What is Vascular Screening?
Vascular Screening uses non-invasive techniques to obtain two measures that help evaluate cardiovascular health. These techniques can provide supplemental information about your heart and blood vessels that cannot be obtained from other noninvasive medical tests such as blood tests and physical exams.
Specifically, the variables assessed by vascular screening are:
- Carotid IMT: Carotid IMT stands for carotid intima-media thickness and refers to the thickness of the inner layers of the carotid artery (an artery supplying blood to your brain).
- Genetics and environmental factors (such as poor diet, smoking, and physical inactivity) combine over time to cause inflammation of the inner layers of the artery and the formation of plaque on the arterial wall. This thickening and presence of plaque can be measured using non-invasive ultrasound technology.
- Carotid IMT can be strong predictor of future vascular events such as stroke and heart attack.
For example, for an absolute carotid IMT difference of 0.1 mm, the future risk of heart attack increases by 10% to 15% and the stroke risk increases by 13% to 18% (1). AHA guidelines state that “in asymptomatic persons >45 years old, carefully performed carotid ultrasound examination with IMT measurement can add incremental information to traditional risk factor assessment (2).”
- Central Hemodynamics: Central systolic blood pressure determines how hard the heart has to work to pump blood through the body. Central diastolic blood pressure determines how much blood flows through the blood vessels of the heart when the heart is relaxing. Stiffer blood vessels increase the pulse wave velocity (the speed of the pressure wave generated by the heart), leading to an increase in central systolic pressure. This augmented systolic pressure may compromise heart function. Assessment of central hemodynamics thus includes measures of central systolic, diastolic and pulse pressure as well as augmentation index and pulse wave velocity. These variables have been shown to be independently associated with organ damage, cardiovascular disease, and cardiovascular events both in the general population and in various disease states (3). Central blood pressures cannot be estimated by standard blood pressure measurement in the arm.
Who should participate in Vascular Screening?
Anyone can benefit from undergoing vascular screening. However, vascular screening may be particularly helpful in individuals with “intermediate risk” for cardiovascular disease because the results from vascular screening may help the individuals’ doctor decide on a treatment plan. For example, the American Society of Echocardiography recommends carotid IMT scanning for patients with a family history of premature heart disease, who have severe abnormalities in a risk factor such as cholesterol or blood pressure, or for women who are less than 60 years old with 2 or more cardiovascular risk factors (4).
What is a screening like?
A typical screening takes 30 minutes from start to finish. The patient is asked to lie on his or her back on an exam room table and relax quietly. A blood pressure cuff is placed on the right arm. First, ultrasound gel is applied to an ultrasound probe and then placed gently on the carotid artery on the neck. The patient will feel slight pressure as the sonographer obtains an image of the carotid artery on both sides of the neck. Software is then used to trace the inner layers of the artery and calculate the thickness of them.
Next, a technician will place a tonometer (a small probe with the head the size of a dime) on the skin near several arteries (on the wrist, neck and hip) while a pulse is obtained for 10 seconds straight. An electrocardiogram (ECG) is also used to measure heart rate with electrodes placed on both arms and the left leg. From these measurements central hemodynamic variables are obtained.
Where will this take place?
The 30-minute screening will take place an exam room in the Department of Preventive Cardiology (704 Jefferson Building, Hartford Hospital).
What do my values mean?
Carotid IMT values are reported as an age, sex and race- based percentile based on values obtained from various large-scale research studies. The presence of carotid plaque and/or carotid IMT ≥ the 75th percentile indicates increased cardiovascular disease risk (4). Similarly, central hemodynamic parameters of arterial stiffness are reported according to age- and sex-based normative values. A central pulse pressure ≥ 50 mmHg predicts adverse cardiovascular disease outcomes (5).
During your testing visit, we will give you a preliminary explanation of our findings. A final report will be reviewed and signed by a cardiologist (Dr. Donna Polk) and provided to you with 3 weeks of your scanning session. You will then be able to provide this information to your physician.
How much does it cost?
A full screening will cost $100. We currently offer 50% off to Hartford Hospital employees and group rates for 6 or more.
Why doesn’t insurance cover these tests?
Both carotid IMT and assessment of central hemodynamic parameters are relatively new tools that are not yet covered by insurance in the State of Connecticut. In order for a test to be covered by insurance it must be sufficiently evidence-based, widely available, and reproducible. While there is increasing evidence supporting use of these techniques for screening and prevention of cardiovascular disease, to date there is not enough widespread use to obtain insurance coverage for them.
Beth Parker, PhD
Dr. Parker, Director of Exercise Physiology Research at Hartford Hospital, completed the carotid IMT Training Program in the Atherosclerosis Imaging Research Program at University of Wisconsin School of Diagnostic Medical Sonography and is a certified sonographer for the Roche DAL-PLAQUE II clinical trial. Dr. Parker performs the ultrasound assessment.
Donna Polk, MD
Dr. Polk, Director o f Preventive cardiology at Hartford Hospital, completed the carotid IMT Training Program in the Atherosclerosis Imaging Research Program at University of Wisconsin School of Diagnostic Medical Sonography. Dr. Polk reviews results from each individual’s vascular scanning session.
Amanda Augeri, MS
Ms. Augeri coordinates the vascular scanning program as well as performs the arterial stiffness measurements.
How do I schedule a screening?
Please contact Amanda Zaleski at (860) 545-3454 or email at Alzaleski@harthosp.org to schedule your screening.
1) Lorenz MW et al., Circulation 2007; 115: 459-467.
2) Greenland P et al., Circulation 2000; 101:E16-22.
3) Agabiti-Rosei E Et al., Hypertension 2007; 50:154-160.
4) Stein JH et al., J Am Soc Echocardiog 2008; 21:93-111.
5) Roman MJ et al., JACC 2009; 54:1730-1734.