Arterial Stiffness
Atherosclerosis is a medical condition in which fatty material is deposited along the walls of arteries. This fatty material thickens, hardens and may eventually block arteries and cause heart disease. Atherosclerosis results in changes of the physical properties of the arterial wall which is linked to the development of plague and Coronary Artery Disease.
The VasoCor system provides a simple, non-invasive study for measuring Arterial Siffness (Atherosclerotic Burden). This module is a fully automated, computer controlled air plethysmograph designed to measure the compliance (or Arterial Stiffness) of the arteries of the calf and thigh. The Arterial Stiffness procedure records measurement of local arterial volume change at seven different cuff pressures. The pressures are centered at the mean non-invasive arm cuff measurement taken at the start of the test. The pressures are in increments of 10 mmHg. This allows the plotting of maximum segmental arterial volume change as a function of cuff pressure.
The Arterial Stiffness Study
The VasoCor system accurately measures Arterial Stiffness by eliminating the effects of absolute pressure & distal resistance while the normal arterial wall stress is evenly balanced. This is accomplished by changing the cuff pressure in the cuff surrounding the measured segment. This produces a well-known curve that exhibits (for normal arterial anatomy) an increasing volume change as cuff pressures are increased to the local diastolic pressure. When the cuff pressure is equal to the local diastolic pressure, the volume amplitude is normal at maximum pressure. When cuff pressure is increased over local diastolic pressure, the volume amplitude decreases due to the fact that the artery is now being collapsed over increasing portions of the cardiac cycle.
Arterial Stiffness Report
The VasoCor device produces a written report with measurements is proven to be an early detection of Coronary Arterial Disease, potential of Stroke and overall arterial health. The report generated by the VasoCor device is based on an extensive multi-center, multi-continent and multi-million dollars clinical trial, involving over 1,000 human subjects. Each patient involves different degrees of cardiovascular disease or risk factors and those without any cardiovascular disease or risk factors. The report lists the patient’s various cardiovascular risk factors, such as smoking, hypertension and obesity, which can be manually entered into the system by the operator.
Clinical Validation
The first clinical trial was suggested by the FDA and involved comparing Arterial Compliance (i.e. Arterial Stiffness) measurements with coronary artery disease as determined by invasive coronary angiography. This trial was known as the Vasogram Improvement Program (VIP). The first of phase of this trial began in the first quarter of 1995 and ended during the third quarter of 2000. This trial enrolled 389 subjects, in four major medical centers in the United States and Europe. This trial revealed that the Vasogram measurements correlated well with traditional cardiovascular risk factors and were clinically useful in estimating degree of coronary artery disease as measured by Coronary Angiography
A second clinical study was performed to assess the reproducibility of the study with expected values from a population of subjects over a large age range without cardiovascular disease. This study is known as the Precision Study. This study was perormed in 2002 with approximately 400 subjects enrolled from three centers in the U.S.This study revealed that the VasoCor technology is accurate and reproducible for determining Arterial Compliance.
With the knowledge that coronary angiography does not identify early cardiovascular disease, a third and final clinical trial called the Accuracy Study was undertaken to compare VasoCor measurements with aortic atherosclerotic disease as measured by Magnetic Resonance Imaging (MRI). This study included 350 subjects with a wide range of cardiovascular disease. This study revealed that Compliance measurements were more predictive of generalized atherosclerosis than any single traditional risk factor or combination of traditional risk factors for cardiovascular disease. Further this technology has been shown to enhance significantly predictions of risk when all standard factors are considered. MRI of the abdominal aorta was used as the measure of CAD.
How is the Arterial Stiffness Data Useful?
The VasoCor is unique in that it provides physicians with a methodology to compare their patient’s arteries compare to healthy subjects of the same gender and age. Further, they will know how their patient’s arteries compare to subjects with known peripheral and coronary arterial disease, which is the direct cause of over one million deaths annually, generating over $100 billion direct and $180 billion indirect treatment costs annually.
The VasoCor device may be used in conjunction with other tests such as the “stress test” or other modalities which are more expensive and time consuming to administer. The VasoCor has been clinically validated in measuring coronary artery disease by Quantitative Coronary Angiography (QCA) and carotid artery disease by B-Mode Carotid Ultra-sound. The Vasogram™ Improvement Program (“VIP”). is the Vasocor’s independent Scientific Advisory Board (SAB), which was responsible for the integrity of the medical and scientific aspects of the study. This data is reviewed from the clinical trials by combining the Arterial Stiffness score with a cardiovascular risk profile, the two combined evaluations will yield a 90% sensitivity rating while the probability or specificity increases from 58% to 90%. This is accomplished with no invasive procedures and at a fraction of the cost.
Where is the VasoCor Arterial Stiffness Test Used?
Potential users of the VasoCor technology include primary care physicians, cardiologists, vascular specialists, clinics, Research Institutions, Pharmaceutical Companies, and hospitals. VasoCor technology will be most helpful in identifying subjects at risk to in the early stages to insure proper treatment to improve patient outcomes. Further, the VasoCor diagnostic tools can be used to avoid more expensive and invasive techniques that both medical providers & patient seek to avoid.
