November 7, 2020
DISRUPT PAD III Compares Shockwave IVL to Angioplasty in Severely Calcified Peripheral Artery Disease
November 7, 2020—Shockwave Medical, Inc. announced that data presented from the DISRUPT PAD III study demonstrated that intravascular lithotripsy (IVL) was superior to percutaneous transluminal angioplasty (PTA) on the primary endpoint of procedural success in the treatment of severely calcified cardiovascular disease.
Additionally, the large randomized DISRUPT PAD III trial of severely calcified peripheral lesions found that IVL was associated with a statistically significant reduction in diameter stenosis, arterial dissections, and bailout stenting versus PTA.
William A. Gray, MD, of the Lankenau Heart Institute at Main Line Health, presented the findings in the late-breaking clinical trial session at VIVA 2020, the Vascular InterVentional Advances annual meeting held as a virtual congress November 6-8, 2020. Dr. Gray and Gunnar Tepe, MD, are coprincipal investigators of the study.
"The combination of an aging population and increasing numbers of patients with diabetes and with renal failure, along with a greater emphasis on percutaneous approaches to patients with lower extremity vascular insufficiency, means interventionalists are increasingly faced with complex lesions in which severe calcification poses a significant challenge to achieving a safe and successful outcome," explained Dr. Gray in comments to Endovascular Today regarding the backdrop of the trial. "In addition, early data suggest that antiproliferative drug uptake may be inhibited by the presence of calcium, thereby reducing long-term vessel patency. IVL is specifically designed to effectively and safely treat these moderate and severely calcified lesions, and with the potential to improve long-term outcomes by promoting antiproliferative drug uptake."
In the company’s announcement, Dr. Gray also emphasized that, until the DISRUPT PAD III trial, there have been few data available to provide treatment guidance for this challenging population, as patients with severe calcification have historically been excluded from endovascular treatment trials.
According to the company, DISRUPT PAD III is a prospective, multicenter, randomized study designed to demonstrate the safety and effectiveness of IVL as a vessel preparation procedure in moderate to severely calcified superficial femoral and popliteal lesions, followed by a drug-coated balloon (DCB) or stent.
The study enrolled 306 patients randomized between IVL and PTA at 45 sites in the United States, Germany, Austria, and New Zealand. In the IVL arm, 83% of patients were classified by the angiographic core lab as having severe calcification, with an average calcified lesion length of 129 mm.
In the data presented at VIVA 2020, IVL demonstrated superiority over PTA in the primary endpoint analysis, defined as procedural success with residual stenosis ≤ 30% without flow-limiting dissection (≥ Grade D), before DCB or stenting. The procedural success rate was 65.8% for IVL versus 50.4% for PTA (P = .0065) as determined by an independent angiographic core lab.
Additionally, Shockwave noted that PAD III showed that IVL achieved more atraumatic treatment based on the following findings:
- Reduction in frequency and severity of major arterial dissections (Grade C and Grade D both P = .03)
- Reduction in the need for bail-out stenting (75% relative risk reduction) and stent implantation rate (4.6% vs 18.3%; P = .0002)
- Lower balloon maximum inflation pressure (6.3 atm vs 11.3 atm; P < .0001)
- Reduction in categorical percent diameter stenosis after treatment with IVL versus PTA (P = .02)
“IVL superiority over PTA in acute procedural success establishes the new standard in safety and effectiveness, and we now have Level I evidence to help inform our lesion preparation strategy,” summarized Dr. Gray in the announcement.
Detailing the findings further in conversation with Endovascular Today, he noted, "In contrast to many other approaches in dealing with calcium, these striking effectiveness outcomes were achieved in an extremely safe and predictable manner, with an absence of perforation, distal embolization, slow flow, or thrombosis."
Dr. Gray also addressed the real world question of added costs associated with adjunctive device use and specifically whether he believes the IVL costs and outcomes compare favorably to other options. "When contrasted with the potential for adverse events that can occur with other approaches to severe calcium, which may require the placement of distal EPD (additional cost) and additional resource utilization (covered stents for perforation, thrombectomy retrieval catheters for distal embolization), along with its comparatively expedient application, IVL brings significant value to these procedures."
As for what's next in terms of data collection for IVL, Dr. Gray explains that DISRUPT PAD III has an important powered secondary endpoint of 12-month patency, and these data are still being gathered. "It will be interesting to see if there is any effect on calcium modification with IVL and outcome effects of DCB on maintenance of vessel patency."