Focus on: Peripheral arterial disease
Peripheral arterial disease can affect the same people as heart attacks and strokes, and the worst cases can be life-threatening. Senior Cardiac Nurse Emily McGrath speaks to expert Patrick Coughlin about PAD.
What is peripheral arterial disease (PAD)?
Peripheral arterial disease (PAD), also called peripheral vascular disease, is a condition caused by a build-up of fatty deposits (atheroma) inside your arteries, meaning less blood can get through. When the same process occurs in the heart, we call it coronary heart disease. Having PAD puts you at risk of coronary heart disease, as well as stroke. PAD usually affects the legs – it can often lead to leg pain when walking and, in severe cases, gangrene and even amputation.
Who is at risk of peripheral arterial disease?
People are at an increased risk as they age. About one in five people over 60 in the UK have some degree of PAD. The same things that raise your risk of heart disease and stroke – including smoking, diabetes, obesity and high blood pressure – also raise your risk of PAD. In particular, we are seeing a rise in PAD as a result of increased cases of diabetes. It affects both men and women and sometimes it can run in families.
What are the symptoms of PAD?
Peripheral arterial disease affects both men and women and sometimes it can run in families
The most common symptom is intermittent claudication – it comes from the Latin word claudicare, meaning to limp. It is usually pain in the leg muscles when walking or exercising – so you walk a certain distance then experience cramp-like pain. A bit like angina when you have coronary heart disease, the pain happens because the muscle isn’t getting enough blood to supply the oxygen and nutrients it needs. Once the muscle has rested, you can walk a similar distance again.
When the blood flow becomes worse, the body can’t deliver enough blood, nutrients and oxygen to the skin and soft tissues. This usually occurs in the feet, as they are furthest from the heart. You may develop persistent pain, ulcers and even gangrene in the feet. This is known as critical limb ischaemia, and rapid treatment is essential to have a chance of saving the leg.
How is PAD diagnosed?
Your GP should refer you to a vascular specialist, who will assess the blood flow and check for pulses in specific places in the leg. Blood flow can also be checked using a Doppler test. Your doctor may measure your ankle–brachial pressure index, where a Doppler test is used to compare blood pressure at the ankle as a ratio to blood pressure in the arm. A normal result would be a ratio of 0.9–1.1. If you have PAD, blood pressure at your ankle will be significantly lower than that of your arm, creating a ratio below 0.9.
Next, the specialist would use duplex ultrasound, a combination of standard ultrasound and Doppler, to give more information about where and how severe the narrowings in your arteries are.
Walking can help manage symptoms if you have PAD
How is peripheral arterial disease treated?
If you have intermittent claudication, your risk of heart attack is three to five times higher than normal. So we would start by trying to reduce your heart attack risk, for example by stopping smoking, testing for (and treating) high blood pressure and diabetes, and taking a blood thinner (such as aspirin) and a statin.
We'd then focus on the symptoms in your leg. If you have claudication, national guidelines recommend enrolling in a three to six-month walking programme. This is unfortunately not widely available on the NHS due to funding. If you can’t access one, you can still follow a structured walking programme on your own, or ask if there’s a cardiac rehabilitation-type programme you can go on.
If PAD is affecting your quality of life, you and your specialist will have to weigh up the risks and benefits of invasive treatment. If your PAD is so severe that you have ulcers or gangrene, we’d act quickly to improve blood supply to the leg. The main treatment is balloon angioplasty. A thin flexible tube is inserted into an artery in the groin, then a balloon is passed to the blockage in the leg artery to open it.
If PAD is affecting your quality of life, you and your specialist will have to weigh up the risks and benefits of invasive treatment
Bypass surgery (similar to heart bypass surgery) is less common now for PAD, but we would consider it if the disease is severe.
Overall, around 1–2 per cent of people with intermittent claudication will undergo amputation within five years, making PAD one of the biggest causes of lower-limb amputation in the UK. By the time patients develop ulcers or gangrene, it is often too late for us to improve circulation, so the only options are amputation or managing the ulcers as well as possible, which in the worst-case scenario may be palliative care. It is vital to seek medical advice if you have any signs of PAD.
What is the prognosis for people with PAD?
Most people with intermittent claudication remain stable or improve. Around one in five go on to develop critical limb ischaemia, the most severe form of PAD. With critical limb ischaemia the outlook is poor – half of patients are likely to die within five years. This is partly because they are likely to have other artery blockages, including those in the heart.
What is the latest BHF-funded research in this area?
I am part of a research project looking at new imaging techniques to see if we can predict treatments that will work. We are using a new type of scanner that can highlight inflammation (which is part of the process leading to PAD and other heart and circulatory diseases) and calcium build-up in artery walls (which leads to hardening of the arteries). We will investigate the role these factors play in the re-narrowing process that can occur following treatment.
If successful, we could discover why inflammation and calcium build-up happen, improve treatments for those most at risk of PAD, and provide a platform to test new drugs and devices to treat PAD.
Further research into PAD is happening at King’s College London, where Bijan Modarai and colleagues are working on BHF-funded research to find new ways to diagnose and treat patients with severe lower-limb ischaemia.
CV - Patrick Coughlin
- Consultant Vascular and Endovascular Surgeon, Addenbrooke’s Hospital, Cambridge
- Researches the development of peripheral arterial disease
- British Society for Endovascular Therapy council member