(Reuters Health) – In so-called “peripheral artery disease,” blood from the heart can’t reach the legs because the arteries are clogged. The result can be painful cramps while walking or climbing stairs, leg numbness or weakness, coldness in the lower leg or foot – and in the worst cases, amputation.
The authors of the new study expected that people with peripheral artery disease, or PAD, who stopped smoking would do better in the long run – but they didn’t expect the benefit to be as large as it was.
PAD patients who continued to smoke were more than twice as likely to die within five years as those who quit within the year, the study found.
Patients with the most extreme condition, called “critical leg ischemia,” who kept smoking were nearly three times as likely to die within five years compared to their counterparts who gave up cigarettes, senior author Dr. John Laird told Reuters Health, the medical director of the University of California, Davis, Vascular Center.
He expected quitters to live longer than smokers, he said, but did not imagine the difference in survival times would be so dramatic.
“Common sense told us we would expect some worse outcomes in smokers. But we were surprised by the magnitude of the difference,” Laird said.
“No matter how far you are along in the disease, it helps to quit smoking,” Laird said. “It gives us more fuel when we’re talking with our patients.”
The risk of dying within five years for the quitters with PAD was 14 percent, compared to 31 percent for those who continued to smoke, the study found.
For patients with critical leg ischemia, the benefit of smoking cessation reduced the risk of dying even more substantially – from a 43 percent mortality rate within five years for smokers to an 18 percent rate for quitters, Laird said.
“The outcome (of critical leg ischemia) is really poor if you continue to smoke,” he said. “Almost half of the patients will be dead within five years. It’s a terminal illness in some ways.”
Smoking increases the risk of developing PAD two to six times, according to the U.S. Centers for Disease Control and Prevention (CDC). The CDC estimates that PAD afflicts 8 million Americans, including up to one in five people age 60 and older.
Prior research established the link between smoking and PAD, and doctors treating PAD patients urge those who smoke to quit, Laird said. Until now, though, physicians lacked evidence of the benefits of giving up smoking after being diagnosed with PAD.
“These patients who were able to quit smoking had a dramatically better outcome,” Laird said. “You’d think that would be the case, but it hasn’t been proven that stopping smoking really makes a big impact.”
“But it really does,” he said.
Dr. Christopher Abularrage called the findings “striking” and described the study as a “great tool” he planned to use to help persuade his patients to stop smoking. He is a vascular surgeon at Johns Hopkins Hospital in Baltimore, Maryland, and was not involved in the current study.
“The point is even if you quit now you can reduce your risk of dying,” he told Reuters Health.
“Some people will say, ‘I’ve been smoking all this time. Why quit now?’ This shows that even if they’re able to quit now, despite all these years of smoking, there’s still an improvement,” Abularrage said.
“The difference between the two groups is very clear,” he said. “It’s definitely something I’m going to use in my practice.”