AP, March 18, 2009
One in 100 black men and women develops 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.
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.
[Editors Note: “Racial Differences in Incident Heart Failure among Young Adults,” by Kirsten Bibbins-Domingo, et al., can be read or downloaded here. There is a charge.]
Kirsten Bibbins-Domingo, Ph.D., M.D., Mark J. Pletcher, M.D., M.P.H., Feng Lin, M.S., Eric Vittinghoff, Ph.D., Julius M. Gardin, M.D., Alexander Arynchyn, M.D., Cora E. Lewis, M.D., O. Dale Williams, Ph.D., and Stephen B. Hulley, M.D., M.P.H.
Background The antecedents and epidemiology of heart failure in young adults are poorly understood.
Methods We prospectively assessed the incidence of heart failure over a 20-year period among 5115 blacks and whites of both sexes who were 18 to 30 years of age at baseline. Using Cox models, we examined predictors of hospitalization or death from heart failure.
Results Over the course of 20 years, heart failure developed in 27 participants (mean [±SD] age at onset, 39±6 years), all but 1 of whom were black. The cumulative incidence of heart failure before the age of 50 years was 1.1% (95% confidence interval [CI], 0.6 to 1.7) in black women, 0.9% (95% CI, 0.5 to 1.4) in black men, 0.08% (95% CI, 0.0 to 0.5) in white women, and 0% (95% CI, 0 to 0.4) in white men (P=0.001 for the comparison of black participants and white participants). Among blacks, independent predictors at 18 to 30 years of age of heart failure occurring 15 years, on average, later included higher diastolic blood pressure (hazard ratio per 10.0 mm Hg, 2.1; 95% CI, 1.4 to 3.1), higher body-mass index (the weight in kilograms divided by the square of the height in meters) (hazard ratio per 5.7 units, 1.4; 95% CI, 1.0 to 1.9), lower high-density lipoprotein cholesterol (hazard ratio per 13.3 mg per deciliter [0.34 mmol per liter], 0.6; 95% CI, 0.4 to 1.0), and kidney disease (hazard ratio, 19.8; 95% CI, 4.5 to 87.2). Three quarters of those in whom heart failure subsequently developed had hypertension by the time they were 40 years of age. Depressed systolic function, as assessed on a study echocardiogram when the participants were 23 to 35 years of age, was independently associated with the development of heart failure 10 years, on average, later (hazard ratio for abnormal systolic function, 36.9; 95% CI, 6.9 to 198.3; hazard ratio for borderline systolic function, 3.5; 95% CI, 1.2 to 10.2). Myocardial infarction, drug use, and alcohol use were not associated with the risk of heart failure.
Conclusions Incident heart failure before 50 years of age is substantially more common among blacks than among whites. Hypertension, obesity, and systolic dysfunction that are present before a person is 35 years of age are important antecedents that may be targets for the prevention of heart failure. (ClinicalTrials.gov number, NCT00005130 [ClinicalTrials.gov] .)
From the Departments of Medicine (K.B.-D., M.J.P.) and Epidemiology and Biostatistics (K.B.-D., M.J.P., F.L., E.V., S.B.H.) and the Division of General Internal Medicine and the UCSF Center for Vulnerable Populations, San Francisco General Hospital (K.B.-D.), University of California, San Francisco, San Francisco; the Department of Medicine, Hackensack University Medical Center, Hackensack, NJ (J.M.G.); and the Division of Preventive Medicine, University of Alabama at Birmingham, Birmingham (A.A., C.E.L., O.D.W.).