Wednesday, May 02, 2007

American Heart Association Deceives Public About Secondhand Smoke, Sets Policy for Meetings in Smoke-Free Cities, then Immediately Violates Policy?

The American Heart Association (AHA) yesterday announced a new policy of holding its conferences only in cities that provide a smoke-free workplace, either through local ordinance or state law. Beginning on May 1, 2007, all AHA scientific meetings must be held only in cities that have enacted smoke-free workplace laws or are located in states that have such laws in place.

According to its press release: "'The American Heart Association has long advocated for smoke-free workplace ordinances at the state and local levels,' said American Heart Association Board Chairman Andrew B. Buroker. 'We are equally committed to protecting the health of our staff and volunteers by providing smoke-free environments for Association-sponsored meetings and conferences.' ... 'We can no longer excuse holding meetings in smoky localities that could put staff, volunteers and visitors at risk for cardiovascular diseases,' said Buroker. 'In order to save many lives, the American Heart Association strongly believes that the nation's indoor public places should be 100 percent smoke-free.' The policy goes into effect on May 1, 2007 for American Heart Association conferences. It requires all meetings and conferences organized or sponsored by the association to be held in communities that have enacted smoke-free workplace laws by a state law or local ordinance."

The AHA justified its policy, in part, by claiming that just 30 minutes of exposure to secondhand smoke reduces coronary blood flow, greatly increasing a person's risk of suffering a heart attack: "Thirty minutes of exposure to secondhand smoke stiffens coronary arteries, slowing the flow of blood to the heart muscle, making a person much more susceptible to a heart attack."

The AHA's 2007 annual scientific conference will be held in Orlando this fall.

The Rest of the Story

In justifying its new policy, the American Heart Association is deceiving the public about the acute cardiovascular health effects of secondhand smoke and misrepresenting the science.

The very study which the AHA is relying upon to support its claim that 30 minutes of secondhand smoke exposure slows the flow of blood to the heart muscle actually showed that 30 minutes of secondhand smoke exposure has no effect on the baseline rate of flow of blood to the heart muscle (see: Otsuka R, Watanabe H, Hirata K, et al. Acute effects of passive smoking on the coronary circulation in healthy young adults. JAMA 2001; 286:436-441).

As I have explained in detail elsewhere (post 1; post 2; post 3; post 4; post 5; post 6; post 7; post 8; post 9), the Otsuka et al. study which is being relied upon to support this statement actually found that 30 minutes of secondhand smoke did not impair basal coronary blood flow in healthy adults. What was impaired was the coronary flow velocity reserve, a measure of the coronary arteries' ability to dilate in response to artificially imposed stressors. This finding does not mean that someone exposed to secondhand smoke suffers decreased coronary blood flow.

Coronary flow velocity reserve is a measure of the ability of the coronary arteries to dilate in order to increase blood flow under experimental conditions. What a decline in coronary flow velocity reserve indicates is something called endothelial dysfunction - an impairment of the ability of the coronary arteries to dilate in response to a variety of stimuli. This ability to dilate is mediated by the endothelial cells -- the cells which line the blood vessel.

The endothelial cells respond to certain stimuli by producing nitric oxide and other chemicals which diffuse into the smooth muscle in the artery wall, sending a chemical message that causes the muscle to relax and therefore causing the artery to dilate. There are a number of exposures that impair the ability of the endothelium to accomplish this function; among them are active smoking, secondhand smoke, high cholesterol, consumption of trans-fats, and consumption of a high-fat meal.

When endothelial dysfunction is triggered repeatedly over a long period of time, it has been shown to result, ultimately, in atherosclerosis (narrowing of the coronary arteries). When this occurs, coronary blood flow is reduced. It is important to note that a reduction in coronary blood flow is not observed acutely when the endothelial dysfunction is being measured from a single experimental exposure (such as in the Otsuka et al. study). The Otsuka et al. study demonstrated that if you simply measure coronary blood flow in a person exposed to secondhand smoke for 30 minutes, it is not significantly reduced.

Thus, the AHA's statement is false and unsupported by the evidence, or at least, very misleading.

There is absolutely no truth to, and no plausibility to the assertion that 30 minutes of secondhand smoke makes healthy people much more susceptible to a heart attack. If you don't already have severe coronary artery disease, 30 minutes of secondhand smoke exposure will not greatly increase your susceptibility to a heart attack. Such an effect is completely implausible, and there is no scientific evidence to support such an assertion.

Interestingly (and importantly), the American Heart Association's statement is completely unqualified. It does not assert that 30 minutes of secondhand smoke exposure makes a person with severe existing coronary artery stenosis much more susceptible to a heart attack (even that assertion would be highly speculative, but at least there is some evidence to support it). The statement implies that anyone exposed to secondhand smoke for 30 minutes faces an increased heart attack risk.

This is so far off from the truth. Essentially, if you don't have pre-existing severe heart disease, your risk of suffering a heart attack from 30 minutes of exposure to secondhand smoke is zero.

The ultimate irony in the American Heart Association's press release is that despite what on the surface looks like a strong and principled stand designed to pressure cities to protect workers from secondhand smoke, the stand appears to be little more than fluff.

The very first city in which the AHA is hosting its first conference in accordance with the new policy is Orlando - a city in which bar workers are exposed to extremely high levels of secondhand smoke. You see - in Florida, smoking is still allowed in bars. If attendees of the AHA conference this fall go out for drinks in the evening in an Orlando bar, they will more likely than not be exposed to high levels of secondhand smoke. Can you imagine all the heart attacks that are going to occur during the conference. It's a good thing that there will be so many cardiologists around.

Does the American Heart Association not realize that a bar is a workplace? Does the American Heart Association not believe that bar workers are deserving of the same protection from the apparently life-threatening acute hazards of secondhand smoke as everyone else in the population? Does the American Heart Association believe that it is justified to exempt this major segment of our working population from health protection?

If anything, by holding its conference in Orlando amid all the fluff of this major announcement, the American Heart Association is rewarding cities that fail to protect their bar workers. Any city that might previously have been afraid of potentially losing the AHA's business now knows that it can "safely" exempt bars from their smoke-free protection laws and still have a chance to serve as a host for the AHA convention.

The hypocrisy of the AHA's press release is startling. Secondhand smoke is so dangerous that only 30 minutes of exposure decreases your coronary blood flow and can trigger a heart attack; however, it's not so bad that we need to protect bar workers from secondhand smoke. Let them keel over from heart attacks - as long as the AHA conference attendees have a place to enjoy their evening cocktails to unwind after a long day of scientific presentations (many of which, incidentally, are going to be about how harmful secondhand smoke is).

Add today's story to the story from Monday about another so-called principled stand taken by the AHA which turns out to be little more than fluff in my opinion, and it looks like the American Legacy Foundation and Action on Smoking and Health are in real trouble. The American Heart Association is now in the driver's seat for my next hypocrisy in tobacco control awards.

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