"Carotid endarterectomy is the most frequently performed operation in peripheral vascular surgery--160,000 to 180,000 of these operations occur each year," said Bruce A. Perler, MD, MBA, lead author of the study. "Even in the best of hands, 1 to 5 percent of patients will have a stroke or die as a complication of the surgery. If we can cut that in half or by two-thirds, that's important."
Dr. Perler, who is the Julius H. Jacobson II Professor of Surgery at The Johns Hopkins University and chief of the division of vascular surgery at The Johns Hopkins Hospital in Baltimore, Md., spoke today at the American Medical Association's 24th annual Science Reporters Conference in Washington, D.C.
The study involved a chart review of 1,566 patients who underwent CEA between 1994 and 2004 at the Johns Hopkins Hospital and Johns Hopkins Bayview Medical Center in Baltimore. Six hundred fifty-seven, or 42 percent, of these patients received a statin medication for at least one week prior to surgery. Patients who received statin drugs were significantly more likely than others in the study to have cardiovascular risk factors, such as high blood pressure, high cholesterol, coronary artery disease, male gender and a history of smoking. Yet these high-risk patients experienced a three-fold lower rate of stroke during the days immediately following surgery and a five-fold lower rate of mortality in the same period.
"Statin drugs have been described as the penicillin of the 21st century because while they're given to lower cholesterol levels, it appears they have a whole host of other biologic effects," Dr. Perler said. "There have been studies showing that in patients at risk of stroke, they have been effective at reducing the primary and secondary stroke rate. But no one had ever looked at whether these drugs could reduce the risk of stroke and death after carotid surgery, which is the gold standard procedure for patients with severe carotid artery disease at risk of stroke from that disease."
Carotid artery disease occurs when the carotid artery, a large artery in the neck that serves as one of the major blood supplies to the brain, becomes blocked with a plaque made of cholesterol and fats. If the artery is completely blocked or if a plaque breaks loose and travels to the brain, it results in stroke. "We now have several randomized prospective trials of patients with significant carotid artery disease that have shown that among patients who are either treated medically or undergo carotid surgery, the long-term stroke risk is significantly reduced among patients who underwent successful carotid surgery," Dr. Perler said.
In CEA, surgeons make an incision over the artery, clamp it and remove the plaque, reopening the vessel. In a small percentage of patients, either bits of plaque or blood clots that form in the artery break off during the surgery and cause stroke. Statins appear to reduce this risk, though physicians aren't quite sure how. "Whether these drugs make those plaques less likely to fracture, less likely to break off or whether it's less likely for clots to form due to their anti-inflammatory effects, we can only speculate," Dr. Perler said.
What is clear, Dr. Perler said, is that patients who are at risk of heart attacks or strokes need to talk to their doctor about taking statins. Though the drugs do have some side effects, including muscle and liver problems, the benefits may outweigh the risks for many people. "They really appear to be powerful drugs that have far-reaching effects beyond simply lowering cholesterol levels," Dr. Perler said.