. Secemsky believes the findings show a meaningful impact when IVUS was used during lower extremity arterial procedures and iliofemoral venous stenting. “These outcomes data, although nonrandomized and with limitations based on being a claims-based analysis, lend general support that when IVUS is incorporated into a vascular procedure, whether arterial or venous, there are improved outcomes for these patients, and that they are important outcomes. ​However, we caution causal interpretation, as the use of IVUS may also reflect other practices of the operator that may lead to improved outcomes. Along with the consensus document demonstrating among experts in the field that the use of intravascular imaging is highly regarded as appropriate in most phases of intervention both on the arterial venous side, I think we need to really improve adoption with regard to education, implementation, and workflow improvements, and focus less about how much more prospective data we need to gather.

As described by Dr. Secemsky, the first-ever global consensus for the appropriate use of IVUS in peripheral vascular disease interventions was presented at VIVA 2021, held October 4-7 in Las Vegas, Nevada.