Is carotid endarterectomy cost-effective? An analysis of symptomatic and asymptomatic patients.

BACKGROUND

The North American Symptomatic Carotid Endarterectomy Trial (NASCET) and the Asymptomatic Carotid Atherosclerosis Study (ACAS) showed significant risk reductions for carotid endarterectomy (CE) but did not consider the cost-effectiveness of CE.

METHODS AND RESULTS

We developed Markov models based on NASCET and ACAS to simulate hypothetical cohorts of patients with carotid stenosis and calculated quality-adjusted life expectancies and direct medical costs for those receiving either CE or medical therapy. For symptomatic patients, we used a surgical stroke risk of 5.8%, a 2-year stroke risk of 27.6% for medical patients, and a post-30-day surgical risk reduction of 87% for ipsilateral strokes. For symptom-free patients, we used a surgical stroke risk of 1.7%, a 5-year stroke risk of 17.5% for medical patients, and a post-30-day surgical risk reduction of 74% for ipsilateral strokes. Cost and quality-of-life estimates were estimated from the literature. The incremental cost-effectiveness ratio of CE versus medical therapy was $4100 and $52700 per quality-adjusted life year (QALY) gained for symptomatic and symptom-free patients, respectively. Incremental cost effectiveness ratios were < $50000/QALY gained for symptomatic patients for wide variations in baseline assumptions. For asymptomatic patients, the incremental cost-effectiveness ratio was $100900/QALY gained if the perioperative risk was 4%, $36400/QALY gained if the risk of untreated patients was doubled, and $13500/QALY gained if the cost of CE was halved.

CONCLUSIONS

Performance of CE is associated with favorable incremental cost-effectiveness ratios compared with other accepted medical interventions; however, the analysis for symptom-free patients was sensitive to a number of parameters.