PAD is an abnormal narrowing of arteries other than those that supply the heart or the brain and most commonly, but not exclusively, affects the legs, giving it another name – LEAD (Lower Extremity Artery Disease).
It is highly prevalent, with an estimated 202 million people with PAD worldwide in 2010, and it affects both genders about equally . The most serious issue with PAD is its association with other cardiovascular diseases, such as coronary artery disease (CAD) and cerebrovascular disease (CD), with studies estimating a 5-year mortality rate of patients with PAD of 30 % (as opposed to 10% for the control group without PAD), of which 75 % of deaths are cardiovascular in nature .
Despite a large percentage of asymptomatic cases of PAD, there are several common symptoms, the most prominent of which are pain and cramping in the legs while walking or exercising. This type of pain is known as claudication and is commonly located in the calf muscles of the affected leg(s), but can also be felt in the buttocks, thighs or feet.
Claudication can be accompanied by cramps, numbness and feeling of heaviness (in the legs), the severity of which often subsides when an individual with PAD takes a rest.
But, pain usually flares up again when an individual resumes walking. This phenomena is called intermittent claudication.
The physiological mechanism behind intermittent claudication is, as recent studies have shown, quite complex, and not limited to diminished blood flow to leg muscles due to atherosclerosis of the arteries. There is also evidence of defective energy metabolism in the exercising ischaemic muscle of individuals with PAD or, in layman’s terms, muscles of those with PAD have difficulties utilising their body’s energy resources . Regardless of exact pathophysiology, intermittent claudication can be mimicked by other medical conditions, such as sciatica (pain felt from the lower back down the leg, most often due to spinal disc herniation pressing on the spinal nerves) which necessitates a search for other PAD-specific symptoms.
Other symptoms of PAD (beside intermittent claudication)
- Weak or entirely absent pulse in the legs and feet. An abnormal pulse in posterior tibial artery (the artery at the back of the lower leg) has a 48.7 % predictive value for PAD .
- The colour of the skin on the affected leg changing to a blueish or pale hue. Individuals with moderate to severe PAD often exhibit pallor in an affected leg when it is in elevated position .
- Lower temperature in the affected leg (in comparison with the unaffected limb or the rest of the body). This can be so pronounced, especially in individuals with severe PAD, that it can be felt by touch, without any complex diagnostic tools.
- Scaly and shiny skin on the affected leg. Skin texture is noticeably different on the affected leg(s) in comparison with an unaffected limb or the leg of a healthy individual.
- Poor toenail and hair growth on the affected leg. A diminished flow of nutrients in the blood leads to malformation of toenails and even complete hair loss.
- Sores, ulcers and wound on the feet, usually non-healing in nature. Most typical for PAD sufferers are arterial insufficiency ulcers (also known as ischaemic ulcers) which are the second-most common type (10 to 30 % of all cases of ulceration) of lower-extremity ulcers .
- Gangrene. The most extreme and obvious symptom/complication of PAD that ultimately requires partial or complete amputation of an affected limb to save a patient’s life. In the United States alone between the years 2000 and 2008, about 6.8 % of patients hospitalised with PAD required lower extremity amputation (LEA) (during the same time period) .
- Erectile dysfunction in men, especially if they are diabetic. There is a strong correlation between PAD and erectile dysfunction (ED), with one study showing that the likelihood of individuals with ED also having PAD was two-fold greater than in the control group without ED .
Peripheral Artery Disease (PAD) is one of the vascular diseases which are often asymptomatic, with studies suggesting that up to 40 % of individuals with PAD have no symptoms, about 50 % have symptoms that could be attributed to other medical conditions and only 10 % have classical PAD symptoms .
One method of identifying undiagnosed PAD is measuring Ankle-Brachial Index (ABI).