CIMT stands for Carotid Intima Media Thickness and refers to the thickness of the inner layers of the artery.
Genetics and environmental factors (including diet, exposure to carcinogens such as cigarette smoke, and exercise - or the lack of exercise, etc) combine over time to cause inflammation of the inner layers of the artery and the formation of plaque on the inner lining of the arterial wall. This thickening can be measured using ultrasound and sophisticated edge-detection software to quantify the amount of disease present. The measurement of the thickness of the intima and media layers of the common carotid artery is predictive of future events (i.e. stroke, and heart attack).
It is a painless noninvasive test utilizing digital ultrasound technology and sophisticated digital edge detection software to measure the inner two layers of the artery - intima and media layers years before they can be seen on traditional PVL Carotid Artery testing.
The CIMT scan is brief (approximately 15 minutes), does not require the patient to disrobe, is noninvasive (no needles), and does not expose the patient to radiation. It is relatively inexpensive and provides valuable information about an individual's risk of experiencing a heart attract, or stroke.
Multiple studies indicate that CIMT measurement detects the presence or absence of atherosclerotic disease (hardening of the arteries) and also allows for assessment of the degree of atherosclerotic burden better than other noninvasive cardiovascular tests available. It is recommended by both the American Heart Association and the American College of Cardiology. The procedure:
CIMT testing has been used in research since 1992. It has only been available in clinical settings since 2002. CIMT testing has been validated in many published studies in the most reputable journals. CIMT has been used in large epidemiologic trials as well as large outcome studies as a surrogate end point for clinical events. There is a high correlation between the disease found in this procedure and the disease found through pathology samples. The amount of disease found in the common carotid artery correlates highly to the amount of disease found elsewhere in the body.
This test is felt to be as predictive in women as it is in men, and helps to eliminate the dilemma clinicians have experienced in diagnosing and treating women for heart disease.
The American Heart Association recommends this test for everyone over 45 years of age, and younger if the patient has multiple risk factors (Family History, Hyperlipidemia, Dyslipidemia, Hypertension, Metabolic Syndrome etc). Patients that are believed to be at intermediate risk for heart disease and stroke by Framingham Risk Assessment are ideal candidates for this procedure. At its annual Prevention Conference V, the American Heart Association concluded that "Carotid artery B-mode ultrasound imaging is a safe, noninvasive, and relatively inexpensive means of assessing subclinical atherosclerosis. The severity of carotid IMT is an independent predictor of transient cerebral ischemia, stroke, and coronary events such as MI. . . in asymptomatic persons > 45 years old, carefully performed carotid ultrasound examination with IMT measurement can add incremental information to traditional risk factor assessment."
The test has been cleared by the Food and Drug Administration (FDA).
Leading physicians across the country have added CIMT to their primary prevention as an initial risk assessment tool and as a secondary prevention tool to monitor the affect of prescribed treatment over time.
CIMT testing has been shown to provide incremental additional data to risk prediction and is the only imaging test which has been recommended by the American heart Association for that purpose.
Research has shown a correlation between CIMT and chronological age. The ArterioVision report provides an arterial age which compares a persons chronological age to their arterial age.
Testing over time can shed light on the efficacy of treatment by tracking thickening or thinning of the intima media as well as tracking the degree of involvement by plaque indicating change in size, number of plaques and plaque characteristics.
The test has two parts. A sononographer or Registered Vascular Technician (RVT) takes sonographic images and later uses a sophisticated computer program to measure the Intima-Media Thickness.
In general it will take about 15 minutes of the patient's time to complete the test. The patient is not required to disrobe and the procedure is well tolerated.
There are no special requirements except to wear and open necked shirt.
Cardiovascular disease is the #1 killer in our population.
Estimates indicate that with the increasing incidence of obesity and Diabetes, cardiovascular disease will increase over the next 20 years.
Even though there has been some improvement in cardiovascular disease assessment and intervention in men, there has been little progress regarding the detection and prevention of cardiovascular disease in women.
As many as 50% of those who died from heart attacks or strokes had no previous signs or symptoms. This test allows early intervention and prevention of disease which has the potential to catch more of these patients so they can be treated before they experience an event.
As many as 50% of those who died from heart attacks or strokes had normal "lipid" profiles and low to intermediate risk by the Framingham Risk Assessment. Carotid IMT will find people with disease who may have been shown to be normal on other tests like stress echo, standard lipid panels, and Coronary Artery Calcium Score.
It is a cost effective diagnostic tool which provides health value and saves lives.
CIMT is more accurate in predicting disease than any other risk factor alone. CIMT measurement is an independent risk factor even in the absence of any other identifiable risk factors.
Progression of disease over time is another independent risk factor.
Studies have shown a 90% correlation between the disease found in the common carotid and the disease found elsewhere in the body. There is a very high correlation between the thickness of the intima media and other risk factors. Perhaps most important is CIMT's correlation and ability to predict coronary and cerebral events.
Use of experienced certified vascular sonographers.
Use of ArterioVision
™ software which has been used worldwide in academic research for over 15 years to predict cardiovascular risk and measure the effect of medications on atherosclerosis.
ArterioVision calculates individual risk for heart attack and stroke by comparing each patient's CIMT with a large database of individuals of the same age and gender to dertermine their "Arterial Age".