A major international study led by Mayo Clinic researchers and funded by the National Institutes of Health (NIH) has found that in people with severe carotid artery narrowing who have not had recent stroke symptoms, a minimally invasive procedure called carotid artery stenting, combined with intensive medical therapy, significantly reduces the risk of stroke compared to medical therapy alone. The CREST-2 program consisted of two parallel, randomized clinical trials conducted at 155 medical centers in five countries, including Australia, Canada, Israel, Spain, and the United States. In one trial, participants received stenting plus intensive medical therapy or isolated medical therapy. In the other, participants received carotid endarterectomy plus medical therapy or isolated medical therapy. All participants received comprehensive medical care, including lifestyle counseling and medication as needed to control blood pressure, LDL cholesterol, and diabetes, as well as help with smoking cessation. In collaboration with researchers from the University of Alabama at Birmingham, scientists analyzed the occurrence of stroke and death within 44 days after the stenting procedure. They also analyzed the occurrence of stroke over a four-year period on the same side of the body as the narrowed artery. The stenting trial showed a significant reduction in stroke: over four years, 2.8% of patients treated with stenting and therapy suffered a stroke, compared to 6% of those who received isolated medical therapy (about half the stroke risk). However, in the endarterectomy trial, the difference in stroke rates (3.7% with surgery vs. 5.3% with medical therapy alone) was not statistically significant. Dr. Brott emphasizes personalized decision-making. "For some patients — particularly those with more advanced narrowing or a plaque that seems unstable or more likely to cause a blockage — stenting may offer additional protection, while for others, isolated medical therapy may be sufficient," he says. Close follow-up and coordinated care helped all participants achieve and maintain significant improvements in their blood pressure and cholesterol levels. Researchers will continue to monitor participants to evaluate long-term outcomes. Serious complications were infrequent in both procedures. The findings offer clearer guidance for doctors and patients considering a preventive procedure. "Decades ago, surgery clearly helped prevent strokes in many patients," says Thomas Brott, M.D., a neurologist at Mayo Clinic in Florida and the study's senior author. "But medical therapy has improved so much that we needed to re-examine the balance between benefit and risk in people who don't have symptoms."
