LOS ANGELES – Carotid artery stenting in older, asymptomatic patients with severe carotid artery stenosis is, in general, as bad an idea as it has already proven to be in symptomatic patients, with a multifold increase in adverse short- and mid-term outcomes, compared with similar older, asymptomatic patients who underwent endarterectomy, according to a combined-study analysis with more than 2,500 patients.
Mitchel L. Zoler/MDedge News
Dr. Jenifer H. Voeks
The risk for poor outcomes in patients with severe but asymptomatic carotid artery disease who underwent carotid artery stenting (CAS), compared with patients who instead underwent carotid endarterectomy (CEA) “abruptly increased around age 75,” in an analysis that combined data from the two major, published, randomized trials that compared these two interventions in this patient population, Jenifer H. Voeks, PhD said at the International Stroke Conference sponsored by the American Heart Association.
These results “largely mirror” the findings from a similar combined analysis of data from four major, randomized trials that compared CEA and CAS in patients with symptomatic carotid disease, she noted (Lancet. 2016 Mar 26;387[10025]:1305-11). The new findings in an expanded population of asymptomatic patients derived from two separate studies showed that, in patients aged 70 years or less, “CAS appears to be a reasonable alternative to CEA, but above age 70, and certainly above age 75, age-related risk factors such as cerebrovascular anatomy and underlying cerebral pathology should be carefully considered before selecting patients for CAS,” said Dr. Voeks, a neurology researcher at the Medical University of South Carolina, Charleston. Many experts also believe that, for asymptomatic patients, intensive medical management may have returned as an alternative to either of these invasive approaches for treating severe carotid stenosis and has achieved a level of equipoise that led to the launch of CREST 2 (Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis Trial). CREST 2 is comparing CEA and CAS with medical management, and is scheduled to report results in 2021.
The data for this analysis in asymptomatic patients came from the first CREST (Carotid Revascularization Endarterectomy Versus Stenting Trial; N Engl J Med. 2010 Jul 1;363[1]:11-23), which included 1,181 asymptomatic patients (nearly half the total enrollment, with symptomatic patients making up the balance) and had no age ceiling, as well as all 1,453 patients from the ACT 1 trial, which enrolled exclusively asymptomatic patients and limited enrollment to patients aged 79 years or less (N Engl J Med. 2016 Mar 17;374[11]: 1011-20). Because the maximum age of patients in ACT 1 was 79 years, for this analysis Dr. Voeks and associates only included the 1,091 asymptomatic CREST patients who also were within the same age ceiling. The resulting cohort of 2,544 included 1,637 patients who underwent CAS and 907 who underwent CEA (because of a 3:1 randomization ratio in ACT 1), creating the largest data set to compare CAS and CEA by age in asymptomatic patients, Dr. Voeks noted. When subdivided by age, 30% of the cohort was younger that 65 years, 54% were 65-74, and 16% were 75-79.
The primary outcome the researchers used for their analysis was the combined incidence of periprocedural stroke, MI, or death, plus the incidence of ipsilateral stroke during 4 years of follow-up post procedure. Among patients who underwent CAS, this outcome occurred in roughly 9% of patients aged 75-79 years and in about 3% of those younger than 65 years, a hazard ratio of 2.9 that was statistically significant. In contrast, the incidence of the primary outcome among patients aged 65-74 years was just 30% higher, compared with patients aged less than 65 years, a difference that was not statistically significant.
Patients who underwent CEA showed no similar relationship between age and outcome. The incidence of the primary outcome among the CEA patients was roughly the same, about 3.5%, regardless of their age.
A second analysis that considered age as a continuous variable showed a sharply spiked increase in the risk for CAS patients, compared with CEA patients once they reached about age 73-75 years. Until about age 72, the rate of the primary outcome was nearly the same regardless of whether patients underwent CAS or CEA, but the risk for adverse outcomes rose “steeply” starting at about age 75 so that by age 79 the rate of the primary outcome approached 300% higher among the CAS patients compared with CEA patients, Dr. Voeks said.
She cautioned that the analysis included just 115 total primary-outcome events, which makes the incidence rate estimates somewhat imprecise, and that the data reflect outcomes in patients who were treated more than a decade ago, but these data remain the only reported results from large randomized trials that compared CAS and CEA in asymptomatic patients.
Dr. Voeks reported no disclosures.
SOURCE: Voeks JH al. Stroke. 2020 Feb 12;51[suppl 1], Abstract 70.