Six-month study outcomes were presented by Dr. William Gray of Main Line Health of Wynnewood, Pa. Additional authors on the abstract included Dr. Jihad Mustapha of Metro Health Hospital of Wyoming, Mich.; Dr. George L. Adams of Rex Healthcare in Raleigh, N.C.; Dr. Gary Ansel of OhioHealth in Columbus, Ohio; and Dr. Michael Jaff, president of Newton-Wellesley Hospital and professor of medicine at Harvard Medical School in Newton, Mass.
Key Six-Month Analysis Conclusions
Findings suggest that on average PVI can restore Rutherford 4-5 patients with critical limb ischemia (CLI) status (e.g. limb pain at rest, cold and/or numbness in feet, open or non-healing wounds on toes or foot) to moderate claudicant status (e.g. limb pain during movement)
Through six months, these data demonstrate on average PAD patients (Rutherford 2-6) post-PVI have maintained good outcomes and positive changes in Rutherford classification
|Change in Rutherford Classification Following Endovascular Intervention|
|Baseline||30 Days||Six Months|
Table 1: All Rutherford Classes show improvement in RC from baseline to 30 days. RC4-5 and RC6 show continued improvement from 30 days to six months, while RC2-3 maintains improvement at six months.
“Following endovascular intervention, we saw a marked improvement across all Rutherford Classes at six months," Gray said. "Rutherford 4-5 and Rutherford 6 patients showed continued improvement from 30 days to six months, while Rutherford 2-3 patients maintained improvement at six months. We also saw a high freedom from major adverse events across all classes. This suggests that endovascular intervention is an alternative treatment option in place of watchful waiting or even primary amputation.”
|RC 2-3||RC 4-5||RC 6|
|Freedom from (FF) MAE (6-month)||92.6%||81.2%||73.7%|
|FF Major Amputation||99.8%||96.8%||87.1%|
|FF Target Vessel Revascularization (TVR)||93.0%||83.1%||85.1%|
Table 2: High freedom from MAEs at six months across all Rutherford Classes. Kaplan-Meier method used to estimate event-free rates. MAE defined as death (≤30 days after the procedure), major amputation of the target limb, and TVR.
According to VascuQoL, a patient-reported, PAD-specific health-related quality of life questionnaire, patients in the LIBERTY 360° study reported improved quality of life across all Rutherford Classes, including such measures as physical activity, symptoms and pain.
Mustapha highlighted the importance the LIBERTY 360° Rutherford 6 data will have on the endovascular field, noting that “LIBERTY 360° is novel in that it addresses all Rutherford Classes, including Class 6, representing some of the most challenging and life-threatening PAD cases. Six-month data suggests that these patients can be treated successfully with endovascular interventions—a significant step in establishing a new standard of care for this difficult-to-treat population.”
Additionally it was shared that the recently released 2016 Guidelines on the Management of Patients with PAD from the AHA/ACC support this data, stating: Revascularization is a reasonable treatment option for patients with lifestyle-limiting claudication and an inadequate response to medical management and exercise; and an evaluation for revascularization options should be performed by an interdisciplinary care team before amputation in the patient with CLI.
“We’re encouraged by the six-month results from LIBERTY 360° and the implications for patients suffering from severe forms of PAD. We look forward to releasing one-year results later this year,” said Scott Ward, CSI chairman and CEO.
As many as 18 million Americans, most over age 65, suffer from PAD, which is caused by the accumulation of plaque in peripheral arteries reducing blood flow. Symptoms include leg pain when walking or at rest. Left untreated, PAD can lead to severe pain, immobility, non-healing wounds and eventually limb amputation. With risk factors such as diabetes and obesity on the rise, the prevalence of PAD is growing at double-digit rates.
Literature shows that Balloon angioplasty and stents can have significant shortcomings in treating hard, calcified lesions. Stents are prone to fractures and high recurrence rates, and treatment of hard, calcified lesions often leads to vessel damage and suboptimal results.
Millions of patients with PAD may benefit from treatment with orbital atherectomy utilizing the Diamondback 360 and Stealth 360 Peripheral Orbital Atherectomy Systems, which are minimally invasive catheter systems developed and manufactured by CSI. These systems use a diamond-coated crown, attached to an orbiting shaft, which sands away plaque while preserving healthy vessel tissue—a critical factor in preventing reoccurrences.
LIBERTY 360° is a prospective, observational, multi-center post-market study that enrolled more than 1,200 patients at 51 sites across the United States, including 501 patients with claudication (Rutherford 2-3), 603 patients with critical limb ischemia (CLI; Rutherford 4-5) and 100 patients with the most severe form of CLI (Rutherford 6). The study included any endovascular device FDA-approved for treatment of PAD. Enrollment was completed in February 2016 and patients will be followed for up to five years.
LIBERTY 360° is among the first PAD studies to investigate patients across the spectrum of symptomatic PAD and will assess numerous parameters including procedural success, rate of major adverse events, duplex ultrasound findings, quality of life, six-minute walk test, wound status, and economic outcomes.
Cardiovascular Systems, based in St. Paul, Minn., develops and commercializes solutions for treating vascular and coronary disease. The company’s Orbital Atherectomy Systems treat calcified and fibrotic plaque in arterial vessels throughout the leg and heart in a few minutes of treatment time, and address many of the limitations associated with existing surgical, catheter and pharmacological treatment alternatives. The FDA granted the first 510(k) clearance for the use of the Orbital Atherectomy System in peripheral arteries in August 2007. In October 2013, the company received FDA approval for the Coronary Orbital Atherectomy System. To date, more than 290,000 of CSI’s devices have been sold across the United States.
The Diamondback 360 and Stealth 360 PAD Systems are percutaneous orbital atherectomy systems indicated for use as therapy in patients with occlusive atherosclerotic disease in peripheral arteries and stenotic material from artificial arteriovenous dialysis fistulae. The systems are contraindicated for use in coronary arteries, bypass grafts, stents, or where thrombus or dissections are present. Although the incidence of adverse events is rare, potential events that can occur with atherectomy include: pain, hypotension, CVA/TIA, death, dissection, perforation, distal embolization, thrombus formation, hematuria, abrupt or acute vessel closure, or arterial spasm.