Second-hand smoke boosts second heart attack risk

NEW YORK (Reuters Health) - Heart attack survivors are more likely to suffer further heart problems if they are regularly exposed to second-hand smoke, Greek researchers report.

Individuals hospitalized for a heart attack or a severe type of chest pain called unstable angina were 61 percent more likely to have another so-called "acute coronary event" during the subsequent 30 days if they reported being exposed to other people's cigarette smoke, Dr. Demosthenes B. Panagiotakos of Harokopio University in Athens and colleagues found.

"Taking into account that the risk of recurrent events in people who have had a cardiac event is much higher during the first 30 days after the event, chronic exposure to second-hand smoke seems to add significantly to the excess risk," they write in the medical journal Heart.

The researchers followed 2,172 patients admitted to six hospitals for a heart attack or unstable angina. Forty-six percent reported being exposed to second-hand smoke on the job or at home.

Eight percent of those not exposed to second hand smoke had a second acute coronary event within 30 days of the first, compared to 11 percent of those who were exposed to other people's cigarette smoking.

When the researchers accounted for other risk factors, they found second-hand smoke exposure upped the risk of a second heart attack or severe angina by 61 percent -- and the effect was about twice as strong in people who were smokers themselves, compared to non-smokers.

Exposure to cigarette smoke on the job was riskier than at-home exposure, more than doubling the risk of a second episode of heart problems.

Based on the findings, the researchers conclude that 45 percent of the second acute coronary events suffered by the people who were exposed to second-hand smoke could be attributed directly to that exposure.

"Although people's right not to be exposed to other people's tobacco smoke at the workplace has become increasingly recognized over the past years, it seems that in Greece (and probably in other regions) this right has been clearly infringed," the investigators note.

SOURCE: Heart, March 2007.