Nicotine's Grip On Smokers: Even Transplant Patients Light Up
Even after three heart attacks James Merriweather continued his daily pack-and-a-half smoking habit.
So, in 1995, after his fourth heart attack â€” his worst â€” a nurse minced no words.
"She told me, point blank, that if I didn't quit, I'd be dead within a year," says Merriweather, of Dover, Del.
New research underscores the battle waged by heart patients such as the 50-year-old writer against the powerful draw of this life-threatening habit.
Indeed, large numbers of heart-transplant patients resume smoking after they get their new hearts. A recent study from the University of Pittsburgh School of Nursing found that more than a quarter (27 percent) of heart-transplant patients smoked after the lifesaving surgery. More than one-third of the previous smokers returned to the habit.
The study involved 202 heart-transplant recipients, â€” 71 percent of whom had been smokers before the surgery.
All but one of the smokers were resuming a habit they had before the transplant. That one exception is a man who admitted to having an occasional cigar.
The Pittsburgh study punctuates the highly addictive nature of smoking, as does another report released at about the same time by the U.S. Centers for Disease Control and Prevention.
The CDC spelled out the grim toll smoking takes on the nation's health, and the financial costs of caring for the people who don't kick the habit.
Smoking costs the nation $150 billion each year in health care and lost productivity, the CDC study found.
That's only the financial side of the picture. The CDC provided the following snapshot of smoking's cost in human lives:
Smoking caused an estimated 440,000 premature deaths each year between 1995 and 1999.
Smoking causes an average man to lose more than 13 years of life, and an average woman to lose 14.5 years.
Smoking during pregnancy leads to premature births, low birth weight and respiratory distress and sudden infant death syndrome, resulting in about 1,000 infant deaths a year.
Lung cancer causes the most deaths among smokers, following by heart disease and lung disease.
Both the Pittsburgh study and the CDC report point to an essential fact, articulated by Carol Stilley, Ph.D., assistant professor of nursing and psychiatry at the University of Pittsburgh School of Nursing:
"Smoking is highly addictive. The relapse rate in the general population is close to 90 percent."
The addictive component of cigarettes is nicotine, which is absorbed readily into the lungs and, in the case of smokeless tobacco, through the mouth or nose.
Once in the bloodstream, nicotine is rapidly distributed throughout the body. It acts in a variety of ways at different sites in the body.
In the brain, nicotine interacts with specific receptors in brain tissue and initiates metabolic (changeable) and electrical activity in the brain.
It also stimulates the release of epinephrine â€” adrenaline â€” into the smoker's bloodstream, forcing the heart to work harder. This may be why smokers have elevated blood pressure.
By constricting blood vessels, including the coronary arteries, nicotine compromises the heart's blood supply.
It also causes the skeletal muscles to relax and interferes with the activity of hormones.
Like illegal drugs, nicotine is considered "reinforcing" â€” that is, its chemical effects are pleasurable to a degree that the smoker will seek it again.
Scott E. Lukas, associate professor of psychiatry at Harvard Medical School says there is more to learn about the influence of nicotine's as a "reinforcer."
Like cocaine, the nicotine increases the amount of dopamine, a neurotransmitter in the brain associated with feeling good, he says. But in his work as a pharmacologist, Lukas finds smoking addictions far more difficult to treat.
"The fact that nicotine seems to hit the same area of the brain that cocaine does is not surprising," Lukas says. "It's because of the secondary reinforcers, that these condition cues are so strong."
Lukas says the smoker's return to cigarettes is not much different from the behavior exhibited in the famed behavioral experiment of Ivan Pavlov. The Russian physiologist observed that animals responded to stimuli that might otherwise have no effect on them.
"Think of Pavlov's dog reaction to the bell ringing," says Lukas, director of the Behavioral Psychopharmacology Research Laboratory at McLean Hospital in Belmont, Mass.
"Many people for whom nicotine has been a good reinforcer for so many years, may quit. But, then they go by a place where they normally buy cigarettes or they smell tobacco or they smell recently lit matches."
Like the salivating response of Pavolov's dogs at the sound of a bell, the smell of tobacco trigger areas of the brain associated with emotional states and memory.
"Those might well be some of the preludes to relapse," Lukas says.
"There are so many additional hurdles that a tobacco smoker has compared to those with other dependences. It's easy to get off, but boy those cues are everywhere and they are very profound."
This may be the case for some of the Pittsburgh study participants. Among those heart-transplant recipients mostly likely to return to smoking were patients whose caregivers also smoked.
Stilley calls smoking a complex behavior involving both social interactions and visual cues.
Interviews with the patients, family members and nurses during the three-year study also found two other strong predictors of a smoking relapse.
Those who clung to the cigarette habit until less than six months before the transplant were much more likely to resume smoking early and to smoke more.
Depression and anxiety within two months after the transplant also made for an early relapse, and for heavy smoking.
Whatever the compelling forces behind addiction, Merriweather can relate to heart transplant patients who light up after the life-saving surgery.
He remembers the day he quit smoking cold turkey. It was January 5, 1995, after heart attacks in 1988, '90, '92 and '94.
In 1996, a medical investigation determined his heart was not in need of a transplant. His cardiologist is scheduling a follow-up investigation for this year.
"I know what a powerful addiction it is," he says. "Like I said, it took four heart attacks to stop me, and, even then, I might still be smoking if not for that blunt assessment from the nurse."