Heart health experts generally agree “the lower the better” when it comes to managing blood pressure in patients at risk to cardiovascular complications, but how low is too low? A study conducted at the Wake Forest Baptist Medical Center has revealed that lowering a patient’s systolic blood pressure, the top number in a standard blood pressure reading, to below 120 will not reduce their risk of suffering an adverse cardiovascular event such as a heart attack, stroke, or heart failure.
"Frequently we treat patients' blood pressure to the lowest it will go, thinking that is what's best," associate professor of public health sciences at Wake Forest Baptist, Dr. Carlos J. Rodriguez said in a statement. "Our observational study found that treating to low pressures doesn't provide any benefit to patients with regard to reducing risk of dangerous heart events like heart attack, heart failure and stroke. This calls into question the notion that lower is better."
Rodriguez and his colleagues recruited 4,480 individuals participating in the Atherosclerosis Risk in Communities Study. The research team measured each participant’s systolic blood pressure at the beginning of the study and every three years over the course of 21 years while checking for the development of a cardiovascular event, defined as a heart attack, ischemic stroke, heart failure, or death related to coronary heart disease.
Researchers classified systolic blood pressure as low (120 or lower), standard (between 120 and 139), and elevated (140 or higher). In participants with high blood pressure who were able to lower their systolic blood pressure to below 140, lowering it to below 120 had no effect on reducing their risk of suffering a cardiovascular event. Rodriguez did note that a larger clinical trial dubbed SPRINT has been launched to either confirm or deny the findings from this study.
"Our study found that the optimal blood pressure range for people with hypertension is120-139, which significantly reduces the risk of stroke, heart attack or heart failure," Rodriguez added. "These findings suggest that you don't need to go lower than that to have the benefits."
According to the American Heart Association, optimal systolic blood pressure is less than 120 and “within certain limits, the lower your blood pressure reading is, the better.” Although low blood pressure is usually considered safe, chronically low blood pressure accompanied by signs and symptoms can become dangerous. Symptoms of low blood pressure include dizziness, fainting, dehydration, lack of concentration, blurred vision, nausea, abnormal breathing, fatigue, and depression.