MIAMI BEACH – Debulking calcified infrapopliteal arteries by performing orbital atherectomy before balloon angioplasty improves outcomes compared with balloon angioplasty alone in patients with critical limb ischemia, according to findings from the randomized, multicenter CALCIUM 360° Trial.
At 12 months’ follow-up, the procedural success rate was 93% in 25 patients with critical limb ischemia and confirmed calcified lesions, who were randomized to receive the combined orbital atherectomy and angioplasty treatment, compared with 82% in 25 similar patients randomized to balloon angioplasty alone, Dr. Jonathan Ellichman reported at ISET 2013, an international symposium on endovascular therapy.
The findings are important given the treatment challenges associated with calcified lesions, the shortcomings of balloon angioplasty alone, and the high costs and mortality associated with amputation in patients with critical limb ischemia, said Dr. Ellichman of the Midwest Cardiovascular Research Foundation, Memphis. In addition, 40% of critical limb ischemia amputees die within 2 years of amputation.
Angiography routinely underestimates the severity of calcification, and its use in patients with calcified lesions is technically challenging and associated with a higher procedural complication rate, leading to increased need for bailout stent placement, he added.
Procedural success for this study was defined as restoration of normal lumen with residual stenosis of 30% or less and with no bailout stenting or dissection types C-F, he said.
The pressures required during balloon angiography were significantly lower for patients in the orbital atherectomy and balloon angioplasty group (maximum average balloon inflation of 5.9 atm, vs. 9.4 atm in the balloon angioplasty–only group). Bailout stenting was required in 7% of 29 lesions treated in the orbital atherectomy and angioplasty patients, and in 14% of 35 lesions in the balloon angioplasty–only patients.
The estimates for freedom from target vessel revascularization and all-cause mortality were 93% and 100%, respectively, at 12 months in the orbital atherectomy and balloon angioplasty group, compared with 80% and 68%, respectively, in the balloon angioplasty–only group.
Patients in this eight-center study included 32 men and 18 women (mean age, 71 years) with 50% or greater stenosis; Rutherford classifications 4-6 in the popliteal, tibial, or peroneal arteries; and more than one patent distal runoff vessel. Those randomized to the orbital atherectomy group were treated with Cardiovascular Systems Inc.’s (CSI’s) Stealth 360° PAD System, which Dr. Ellichman said is his device of choice for treating calcified lesions because of its capabilities with angulated, tortuous tibial vessels.
"Greater than 90% (of patients) in both groups had moderate to severe calcification, which is really the sweet spot for the CSI device," he said.
Based on these findings, it appears that combined orbital atherectomy and balloon angioplasty restores flow in patients with critical limb ischemia, and improves outcomes with respect to patency, limb salvage, and survival. These findings, and their potentially significant economic impact, should be evaluated in larger confirmatory studies, he said.
The CALCIUM 360° Trial was sponsored by CSI, the maker of the Stealth 360° device. Dr. Ellichman reported having no financial disclosures.