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Early detection of
Peripheral Arterial Disease


TopDocDX Vascular+

The TopDocDX Vascular+ is an innovative system with a cuff-based technology for performing the ankle-brachial index (ABI) and TBI exam to assist in the diagnosis of peripheral arterial disease (P.A.D.).

The TopDocDX Vascular+ provides accurate determination of the ABI and TBI across the full range of P.A.D. TopDocDX Vascular+ provides new technologies to better serve the needs of health care providers and patients.

This new technology is a significant improvement in ankle and pressure determination and P.A.D. assessment over traditional forms of oscillometric ankle pressure estimation.

The TopDocDX Vascular+ has four blood pressure cuffs (up to 8) with pulse volume recording (PVR) technology.

The system also includes include three PPG Sp02 Finger and Toe pressure sensors for accurate TBI assessment.


Clinical Indicators

Initial assessment is the most vital step in managing a patient's health. As such, extracting as much information and achieving a broad road map of the arterial anatomy is crucial for proper arterial and vascular assessment.

The information collected during the TopDocDX Vascular+ using the arm and ancle cuffs and the finger PPG sensor is disseminated into a wide range of measurements. This data is then extrapolated into a number of indexes and further classifications which include the following:


  • Ankle/Brachial Index (ABI)

  • Arterial Stiffness Index (ASI)

  • Toe/Brachial Index (TBI)

  • Ejection Elasticity Index (EEI)

  • Dicrotic Elasticity Index (DEI)

  • Dicrotic Dilation Index (DDI)

  • Augmentation Index (AI)


Clinical Applications

The information deduced from the TopDocDX Vascular+ is invaluable for detecting risk factors and facilitating the identification of patients who may be at risk for cardiovascular events. Studies have shown that the Arterial Stiffness Index (ASI) illustrates a strong correlation between the functioning and integrity of coronary arteries and atherosclerotic lesions. This particular connection is significant in that atherosclerotic lesions are fatal yet may remain asymptomatic for decades. Over 60 million Americans carry these life-threatening issues so isolating high-risk individuals is most valuable.

The indexes generated by the TopDocDX Vascular+ are far-reaching and provide important patient insight into a number of existing and potential health risks. These cardiovascular issues include the following:

  • Atherosclerosis

  • Infectious vasculitis

  • Congenital abnormalities

  • Hypertension

  • Hyperlipoproteinemia

Diagnosis of Peripheral Artery Disease (PAD)

Peripheral Artery Disease (PAD) is a common manifestation of atherosclerotic vascular disease where the arteries in your legs or arms are narrowed or blocked. Its incidence increases with age and in the presence of known cardiovascular risk factors (e.g., smoking and diabetes). People with PAD are at an increased risk of heart attack, stroke, poor circulation and leg pain. TopDocDX Vascular+ evaluates PAD using the Ankle Brachial Index (ABI). The ABI compares your systolic blood pressure measured at your ankle with your systolic blood pressure measured at your arm. A low ABI can be a strong indicator of PAD and risk of circulatory problems.

Arterial Stiffness occurs as a consequence of biological aging and Arteriosclerosis, which occurs when arteries become thick and stiff, sometimes restricting blood flow to your organs and tissues. Arterial Stiffness is associated with an increased risk of cardiovascular events such as heart attack and stroke, the two leading causes of death in the developed world. Depending on the cause, Arterial Stiffness may be treated and prevented. TopDocDX Vascular+ evaluates Aterial Stiffness using Pulse Wave Velocity (PWV), Peripheral Augmentation index (AI), and Central Aortic Systolic Pressure (CASP).


Why Arterial Vascular Assessment Matters

Peripheral Artery Disease (PAD) is a dominant concern for physicians and it is intrinsically linked to arterial health. PAD is the occlusion of arteries due to the buildup of fatty, cholesterol deposits called plaque lining the interior of arteries. As the formation of plaque accumulates, the arteries narrow, stiffen and decline in functionality. This reduces blood flow, usually to the legs and, if left to worsen, can lead to tissue death or even amputation. Research estimates that eight to 12 million people are affected by PAD in both the U.S. and Europe. Like many other cardiovascular diseases, over three quarters of the population that develops Peripheral Artery Disease (PAD) do not show symptoms. Patients with PAD have an increased risk of stroke, heart attack and ischemic attack and PAD patients are six times more likely to die from cardiovascular disease within 10 years of being diagnosed versus healthy adults.

