EXPERT ANALYSIS FROM the northwestern vascular symposium
CHICAGO (FRONTLINE MEDICAL NEWS) – Carotid angioplasty and stenting (CAS) isn’t associated with a lower 30-day stroke risk than carotid endarterectomy (CEA) for revascularization of the internal carotid artery in patients with contralateral carotid occlusion, Leila Mureebe, MD, said at a symposium on vascular surgery sponsored by Northwestern University, Chicago.
“Procedure type is not protective. So we urge ongoing restraint for the wider application of CAS at this time. We know that CEA is well tolerated, with outstanding real-world outcomes,” noted Dr. Mureebe , a vascular surgeon at Duke University in Durham, N.C.
The reported prevalence of contralateral carotid occlusion (CCO) in patients undergoing revascularization for carotid artery disease is 3%-15%. Of late Dr. Mureebe has been particularly interested in two questions regarding CCO in patients undergoing revascularization of their other carotid artery: Is CCO truly a risk factor for perioperative stroke? And if so, can this risk be mitigated by the choice of procedure?
To answer the first question, Dr. Mureebe and her coinvestigators performed a meta-analysis of eight representative studies published between 1994 and 2012; they determined that CCO in patients undergoing CEA was indeed associated with a near doubling of perioperative stroke risk, compared with that of patients without CCO.
In order to learn whether CAS mitigates this risk, she and her coworkers analyzed the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database for the period between 2011 and 2015, in which they identified 15,619 fully documented CEA and 496 CAS.
“This NSQIP data is not just academic medical centers or big centers. I think it’s a pretty good look at what’s actually being done in the real world today,” according to Dr. Mureebe.
The analysis showed that CCO has already had an effect on practice. A higher proportion of patients with CCO now undergo stenting as opposed to endarterectomy. Only 4.6% of all CEAs were done in patients with CCO, compared with 11.5% of CAS procedures. Moreover, the majority of revascularizations in the setting of CCO were performed in patients with asymptomatic disease: 57% of all CEA and 53% of the CAS. The CAS finding was surprising given that reimbursement for CAS is at present limited to symptomatic patients at high surgical risk who have a significant internal carotid artery stenosis, Dr. Mureebe observed.
The 30-day stroke rate in patients with CCO was 3.22% after CEA and 1.75% after CAS, a difference that wasn’t statistically significant. In patients without CCO, the stroke rate was 2.03% after CEA and 2.96% after CAS.
Next, the investigators analyzed differences in stroke rates according to symptom status. Among patients with CCO and preprocedural transient ischemic attack, stroke, or transient monocular blindness who underwent CEA, the 30-day stroke risk associated with CEA was 5.2%, a significantly higher rate than the 2.1% rate seen in patients without symptoms. The number of patients with CCO undergoing CAS was too small to draw conclusions regarding possible differences in stroke risk based upon symptom status.
In the NSQIP database, patients with CCO had higher prevalences of heart failure, hypertension, and smoking. For this reason, Dr. Mureebe said she suspects CCO is a surrogate for greater atherosclerotic disease burden and not an independent risk factor for periprocedural stroke. If future studies of the minimally invasive transcarotid artery revascularization procedure also show a higher rate of bad outcomes in patients with CCO, that would further support the hypothesis that CCO is a marker of higher atherosclerotic disease burden, Dr. Mureebe said.
A limitation of the NSQIP database is that it captures only those CAS cases done in operating rooms. “Maybe patients undergoing CAS in the OR are different from those undergoing CAS in a radiologic suite or cath lab,” she noted.
Dr. Mureebe reported having no financial conflicts of interest regarding her presentation.
SOURCE: Mureebe L. 42nd Annual Northwestern Vascular Symposium .