The study, published in Circulation's rapid access online edition, centers on Pueblo, Colo., located in southern Colorado.
In 2003, Pueblo residents voted to ban smoking in all buildings that are open to the public, including bars, restaurants, and bowling alleys.
Eighteen months later, Pueblo's hospitalization rates for heart attack were nearly 30% lower than they had been a year and a half before the ban began, report Carl Bertecchi, MD, and colleagues.
Bertecchi works in Pueblo at the University of Colorado Health Sciences Center.
Bertecchi's team checked heart attack hospitalizations of Pueblo residents over a three-year period, before and after the law took effect.
During that time, 855 Pueblo residents were hospitalized for heart attacks. Cases started dropping within months of the ban's launch.
"You can save lives with drugs and expensive, sophisticated devices, but this single community action lead to 108 fewer heart attacks in an 18-month period," Bertecchi says, in an American Heart Association news release.
Clearing the Air
The study doesn't prove that the no-smoking ban was solely responsible for the drop in heart attack hospitalizations.
But no such decline was seen in Colorado Springs -- located 45 miles from Pueblo -- or in El Paso County, which neighbors Pueblo County.
A prior, smaller study from Helena, Mont., also showed a drop in heart attack hospitalizations after a public smoking ban went into effect.
"Taken together, we suggest that these data indicate a smoking ordinance may be a vehicle for reducing the burden of ischemic heart diseaseheart disease," write Bertecchi and colleagues.
They predict that the health benefits of such laws will take decades to reach their full potential.
But when it comes to heart attacks, the perks "may be realized much more rapidly," Bertecchi's team writes, noting that the heart may be particularly sensitive to tobacco smoke.