LIBERTY 360°: Peripheral endovascular interventions successful regardless of Rutherford class

CHICAGO — Regardless of severity of a patient’s lower-extremity peripheral artery disease, interventions including balloons, atherectomy and stents were associated with positive 30-day outcomes, according to initial results from the LIBERTY 360° study.

The study of nearly 1,200 patients with lower-extremity PAD, stratified by Rutherford class 2-3 (n = 500; mean age, 70 years; 67% men), Rutherford class 4-5 (n = 589; mean age, 70 years; 62% men) and Rutherford class 6 (n = 100; mean age, 68 years; 73% men), is designed to evaluate procedural, long-term clinical and economic outcomes of endovascular device interventions in the population (Adams 2016) , George L. Adams, MD, MHS, said in a presentation at The Amputation Prevention Symposium (AMP).

Adams, Director of cardiovascular and peripheral vascular research at Rex Hospital in Raleigh, North Carolina, presented procedural and 30-day outcomes from the study, in which any endovascular device could be used.

The higher the Rutherford class of the patient, the more target lesions were treated (RC2-3, 1.2; RC4-5, 1.3; RC6, 1.5), Adams said.

Approximately 50% of lesions were calcified, and the percentages of calcification grade were consistent across Rutherford classes.

Lesion length increased and chronic total occlusions were more frequent with increasing Rutherford class, according to Adams.

More than 95% of patients were treated with a balloon, more than two-thirds were treated with atherectomy and more than 15% were treated with stents.

Among those who received balloons, a plain balloon was used in approximately 80% of those with Rutherford classes 2 to 5 and in approximately 70% of those with Rutherford class 6, whereas drug-coated balloons were more likely to be used in those with Rutherford class 2-3, and cutting, focal force and scoring balloons were more likely to be used in those with Rutherford class 6.

The most common type of atherectomy used was orbital atherectomy (Diamondback 360°, Cardiovascular Systems Inc.), and approximately 45% of the time in those with Rutherford classes 2 through 5, and approximately 60% of the time in those with Rutherford class 6, according to Adams.

Bare-metal stents were used approximately twice as often as drug-eluting stents, with covered stents rarely being used.

Procedural complications rarely (0.8% to 2%) resulted in postprocedural hospitalization.

The researchers asked the treating physician of each patient whether the desired outcome was achieved. The answer was yes for 97.1% of patients with Rutherford class 2-3, for 95.5% of patients with Rutherford class 4-5, and 97.3% of patients with Rutherford class 6; with no significant differences between the classes (P ≥ .05), Adams said.

Mean target lesion percent stenosis declined from 80.6% at baseline to 29.5% after the procedure in patients with Rutherford class 2-3, from 83.6% at baseline to 33.7% after the procedure in patients with Rutherford class 4-5, and from 80.5% at baseline to 34.8% after the procedure in patients with Rutherford class 6.

Among those with Rutherford class 2-3, procedural success occurred in 84.5% and final percent stenosis of less than 50% occurred in 90.8%. Those figures, respectively, were 77.5% and 84.2% for patients with Rutherford class 4-5 and 70.5% and 77.7% for patients with Rutherford class 6.

The rate of freedom from major adverse events at 30 days was 99% in those with Rutherford class 2-3, 95.7% in those with Rutherford class 4-5 and 90.7% in those with Rutherford class 6, Adams said.

At 30 days, freedom from major amputation was 100% in those with Rutherford class 2-3, 98.8% in those with Rutherford class 4-5, and 95.8% in those with Rutherford class 6; freedom from target vessel revascularization was 99.4% in those with Rutherford class 2-3, 96.9% in those with Rutherford class 4-5, and 97.9% in those with Rutherford class 6; and freedom from death was 99.6% in those with Rutherford class 2-3, 99.7% in those with Rutherford class 4-5 and 95.9% in those with those with Rutherford class 6, according to Adams.

“The early findings in this novel all-comers PAD study suggest that ‘watchful waiting’ in Rutherford class 2-3 and ‘primary amputation’ in Rutherford class 6 may not be necessary,” Adams said. “Peripheral vascular intervention can be successful in these patient populations as well.” – by Erik Swain

Reference:

Adams GL, et al. The LIBERTY 360° Study Design. American Heart Journal. 2016;174:14-21.

Adams GL, et al. LIBERTY 360° Study Procedural and 30-day Outcomes of Endovascular Device Interventions in Patients with Symptomatic Lower Extremity Peripheral Artery Disease Presented at: AMP: The Amputation Prevention Symposium; Aug. 10-13, 2016; Chicago.

Disclosure: The study was funded by Cardiovascular Systems Inc. Adams reports financial ties with Abbott Vascular, Asahi, Bard, Boston Scientific, Cardiovascular Systems Inc., CloSys, Cook Medical, Cordis, Daiichi Sankyo, Lake Region Medical, Medtronic, Penumbra, Spectranetics, Terumo and Volcano.