Key Factors Raise Heart Failure Death Risk
One surprise: obesity may actually be protective, researchers say
THURSDAY, June 30, 2005 (HealthDay News) -- Nearly 1 million Americans will be hospitalized with heart failure this year, and a new study singles out those patients at highest risk for in-hospital death.
Some of the risk factors are obvious. Older people, and those who are anemic or who have suffered a stroke, are more likely to die, the researchers found. But some associations seemed to defy common sense -- most notably, a higher death rate for people of "desirable" weight.
The study of 2,604 Worcester, Mass., residents hospitalized for heart failure in the year 2000 was necessary because "a paucity of data exists about the magnitude and short-term outcomes associated with this clinical syndrome," according to the report, published in the June 29 issue of the American Journal of Medicine.
This is one of several such studies being funded by the National Institutes of Health, explained lead researcher Robert J. Goldberg, a professor of medicine and epidemiology at the University of Massachusetts, Worcester.
"We're trying to look at three things: magnitude of heart failure incidence, the death rate, and how patients are being managed," he said.
The study results "give clinicians guidance about who is at high risk of dying after hospitalization for heart failure," Goldberg said.
His team found that the incidence of heart failure -- in which the heart progressively loses the ability to pump blood -- was higher for women (250 cases per 100,000 population) than for men (194 per 100,000).
Overall, about one in every 20 patients hospitalized for heart failure died while still in the hospital. That death rate was slightly higher, 5.5 percent, when it was a first-ever documented episode of heart failure, the researchers noted.
Then came correlations of risk against specific factors. The odds of dying in hospital after heart failure was higher for people with specific blood markers such as high concentrations of blood urea nitrogen and serum creatinine, or low levels of blood sodium and lower blood pressure.
Most intriguing: overweight and obese patients were slightly more likely to avoid death while in hospital than their normal-weight peers. While "paradoxical," these findings "are consistent with limited published data," the authors noted.
Doctors can use these factors in individual patients to select those "who should be monitored more aggressively, who should be seen on a regular basis, and who might need different therapeutic regimens," Goldberg said.
The study will be continued, he said. "Eventually, we hope to look at changing trends in these outcomes."
The study by and large enforces what cardiologists already know, said Dr. Robert Hobbs, a heart failure specialist at the Cleveland Clinic. The Worcester work simply "confirms in a single town what we have known nationally for years," Hobbs said.
"The people who come into the hospital with heart failure are really a mixed bunch of people," he said. With younger patients, especially, "it is a very heterogeneous population," he added.
For a full explanation of heart failure and its treatment, head to the American Heart Association.