Secondhand smoke really does cause heart attacks

Even legislation declaring only some public places off-limits to smoking reduced the rate of heart attacks by 11 percent, researchers have found. The greatest benefits were seen among women, all adults between the ages of 65 and 74, and non-smokers.

Coronary heart disease is the number one killer in the world, and was responsible for 9.2 percent of all deaths in Spain in 2011. More than 50,000 people were hospitalized in that year for heart attacks (acute myocardial infarctions) alone. Researchers estimate that 20 percent of all heart disease in European countries is caused by tobacco smoke.

"Smoking and second-hand smoke are major and preventable public health hazards and risk factors for coronary heart disease, the single most common cause of death and morbidity worldwide," the researchers wrote.

Ban provides immediate benefits

In 2006, a law went into effect in Spain banning smoking in the workplace or in any hospitality establishment larger than 100 square meters. It also imposed new regulations on the advertisement and sale of tobacco, but did not regulate smoking in hospitality establishments smaller than 100 square meters. Smoking in such establishments was finally banned in 2011.

To assess whether the partial ban had reduced the rate of heart attacks in the intervening years, the researchers analyzed information on 3,703 heart attacks that occurred in the province of Girona between the years of 2002 and 2008. Heart attacks occurring between 2002 and 2004 (before the implementation of the partial ban) were analyzed separately from those occurring between 2006 and 2008 (after the implementation).

Prior studies on the connection between second-hand smoke and heart attacks have typically used data from hospitals. The limitation of such studies; however, is that only one-third of all heart attacks occur in hospitals. In the current study, researchers used a population-wide database to gather more accurate results.

They found that the total heart attack rate in the province dropped by 11 percent following the law's implementation, even among those not treated at a hospital. Among nonsmokers, the rate of heart attacks was reduced by 15 percent, whereas among those over age 65, it was reduced by 18 percent.

The researchers believe that "the population group that has benefited the most from the law passed in 2006 is that of non-smokers, since their passive exposure to tobacco smoke has decreased."

The researchers were unable to study the effects of the more complete public smoking ban implemented in 2011, but they believe that it is likely to reduce heart attack rates even further.

Coronary heart disease is characterized by an insufficient blood supply to the heart. This may eventually starve the heart of oxygen, causing the cell death known as a heart attack. Coronary heart disease is estimated to cost the Spanish public approximately 1.46 billion Euros per year.