Background: Carotid arterial stent (CAS) systems are an alterative to carotid endarterectomy for the treatment of moderate to severe carotid stenosis, but the effectiveness of CAS compared to endarterectomy in preventing stroke and death is uncertain. This study's objective was to compare the clinical outcomes among Medicare beneficiaries undergoing carotid revascularization before and after CAS became widely available.
Objectives: This observational, retrospective cohort study compared 46,784 patients undergoing carotid revascularization from August 2005-March 2006 (the coverage era) to propensity-score-matched patients undergoing carotid revascularization between October 2002-September 2004 (the pre-coverage era), before widespread Medicare coverage of CAS.
Methods: Mortality was compared at 90 and 270 days after revascularization, as were the combined outcomes of periprocedural acute myocardial infarction and any stroke or death within 90 and 270 days after revascularization, between the two eras. Comparisons were also made between localities with high (23% of carotid procedures being CAS) and lower (9% of carotid procedures being CAS) adoption rates of carotid stents during the coverage era.
Results: There were no significant differences in 90-day mortality (2.2% vs 2.2%; P = .79), 90-day combined outcomes (4.5% vs 4.3%; P = .13), or 270-day mortality (4.8% vs 4.6%; P = .17) between the coverage and pre-coverage eras, but there were more 270-day combined outcomes in the coverage era (7.7% vs 7.3%; P = .03). In localities with higher adoption of carotid stents, there was higher 90-day mortality (adjusted odds ratio [OR] 1.15; P = .16), 90-day combined outcomes (OR = 1.17; P = .03), 270-day mortality (OR = 1.13; P = .07), and 270-day combined outcomes (OR = 1.10; P = .09) in the coverage era. There were no differences in event rates between eras in areas with lower carotid stent adoption.
Conclusion: The adoption of carotid stents for treatment of carotid stenosis was associated with increased rates of adverse clinical outcomes after carotid revascularization.