NEW YORK (Reuters Health) – In patients with asymptomatic carotid stenosis (ACS), microemboli and cardiovascular events can be markedly reduced by aggressive medical therapy, Canadian research shows.
This finding has direct implications for surgical management of carotid disease, lead author Dr. J. David Spence, from the Stroke Prevention and Atherosclerosis Research Center, London, Ontario, told Reuters Health.
With intensive medical therapy, he noted, “less than 5% of patients with asymptomatic carotid stenosis can benefit from endarterectomy or stenting. Surgery or stenting for asymptomatic carotid stenosis should only be performed in patients with transcranial Doppler microemboli.”
As reported in the December 14th online issue of the Archives of Neurology, Dr. Spence’s team compared microemboli rates and cardiovascular events in patients with ACS who were seen at their center before and after intensive medical therapy was implemented in 2003. The earlier group included 199 patients seen from 2000 to 2002, while the later cohort included 269 patients seen from 2003 to July 2007.
According to the report, in 2003 the focus of therapy shifted from simply treating risk factors to focusing on reducing the plaque burden in the arteries. Components of intensive medical therapy included treatment with the maximum tolerable statin dose (regardless of low-density lipoprotein level) and an angiotensin-converting enzyme inhibitor or an angiotensin-receptor blocker. Patients with insulin resistance were also treated with metformin or pioglitazone.
Microemboli rates were 12.6% in the early group and 3.7% in the later group (p < 0.001). This fall correlated with improved control of lipid levels and slower progression of carotid plaque burden.
Cardiovascular event rates also dropped with intensive medical therapy. Prior to 2003, the rate of stroke, death, MI, or carotid endarterectomy due to symptomatic disease was 17.6%. After 2003, it was 5.6% (p < 0.001). Plaque progression also decreased significantly after implementation of intensive medical therapy (p < 0.001).
These findings are “hugely important in the US, where approximately 70% of carotid endarterectomy and stenting are being performed for asymptomatic stenosis; our study shows that 95% of that activity is inappropriate,” Dr. Spence emphasized.
For the general public, he has this advice: “If someone offers to perform carotid endarterectomy or stenting for your asymptomatic carotid stenosis without first detecting microemboli, you should walk quickly in the other direction.”
Arch Neurol 2009.