Miller School Study Findings Dispute Revised Blood Pressure Guidelines
New research finds that a recent revision in national guidelines for treating high blood pressure in people 60 and older could put this population at greater stroke risk. The increased stroke risk is even more pronounced among Hispanics and blacks, the research showed.
Those are the findings of a new study in the American Heart Association’s journal Hypertension, led by Ralph L. Sacco, M.D., M.S., professor and Chair of Neurology and Olemberg Family Chair in Neurological Disorders at the University of Miami Miller School of Medicine.
In 2014, the Eighth Joint National Committee (JNC8) revised the U.S. guidelines for treating high blood pressure in people 60 years and older who do not have diabetes mellitus or chronic kidney disease. The newest version of the guidelines raised the target maximum for blood pressure’s top number, or systolic blood pressure, from 140 to 150 mmHg in that patient population.
“We started this analysis very soon after JNC8 came out with the recommendation because we were concerned about the recommendation’s potential effect on stroke prevention,” Sacco said. The researchers received support from the National Institutes of Health.
Sacco and colleagues from the Miller School of Medicine and Columbia University studied 1,750 people ages 60 years and older, who were free of stroke, diabetes and chronic kidney disease.
Researchers measured participants’ systolic blood pressure at the study’s start and noted during an average 13 years if any of those patients had strokes. Among those studied, 63 percent were women, 48 percent were Hispanic, 25 percent white, and 25 percent black. Forty-three percent of participants had systolic readings of less than 140 mmHg; 20 percent were between 140 and 149 mmHg; and 37 percent had systolic pressures of 150 mmHg and higher.
• Over the median 13 years of follow-up, 182 people developed stroke.
• Having a systolic blood pressure of 140 to 149 mmHg elevated stroke risk as much as having systolic blood pressure greater than 150.
• Those with 140 mmHg systolic blood pressure and higher at the start of the study were 70 percent more likely to suffer a stroke compared to adults with normal systolic pressure, which is less than 140 mmHg.
• The increased stroke risk was most notable among Hispanics and non-Hispanic blacks.
“The findings suggest one should not liberalize or change the treatment threshold for blood pressure in people older than 60 without chronic kidney disease or diabetes,” said Sacco. “For stroke prevention, maintaining a blood pressure target of 140 mmHg is important.”
There are limitations to the study, according to Sacco. One is that it’s an observational, not a randomized study, which means the researchers observed what happened in the study population rather than randomly assigning people to treatment groups for comparison. A study strength is that it had strong minority representation. That’s important, Sacco said, because blacks and Hispanics have greater risks of stroke and more hypertension than whites.
“As a result, more aggressive treatment of blood pressure in those population groups is even more critical. In general, our findings support adherence to the current American Heart Association guidelines that consistently recommend treatment for blood pressure above 140-90 mmHg in order to improve cardiovascular health and reduce stroke.”
Miller School co-authors are Chuanhui Dong, Ph.D., research associate professor of neurology, David Della-Morte, M.D., Ph.D., research scientist in neurology, Tatjana Rundek, M.D., Ph.D., professor of neurology, Clinton B. Wright, M.D., M.S., associate professor of neurology, and Mitchell S. V. Elkind, M.D., M.S., of Columbia University.