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Peripheral Arterial Disease: Early Diagnosis and QuantaFlo



Peripheral arterial disease: early diagnosis and quantaflo

QuantaFlo Systems, by Semler Scientific, can help diagnose the elusive and potentially deadly PAD before any symptoms appear, and that can help millions of Americans.

Did you know that an estimated 8 to 12 million people in the United States have peripheral artery disease, yet 60% have no symptoms? Smoking, diabetes, obesity, high blood pressure, high cholesterol, and being over 50 puts you at high risk of having PAD.

Do you know of someone at risk?

Peripheral arterial disease (PAD) is a condition that can result in crippling pain, heart attack, stroke, kidney failure, even gangrene and is considered of high mortality, but it is amenable to secondary prevention. This means primary prevention and early diagnosis are critical, and that’s where the QuantaFlo test comes in. But what exactly is PAD, and how does QuantaFlo Help?

Peripheral artery disease (PAD) is a disease in which arteries that carry blood to your organs, head, and limbs develop build-ups of atherosclerotic plaque. Plaque consists of fat, calcium, fibrous tissue, cholesterol, and other substances in your blood.

When the body’s arteries get a build-up of this plaque, a condition called atherosclerosis can develop. Over time, this plaque continues to build, hardens the arteries, and can cause blockages. When this happens, the flow of the oxygen-rich blood to your organs and extremities is reduced.

PAD usually affects the arteries in the legs, but it also can affect the arteries that carry blood from your heart to your kidneys, head, arms, and stomach.

Blocked blood flow to your limbs may cause pain and numbness. The risk of getting an infection in the affected limbs also increases. The body may have a difficult time fighting this infection.

If the condition is severe enough, restricted blood flow can cause gangrene (tissue death). In severe cases, this can lead to amputation.

More than 202 million people have PAD worldwide, with approximately 70% residing in low-to-middle-income countries. (1)

It is estimated that there is an increase of 3–7% in the prevalence of PAD that is correlated with aging. “Although it was believed that the prevalence of PAD is common in men, the prevalence of PAD in women is at least equal, if not higher.” (2)

Smoking is the leading risk factor for PAD. If you are a smoker or have had a history of smoking, the risk of getting PAD is increased. Other factors, such as having satisfied conditions, or diseases, such as diabetes, also increase the risk of PAD.

Lower extremity PAD is the third leading cause of atherosclerotic cardiovascular morbidity, following coronary artery disease (blockages in the heart) and stroke (blockages in the head or neck). (3)

Peripheral Arterial Disease Symptoms

People who have PAD may experience symptoms when they walk or climb stairs. These symptoms may include pain, aching, numbness, or a feeling of heaviness in your leg muscles.

Symptoms also may include cramping in the affected limbs and the thighs, buttocks, calves, and feet. These symptoms may go away after a period of rest. The name for these symptoms is “intermittent claudication.”

When you participate in physical activity, your muscles need more blood flow. If the blood vessels are restricted or blocked, your muscles won’t get the blood flow they need, and you will experience these symptoms. When at rest, your muscles don’t need as much blood, so the symptoms will ease.

Other signs and symptoms of PAD may include:

¥          Weak or absent pulses in the legs, feet, or arms

¥          A pale or bluish color skin tone

¥          A lower temperature in one limb compared to the other

¥          Wounds or sores on the legs, feet, or toes that heal slowly, or not at all

¥          Poor nail growth on the fingers or toes and a decrease in hair growth

¥          Erectile dysfunction, especially for men that have diabetes

Many people who have PAD don’t show any signs or symptoms. However, you should ask your doctor if you should be checked for PAD if you’re:

¥          Aged 50 or older and have a history of smoking or diabetes

¥          Younger than 50 and have diabetes and one or more risk factors for atherosclerosis

¥          Aged 70 or older

Peripheral Arterial Disease Test

When discussing PAD with your doctor, he or she may ask:

¥          Whether you have any risk factors for PAD, like smoking or having diabetes

¥          About your diet

¥          If there is a history of blood vessel or heart diseases for anyone in your family

¥          If you are currently taking any medicines, both prescription and over-the-counter

¥          If you are experiencing any your symptoms when sitting, standing, walking, climbing, or exercising

It will probably be suggested to take a physical exam. During the physical, your doctor will look for any signs of PAD. The blood flow in your legs, feet, or hands may be checked to see if you have a weak or absent pulse.

The pulses in the arteries of your limbs might also be checked for any abnormal whooshing sounds, which are called bruits. The doctor can hear them using a stethoscope. A bruit could be a warning sign of a narrowed or blocked artery.

Your doctor may make a comparison between limbs to see if the blood pressure is lower in your affected limb. You may also be checked for any changes in your skin, hair, or nails, or poor healing of wounds that may indicate PAD.

However, the initial clinical exam, such as described, is a historically poor predictor of the presence of PAD, as so many people are asymptomatic.

There are also a series of diagnostic tests that can be performed by your doctor:

¥          Ankle-Brachial Index

An ankle-brachial index (ABI) is a simple test that is often used to diagnose P.D. The ABI compares the blood pressure in your arm to the blood pressure in your ankle. This shows how well the blood is flowing through your limbs.

While ABI can show if PAD is affecting your limbs, it doesn’t display correctly which of the blood vessels are restricted or blocked.

A typical ABI result is 1.0 or higher (with a range of 0.90 to 1.30). (4)

This test takes around 10 to 15 minutes to measure both ankles and arms. You can take this test annually to see if PAD is worsening.

¥          Treadmill Test

A treadmill test can reveal the severity of your symptoms and at what level of exercise initiates them. As the name implies, you will be walking on a treadmill. This will show if you experience any problems during regular walking.

