SCOTTSDALE, ARIZ. – The cost of materials makes carotid artery stenting 40% more expensive than carotid endarterectomy with no relative clinical advantage, a retrospective study of 306 cases found.
Coronary artery stenting is not cost effective in the routine management of carotid disease, Dr. Gregory D. Crenshaw and his associates reported at the annual meeting of the Southern Association for Vascular Surgery. The study won an award as the best study presented at the meeting.
The investigators compared 30-day clinical outcomes and hospital costs for 174 patients who underwent carotid endarterectomy (CEA) and 132 who underwent carotid artery stenting (CAS) with embolic protection at a single tertiary-care institution during January 2008–September 2010. Nine other patients who underwent CAS during that time were excluded because they had additional procedures that could bias the economic analysis.
Hospital costs in 2010 dollars averaged $9,426 for CAS, 40% higher than the mean $6,734 cost of CEA, said Dr. Crenshaw, a vascular and endovascular surgery fellow at the Ochsner Clinic Foundation, New Orleans.
Supply costs drove most of the difference, with supplies for CAS procedures averaging $3,667 more than for CEA. In 2010 terms, a carotid stent in the study cost $2,100-$2,495 and an embolic protection device cost $1,594-$1,695, compared with a cost of $90-$100 for a synthetic carotid patch used with endarterectomy.
Rates of adverse events did not differ significantly between groups. Stroke, MI, or death occurred in 2.3% of patients undergoing CEA and 3.8% of patients undergoing CAS.
Dr. Gregory D. Crenshaw
Analyses of subgroups found the same trends in all subgroups – higher cost but no clinical advantage with carotid artery stenting, compared with carotid endarterectomy.
The investigators assessed hospital costs (not charges) by creating relative value units (RVUs) for expenses in the categories of labor, supplies, facility or equipment, and miscellaneous. The RVUs in the study were not related to Medicare work RVU valuations. The analysis did not include professional fees. Total expenses were normalized to 2010 costs based on the medical consumer price index.
The findings support previous studies suggesting similar clinical results from the two treatments but higher costs with carotid artery stenting.
The 2,502-patient Carotid Revascularization Endarterectomy Versus Stenting (CREST) trial found rates of 6.8% for CEA and 7.2% for CAS for a composite end point of periprocedural stroke, MI, death, or an ipsilateral stroke within 4 years (N. Engl. J. Med. 2010;363:11-23). In six studies between 1998 and 2010, the cost of carotid artery stenting exceeded that of carotid endarterectomy by 5%-118%, Dr. Crenshaw said.
When there is "clinical equipoise" between two therapies, costs become increasingly important, especially in the current era of rising health care costs and the need for efficient use of health care dollars, he said.
In Dr. Crenshaw’s study, the CEA group had a higher proportion of symptomatic patients (44%) and urgent cases (13%), compared with the CAS group (34% and 10%, respectively), but these differences did not achieve statistical significance. Compared with the endarterectomy group, the stenting group had significantly higher prevalences of coronary artery disease (61% vs. 37%) and congestive heart failure (18% vs. 5%).
Hospital costs were significantly higher with carotid artery stenting than with carotid endarterectomy for symptomatic or asymptomatic patients and for elective surgeries. Higher hospital costs for urgent cases treated by stenting compared with endarterectomy did not reach statistical significance.
Higher costs for symptomatic patients compared with asymptomatic patients in each subgroup were due to longer stays in the hospital and possibly due in part to extra costs for diagnostic imaging, he said. Overall, length of hospitalization was similar between the endarterectomy and stenting groups, a mean of 2 days in each.
Although the study was limited by not including professional fees in the analysis, including professional fees likely would not have changed the conclusions, he said. Medicare reimbursement for carotid artery stenting and for carotid endarterectomy is identical (averaging $1,167 in 2011). The average Medicare reimbursement for anesthesia for carotid endarterectomy is $350-$425, which also would not have changed the results significantly.
Dr. Crenshaw said he has no relevant conflicts of interest.