TCAR vs Carotid Endarterectomy: Is One Superior in Reducing Stroke Risk?

In patients with standard surgical risk undergoing endarterectomy for carotid stenosis, the risk of 30-day stroke, myocardial infarction (MI), death, or 1-year ipsilateral stroke is similar to those undergoing transcarotid artery revascularization, according to a recent study published in JAMA Neurology.

Thus, they conducted this retrospective, propensity-matched cohort study to compare stroke, MI, and death outcomes after transcarotid artery revascularization versus carotid endarterectomy in patients at standard surgical risk.

Schermerhorn et al used data from the multicenter Vascular Quality Initiative Carotid Artery Stent and Carotid Endarterectomy registries to identify 2,962 patients undergoing transcarotid artery revascularization (mean age, 70.4 years; 64.5% men), and 8,886 undergoing endarterectomy (mean age, 70 years; 65.0% men). Most were White (89%), asymptomatic (45.8%-51.5%), and hypertensive (88.5%-90%), with no diabetes, and most were taking aspirin and statins.

Stenosis was >80% in 77.7% of those undergoing transcarotid artery stenting and in 58.4% of those undergoing carotid endarterectomy. After 1:3 propensity score matching to mitigate differences between the two cohorts, greater than 80% stenosis was seen in 77.7% versus 78.3%, respectively.

Patients who were 80 years and older, had unstable angina, MI within the past 6 months, moderate or severe congestive heart failure, chronic obstructive pulmonary disease and using home oxygen, on dialysis, with creatinine greater than 2.5 mg/dL were excluded.

"CMS approves carotid stenting for patients 75 years and older because this was the age cutoff used in the Carotid Artery Revascularization Using the Boston Scientific FilterWire EX/EZ and the EndoTex NexStent (CABERNET) trial. However, patients aged between 75 and 80 years were included because this age group is not widely considered to be at high risk. Patients undergoing transcarotid artery revascularization due to multivessel coronary artery disease or need for cardiac or major surgery were not excluded because these variables are not similarly captured in the carotid endarterectomy database and therefore could not be equally excluded from both cohorts," noted Schermerhorn and fellow researchers.

The risk of the primary composite endpoint—30-day stroke, death, or MI or 1-year ipsilateral stroke—was no different in the two groups, at 3.0% in those undergoing transcarotid artery revascularization versus 2.6% in those undergoing endarterectomy, for an absolute difference of 0.40% (95% CI, –0.43 to 1.24%; RR, 1.14; 95% CI, 0.87-1.50; P=0.34). Transcarotid artery revascularization, however, was associated with a higher risk of 1-year ipsilateral stroke (1.6% versus 1.1%, respectively; absolute difference, 0.52%; 95% CI, 0.03-1.08; RR, 1.49; 95% CI, 1.05%-2.11%; P=0.02). It was not associated with any difference in 1-year all-cause mortality (2.6% versus 2.5%; absolute difference, –0.13%; 95% CI, –0.18 to 0.33%; RR, 1.04; 95% CI, 0.78-1.39; P=0.67).

In an accompanying editorial, Seemant Chaturvedi, MD, of the Department of Neurology and Stroke Program, University of Maryland School of Medicine, Baltimore, commented on these results, first noting the inclusion of transcarotid artery revascularization (TCAR) in the therapeutic landscape in addition to carotid endarterectomy (CEA), which has a "track record of longer than 65 years."

"Proponents of TCAR proclaim that is now a worthy challenger to CEA and should be considered an equal and complementary alternative. But there are several elephants in the room that must be addressed before one can accept this assertion," he wrote.

The first is the "long track record of CEA," which has been extensively studied in large clinical trials. Next is that in this study, CEA was superior to TCAR for the endpoint of periprocedural stroke.

"Although the absolute difference was modestly different (1-year stroke rate 1.6% with TCAR; 1-year stroke rate 1.1% with CEA), at the population level and with a broad group of operators, the magnitude of the difference between CEA and TCAR could conceivably widen in favor of CEA," wrote Chaturvedi.

Third is that the use of propensity score matching actually reduces the sample size. "The propensity score–based approach reduces the likelihood of finding a difference in outcomes between the two groups. In addition, the 5% upper limit for the noninferiority margin appears overly generous in favor of TCA," noted Chaturvedi, adding that the number of symptomatic patients included is another factor to consider.

"The largest elephant in the room is that it is not clear if many patients in the study need either procedure. With advances in intensive medical therapy, the value of carotid revascularization has come under scrutiny," he continued.

Ultimately, concluded Chaturvedi, "In many instances, the enthusiasm for a new surgical or interventional approach exceeds the amount of high-quality evidence in support of the procedure. At present, this appears to be the case for TCAR. Before referring patients for TCAR in significant numbers, especially for symptomatic patients, neurologists should wait for data that come from large, adequately powered trials with postprocedure assessment done by individuals with neurologic expertise. Until then, if the patient requires a carotid revascularization procedure CEA is like a car that has been driven for more than 100,000 miles. Your patient will know that it has stood the test of time, there are many appropriate ’drivers’ available, and the expected complications will not be a surprise. For carotid revascularization, the time-tested approach seems best to optimize patient outcomes."

Study limitations include that physicians chose the procedure based on expertise and clinical judgement, that the carotid artery stent registry collects predefined variables defining anatomic high surgical risk factors for qualification for carotid stenting that are not included in the carotid endarterectomy registry, that researchers did not differentiate between ischemic and hemorrhagic strokes, that MI events were limited to periprocedural in-hospital periods while stroke events were recorded after discharge, incomplete postdischarge follow-up that was higher for endarterectomy patients, and lower 1-year follow-up rates.

This study was supported by the Society for Vascular Surgery Patient Safety Organization.

Schermerhorn reported no disclosures.

Chaturvedi reported grants from NINDS CREST 2 for being an executive committee member outside the submitted work.

Liang P, et al "Risk of stroke, death, and myocardial infarction following transcarotid artery revascularization vs carotid endarterectomy in patients with standard surgical risk" JAMA Neurol 2023; DOI: 10.1001/jamaneurol.2023.0285.

Chaturvedi S "Transcarotid artery revascularization for stroke prevention—Multiple elephants in the room" JAMA Neurol 2023; DOI: 10.1001/jamaneurol.2023.0293.