DISRUPT PAD Results Presented for Shockwave Medical's Lithoplasty System

May 11, 2015—Shockwave Medical Inc. announced positive 6-month clinical results from the DISRUPT PAD study. DISRUPT PAD is a single-arm, multicenter study evaluating the safety and utility of Shockwave’s Lithoplasty balloon catheters for the treatment of peripheral artery disease (PAD). 

Coprincipal investigator Andrew Holden, MBChB, presented DISRUPT PAD results from 35 patients with calcified vascular stenosis of the superficial femoral artery and popliteal artery at the 2015 Charing Cross Symposium, which was held April 28th to May 1st in London, United Kingdom.

In the company’s press release, Dr. Holden commented, “These data, which show sustained clinical benefits with no reintervention at 6 months, follow the ‘stent-like’ acute procedural results presented last fall at the VIVA 2014: Vascular Interventional Advances annual conference in Las Vegas, Nevada.” Dr. Holden is Director of Interventional Radiology at Auckland Hospital in Auckland, New Zealand.

In January, Shockwave Medical received European CE Mark approval for use of Lithoplasty in the treatment of PAD. Lithoplasty is not available for sale in the United States.

According to Shockwave, the results from DISRUPT PAD demonstrate safe and effective dilatation of calcified stenosis with no acute failures, favorable residual stenosis, no major adverse events, and no need for stent placement. At 6 months, freedom from reintervention was 100% and patency assessed by duplex ultrasound was 83%. Primary efficacy results demonstrated 100% success, defined as ability to achieve less than 50% residual stenosis using Lithoplasty with or without adjunctive angioplasty. Device success was 87% using Lithoplasty alone. 

The company noted that the device achieved an average residual stenosis of 23% (initial 76%), with no difference in the ability to dilate lesions between moderate (36%) and severely (64%) calcified lesions.

Lithoplasty is a balloon-based technology that utilizes integrated lithotripsy, a pulsatile mechanical energy commonly used to break up kidney stones, to disrupt both superficial and deep calcium and normalize vessel wall compliance prior to low-pressure balloon dilatation. Lithoplasty is designed to be naturally gentle to soft tissue (nondiseased portions of the vessel) while remaining hard on calcium, the tissue that limits vessel expansion and the effectiveness of current technologies.

The company advised that early clinical results demonstrate the safety, tolerability, deliverability, and effectiveness for Lithoplasty as both a treatment for PAD and as a pretreatment of calcified coronary lesions before stenting.

Shockwave will be conducting further clinical studies of the performance of Lithoplasty, including the European multicenter DISRUPT CAD study for the treatment of coronary artery disease planned for later in 2015. The device will also be evaluated in aortic valves beginning later this year.

The Lithoplasty system, which is designed to be effective on all types of calcium, is delivered on a standard balloon catheter platform and combines the calcium disrupting power of lithotripsy with the familiarity and simplicity of a balloon in a single enabling device. Lithoplasty applies a brief series of powerful mechanical pulses designed to safely travel through soft tissue to disrupt and pretreat calcium. The integrated balloon is then dilated at low pressures to expand the lesion evenly, potentially minimizing acute soft tissue injury that could lead to the need for additional interventional treatments, or long-term restenosis, stated Shockwave Medical.