Deepak L. Bhatt, MD, MPH
Deepak L. Bhatt, MD, MPH, executive director of Interventional Cardiovascular Programs, Brigham and Women’s Hospital Heart & Vascular Center, and professor of medicine, Harvard Medical School, both in Boston.
Even people who don’t know a whole lot about health probably realize that having plaque in the arteries around your heart increases the risk of having a heart attack… but not so many think about the fact that having plaque in the carotid arteries, the ones in your neck that carry blood to your brain, increases your risk of having a stroke. In fact, for most people with severe narrowing of these arteries, the first hint that any problem exists isa stroke — if they’re lucky, it’s just a mini one known as a transient ischemic attack (TIA), but not always.
Of course, if you are found to have carotid narrowing, there will be precise guidelines to help your doctors keep you safe and get you as healthy as possible, right?
Unfortunately, no. I uttered an audible “humph” recently when I read new guidelines, issued jointly by the American Heart Association, American Stroke Association and the American College of Cardiology, on how patients with carotid artery blockage ought to be treated. The guidelines seem to present counterintuitive advice… and it turns out that the issue is not exactly black and white.
There was a bit of a flurry in the media when these two esteemed organizations released guidelines reporting that the two existing procedures for treating carotid artery blockages are “equally effective” and are both good choices. This flew in the face of what most people would tend to believe since one procedure, endarterectomy (surgical removal of the plaque), involves general anesthesia, cutting and all the usual risks of such surgery, while the other — stenting(propping open the artery with wire mesh) — does not.
Adding further to the confusion is the fact that other research had demonstrated that patients who receive stents have a much greater risk for stroke or death in the days following the procedure than those who have the surgery.
What to make of all this? I called one of the study authors, Deepak L. Bhatt, MD, MPH, director of the Integrated Interventional Cardiovascular Program at Brigham and Women’s Hospital and the VA Boston Healthcare System, for clarification.
To understand the risks associated with the procedures, Dr. Bhatt said, it helps to be a bit more familiar with the way they work…
Endarterectomy. The patient is placed under anesthesia… the neck and artery are cut open… the problematic carotid artery is clamped (a shunt is sometimes used to divert blood flow around the area of the neck being operated on)… and the plaque is removed. The artery and the neck are then stitched back together and blood flow is restored.
The risks:Along with the usual risks of surgery (infection, bleeding, etc.), this surgical procedure also carries a heightened risk for heart attack, Dr. Bhatt said. “Not surprisingly, patients who have blockages in their neck arteries often have blockages in their heart arteries, and because of the additional strain of anesthesia are at higher risk for heart attack during the surgical procedure.” There is also a slight risk that the procedure will cause damage to the cranial nerves that run through the neck — nerves that control activities such as speaking and swallowing.
Stenting.Though it certainly carries its own risks, stenting is thought to be much less invasive than endarterectomy. A surgeon threads a catheter through an artery in the groin and up to the carotid blockage. Once it’s there, a small balloon at the end of the catheter is inflated, causing a wire mesh stent to be pressed into the walls of the artery to prop it open. Along with the catheter, a filter is inserted to catch any debris dislodged by the procedure and is then withdrawn.
The risks:While stenting doesn’t involve cutting and stitching as endarterectomy does, it happens to carry a higher risk that plaque or a blood clot will break off and go to the brain — causing a stroke. The greatest risk is during the procedure or shortly afterward. This is why the risks between the two procedures overall are statistically similar, Dr. Bhatt explained.
So, while on the surface it may seem that stenting is a safer procedure to perform, it turns out that there is actually a 65% greater risk of major stroke in the 30 days following stenting than for endartectomy patients in that same period of time. However, said Dr. Bhatt, to understand what this means in practical terms, it is important to realize that stenting also carries a 55% lower risk for heart attack and 85% lowerrisk for cranial nerve injury.
The percent differences sound huge, so what are the real risks? The Carotid Revascularization Endarterectomy vs. Stenting Trial (CREST) completed last year found that 2.3% of endarterectomy patients had heart attacks, compared with 1.1% of stenting patients (advantage stenting)… while 4.1% of stenting patients had strokes, compared with 2.3% of endarterectomy patients (advantage endarterectomy).
If it happens that you have a ministroke or some other test reveals that you have carotid artery narrowing, your doctor will next seek to determine whether the arteries are more than 50% blocked. Aspirin and cholesterol-lowering are considered the standard treatments if the blockage is less than 50%. If it turns out that you need more aggressive therapy — meaning an endarterectomy or stenting — talk to your doctor about the overall risk factors involved, and your own medical profile, e.g. your weight, medications you may be on and history of heart attack. You’ll be increasing the chances for a decision that’s both the safest and the most carefully tailored to you.