By Michael Smith, North American Correspondent, MedPage Today
The lifetime risk of heart failure appears to be lower for black men than for whites, researchers reported.
But the apparent difference – about 10% percentage points — is probably a result of higher rates of other causes of death common among African-American men, according to Mark Huffman, MD, of Northwestern University Feinberg School of Medicine in Chicago, and colleagues.
The effect of important risk factors, such as blood pressure and body mass index, was similar by both race and sex, Huffman and colleagues reported online and in the April 9 issue of the Journal of the American College of Cardiology.
The findings come from an analysis of three prospective observational cohorts and are among the first to compare lifetime risks by race and sex, Huffman and colleagues reported.
Earlier studies, in the mostly white Framingham and Rotterdam cohorts, have estimated the lifetime risk of heart failure to be in the range of 20% to 33%, they noted.
Other studies have suggested a higher short-term risk of heart failure for blacks, but there is still only limited information on the lifetime risk.
To help fill the gap, Huffman and colleagues looked at data collected in three cohorts — the Chicago Heart Association Detection Project in Industry (CHA), the Atherosclerosis Risk in Communities (ARIC) study, and the Cardiovascular Health Study (CHS).
They estimated lifetime risks for developing heart failure by both race and sex, to age 95, with death without heart failure as the competing event. The index age – the age at which participants began to contribute data — was 45 in the CHA and ARIC cohorts and 65 in the CHS group.
All told, they analyzed data on 39,578 participants, including 33,652 whites and 5,926 blacks, who were followed for 716,976 person-years. Among them, 5,983 participants developed heart failure.
In the CHA cohort, the remaining lifetime risks for heart failure from ages 45 through 95 were similar for white and black women, Huffman and colleagues found.
On the other hand, the risk for white and black men was 30.2% (95% CI 28.9% to 31.5%)) and 20.1% (95% CI 15.8% to 24.4%), respectively, with non-overlapping confidence intervals.
In the CHS cohort, the lifetime risk for heart failure from 65 through 95 was 41.6% (95% CI 38.0% to 45.1%) for white men and 29.1% (94% CI 21.1% to 37.1%) for blacks, but the confidence intervals again did not overlap.
For women in the CHS cohort, the lifetime risks did not differ significantly by race — 38.5% (95% CI 35.2% to 41.9%) for white women and 46.1% (95% CI 38.0% to 54.1%) for blacks, with non-overlapping confidence intervals.
In the ARIC cohort, the remaining lifetime risk from 45 through 75 — near the limit of follow-up – was 19.1% (95% CI 17.0% to 21.2%) for white men and 21.3% (95% CI 17.5% to 25.1%) for black men, with overlapping confidence intervals indicating similar risks.
In women, the lifetime risk was 13.4% (95% CI 11.3% to 15.4%) in white women, compared with 23.9% (95% CI 20.1% to 27.6%) for black women. The confidence intervals did not overlap.
The researchers also reported that the lifetime risk for heart failure tended to increase with higher BMI, regardless of the index age of participants or their race and sex, and was lower among participants with optimal blood pressure.
Taken together, the findings show that lifetime risks for heart failure are high — ranging from 20% to 45% — and seem similar for black and white women, but “somewhat lower” for black men versus white men, Huffman and colleagues said.
But the latter finding appears to be a combination of higher overall risk for heart failure among African Americans “counterbalanced” by competing risks for death from other causes common in this group, such as homicide, renal failure, and HIV infection.
Huffman and colleagues cautioned that the three cohorts evaluated heart failure differently, had different entry criteria and different index ages, and that data were collected from participants at different time points.