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What you need to know about Atherosclerosis
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Atherosclerosis is the process of fat and cholesterol deposition in the wall of the artery. Also called atheroma, hardening of the arteries, or plaque, this process is the precurser for serious complications including stroke, heart attack, sudden death, and poor leg artery circulation. This process starts with fatty streak lesions and progresses to fibrous lipid-rish plaque and ultimately to complicated plaques which can rupture and cause complications. (Fig 1)
This process starts VERY EARLY in life; in fact, the process starts in teenage years and by the time you are in your 30’s a significant portion of the inside of your arteries are covered with plaque. (Fig 2)
As you would expect, the development of atherosclerosis is accelerated in young persons with other risk factors. (Fig 3)
Heart attacks, strokes and many other complications of atherosclerosis occur suddenly when a plaque ruptures and the body tries to heal this with a blood clot (thrombus). This movie shows in time lapse what this 20-30 year process looks like: Movie
In some cases, the plaque progressively worsens until it obstructs blood flow in the artery resulting in angina (chest pain) or claudication (leg pain). These conditions may be treated by angioplasty or bypass surgery.
The problem:
Most patients (and many physicians) do not understand that atherosclerosis, like hypertension or hyperlipidemia, is a SILENT process. Once symptoms develop the disease is very far advanced. An electrocardiogram, chest x-ray, treadmill stress test, or physical exam can NOT detect atherosclerosis. Only a study that can look at the vessel wall directly can diagnosis atherosclerosis in the early stages, when treatment can prevent complications. These imaging studies include looking at the carotid (neck artery) vessel wall with ultrasound (carotid IMT), looking for calcium deposits in the coronary artery (calcium score), looking at the coronary vessel wall by CT (CT angiogram) or, for some large vessels, an MRI scan. In many cases these studies are considered preventative, and are not covered by insurance. Thus, your physician cannot diagnosis the disease early and instead waits for symptoms to develop.
The Santé solution:
At Santé, we use advanced technology to diagnose and monitor atherosclerosis:
Measurement of endothelial function:
The endothelium is a single layer of cells that line your arteries. They are your first line of defense and the earliest to be damaged by the atherosclerosis process. The VasoPat test gives us a reproducible measure of the health of your arteries, allowing us to treat you as early as possible.
Coronary calcium score:
While many have given coronary calcium score a negative connotation, it is actually a very simple and important predictive tool for cardiovascular prognosis. The higher the calcium score, the worse the prognosis. (Fig 4)
The calcium score is a far more predictive test ( by a factor of 5) than any of the standard risk factors, since it detects the actual presence of atherosclerosis. (Fig 5)
Carotid IMT
Using external ultrasound we can measure the thickness of the carotid artery intima (where the plaque grows). Carotid IMT correlates with future events. Aggressive treatment can actually reverse this process. (Fig 6)
Cardiac CTA
Cardiac CT is similar to a cardiac catheterization except that it is non-invasive and uses lower radiation doses. In addition to seeing where arterial narrowings are located, we can actually see into the wall of the artery and detect “subclinical” atherosclerosis- before it results in symptoms. At Santé we are studying Cardiac CT as a technique for monitoring the atheroma burden and assessing therapy results. (Fig 7)
Our state of the art CT scanner provides superb images of the heart arteries in 15 minutes without even removing your clothes and with 1/2 to 2/3 of the X-ray dose required for an invasive catheterization.
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