Researchers Call for New Trials to Resolve Carotid Stenting Debate


November 18, 2010

November 18, 2010 – After the initial findings from the CREST trial, debate continues to swirl as proponents of both carotid endarterectomy (CEA) and carotid angioplasty and stenting (CAS) claim superiority for their preferred intervention.

As a result, Wesley S. Moore, M.D., professor and chief emeritus of the division of vascular surgery at UCLA Medical Center, has proposed a moratorium on both procedures as a way to accelerate a new, clarifying clinical trial for patients with carotid stenosis.

During the VEITHsymposium, Moore called attention to the initial delay and difficulties in recruiting patients and the subsequent decision to include asymptomatic patients in order to reach the 2,500 cohort. Including both asymptomatic and symptomatic patients diluted the study’s power to compare the two procedures because asymptomatic patients tend to have fewer complications than symptomatic patients.

That flaw attenuated the somewhat conflicting findings that have fueled the ongoing controversy over CREST’s outcomes. In aggregate, the primary endpoints of death, stroke and myocardial infarction were 4.5 percent for CEA and 5.2 percent for CAS, which were not statistically significant. However, when the primary endpoints of death and stroke were analyzed alone, the rate was 2.3 percent for CEA versus 4.4 percent for CAS and those differences were statistically significant at P=0.005. There were more non-fatal myocardial infarctions with CEA, which resulted in equalizing the aggregate of the three primary endpoints between the two procedures.

Attempts at subset analysis designed to separate results in symptomatic versus asymptomatic patients were limited by sample size. Nonetheless, the stroke rate for CEA in symptomatic patients was 3.2 percent versus 6 percent in CAS with P=0.019. The stroke rate for CEA in asymptomatic patients was 1.4 percent versus 2.5 percent for CAS, but that difference did not achieve statistical significance in spite of a clear trend in favor of CEA.

That apparent tilt towards CEA is also reflected in the results of a nationwide sample of more than 400,000 hospital patients who underwent either CAS or CEA for carotid revascularization between 2005 and 2007. As reported by Mohammed H. Eslami, M.D., of the division of vascular and endovascular surgery at the University of Massachusetts Medical School, CAS significantly increased the odds of stroke in asymptomatic patients. However, the data also showed that utilization of CAS jumped 66 percent between 2005 and 2006, with some improvement in outcomes in that period as well.

Further complicating the matter, Moore said that treating asymptomatic patients with statins and ACE inhibitors has greatly reduced the risks for stroke and death for patients with carotid disease. This calls into question whether either surgical intervention on its own, as was the case in CREST, is the appropriate therapy for those patients.

To resolve these issues, he endorsed the need for a new three-arm trial of asymptomatic patients comparing outcomes of CAS combined with optimal medical treatment, CEA combined with optimal medical treatment, and medical treatment alone. Also, he called for a temporary halt for CAS or CEA treatment of asymptomatic patients with carotid stenosis so that the pool of potential subjects for the new trial would be as large as possible.

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