ORBIT II: Atherectomy system associated with durable long-term results, potential cost savings

SAN DIEGO — Use of an orbital atherectomy system to remove severely calcified plaque in the coronary arteries prior to stent placement resulted in low rates of major adverse cardiac events at 2 years, according to results of the ORBIT II trial presented at the Society for Cardiovascular Angiography and Interventions Scientific Sessions.

Findings from an economic analysis also indicated that the Diamondback 360 Orbital Atherectomy System (Cardiovascular Systems Inc.) was cost-effective up to 1 year after treatment, Jeffrey Chambers, MD, FSCAI director of the cardiac catheterization laboratory at Mercy Hospital in Minneapolis, Minn., reported here.

The prospective, multicenter, single-arm study included 443 patients with severely calcified coronary lesions enrolled at 49 U.S. centers. Patients were treated with the orbital atherectomy system, which is designed to remove calcified plaque from the artery via orbital sanding prior to stenting.

The primary safety endpoint was MACE, including cardiac death, MI or target vessel/target lesion revascularization. The primary efficacy endpoint was procedural success, defined as stent delivery with a final residual stenosis < 50% without in-hospital MACE.

Initial results indicated favorable in-hospital, 30-day and 1-year outcomes following treatment. The data presented at SCAI 2015 included 2-year safety results in 419 evaluable patients and a long-term economic analysis.

MACE occurred in 19.4% of patients, including MI in 9.7%, TVR in 8.1% (6.2% TLR, 2.9% non-TLR) and cardiac death in 4.3%, according to a per-protocol analysis.

A subanalysis comparing patients with diabetes (n = 160) and without diabetes (n = 283) treated with orbital atherectomy revealed similar overall rates of MACE (20.6% in patients with diabetes vs. 18.7% in patients without diabetes; P = .71), cardiac death (5.3% vs. 3.7%; P = .45), MI (8.1% vs. 10.6%; P = .4) and TVR (8.7% vs. 7.8%; P = .75). Chambers said further studies are needed to better understand the impact of diabetes on the treatment of calcific CAD.

The 1-year economic analysis compared approximately 300 ORBIT II participants aged older than 64 years with 300 Medicare recipients for the index procedure and patients from the HORIZONS-AMI/ACUITY pooled analysis for both revascularization and cardiac death in the following 1-year. “From a facility or health system perspective, the total of projected cost-offsets in the first year in this elderly population would, on average, fully cover the cost of the orbital atherectomy system at $3,795 and possible extra $1,118 cost offset/savings — thus, up to a total possible cost offset/savings of $4,913 at 1 year,” Chambers said during a presentation.

The researchers also calculated an incremental cost-effectiveness ratio of $11,895 after treatment with the orbital atherectomy system, which is “far below the high-value threshold of $50,000 per quality adjusted life year,” Chambers said.

“Patients with complex coronary disease with severely calcified coronary arteries who were treated with orbital atherectomy as a lesion preparation tool to facilitate stent placement have good initial outcomes and durable 2-year results, with potential cost-saving benefits.” Chambers concluded.  – by Adam Taliercio

Reference:

Chambers, et al. Late-Breaking Clinical Trials. Presented at: Society for Cardiovascular Angiography and Interventions Scientific Sessions: May 6-9, 2015; San Diego.

Disclosure: Chambers reports receiving consultant fees/honoraria from Cardiovascular Systems Inc.