TopDocDX Vascular+ enables specialists to isolate issues, track problems and manage patient health using noninvasive, oscillometric readings that are performed automatically and easily.


The value of PVR waveforms measurement

TopDocDX Vascular+ also records the arm and ankle pulse volume waveforms (PVR) which provide pictorial evidence to aid a clinician's diagnosis; this is of particular value in patients who are prone to arterial calcification, such as diabetics.

PVR analysis provides a second line of investigation that can highlight when this has occurred whilst also providing qualitative information with regard to the arterial status of the limb.

The superior diagnostic capabilities of the TopDocDX Vascular+ were highlighted in a recent clinical study: a patient's ABIs were found to be within the normal range. However, inspection of the PVRs indicated moderate to severe PAD suggesting that arterial calcification had caused artefactual elevation of the ABIs to within the normal range. The patient was subsequently referred to a vascular surgeon; moderate to severe PAD was confirmed and the patient thereafter underwent successful angioplasty.

PVR waveform by applying pressure cuffs to the limb to detect the miniscule fluctuations in limb volume that occur with each heartbeat. Since Doppler sensitivity may be diminished due to arterial calcification, PVR is usually the option of choice for obtaining peripheral arterial waveforms from patients with noncompressible arteries, such as patients with diabetes and renal disease.

The arterial PPG probe is another modality used for detecting small changes of blood volume from the finger and toe. When used with a digit cuff, the PPG is quite useful for measuring toe pressures of patients with noncompressible arteries. The TBI exam compares toe pressures to brachial pressures.

With the TopDocDX Vascular+, the PPG probe can also be used for obtaining limb pressures for the supine ABI and segmental exams.

TopDocDX Vascular+ also records Brachial-ankle pulse wave velocity (baPWV).

It is a method to estimate arterial stiffness, which reflects the stiffness of both the aorta and peripheral artery.


Pulse Wave Velocity (PWV) Analysis

TopDocDX Vascular+ Pulse Wave Velocity (PWV) analysis is based on physiological phenomenon, observable and measurable in the arterial elasticity and stiffness during blood circulation. During one heart systole a certain blood volume is expelled. This propagates through the arteries due to the reciprocal transformation between kinetic energy of a segment of the expelled blood volume and the potential energy of a stretched segment of the resilient vascular wall. We can observe the changes in pressure, blood flow, velocity and profile throughout the whole pulse wave. It can be used for classification of the artery elasticity.

The condition of the small and large arteries is key to prevention and diagnosis of cardio-vascular related illness. In particular, the stiffness and augmentation of the major arteries is a strong indication of potential health problems including heart attacks, heart failure, sclerosis, and renal complications. PWV Analysis and arterial stiffness indexes (EEI, DDI and DEI) can suggest to healthcare professional to begin appropriate treatment long before the symptoms or clinical signs appear.

Age and systolic pressure strongly correlate with PWV. In fact, the most important factor contributing to increase in PWV is age because of increased arterial stiffness caused by medial calcification and loss of elasticity. The measurement of pulse wave velocity is useful in the study of the effects of aging, vascular diseases, vaso-dilating and vaso-constricting agents on arteries.

TopDocDX Vascular+ Pulse Wave Velocity measurement is a convenient method of quantifying arterial stiffness and augmentation. PWV provides invaluable insight into cardiovascular health, management of disease progression and monitoring the effects of medication, treatments, lifestyle and dietary habits.

Peripheral Arterial Tone (PAT)

PAT (Peripheral Arterial Tone) technology measures arterial tone changes in peripheral arterial beds. This information collected gives specialists important insight into the autonomic nervous system as well as the cardiovascular system. PAT technology is a noninvasive measure that is currently used to detect heart disease, erectile dysfunction and obstructive sleep apnea, however, it has also proven highly effective in the detection and monitoring of other cardiovascular conditions.

As PAT data imparts early-stage information, PAT technology is highly valuable in disease detection and follow-up, thereby improving patient treatment and healthcare costs. In addition to detecting cardiovascular disease, the PAT system also presents potential for improving the diagnosis and management of other medical conditions including metabolic syndrome, diabetes, peripheral arterial disease and many others.


