Localities that ban smoking in bars, restaurants and other public places witness a quick drop in heart attacks, two new studies show. The research — which incorporated data from a total of 24 studies of smoking bans across the country — found at least a 17 percent reduction in heart attacks one year after the bans had been enacted. “That’s when you lump all these studies together,” said Dr. David G. Meyers, a professor of cardiology and preventive medicine at the University of Kansas and lea