Intravascular Lithotripsy Promising Vessel-Prep Strategy for Peripheral Artery Calcification

By Reuters Staff

June 25, 2021

NEW YORK (Reuters Health) - For patients with calcified femoropopliteal arteries, intravascular lithotripsy (IVL) is a safe and effective vessel preparation strategy that facilitates a "leave-nothing-behind" approach to definitive endovascular treatment, report the Disrupt PAD III study investigators.

"In patients with peripheral artery disease (PAD), vascular calcification interferes with delivery of endovascular therapies, is associated with suboptimal vessel expansion, and increases the risk of vascular complications including restenosis, dissection, perforation, and distal embolization," they explain in a paper in JACC: Cardiovascular Interventions.

The Disrupt PAD III study assessed the safety and effectiveness of IVL versus percutaneous transluminal angioplasty (PTA) as a vessel-preparation strategy prior to definitive treatment with a drug-coated balloon (DCB) or stent in patients with calcified femoropopliteal lesions.

The study used the IVL system from Shockwave Medical, which funded the study. There were 153 patients in each group.

The primary endpoint was core lab-adjudicated procedural success (residual stenosis of 30% or less without flow-limiting dissection) prior to DCB or stenting.

Compared with PTA, IVL had a higher procedural success rate (65.8% vs. 50.4%; P=0.01) and a higher percentage of lesions with residual stenosis of 30% or less (66.4% vs. 51.9%; P=0.02).

As compared to PTA, IVL resulted in markedly fewer severe dissections (1.4% vs. 6.8%; P=0.03) and significantly less need for post-dilation (5.2% vs. 17.0%; P=0.001) or stent placement (4.6% vs. 18.3%; P<0.001). Rates of major adverse events and clinically driven target lesion revascularization at 30 days were comparable between groups.

"While these short-term results are encouraging, longer-term follow-up (ongoing in this study through 2 years) will be needed to evaluate treatment durability after IVL. The powered secondary endpoint of primary patency at 12 months will be analyzed following appropriate follow-up for all enrolled patients," write Dr. Gunnar Tepe of RoMed Klinikum, in Rosenheim, Germany, and colleagues.

They say it's also important to note that IVL was compared with PTA for vessel preparation, and therefore the comparative effectiveness of IVL versus other strategies such as atherectomy remains unclear.

In a linked editorial, Dr. Christopher White of Ochsner Health, in New Orleans, and Dr. Joshua Beckman of Vanderbilt University, in Nashville, say the investigators are to be "congratulated" for providing early results comparing IVL with PTA in patients with mostly claudication and complex long, calcified lesions.

"Of greatest interest to us," they write, "was the result at the end of the procedure: following definitive therapy, there was no difference in the angiographic result between the 2 groups." Final residual stenosis following DCB and/or stent placement was 21.5% with IVL and 20.7% with PTA; P=0.39).

"The use of IVL did not result in superior luminal gain, which we would have expected if these calcified lesions truly impaired balloon expansion," the editorialists say.

"We now have a RCT studying an expensive lesion preparation strategy, showing equivalent post-procedural angiographic results, that will (or will not) demonstrate utility with the 1-year patency results," Dr. White and Dr. Beckman write.

Whether longer-term outcomes depend on the vessel-preparation strategy or the choice of definitive treatment is unclear.

"If the past is any guide, our money is on the definitive therapy side of this argument, not the lesion preparation side. For us, patient outcomes drive value, not the intermediate result of vessel appearance at procedure's end," the editorialists conclude.

Several authors have disclosed financial relationships with Shockwave Medical.

SOURCE: and JACC: Cardiovascular Interventions, online June 14, 2021.