Black adults with high blood pressure have increased risk of mortality, heart failure hospitalization

After adjusting for multiple variables, an observational study found that every 10 mm Hg increase in systolic blood pressure was associated with a 12 percent increased mortality risk and a 7 percent greater risk of heart failure hospitalizations among black adults.

The risks were higher among adults younger than 60 years old compared with those who were 60 or older.

Lead researcher Tiffany C. Randolph, MD, of the Cone Health Medical Group HeartCare in Greensboro, North Carolina, and colleagues published their results online Dec. 7 in the Journal of the American Heart Association.

The researchers noted that in 2014, the Joint National Committee (JNC) published guidelines that recommended a blood pressure goal of less than 150/90 mm Hg for adults who were 60 or older and did not have chronic kidney disease or diabetes. The goal for adults with chronic kidney disease or chronic kidney disease was increased to less than 140/90 mm Hg.

“Given that blood pressure targets are not attained in up to 50 percent of clinical practice, providers may want to proceed cautiously when liberalizing these targets in a group at higher risk of all the downstream effects of hypertension, such as heart attack, stroke, and chronic kidney disease,” Randolph said in a news release.

For this analysis, the researchers examined 5,280 participants from the Jackson Heart Study, which investigated risk factors for cardiovascular disease in black adults. The adults had three visits: the first between 2000 and 2004, the second between 2005 and 2008 and the third between 2009 and 2013.

The median age of the participants was 56 years old, and 36.5 percent were men. The median systolic blood pressure was 125 mm Hg and the mean diastolic blood pressure was 79 mm Hg. In addition, 60 percent of the participants had hypertension at baseline and 50 percent of the overall group had received at least one blood pressure medication.

The unadjusted mortality rates were 22.9 percent for adults with a systolic blood pressure of 150 mm Hg or greater, 15.9 percent for adults with a systolic blood pressure of 140 to 149 mm Hg, 11.4 percent for adults with a systolic blood pressure of 130 to 139 mm Hg and 7.0 percent for adults with a systolic blood pressure of less than 130 mm Hg. The trend in mortality rates was similar after the researchers adjusted for age.

After the multivariable adjustment, each 10 mm Hg increase in systolic blood pressure was associated with a 12 percent increase in the risk of mortality, while each 10 mm Hg increase in diastolic blood pressure was associated with a 15 percent reduction in mortality

Meanwhile, the heart failure hospitalization rates were 14.1 percent for adults with a systolic blood pressure of 150 mm Hg or greater, 10.3 percent for adults with a systolic blood pressure of 140 to 149 mm Hg, 8.3 percent for adults with a systolic blood pressure of 130 to 139 mm Hg and 4.8 percent for adults with a systolic blood pressure of less than 130 mm Hg. The rates were similar after adjusting for age.

The researchers noted that each 10 mm Hg increase in systolic blood pressure was associated with a 10 percent increase in the unadjusted risk of heart failure, while there was no association between diastolic blood pressure and heart failure incidence. After adjusting for age, blood pressure was not associated with heart failure incidence, according to the researchers.

They mentioned a few limitations of the study, including that they could not assess the associations between blood pressure and stroke of MI. They also only used one blood pressure reading at baseline and could not measure the association between variability of blood pressure and outcomes. In addition, participants volunteered to be in the study, so the results might not be generalizable to other groups of black adults.

“This observational study should make us question whether the current JNC guidelines have identified the optimal target for blood pressure control in the African American population,” Randolph said. “To fully answer this question, we will need additional large, randomized, controlled trials that enroll a diverse population. Until then, providers will have to continue assessing risk and working with patients to set blood pressure goals based on all the available data and individual patient concerns.”