SUNDAY, Nov. 12, 2006 (HealthDay News) -- Three weeks after she underwent coronary artery bypass surgery, a 71-year-old former smoker realized she could no longer complete the notoriously difficult Sunday crossword puzzle in The New York Times.
"The operation made me dumber," she told researchers investigating smoking and cognitive decline. And, they said, she could no longer even finish the less-difficult Thursday puzzle.
The woman had quit smoking 20 years before her heart surgery but her previous habit probably affected her recovery, the researchers told a news conference Sunday at the annual meeting of the American Heart Association (AHA) in Chicago.
Their research shows that people with a history of smoking were twice as likely to experience cognitive decline as those who never smoked.
Among 240 patients who had undergone coronary artery bypass graft (CABG) surgery at Morristown Memorial Hospital in Morristown, N.J., 60 percent showed evidence of cognitive decline. Those with a history of smoking were more at risk.
"It probably has to do with the mechanisms of injury of smoking itself. Inhaling carbon monoxide over time is probably not good for the brain, and nicotine causes blood vessels to shrink and affects small vessels more than large vessels," said Dr. James P. Slater, a cardiac surgeon at Morristown Memorial Hospital. "During periods of stress, such as surgery, the vessels are not able to deliver as much blood, and therefore oxygen, to the brain."
"The injury may not be to the brain cells per se but to the microvasculature, or small blood vessels, in the brain," added Dr. Robert Bonow, past president of the AHA, chief of cardiology at Northwestern University Feinberg School of Medicine, and moderator of the news conference.
The findings do throw new light on the impact of heart surgery on different patients.
"Over the last decade, heart surgery itself has been implicated as the problem, and it's clear to us that patients bring their own risk to the table, and this risk is a behavioral risk," Slater said.
It's unclear how to remedy the problem, or even what to tell patients, especially if the risky behavior occurred two decades before, the doctors added.
The long-term effects of smoking on weight were the focus of a second study presented at the meeting Sunday. This research found that smokers and nonsmokers gained weight at the same rate over a period of 20 years, regardless of race or gender.
"If you quit, you may gain an extra 4 to 5 pounds, or, if you start, you may delay the onset of progressive weight gain by two to three years, but that's it," said Dr. Samuel Gidding of A.I. DuPont Hospital for Children in Wilmington, Del.
Also, he noted, over the two-decade timeframe of the study, the smoking starter and quitter groups were really populated by the same people bouncing back and forth.
"Because they are ping-ponging back and forth, ultimately, the rate of weight change is the same," Gidding said. "There's very little impact of smoking status on weight other than four to five pounds either way when you start or quit. And if you ping-pong back and forth, it becomes totally neutralized."
For more on smoking and heart disease, visit the American Heart Association.