Introduction

Peripheral arterial disease (PAD) is a major cause of limb loss in Singapore. However it does not receive as much attention as diseases involving the other vascular beds: namely, coronary artery disease and cerebrovascular disease. Yet it is a good predictor of heart attack and stroke risk.

Causes

PAD develops when arteries in the legs become clogged with plaque – such as fatty deposits and cholesterol – that limits or completely blocks blood flow in the legs. This causes muscle pains in the calves, thighs, and buttocks.

Like atherosclerosis, PAD is caused by the buildup of fatty deposits — called plaque — in the arteries. Having blocked arteries can keep oxygen-rich blood from reaching the muscles when the muscles need it most. This lack of oxygen causes the pain. PAD can increase your risk of heart attack and stroke. But the good news is that PAD can be easy to diagnose and is treatable.

With pain limiting their movements, the patients move gradually from an active lifestyle to a sedentary one. This results in immobility and a shorter life expectancy due to the increased risk of high blood pressure, heart attack, and stroke.

Risk factors

The risk factors for PAD include hypertension, high cholesterol, and diabetes – all of which are common illnesses in our population. One-third of diabetics over the age of 50 develop the disease.

Another high-risk activity, such as smoking, brings on the disease much sooner. So PAD patients, who otherwise would be in their late 70s or 80s, could start to feel symptoms as early as their 50s or 60s.

Symptoms

The symptom involves intermittent claudication, or momentary limping because of pain. For example, when a patient with a blockage in his leg walks 100 metres, he starts developing pain in the calf muscle of the affected leg. He stops and rest for a few minutes; the pain goes away and he can go another 100 metres before it comes on again.

In the most extreme cases, if left unchecked, it can cause ulcers, gangrene, and amputation.

Treatment

One way to prevent that is by checking their ankle and arm pressures during routine clinic consultations, which should be the same. The ankle-brachial index (ABI) is calculated by dividing ankle pressures by arm pressures. A value of 0.9 to 1 is normal. If it comes back as 0.5, then that implies that the patient has significant disease.

Specific management of PAD involves:

1. Lifestyle changes
These include quit smoking; eating a balanced diet that is high in fibre and low in cholesterol, fat and sodium; and exercise.

2. Management of other related health problems, such as high blood pressure, diabetes or high cholesterol.

3. Practise good foot and skin care to prevent infection and reduce the risk of complications.

4. Medications
Medications may be recommended to treat conditions such as high blood pressure (anti-hypertensive medications) or high cholesterol (statin medications). An antiplatelet medication such as aspirin or clopidogrel (Plavix) may be prescribed to reduce the risk of heart attack and stroke.

5. Intervention
More advanced PAD can be treated with interventional procedures such as angioplasty (to widen or clear the blocked vessel), angioplasty with stent placement (to support the cleared vessel and keep it open), or atherectomy (to remove the blockage). In some cases, surgical procedures such as peripheral artery bypass surgery may be performed to re-route blood flow around the blood vessel blockage.

Despite the availability of healthcare in Singapore, PAD is still “under-diagnosed” for several reasons. One being that checking the arm and ankle pressures is not as routine as it should be.

In the US, the determination to increase awareness has recently led to increased training for vascular medicine specialists for routine ankle-brachial check-ups and early detection for treatment.

The goal of therapy is to improve blood supply to their leg muscles so that patients maintain their functional level of activity. Once patients become couch potatoes it’s hard to get them off the couch. They need to be kept active to maintain their health.