Aug. 22, 2011 -- A happy marriage lengthens the lives of cardiac bypass patients, according to researchers who suggest that supportive spouses can provide encouragement to make it through tough lifestyle changes.
In a key indication that marriage influences long-term survival, the researchers found that 15 years after having clogged arteries replaced with grafted vessels, happily wedded patients were more than three times likelier to be alive than those who were widowed, divorced, separated or single.
However, the magnitude of that marriage bonus differed along gender lines. Men who underwent bypass surgery lived longer by virtue of simply being married, regardless of how happy or miserable the union.
Women's survival after the surgery depended more on the quality of the marriage. Happily married women were nearly four times likelier to be alive at the 15-year mark than those who were going it alone. But an unhappy marriage didn't do much to help women live longer after bypass surgery, according to the study led by Kathleen King, an emeritus nursing professor at the University of Rochester in New York.
"The most dramatic thing to me is [that] just being married, especially if you had a happy marriage, had that big an effect 15 years later," King told ABCNews.com.
Having a husband or wife might make heart patients more likely to take steps to improve their health, giving them "a salient 'reason to live,'" King and her colleagues wrote in the study that was published online today in the journal Health Psychology.
King said that for purposes of the study, researchers counted the small number of patients with "significant others" as married. She believes that the beneficial effect of marriage stems from the close connection to another person, and that "it's not whether or not they're married; it's whether or not they have somebody there with them."
The findings reinforce previous studies linking marital satisfaction to slower development of cardiovascular disease, and others that found that couples with lower levels of hostility in their marriages had lower levels of the inflammation associated with cardiovascular disease.
The researchers tracked 225 University of Rochester heart patients following cardiac bypass. Fifteen years later, 124 were still alive. Most of the patients, who ranged in age from 33 to 80, were white. Nearly 77 percent were men.
Study Factored in Not Just Marriage, but Marital Happiness
Patients underwent their bypasses between 1987 and 1990. Fifteen years later, 83 percent of the happily married women had survived, compared with 28 percent of the less happily married women and 27 percent of the single women. Among the men, 83 percent of the happily married were still alive, compared with 60 percent of the less happily married and 36 percent of the single.
Unlike some previous studies examining the effect of marriage on well-being, the new study also took into account marital happiness. A year after their operations, study subjects were asked to rate their relationship on a scale ranging from "very unhappy" to "perfectly happy." Highly satisfying marriages seemed to significantly benefit long-term survival.
The researchers said that their work had several limitations. The study group was "almost exclusively white," although there has been increased attention to cardiovascular health among minorities since the researchers collected their data. In addition, having just 52 women, compared with 173 men, made it hard to broadly apply the findings to other women.
"Hopefully, future studies will be able to include a more diverse sample," they said.