The magnitude of benefit from early carotid endarterectomy (CAE) treatment in patients with asymptomatic carotid stenosis has waned over the last two decades, new research suggests.

As a consequence, initial medical therapy may now be a more acceptable treatment strategy for patient management, according to a study published in JAMA Neurology.

A US study comparing the effectiveness of CAE or medical therapy in 5,221 patients between 2005 and 2009 found the 5-year risk of fatal nonfatal strokes was lower in patients who underwent CAE (5.6% v 7.8%).

The risk difference was substantially lower than that seen in previous trials such as the 2004 Asymptomatic Carotid Surgery Trial which noted a stroke risk difference of 5.4%.

The number needed to treat to prevent a single stroke within five years was 43 in the current study and 18 in the previous study.

The current study showed a five-year survival of 77.3% in the CEA cohort and 71.9% in the medical therapy cohort.

It also found a 30-day perioperative complications rate in the CEA cohort of 2.4%

“This analysis suggested that little to no difference existed between the two treatment strategies after accounting for competing causes of death.”

“These analyses, when taken together, suggest that in real-world practice medical therapy may be an equally acceptable treatment strategy for patients with asymptomatic carotid stenosis.”

“The decreased stroke risk in patients with carotid artery stenosis, the persistent up-front perioperative risks, and the small difference in stroke risk between the 2 treatment strategies suggest that patients treated with CEA would now require a longer time to accrue enough stroke reduction benefit to justify the up-front risks of the surgical procedure.”

The investigators, from the University of California San Francisco, acknowledged some limitations to their study such as the population of mainly older male veterans.

“As such, the findings may not be generalizable to the entire population of patients who receive carotid intervention for asymptomatic carotid stenosis,” they said.