Checking for clogged arteries doesn’t help inveterate smokers kick the habit if they are already in a quit-smoking program, Swiss researchers have found.

Yet that’s sometimes the justification when doctors recommend the expensive scan, called carotid plaque screening, which experts say has no proven benefits in people without symptoms of heart disease.

“When people get a very good smoking cessation program, carotid plaque screening does not add anything,” Dr. Nicolas Rodondi, who led the new study, told Reuters Health.

Some previous research had suggested that showing people dire pictures of cholesterol buildup, or plaque, in their arteries might be the stick they need to make healthy changes to their lifestyle.

But at least for smokers, the new study slashes those hopes.

“It proves that in trying to motivate smokers to quit, this strategy is not going to be useful,” said Dr. Patrick O’Malley of the Uniformed Services University in Bethesda, Maryland, who wrote an editorial about the findings.

During carotid plaque screening, doctors use ultrasound to get a picture of the arteries that supply blood to the brain. The procedure is gaining popularity both in the U.S. and in Europe, but it’s not clear that it actually helps patients.

“There is absolutely no proven benefit,” O’Malley told Reuters Health. “It’s still a promising test, but it is being overutilized in practice.”

While some organizations currently recommend the routine carotid plaque screening, the government-backed U.S. Preventive Services Task Force advises against it when people have no symptoms of heart disease.

Scans vs. counseling

The new study, published in the Archives of Internal Medicine, is based on more than 500 long-time smokers aged 40 to 70 who all wanted to quit and had no symptoms of heart disease.

All of them had six sessions of counseling over a year, plus a phone call, nicotine patches and brochures on smoking cessation. In addition, half were randomly chosen to be screened for carotid plaque, which most turned out to have.

Although smoking contributes to plaque, which is a risk factor for heart attack and stroke, the ultrasound pictures didn’t seem to have any effect.

After one year, a quarter of those who got screened had been smoke-free for at least a week based on their own reports as well as breath analyses. for those who didn’t get screened, the number was 22 percent — a difference that could easily be chalked up to chance.

And whether or not people had plaques visible on the scans didn’t make a difference either.

“Smokers are a different breed, they tend to have a different psychological profile,” said O’Malley. “They are more recalcitrant.”

According to Rodondi, carotid artery screening costs $400 in Switzerland — about the same as six sessions of quit-smoking counseling with a doctor.

And while the scan may not be worth its price tag, the smoking cessation program is, he added.

“We are very successful with the smoking cessation program,” Rodondi told Reuters Health. “When smokers try to stop smoking by themselves they only get a five-percent smoking cessation rate at one year.”

In an earlier study, O’Malley found that heart scans don’t seem to be of much help in changing risk factors for heart disease either.

While he said it’s still possible that medical scans might motivate some non-smokers to lead healthier lives, he said the new technology mostly distracts from establishing a good rapport between doctors and smokers — something that might ultimately help them kick the habit.

“It’s just difficult — It’s an addiction,” O’Malley said. “But I think people underestimate the value of building a relationship with patients and a longitudinal plan.”