TUESDAY, June 3, (HealthDay News) -- For reasons not easily understood, many patients with the worst type of heart disease think they will live longer than their doctors tell them they will, new research shows.

Very carefully, cardiologists at Duke University began telling people being treated for heart failure -- the progressive loss of ability to pump blood -- that the condition would shorten their lives. They weren't believed.

Instead, many patients preferred to believe that they would have the normal life span expected of men their age, according to a report on this unusual bit of research, published in the June 4 issue of the Journal of the American Medical Association.

Life expectancy for people with heart failure is on average as bad or worse than for patients with cancer, said study author Dr. Larry A. Allen, a clinical instructor in cardiology. "The expectation is just four to five years with symptomatic heart failure, and those we see in the specialty clinic do even worse," he said.

It's hard for most people to face the truth about heart failure. "My general impression is that many of these patients don't comprehend how serious their illness is and how it might affect their survival," Allen said.

According to U.S. government statistics, about 5 million people in the United States have heart failure, and it results in about 300,000 deaths each year.

Pressing home the truth is important because "misperceptions about survival can hinder patients from making rational decisions about medical therapy and the end of life," Allen said.

So, he and his colleagues used the somewhat new Seattle Heart Failure Model to make predictions about 122 people being treated for heart failure, and to tell them the life span predicted by the model, which gives a fairly detailed description of what a heart failure patient can expect.

On average, the model predicted each person could expect 10 more years of life. Sixty-three percent of the people in the trial differed with that outlook, estimating an average of 13 more years ahead.

The researchers followed those people for three and a half years and found that the Seattle Heart Failure Model predictions were indeed accurate. "They even died at a slightly higher rate than predicted," Allen said.

Such information must be handled with great care, he said. "Obviously it needs to be carefully and gently explained to people," Allen said. "But if they understand what the range of prognoses will be for them, they can make more rational decisions about care."

Predictions could even improve lives, he said. "I certainly think we can improve life expectancy," Allen said. "We can motivate them to make good decisions about health care."

But caution is required, said Dr. Clyde W. Yancy, medical director of the Baylor Heart and Vascular Institute in Dallas, who wrote an accompanying editorial.

"This is one area where we need very precise tools so that we don't make mistakes," Yancy said. "If a mistake is made, it should be longer rather than shorter, so that we hold out hope as long as possible."

There are still some refinements to be made in the Seattle model, prepared at the University of Washington, Yancy said. Nearly half the people in the Duke study were black, and "there were no such candidates in Seattle," he said.

And then there is the difficulty that physicians face in talking about shortened life spans, he said. "We physicians are not equipped with communication skills in that area," Yancy said. "Extending our discussions to a quantitative dialogue requires tools that we have not yet refined."

More information

Learn about heart failure and its consequences from the U.S. National Heart, Lung, and Blood Institute.

SOURCES: Larry A. Allen, M.D., clinical instructor, cardiology, Duke University, Durham, N.C.; Clyde W. Yancy, M.D., medical director, Baylor Heart and Vascular Institute, Dallas; June 4, 2008, Journal of the American Medical Association

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