No substantial benefit found in lowering blood pressure past 120 mmHg

How low can it go? Apparently, decreasing elevated blood pressure into the standard range in hypertensive patients can do as much good as bringing it down even lower, according to a study published online June 16 in JAMA Internal Medicine.

While elevated blood pressure signified a 46 percent increased risk for cardiovascular incidents against the lowest blood pressure group, there was no difference noted between the survival in the standard and low systolic blood pressure groups, results showed.

According to the Centers for Disease Control and Prevention, hypertension and high blood pressure affect one in three Americans. While it affects all races and genders, it is most prevalent in African Americans. Carlos J. Rodriguez, MD, MPH, from Wake Forest University School of Medicine in Winston-Salem, N.C., and colleagues followed 4,480 white and African-American individuals across an approximately 21.8 year span to see the effects of blood pressure on risks for cardiac events.  

Participants were split into three groups at baseline: high, standard and low blood pressure. All had a history of hypertension, defined in this study as a systolic blood pressure of greater than 140 mmHg and a diastolic blood pressure of above 90 mmHg at baseline, a history of physician diagnosis of hypertension, or the use of antihypertensive medications.

They found that higher blood pressure did indeed have a higher risk for cardiovascular events:  Systolic blood pressure above 140 mmHg went along with a higher rate of heart failure, ischemic stroke, and death from myocardial infarction or coronary heart disease.  

“We found that African Americans had the highest absolute AAIR [age-adjusted incident rate] differential when comparing the highest SBP [systolic blood pressure] group (38.6 per 1,000 person years) vs. the lowest (28.6 per 1,000 person-years), which suggests that African Americans were more likely to have a greater absolute benefit of reduced cardiovascular events from achieving SBP levels below 140 mmHg than any other group,” stated Rodriguez et al.

However, they found very little difference between the risks for the low systolic blood pressure group and the standard blood pressure group. Both of these groups appeared to be better at maintaining self-care, whether through proper use of medications or lifestyle changes, whereas only 46 percent of patients in the elevated systolic blood pressure group were consistent in taking medications for their condition.

Paul Arthur James, MD, of the University of Iowa in Iowa City, responded in an editorial stating, “A rate of 46 percent medication use among patients with hypertension is unfortunately all too common in the real world and speaks to the need for new strategies to help patients manage their chronic disease complicated by social and economic problems. It indicates the need to find new ways to achieve BP control in diverse and high-risk populations.”

James recommended alternate clinical models to support patients who have difficulty taking their medications.