Your doctor may perform an ABI test before and after taking the treadmill test. This is to compare the blood flow in your legs and arms before and after the exercise.

¥          Doppler Ultrasound

A Doppler Ultrasound checks the blood flow of the major veins and arteries in your limbs.

Using a handheld device that is placed on your body and moved back and forth over the affected areas, a computer then converts the sound waves into a picture showing blood flow in the veins and arteries.

The results of the Doppler Ultrasound can reveal whether or not a blood vessel is blocked. These results can also show the severity of PAD.

¥          Arteriogram

An arteriogram is an x-ray of your arteries and provides a virtual “roadmap.” Your doctor can order this test to find out precisely where an artery is blocked.

First, a dye is injected through a catheter or needle into one of your arteries. After the dye is injected, they will take an x-ray. The x-ray will show the location and extent of the arterial blockage.

Some doctors may use a different method of an arteriogram that relies on tiny ultrasound sensors. These sensors provide images from the interior of the blood vessels. This newer method is called intravascular ultrasound.

¥          Magnetic Resonance Angiogram

A magnetic resonance angiogram (MRA) uses magnetic and radio wave energy to capture images of your blood vessels. MRAs are a type of magnetic resonance imaging (MRI).

An MRA will show the severity and location of a narrowed blood vessel. If you have a stent, surgical clips, mechanical heart valve, pacemaker, human-made joint, or any other metallic device in your body, you probably won’t be able to take an MRA.

¥          Blood Tests

Your physician may want you to take some blood tests to check for PAD risk factors. Blood tests can help to diagnose certain conditions such as high blood pressure and diabetes.

¥          QuantaFlo™

The QuantaFlo™ System from Semler Scientific is a fast and easy test you can use to aid in the diagnosis of PAD. It’s FDA cleared, patented, and in use in doctor’s offices throughout the country. (4)

The QuantaFlo PAD test consists of software that can be installed on any Windows-based computer or tablet, along with a proprietary sensor that attaches to both the fingers and toes. It delivers accurate test results in about five minutes. It is intended for use in primary care offices specialty medical practices, and by medical professionals at health fairs and during home visits.

The QuantaFlo test kit is as accurate as a conventional simple ABI test. (5)

Peripheral Arterial Disease Treatment

The ultimate goals of treating PAD would include reducing the risk of having a heart attack and stroke, reducing the symptoms of claudication, improving the patient’s mobility and overall quality of life, preventing further complications, and ultimately increasing lifespan.

Treatment is based on your signs and symptoms, personal risk factors, and the results of any tests that were performed.

Participating in treatment for PAD may help to slow or stop the progression of the disease altogether. It also helps in the reduction of any further complications.

Without treatment, PAD has a high likelihood of continued progression. If this happens, you may suffer from severe tissue damage due to inadequate blood flow. In extreme cases of PAD, gangrene may set in, and amputation of the affected part of the body may be necessary.

Treatments for PAD may include changes in your lifestyle that are more heart-healthy, various medications, and procedures or surgery.

Heart-Healthy Lifestyle Changes

¥          Quitting smoking

¥          Physical activity

¥          Eating healthier food choices

Angioplasty and Stent Placement

To restore the blood flow through a narrowed or blocked artery, your doctor may recommend angioplasty.

In this procedure, a thin tube with a balloon at the end is inserted into the blocked artery. The balloon is inflated. This pushes the plaque against the wall of the artery, thereby widening the artery and restoring the flow of blood.

A stent may be inserted in the artery during an angioplasty. The stent allows the artery to stay open after the procedure is finished. Some stents have a medicinal coating that helps to prevent future blockages in the artery.

Bypass Grafting

Bypass grafting surgery may be suggested if the flow of blood in your limb is blocked or partially blocked. During this surgery, a blood vessel from another part of your body is used to make a graft.

This graft goes around the part of the artery that is blocked. This allows the blood to bypass the blockage. This form of surgery won’t cure PAD, but it may help blood flow to the affected area.


Atherectomy removes the buildup of plaque from an artery. During this procedure, a catheter inserts a small cutting device into the affected artery. The plaque is then shaved or cut off.

Then the fragments of plaque are either removed through the catheter or taken away in the bloodstream. An atherectomy can also be performed by using a laser that will dissolve the blockage.

Living with PAD

If you have PAD, you are more likely to have a heart attack, coronary heart disease, stroke, and transient ischemic attack (“mini-stroke”). However, there are steps you can take to treat and control your PAD and help to lower the risk of contracting these other conditions.

If you have been diagnosed with PAD, you might feel discomfort in your leg muscles after walking. Take a break now and then to allow the pain to subside before resuming walking again. This may help to increase the distance that you can walk again without pain.

Speak with your doctor about participating in a supervised exercise program. Exercising has been proven to help reduce the symptoms of PAD.

Inspect your body regularly for possible infections or sores. Wear shoes that fit well. Maintain proper foot hygiene and seek medical treatment for bunions, corns, or calluses.

Visit your doctor regularly for checkups. Take all medicines as prescribed by your physician.

Changes in your lifestyle can help prevent PAD and other related medical problems, such as strokes, coronary heart disease, transient ischemic attack, and heart attacks.

While there is no cure for PAD, you can reduce your risk of complications by staying active, taking all prescribed medications, not smoking, maintaining a healthy lifestyle, and knowing how and when to address any medical issues that may come up. (6)

(1) F.G.R. Fowkes, D. Rudan, I. Rudan, V. Aboyans, J.O. Denenberg, M.M. McDermott, et al.
Lancet, 382 (9901) (2013), pp. 1329-1340
(2) J. Layden, J. Michaels, S. Bermingham, B. Higgins
BMJ (2012), p. 345