Middle-aged adults with blocked leg arteries may face high risk of amputation

People in their 50s with severely narrowed leg arteries may face a high risk for major amputations despite having emergency surgery to restore blood flow to their legs, new research shows.

The findings, published Monday in the American Heart Association journal Circulation, highlight the need for early detection and treatment of peripheral artery disease, or PAD, before it progresses to an advanced stage.

"This study shows that early diagnosis and treatment are of vital importance for people with PAD," said Dr. Qiuju Li, the study's lead author and a research fellow in medical statistics in the department of health services research and policy at the London School of Hygiene and Tropical Medicine. "People under 60 with severe forms of PAD have particularly poor outcomes. Better preventive strategies are warranted."

Peripheral artery disease occurs when plaque builds up in the arteries that carry blood from the heart to other parts of the body, restricting proper blood flow. Most often, this occurs in the legs and the feet, though it can also affect the arms, hands and fingers. The condition can lead to amputations and death.

Several types of surgery can restore blood flow to the legs, a procedure called lower limb revascularization. One is angioplasty, in which a tiny balloon is inflated inside the arteries to clear away plaque and can be followed by inserting small wire mesh tubes called stents that hold the arteries open. Another is bypass surgery, which creates a new path around a blocked artery using a piece of another blood vessel or an artificial one. Some people require a combination of both procedures.

The goal of revascularization is to prevent the loss of a limb and prolong survival. However, even after surgery, many people with PAD still need limbs amputated and face a high risk of dying.

In the new study, researchers analyzed data for 94,690 people in England who underwent revascularization for PAD from 2013 to 2020. Participants were 50 or older, and about 65% were men.

Nearly 35% of the participants had nonelective surgery, meaning it was considered medically necessary. The remainder elected to have surgery to restore blood flow. Compared with those who had elective surgeries, people who had nonelective revascularizations tended to be 80 years or older, frailer and more likely to have diabetes and tissue loss.

After a median follow-up of nearly five years, 9,464 people had a major amputation, defined as leg amputation above the ankle. The amputation rate was significantly higher for people who had nonelective revascularizations: 15.2% after one year and 19.9% after five years. In comparison, those who elected to have surgery had a 2.7% amputation rate after the first year and a 5.3% rate five years later.

The risk of amputation, however, was higher among younger adults whose revascularizations were medically necessary. Participants between ages 50 and 54 showed an 18% risk of a major amputation after one year and 28.8% after five. Meanwhile, the risk for those ages 80 to 84 was 11.9% after a year and 17% after five. For people who chose to have the surgery, the risk of major amputation stayed comparatively low regardless of age.

And the death rate within five years of surgery was nearly twice as high for those who had revascularization in an emergency – 64% versus 33% – than for those who elected to have the surgery.

The findings are counterintuitive, said Dr. Venita Chandra, a clinical professor of surgery in the division of vascular surgery at Stanford University in California. "You expect older people would have higher rates of major amputation after lower limb revascularization, but actually it was the opposite. Patients who were younger were at higher risk of major amputation" after emergency surgery.

It could be that young people are not getting diagnosed with PAD until after it has reached an advanced stage, said Chandra, who was not involved in the research. "PAD is notoriously underdiagnosed," she said. "It is just not on everyone's radar. Maybe our training programs don't emphasize it enough. We need to be diagnosing and caring for these patients earlier."

PAD can develop at any age, but the risk goes up with age. The majority of people in the U.S. who have PAD are 65 or older. A family history of PAD, heart disease, stroke or blood vessel disease also increases the risk. So does smoking, not getting enough physical activity, stress and eating foods high in saturated fats.

Other medical conditions also can raise the risk, including diabetes, kidney disease, blood clot disorders, high blood pressure, obesity and high cholesterol. Pregnancy-related conditions such as preeclampsia and gestational diabetes raise the risk for PAD later in life.

Lifestyle changes and medications are recommended during the early stages of disease. When those aren't sufficient, revascularization becomes necessary, especially once a person experiences complications such as tissue loss or wounds that won't heal, Chandra said.

"If that happens, you need revascularization as soon as possible and should have already had one before you got to this point," she said. "Goal-directed medical therapy can make a difference, and that's not being done enough. We need to treat people properly for this disease on the whole."