August 13, 2020
2 minute read
Disclosures: Keyhani does not report any relevant financial information. Please see the study for relevant financial information from all other authors.
According to the researchers, the absolute reduction in the risk of fatal and non-fatal strokes in patients who underwent early carotid endarterectomy was less than half the difference in risk compared to trials initiated 20 years ago.
The study published in JAMA Neurology also determined that this absolute reduction was no longer statistically significant when the concurrent risk of death without stroke was taken into account.
“Given the initial perioperative risks associated with carotid endarterectomy, initial medical therapy may be an equally acceptable treatment strategy for the management of patients with asymptomatic carotid stenosis,” Salome Keyhani, MD, MPH, professor of medicine at the University of California, San Francisco, School of Medicine, and his colleagues wrote.
In this comparative efficacy study, researchers evaluated data from 5,221 veterans aged 65 or older who underwent carotid imaging from 2005 to 2009. Patients were excluded if they had lower carotid stenosis at 50%, haemodynamically insignificant stenosis and a history of transient ischemic attack or stroke 6 months before imaging.
Two cohorts were formed: patients receiving initial medical treatment (n = 2,509; mean age 74 years; 99% male) and those receiving carotid endarterectomy (n = 2,712; mean age 74 years 99% men). Both treatment options were administered within one year of carotid index imaging. A follow-up was carried out for 5 years. The analyzes used in the asymptomatic carotid surgery trial were replicated in this trial to estimate the comparative effectiveness of carotid endarterectomy and initial medical therapy in preventing nonfatal and fatal strokes.
The rate of stroke or death within 30 days after carotid endarterectomy was 2.5% (95% CI, 2-3.1). At 5 years, the risk of fatal and non-fatal stroke was lower in the carotid endarterectomy group than in the initial medical treatment group (5.6% versus 7.8%; risk difference, 2.3%; CI at 95%, 4 to 0.3).
When concurrent risk of death was incorporated, the difference in risk between patients who underwent carotid endarterectomy and those who received initial medical treatment was smaller and not statistically significant (difference in risk, 0.8%; 95% CI , 2.1 to 0.5).
In patients who met the inclusion criteria for randomized controlled trials, the risk of fatal and nonfatal stroke at 5 years was 5.5% (95% CI, 4.5-6.5) for the group carotid endarterectomy and 7.6% (95% CI, 5.7-9.5) for the initial medical treatment group (difference in risk, 2.1%; 95% CI, 4.4 to 0, 2). A risk difference of 0.9% occurred when taking competing risks into account (95% CI 2.9 to 0.7).
“The decreased stroke risk in patients with carotid artery stenosis, the persistent initial perioperative risks, and the small difference in stroke risk between the two treatment strategies suggest that patients treated with carotid endarterectomy would now have need more time to accumulate enough stroke-reducing benefits to justify the initial risks of surgery,” Keyhani and colleagues wrote.