Coronary Artery Respiratory Assessment (CRA)

Coronary artery disease (CAD) occurs when the blood vessels that transport blood to the heart are narrowed and hardened due to plaque buildup (atherosclerosis). This narrowing compromises the flow of nutrient-rich, oxygenated blood to vital organs which can lead to stroke, heart attack and death. In fact, coronary artery disease is the leading cause of death among American adults. As such, detection are treatment are at the forefront of relevance.

The photoplethysmograph (PPG) waveform has profound prognostic value for coronary artery disease. Studies show that fluctuations measured in photoplethysmograph (PPG) amplitude are directly related to coronary artery disease (CAD) and present powerful predictions of risk.

Photoplethysmograph (PPG) is measured using a non-invasive, radiation-free platform. This proprietary test system was developed by TopDocDX Vascular+ and utilizes a biosensor finger probe to collect data. The patient is then asked to perform a series of controlled breathing exercises. The coronary respiratory response (CRR) is derived from spectral analysis of the PPG signal during instructed breathing.

The PPG signal is automatically extracted and captured for processing. Using algorithms and analyzing software, a reading is produced which offers a timely and accurate diagnosis of Significant Coronary Artery Disease (S-CAD)


Clinically Proven

Recent clinical studies undertaken by the following authors have shown that ABI is effective at measuring ABIs in many patient groups:

Lewis, Hawkins, Barree, Cawley and Dayananda (2011) have shown on 295 limbs (55% diabetic):

  • Good agreement between ABI and Doppler measurements.

  • ABI measurement takes significantly less time than Doppler.

  • The need to rest the patient is eliminated by the simultaneous cuff inflation of ABI.

  • ABI has the potential to be used as a screening tool for PAD in primary care settings.

  • ABI improves the whole patient experience.

  • Minimal training is required due to its ease of use.

Lewis, Mahoney and Evans (2012) have shown on 149 limbs:

  • Excellent correlation and good agreement between ABI and Doppler measurements.

  • The time taken to perform the automatic ABI tests was significantly quicker than with Doppler.

  • PVR waveforms showed good agreement with Doppler waveforms.

  • Using an ABI cut off of 0.8, Sensitivity=82%, Specificity=97%, Accuracy=94%.

Lewis (2012) has concluded that:

  • Automated ABI reduces operator error, allows a less highly skilled clinician to perform the test, and enables pressures at the arms and ankles to be measured simultaneously which would consequently reduce the test time as patients would not need to be rested.

  • Automated ABI systems based on oscillometric technology poorly correlate with Doppler ABI especially in the presence of moderate to severe PAD.

  • ABI has been clinically validated over a range of ABIs from 0.4-1.4 and produces a PVR waveform from both ankles which is particularly useful when the ABI is >1.3.

  • ABI is ideal for use in general practice for screening and diagnosing PAD and can be easily used by a practice nurse or healthcare assistant.

Tadej (2013) has shown that:

  • The introduction of ABI into a new clinical pathway can reduce inappropriate referrals and lead to the prioritization of clinical services.

  • The ABI opens up a new chapter in the ABI testing relating to patients "at risk" of developing PAD.

Davies, Lewis and Williams (2014) have shown on 736 limbs:

  • 8% had an ABI > 1.3 suggesting possible arterial calcification. Of these, 10% had PAD as indicated by analysis of PVRs.

  • PVR waveforms can be easily utilized as an adjunct to ABI measurements to identify patients who may benefit from further vascular assessment and intervention.

Lewis (2014) has shown on 390 limbs (27% diabetic):

  • ABI had excellent correlation and agreement against Ultrasound Duplex Scans.

  • Overall accuracy of ABI ABI was 88% compared to Duplex.

  • Overall accuracy of ABI using PVR waveforms increased to 95% when compared to Duplex Scans.

  • Range of ABIs measured with ABI were 0.29 - 1.57.

Davies, Kenkre and Williams (2014) undertook a GP study and reported that:

  • Doppler ABI measurements are infrequently and often incorrectly used (42% out of compliance with current ABI guidance).

  • Lack of time and inadequate training have been identified as factors associated with this find.

The TopDocDX Vascular+ system is a Class II medical device that is US FDA 510(K) cleared.

TopDocDX Vascular+ testing procedure is covered by the most major insurance providers, under CPT code 93922 and 93923.


Non-Invasive, Painless, Preventative Testing,  to

Prevent Possible Life Threatening Conditions From Before They Are A Threat

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