Nationwide Smoking Ban Cuts Incidence of Acute Coronary Syndrome in Nonsmokers

September 14, 2009 (Barcelona, Spain) — A nationwide smoking ban in public places in Iceland resulted in a significant 21% reduction in acute coronary syndrome (ACS) among nonsmoking men in the five months after the ban was introduced, according to a study presented at the European Society of Cardiology (ESC) 2009 Congress [1]. The immediate reduction was seen in men only, not in women, Dr Thorarinn Gudnason (Landspitali University Hospital, Reykjavik, Iceland) said.

“The 21% reduction that we saw in our study is comparable to what is seen with some of the most potent therapies in cardiovascular medicine,” Gudnason told heartwire . “Obviously, we have to expand the study to include a larger population and other nations, and we will have to talk to some of our friends in Europe. But if this is a true effect, the smoking ban will be very beneficial for public health, and it will also be very cost effective.”

Save Lives. Save Money, Too

Smoking-related illness in Iceland costs 29 billion kronur (~$234 million) each year. Subtract the 7 billion kronur (~$56 million) that the state gets from taxes from tobacco sales, and the net cost is 22 billion kroner (~$178 million). “The Icelandic Medical Association made a calculation of the cost of smoking and there is a large movement in Iceland now discussing this. We are in the midst of an economic crisis, so we have to think about how we are spending our money,” Gudnason said.

Most of the studies showing that passive smoking is a health hazard focused on acute myocardial infarction and were retrospective in nature. When Iceland enacted its nationwide ban, in June 2007, Gudnason and his colleagues jumped at the chance to study the ban’s effect in a prospective manner. They chose a reduction in the incidence of ACS rather than AMI as an end point, because they wanted to focus more on the pathophysiology of the closure of the coronary arteries, plaque rupture, and thrombus formation that lead up to AMI “and not some surrogate end point like changes on an EKG,” Gudnason explained.

The study population consisted of 378 patients (281 men, 97 women; p<0.01) who underwent coronary angiography due to ACS during the 5 months immediately before or after the ban was enacted. ACS was defined as clinical symptoms of unstable coronary artery disease (chest pain at rest), as well as at least one of the following: elevated cardiac enzymes, ischemic changes on EKG at rest, or an abnormal exercise stress test during the same unstable episode.

Are Women Protected by Their Hormones?

In the five months before the ban, 157 men underwent angiography for ACS; in the five months after the ban, 124 men underwent angiography for ACS (p<0.05). However, no effect was seen among women; 49 had angiography before and 48 had angiography after the ban, Gudnason reported.

By the time women begin to get atherosclerosis, they have probably stopped going to smoky bars, he hypothesized, speculating on the lack of effect in females. “You probably have to have some atherosclerosis in the arteries for ACS, and women get atherosclerosis later than men. They are more often in smoky environments while they are younger, and therefore less prone. By the time they do get atherosclerosis, they are in their 70s or 80s, and are not as much in smoky environments. We haven’t studied this, it’s just speculative.”

Dr Lars Ryden (Karolinska Hospital, Stockholm, Sweden) and Dr Werner Benzer (Medical University of Vienna, Austria), comoderators of the oral abstract session, called the Icelandic study, although small, completely consistent with other data that support an immediate effect of a smoking ban.

“The interesting point, which was new, was the discrepancy between men and women. This needs further study, but the proportion of women was not that large, so we have to be a little bit cautious. Still, it is another thing that verifies that we shouldn’t be subjected to secondary smoke,” Ryden told heartwire.

Benzer added that “before menopause, women have healthy hormones, so that could be a reason for the difference, that women are not affected as much from smoking at that particular age. I have the same impression, that the difference between women and men would be interesting to investigate in further studies.”

Italian Success Story

Another smoking ban success story was reported from the region of Piedmont in Italy [2]. Researchers, led by Dr Francesco Barone Adesi (University of Turin, Italy) used the hospital-discharge records from the region to estimate changes in admissions for acute coronary events in the first 30 months after the introduction of a national smoking ban, in January 2005.

They found that admission rates had decreased by 6% following the ban, which was restricted to people younger than 70 years of age. Barone Adesi said these figures "made sense," because people older than 70 years generally do not frequent public places where smoking might have taken place, an effect of a smoking ban in this age group would not be expected. A much greater effect was seen on the weekends, which he suggested reflected increased visits then to public places, such as bars and restaurants.

The observed reduction in the number of admissions for acute coronary events started in the same month in which the ban came into effect and remained evident for the entire study period. No change in the underlying trend was found, suggesting that most of the reduction came into effect immediately after the introduction of the ban.

"I don't know of any other intervention that could lead to such an immediate reduction in hospital admissions, and this intervention has the added bonus of being free," Barone Adesi said.

Hazard Ratio of Rates of Admission for Acute Coronary Events After the Smoking Ban, Compared With Events Before the Ban

Heartwire from Medscape © 2009  Medscape, LLC

Cite this: Nationwide Smoking Ban Cuts Incidence of Acute Coronary Syndrome in Nonsmokers - Medscape - Sep 14, 2009.