As an addendum to the previous post, I should mention two more recent studies of smoking bans and heart attack rates. The first, from Brad Rodu, Nicholas Peiper and Philip Cole, published a couple months ago in Journal of Community Health, examines rates in six states and finds no effect:
The AMI mortality rate among persons age 45 + years (deaths per 100,000 persons, age-standardized to the 2000 US population) in the 3 years before adoption of the smoke-free ordinance (the expected rate) was compared with the rate observed in the first full year after the ban (the target year) in six US states. Target-year declines were also compared to those in states without smoking bans. Target-year declines in AMI mortality in California (2.0%), Utah (7.7%) and Delaware (8.1%) were not significantly different from the expected declines (P = 0.16, 0.43 and 0.89, respectively). In South Dakota AMI mortality increased 8.9% in the target year (P = 0.007). Both a 9% decline in Florida and a 12% decline in New York in the 2004 target year exceeded the expected declines (P = 0.04 and P < 0.0002, respectively) but were not significantly different (P = 0.55 and 0.08, respectively) from the 9.8% decline that year in the 44 states without bans. Smoke-free ordinances provide a healthy indoor environment, but their implementation in six states had little or no immediate measurable effect on AMI mortality.
The second unpublished study [pdf] looks at rates in 74 US cities that implemented smoking bans. It finds a decline of a mere 3% following implementation. Contrary to expectation, the effect disappears entirely when restricted to the 43 cities whose bans were meaningful. All things considered, it lends support to the idea that smoking bans have no short-term impact on heart attack rates.
[Thanks to Chris Snowdon and Michael McFadden for the links.]