Mortality risks after carotid artery stenting in medicare beneficiaries

Medicare beneficiaries who underwent carotid artery stenting (CAS) had a 32 percent mortality rate during an average two-year follow-up, suggesting the benefits of CAS may be limited for some patients, according to a study published online by JAMA Neurology.

CAS is an approach to treat narrowing of the carotid arteries called carotid stenosis. The Centers for Medicare & Medicaid Services in 2005 issued a national coverage determination so CAS would be covered for Medicare beneficiaries at high surgical risk. Randomized clinical trials (RCTs) have examined CAS. However, RCT results may not be generalizable to real-word patients and outcomes during the periprocedural (30-day) period and long-term have not been described in real-world Medicare beneficiaries, according to the study background.

Jessica J. Jalbert, Ph.D., of Harvard Medical School, Boston, and coauthors examined data for 22,516 Medicare beneficiaries who underwent CAS between 2005 and 2009. The average age of the patients was 76.3 years, 60.5 percent were male, 93.8 percent were white, 91.2 percent were at high surgical risk, 47.4 percent had clinical symptoms and 97.4 percent had carotid stenosis of at least 70 percent.

Authors found rates of crude 30-day mortality, stroke or transient ischemic attack, and myocardial infarction (heart attack) were 1.7 percent, 3.3 percent and 2.5 percent, respectively. Mortality during the two-year average follow-up was 32 percent, with rates of 37.3 percent among symptomatic patients and 27.7 percent among asymptomatic patients. All symptomatic patients, except for those younger than 75 years, had mortality risks that exceeded one-third; patients at least 80 years old and those admitted nonelectively were among those with the highest risks.

"Excess periprocedural risks and the presence of significant competing risks could negate the benefits of CAS and alter the benefit-risk assessment relative to carotid endarterectomy [surgery to remove artery plaque] in these patients. ... Real-world observational studies comparing CAS, carotid endarterectomy and medical management are needed to determine the performance of carotid stenosis treatment options for Medicare beneficiaries," the study concludes.