ATLANTA, GA—Patients with femoropopliteal artery disease maintain primary patency through one year after drug-coated balloon (DCB) angioplasty when surgery is performed under IVUS guidance rather than angiography alone New data shows that improvements have been made.

Results from the randomized controlled IVUS-DCB trial provide the latest support for intravascular imaging in peripheral interventions.

Although DCB has an established role in femoropopliteal artery disease, “challenges such as vascular recoil, residual stenosis, and arterial dissection remain significant limitations of DCB treatment,” said researcher Young-Guk Ko, MD. (Severance Hospital and Yonsei University, Seoul, South Korea). South Korea) when presenting data Monday at the American College of Cardiology’s 2024 Scientific Sessions.

More informed vessel preparation and postoperative optimization can help improve outcomes, and IVUS, which provides details about vessel dimensions and plaque characteristics, is ideally suited for this task. He added that there is. “However, clinical data regarding the benefits of IVUS in the endovascular treatment of femoropopliteal artery disease using DCBs are limited.”

As Dr. Sahil Parikh (NewYork-Presbyterian/Columbia University Irving Medical Center, New York, NY), IVUS-DCB discussant at the late clinical session, pointed out: “The role of IVUS in coronary intervention is clearly established.” . . . It is less established in peripheral interventions, and in fact this is only the second large randomized trial to examine IVUS and angiographic guidance for interventions in the femoropopliteal region. ” The first trials were announced in 2022.

Eric Secemsky, MD (Beth Israel Deaconess Medical Center, Boston, Massachusetts) did not participate in IVUS-DCB, but has led several efforts to expand knowledge about intravascular imaging in peripheral interventions. Ta. “We are very mature in the coronary domain,” but the peripheral domain is lagging behind, in part because the physicians treating these cases span different specialties and diverse anatomies. Sesemski told TCTMD that this was because he was working in a hospital. “Many of us, anecdotally, were very attentive to the implications of intravascular imaging. [could have] On improving vascular interventions. Although existing observational data have made a strong case for imaging, “the strength of this study is that it is one of the few that provides positive evidence,” he added. “It’s sorely needed.”

IVUS-DCB exam

For IVUS-DCB, Ko et al. studied 237 patients (mean age approximately 70 years, 85 % were male) and randomly assigned to IVUS. Guidance can be performed in addition to angiography, or angiography alone. Analyzes were performed on an intention-to-treat basis. There was one crossover in the IVUS group and he had two crossovers in the angiography group.

All patients were Rutherford class 2 to 5 at baseline. Almost two-thirds (63.2%) had diabetes and 20.2% had chronic kidney disease. Approximately 1 in 4 of her patients had limb-threatening chronic ischemia. Preoperative ankle-brachial index (ABI) was 0.6 in both groups. One-third of the lesions were TASC-II A/B and two-thirds were C/D. The mean lesion length was just over 200 mm, approximately 60% had chronic complete occlusion, and nearly 30% had severe calcification.

As expected, procedural characteristics differed between the two study arms.

The mean vessel diameter before angioplasty was 5.0 mm in the IVUS group and 4.5 mm in the angiography group, and the mean maximum pressure was 11.8 mm Hg and 8.9 mm Hg, respectively.P both < 0.001). Adjuvant postdilatation was used in 26.1% of IVUS cases and 13.6% of angiography only cases (P = 0.03). The mean maximum pressure after DCB use was 13.7 vs. 9.6 mm Hg (P = 0.001). Bailout stenting occurred in 20.5% of the IVUS group and 14.5% of the angiography group (P = 0.30). In both groups, the dissection rate was approximately 60%, mostly her type B.

After angioplasty, the minimum lumen diameter was larger in the IVUS group (mean 3.90 mm vs. 3.71 mm for angiography only). P = 0.03), smaller diameter stenosis (mean 21.5% vs. 25.4%; P = 0.02).

Both technical success rates (residual stenosis <30% without compromising blood flow) and procedural success rates (technical success without acute complications) using IVUS compared with angiographic guidance was higher, 76.5% vs. 61.0%.P= 0.02), 73.9% vs. 60.2% (P = 0.03), respectively. Postoperative ABI was also higher in his IVUS group than in his angiography group (mean 0.99 vs. 0.93; mean 0.99 vs. 0.93). P = 0.001), “reflects better hemodynamic outcomes,” Ko said.

