"Being overweight or obese, compared with being normal weight or very obese, appears to confer a survival advantage following a heart attack or near heart attack -- collectively called acute coronary syndrome.

However, researchers caution that these findings must be interpreted carefully "and should not be used as evidence against weight reduction."

The findings come from a study that was comparing two drug treatments for people with an acute coronary event. The researcher noticed that mortality rate "was higher for normal weight versus those with a higher BMI" -- i.e., body mass index, a measure of weight in relation to height -- Dr. Eric L. Eisenstein told Reuters Health.

"However, higher BMI individuals were also younger and had other risk factors," he explained, so it wasn't clear that weight itself was a survival factor.

Eisenstein, at the Duke Clinical Research Center, Durham, North Carolina, and his colleagues now report in the American Journal of Medicine that the mortality rate was indeed higher for normal-weight subjects than for other BMI groups when other factors were accounted for.

Compared with normal-weight subjects, after adjustment, the chances of dying within the 30 days after an acute coronary syndrome were reduced by 34 percent in the overweight patients, by 39 percent in the obese and 11 percent in the very obese. The results were similar for dying within 90 days and 1 year.

Eisenstein pointed out that "because overweight and obese individuals in this study have better 1-year incremental survival, it does not follow that they will have a longer life. Age is a primary determinant of life expectancy."

Therefore, he concluded, "although patients who are overweight may, for a variety of reasons, have better initial survival after an acute coronary event, managing obesity remains an important target for risk factor modification and reduction of morbidity and mortality from heart disease in the long run.""Brigham & Women's Hospital {CLICK FOR MORE}