Articles
Your Health Alert
Week 11
Monday, December 29th, 2008
Daily Camera, Boulder, CO
The Best Predictor of Strokes
Strokes are the third leading cause of death in America, and the leading cause of disability. But just like heart attacks, strokes can be prevented!
A stroke is a direct result of having plaque build up in the carotid arteries of your neck. When this plaque seals the carotid artery closed and restricts blood from getting to the brain, you have a stroke. That is why it is very important to look for plaque in the carotid arteries, but be careful what test you get to look for it.
We do a carotid intima media thickness (CIMT) scan with our top of the line GE Vivid I scanner on each patient, as well as an EBT Heart Scan (which we talked about last week). That way our patients have the best detection possible for both heart attacks and strokes. However, it is important to note that the CIMT is not the same test that is available thru commercial vans that come thru town, and it is 10 times more predictive than the simple carotid scan.
The CIMT test looks for plaque in the carotid artery, and shows the thickness the artery wall. From that we get a vascular age which is compared to the patient’s real age. The vascular age works like this, as a person gets older, their carotid artery will naturally get thicker. So, we can say that for your age, your artery should be this thick, in millimeters. However, if it is thicker than it should be, or if it is thickening too quickly, that is a major sign of cardiovascular disease.
This thickness can be sequentially followed to assess the efficacy of treatment. The American Heart Association says, “Carotid Artery B-mode Ultrasound imaging is a safe, non-invasive and relatively inexpensive means of assessing subclinical atherosclerosis. The technique is valid and reliable.” It is more sensitive than angiography for detecting early atherosclerosis and plaques at risk of rupture. I routinely use this on all patients and think it should be done as often as a PAP smear or prostate check. Simply put, a CIMT is the best test you can get to ensure that you are not at risk for a stroke.
Sometimes atherosclerosis shows up in the abdominal aorta, the or big artery that carries blood to the intestines, kidneys and legs. This can result in an aneurysm or balloon-like outpouching of the artery. Ninety percent of these have no symptoms until they rupture and then ninety percent of the victims die. But they can be seen by the same ultrasound machine that does the CIMT. So I recommend that each adult also get an abdominal aorta ultrasound scan because as many Americans die each year from a ruptured abdominal aortic aneurysm as women die of breast cancer or men die of prostate cancer.
I also recommend a simple test called the Ankle / Brachial Index that compares blood pressure in the arms with the legs. It can detect peripheral arterial disease (PAD) or blockage in other arteries like the femorals. If present it is associated with six times increased risk of death from cardiovascular disease.
Other tests that are done to find this sneaky disease include the treadmill and nuclear treadmill tests. I explained in week 3 why they miss over 68% of significant coronary disease. I don’t use them unless the patient is symptomatic or has a very high calcium score on the heartscan. If needed the cardiologists can do a coronary catheterization and angiogram to find narrowing of the artery.
A newer test is IVUS or intravascular ultrasound where a small ultrasound transducer is attached to the tip of a catheter which is then snaked thru the coronaries. It can see hard and soft plaque; but this test is invasive and not practical for screening in most cases.
So I look for plaque wherever I can. And when I find it I treat it aggressively because it is deadly and you usually did not even know you had it. Next week I will discuss some ways to treat it – you will not believe the most important one.
Joe Turnbow, M.D.
Copyright 2008, Heart Attack Prevention Strategies P.C. All rights reserved.