There were no major limb amputations throughout the year in either group, and rates of all-cause mortality, CV mortality, and major bleeding did not differ between IVUS and angiography.

By 12-month follow-up, the primary patency rate (the primary endpoint of this study was defined as freedom from clinically induced TLR and imaging dual restenosis) was significantly higher than IVUS. and 70.1% in the angiography-only group (HR 0.46; 95% CI 0.25-0.85; log-rank P = 0.01). Patients assigned to IVUS also had greater freedom from clinically triggered TLRs (92.4% vs 83.0%; HR 0.41; 95% CI 0.19-0.90; log-rank) P = 0.03), with sustained clinical improvement of at least one Rutherford class without clinically induced TLRs (89.1% vs 76.3%; HR 0.45; 95% CI 0.23-0.86; log-rank) P = 0.02).

The difference in primary patency favoring IVUS at 12 months was significant for TASC-II type C/D lesions (84.8% vs 54.7%, HR 0.33, 95% CI, 0.17-0.67, log rank) P = 0.002) but not type A/B lesions, both groups had similar initial patency rates (96.9% and 94.1%; P =NS). “The benefit of IVUS guidance on primary patency after DCB treatment was more evident in complex femoropopliteal lesions,” Ko said.

Predictors of increased restenosis included lesion length of at least 200 mm and subintimal recanalization, whereas IVUS was associated with decreased restenosis.

The main difference is the increased lumen gain during the index intervention, which is thought to lead to improved primary patency after 1 year. Sahil Parikh

As for the cause of differences in primary patency, Dr. Sesemski said one of the biggest impacts of IVUS is proper sizing, including accurately identifying the appropriate reference vessel diameter and lesion length. I did. “This was another great demonstration that larger balloons and larger minimal lesion diameters can be achieved using IVUS,” he said. “And that didn’t come at the expense of further dissection. There was a fair amount of dissection, but they were evenly balanced.”

The finding that beyond the initial effect, the primary patency curve continued to widen over time suggests another mechanism, Sesemsky added. “I think this suggests that the drug from the balloon is working more effectively because it’s better positioned. Drug delivery is based on placement.”

Parikh said in his remarks that there are several possible explanations for why IVUS provided benefit in the trial. “The main difference appears to be a greater lumen increase at the time of the index intervention, which translates into improved primary patency one year later,” he said. Other factors beyond vessel diameter may include plaque characteristics such as the presence of calcification or thrombus that have not yet been quantified.

Koh said understanding these aspects is the next step in the research. “I think it’s possible because we have more IVUS data.” [use to] While identifying specific IVUS features that predict restenosis in long-term follow-up, within the scope of our study; [patients] “Both infection and event rates in the IVUS group were too small to identify such risk factors,” he explained.

Parikh also called attention to the low rates of salvage stenting in both arms of the trial. “Rescue stent placement rates are typically much higher when intravascular ultrasound is used. It looks like a bomb has gone off inside the artery, but interventionists reflexively place a stent. Here, there was only a small difference between the two groups,” he said, explaining how the researchers persuaded operators to “restraint their use of rescue stents.” Asked.

According to Ko, the answer lies in South Korea’s national health insurance system, which only covers one rescue stent and leaves the rest to the patient.

Of note, the use of intravascular imaging in coronary interventions remains suboptimal, although there is more evidence for intravascular imaging. Therefore, there is a question of how quickly it will be uptaken in peripheral cases.

Sesemski said there is already some growth, albeit slow. “Breaking down the main barriers to increasing uptake raises three key questions,” he noted. “Is there enough evidence to support that? Will my case be slow? And how do I find a way to interpret these images?”

Of course, the evidence is emerging, so the next step will be to address other barriers. The first is to “demonstrate that if you can implement it as part of your workflow, there’s no significant time increase,” Secemsky says. “And I think the education part is important, too. A lot of people have to do intravascular imaging in their jobs. It works well if you’re in the lab… but there are far too many more advanced operators who don’t have access to this kind of training opportunity or expertise and are stuck just looking at images and guessing. He noted that additional training can help these people learn new skill sets and feel more comfortable.