Wie man ABI berechnet

Peripheral artery disease (PAD) quietly affects millions of adults, but early detection can make all the difference in preventing serious complications such as limb loss, heart attack, or stroke. One of the most valuable diagnostic tests for finding PAD is the ankle brachial index (ABI). If you’re 45 or older, or caring for someone at risk of vascular disease, understanding the ABI test can be a powerful step toward protecting vascular health. In this blog, we’ll explain what the ABI test is, why it’s important, how it’s calculated, and what the results can reveal about your overall well-being.

What Is an ABI Test?

The ankle brachial index is a straightforward, non-invasive test that helps check for poor blood flow in the legs. By comparing blood pressure measured at your ankle with blood pressure at your arm, a vascular specialist can quickly see if there are blockages or narrowed arteries, a common sign of PAD. Because PAD often begins without symptoms, the ABI test can detect it before it causes pain or complications, making it an essential preventative tool for those at risk.

Why Is the ABI Test Important?

The ankle-brachial index test is a simple, painless way to check the blood flow in your legs and diagnose PAD. It’s important because it can:

• Catch problems early – Find signs of peripheral artery disease before symptoms get worse.
• Guide your treatment – Help your doctor decide if you need lifestyle changes, medication, or other care.
• Track your progress – Monitor your circulation over time to keep your legs and heart healthy.

A low ABI may mean you have PAD and could also signal a higher risk for heart attack or stroke. That’s why this quick test can be a big step toward protecting your legs and your life. 

Who Performs the ABI Test?

At most vascular clinics, the ABI test is performed by an ultrasound technologist or interventional radiologist. They’ll gently place blood pressure cuffs on your ankles, then use a small handheld device called a Doppler to listen to how well blood is moving through your arteries. Once the test is complete, your vascular specialist will review the results with you, explain what they mean, and discuss any next steps to improve your circulation in your legs.

How to Calculate ABI: A Step-by-Step Guide

Understanding how the ankle-brachial index is calculated can help you feel more confident and involved in your care. While it may sound technical at first, the process is actually straightforward once explained step-by-step.

Step 1: Preparation

You’ll start by lying down on an exam table and resting for about 10 minutes to ensure your blood pressure is steady. You’ll need to remove your shoes and socks so that your ankles are easily accessible for the test.

Step 2: Measuring Arm Blood Pressure

Your provider will use a regular blood pressure cuff and a small Doppler device to measure the systolic (top) blood pressure in each arm. They’ll listen for blood flow in the brachial artery, located near your elbow. The higher of the two readings will be used as the reference point for your ABI calculation. If there’s a big difference between the two arm readings, more than 10–15 mm Hg, your provider may look into it further, as it could be a sign of narrowing in the arteries of your upper limbs.

Step 3: Measuring Ankle Blood Pressure

For the ankle portion of the test, a blood pressure cuff is placed just above your ankle. Your provider will check two arteries in each foot: the dorsalis pedis, found on the top of your foot, and the posterior tibial, found along the inside of your ankle. Using the Doppler probe to listen to blood flow, they’ll measure the systolic pressure in both arteries. The higher of the two readings for each ankle is then used in your ABI calculation.

Step 4: ABI Calculation

For each leg, the ABI is calculated as the ratio of the highest ankle systolic pressure (from either artery) divided by the highest arm systolic pressure. For example, if your highest ankle pressure is 120 mm Hg and the highest arm pressure is 140 mm Hg, your ABI would be 120 divided by 140, which equals 0.86. Both legs are measured, and results are recorded, usually to two decimal places.

Understanding Your ABI Results

Once your ABI results are ready, your doctor will explain what they mean for your blood flow and overall vascular health. ABI results are grouped into ranges:

• 1.00 to 1.40 – Normal: Blood is flowing well through your arteries.
  
• 0.91 to 0.99 – Borderline: This may be an early sign of PAD, and your doctor may suggest follow-up testing.
  
• 0.90 or lower – PAD Present: This usually means your arteries are narrowed or blocked.
  
• 0.41 to 0.90 – Moderate PAD: Blood flow is reduced, which can affect healing and mobility.
  
• 0.40 or lower – Severe PAD: There’s a high risk of serious complications like non-healing wounds or tissue loss.
  
• Above 1.40 – Arteries May Be Stiff or Calcified: Often seen in older adults or people with diabetes. Your doctor may recommend another test, such as the Toe Brachial Index, for more accurate results.

Remember, the ABI test is just one piece of the puzzle. Your provider will review your results, along with your symptoms, medical history, and other risk factors, before determining the best next steps.

Who Should Consider an ABI Test?

Peripheral artery disease is more common than many people realize, especially in older adults and those with certain health risks. While PAD can cause symptoms like Beinschmerzen when walking (claudication), Taubheit, coldness, slow-healing wounds, oder changes in skin color on the legs and feet, many people have no symptoms at all, even as the condition worsens.

That’s why doctors often recommend an ABI test for people who:

• Are 65 or older
• Have diabetes, high blood pressure, or high cholesterol
• Currently smoke or have smoked in the past
• Have a family history of heart disease or vascular disease
• Live with obesity or have a primarily sedentary lifestyle

Even if you feel fine, your physician may suggest an ABI test if you show signs of poor circulation or have multiple risk factors. Early detection gives you the best chance to protect your leg health and prevent serious complications.

What Happens After a PAD Diagnosis?

If your ABI test shows signs of PAD, your doctor may recommend further tests, such as an exercise ABI, Doppler ultrasound, or angiography, to better understand the extent of the blockage. Treatment often begins with lifestyle changes to improve blood flow, along with medication to manage cholesterol, blood pressure, or blood sugar levels. In some cases, minimally invasive procedures may be needed to open narrowed arteries and restore healthy circulation.

Take Charge of Your Vascular Health

The ABI is a simple, powerful screening tool for PAD, offering clear benefits for early detection and ongoing care. Understanding how the test works and what the results mean helps you take an active role in your health or advocate for those you love.
If you or a loved one has been diagnosed with PAD, remember that timely treatment can protect your mobility, independence, and overall quality of life. Don’t delay a follow-up; einen Termin vereinbaren with the nationally recognized vascular specialists at American Endovascular today. Our team will help guide you to better health and peace of mind.