One in 100 black men and women develop heart failure before age 50, according to one of the first long-term studies to look at the life-threatening condition in younger adults.
The research suggests blacks in that age group suffer the condition at a rate 20 times higher than whites do — an astounding difference more pronounced than earlier studies had indicated.
However, those findings are based on a very small number of heart failure cases, the authors said, so more study is needed.
The takeaway message is that doctors should be more aggressive about treating young blacks who may be at risk, some experts said.
"Usually this is a disease of the elderly," said Dr. Kirsten Bibbins-Domingo, one of the study's authors. "When this disease happens in 30 and 40 year olds, it's quite dramatic."
The research appears in Thursday's New England Journal of Medicine.
Heart failure occurs when the heart loses its ability to pump sufficient blood through the body. It's often fatal, but not always — some suffer disabling shortness of breath, fatigue and retention of fluids in their legs or lungs.
Earlier studies of heart failure, focused mainly on older people, showed heart failure rates were two to three times higher in blacks than whites.
In the new study, the researchers looked at data from more than 5,100 blacks and whites in Chicago; Minneapolis; Birmingham, Ala.; and Oakland, Calif. The participants were ages 18 to 30 at the time they joined the study more than 20 years ago.
Over the years, 27 people developed heart failure by age 50 and all but one were black. Five people died, all of those black.
At the outset, blood pressure levels and weights were similar, no matter which race, said Bibbins-Domingo, an epidemiologist at the University of California at San Francisco.
But the researchers found that a disproportionate number of blacks developed high blood pressure in their young adulthood and went on to suffer heart failure. Blacks also were more likely to develop diabetes and chronic kidney disease, and to suffer an impairment in the heart muscle's ability to contract.
It's not clear why more blacks develop those problems so early, Bibbins-Domingo said. Possible explanations range from income and social environment to genetics, she added.
Another mystery: Researchers told those who were diagnosed with high blood pressure to see their doctors about it. But 10 years into the study, the condition was untreated or poorly controlled in 3 out of 4 black patients diagnosed.
That's likely a failure by both doctors and patients, said Dr. Eric Peterson, a Duke University professor of medicine who wrote an editorial accompanying the study.
Treatments need to be effective and affordable, and doctors also must follow up with patients to make sure they're taking their medicines and, if they aren't, find out why and address the obstacles, he added.
"We as physicians are so quick to say it's the patients' fault. But I would argue the system has failed," Peterson said.
Copyright 2009 The Associated Press.