Smoking bans in public places can reduce the number of heart attacks by as much as 36 percent, offering fresh proof that the restrictions work, U.S. researchers said on Monday.
They urged widespread bans on smoking in enclosed public places to prevent heart attacks and improve public health.
"This study adds to the already strong evidence that secondhand smoke causes heart attacks, and that passing 100 percent smoke-free laws in all workplaces and public places is something we can do to protect the public," James Lightwood of the University of California-San Francisco, whose study appears in the journal Circulation, said in a statement.
The team pooled data from 13 studies of smoking bans in communities in the United States, Canada and Europe.
They said heart attack rates fall immediately after smoking bans are put in place, dropping by 17 percent in the first year and by as much as 36 percent after three years.
Lightwood said in a telephone interview that prior studies have been inconsistent in their findings, but their analysis found that smoking bans had a compelling effect.
"A well-designed smoking restriction law can significantly reduce heart attacks in the community and has a beneficial impact on public health," he said.
Dr. David Goff of Wake Forest University School of Medicine in North Carolina said the findings suggest smoke-free laws could lower health costs.
"At a time of great concern over the financial sustainability of our healthcare system, smoke-free laws represent an inexpensive approach to reducing heart attacks, and, probably, other cardiovascular conditions," Goff said in a statement.
According to the U.S. Centers for Disease Control and Prevention, long-term exposure to secondhand smoke can raise heart disease rates in adult nonsmokers by 25 percent to 30 percent.
Secondhand smoke kills an estimated 46,000 Americans every year from heart disease alone, the CDC and Heart Association say. Smoking also causes several types of cancer, stroke and emphysema or chronic obstructive pulmonary disease.