Carotid Stenting May Be More Costly Than Endarterectomy

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Carotid artery stenting (CAS) incurs greater expense but provides no better clinical outcomes than carotid endarterectomy (CEA), according to a retrospective single-center analysis published online March 27, 2012, ahead of print in the Journal of Vascular Surgery.

Researchers led by W. Charles Sternbergh III, MD, of Ochsner Clinic Foundation (New Orleans, LA), examined hospital cost and 30-day clinical outcomes in 306 patients who underwent CEA (n = 174) or CAS (n = 132) at their institution from January 2008 through September 2010.

Apart from professional fees, which were not included in the analysis, costs of the index hospitalization were divided into 4 categories:

• Labor
• Supply
• Facility/equipment
• Miscellaneous

Stenting 40% More Expensive

The total mean hospital cost was approximately 40% higher for CAS vs. CEA, driven by the significantly higher direct supply costs for CAS (table 1). There were no significant differences between the 2 groups with regard to labor or facility/equipment costs.

Table 1. Cost Comparison

In subgroup analyses across symptomatic, asymptomatic, elective, and urgent subgroups, CAS was consistently more expensive than CEA in all except the urgent subgroup (P = 0.071). Patients who underwent CAS as part of a trial or registry (54%), however, incurred fewer costs compared with those treated outside of trials ($7,779 ± $3,525 vs. $11,279 ± $7,114; P = 0.0004). The same pattern was not seen for CEA.

In terms of clinical outcomes, 30-day major adverse events (composite of any stroke, death, and MI), occurred in 2.3% of the CEA group and 3.8% of the CAS group (P = 0.5).

Overall length of stay was the same in both groups at 2.1 days (P = 0.9). Those with symptomatic disease or who had urgent intervention, however, had much longer stays than elective patients or those who had asymptomatic disease. In patients undergoing urgent intervention, post-procedure length of stay was 3.5 days in the CEA group and 4.3 days in the CAS group.

Trial vs. Real-world Differences as Yet Unexplained

According to the study authors, the findings regarding the lower costs for CAS patients enrolled in a trial or registry are novel and “refute the notion that the differential in cost between CEA and CAS is due, in part, to additional costs associated with protocol-mandated imaging and testing for trial patients.” They also point to recent data suggesting that clinical outcomes generated in post-trial CAS registries are actually better than real-world practice.

Although the explanation for higher costs and poorer outcomes in CAS patients treated outside a research setting are speculative, Dr. Sternbergh and colleagues question whether such patients represent the highest risk subgroup and therefore also the more costly population to treat.

While there are additional anesthesia professional fees incurred with CEA that are generally unnecessary for CAS, the study authors say an average Medicare reimbursement for anesthetic services for a CEA procedure ranges from approximately $300 to $425.10. With CAS being $2,692 more expensive than CEA, including professional fees would not have changed the study’s conclusion, they add.

The researchers conclude: “Given the significant cost premium of CAS and its lack of improvement in clinical outcome when compared to CEA, CAS cannot be considered routinely cost-effective in the management of carotid artery disease.”

A Question of Perspective

In an e-mail communication with TCTMD, David J. Cohen, MD, of the Saint Luke's Mid America Heart Institute (Kansas City, MO), said it is important to recognize that because the study was a nonrandomized comparison, differences in patient characteristics, both observed and unobserved, may underlie some of the cost differences.

The study authors acknowledge this possibility, noting that CEA patients were more likely to have symptomatic disease, while the CAS group had a higher rate of asymptomatic disease, which is a risk factor for periprocedural stroke. There also was a higher prevalence of CAD and congestive heart failure in the CAS group, suggesting that they also had a higher potential cardiac morbidity.

“In addition, costing studies are very difficult to compare because [their] methodology is not easily standardized and there are wide variations in how overhead costs are allocated across cost centers at different hospitals,” Dr. Cohen said. “In general, treatments like carotid stenting that involve high-cost disposables (ie, stents, balloons, embolic protection devices) involve much higher variable costs than procedures like surgery where the major cost driver is time in the operating room, which may not be variable in the short to intermediate term.”

Dr. Cohen also pointed out that from the hospital's perspective, where the main issue is the balance between cost of care and revenue, “it may be perfectly reasonable to exclude many fixed costs from an economic comparison. And this appears to have been the approach taken by the authors.”

A study taking a societal perspective, on the other hand, would include not only physician costs and those arising from treatment but also a larger proportion of overhead-related costs, which are not fixed in the long run, he said. “It is therefore conceivable,” Dr. Cohen observed, “that 2 analysts studying exactly the same patients could arrive at different answers with respect to costs depending on the extent to which fixed costs were included in the analysis.”

Multicenter Trials Find No Cost Difference

In a telephone interview with TCTMD, William A. Gray, MD, of Columbia University Medical Center (New York, NY), characterized the study as reasonably well done from a methodologic standpoint, but added that one of the biggest issues with such studies is that they involve “charges converted to costs, and that has a whole host of problems associated with it.”

Dr. Gray added that data from 2 large multicenter studies refute the suggestion that carotid stenting is more expensive. In a published analysis from SAPPHIRE, he said there was no difference in costs at hospitalization and at 1 year. Cost data from the CREST trial, meanwhile, have yet to be published, but Dr. Gray said those data “also show no difference between endarterectomy and stenting.”

Therefore, looking at the picture as a whole, he said it is important to reconcile this single-center study with reports that are likely more robust from a methodologic standpoint.

“Not to be too critical, but we have to acknowledge that in the pantheon of analyses, this falls underneath those multicenter prospective studies,” Dr. Gray concluded.

 

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Source:
Sternbergh WC, Crenshaw GD, Bazan HA, et al. Carotid endarterectomy is more cost-effective than carotid artery stenting. J Vasc Surg. 2012;Epub ahead of print.

 

 

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