High blood pressure: How low is low enough?

By ACSH Staff — Jun 23, 2015
Yes, if you have hypertension (HTN, or high blood pressure), your risk of cardiovascular ills heart attack or stroke is increased.

909105_45608666Yes, if you have hypertension (HTN, or high blood pressure), your risk of cardiovascular ills heart attack or stroke is increased. We ve known that for decades, and lowering blood pressure (BP) in hypertensive people with a variety of drugs has been shown to decrease these risks. But the question still remains how low should blood pressure go?

To answer this question, a large study is underway with hypertensive patients. Half are assigned to get their systolic pressure (the top number) to less than 120, while the others are to get theirs down below 140. Current guidelines aim for a systolic blood pressure below 140. This study should shed light on whether an even lower BP adds even more benefits but it won t be complete for another couple of years. So in the meantime, what should doctors aim for when counseling their hypertensive patients?

The confusion is at least partly historical. It s been obvious for years that blood pressure increases with age. One theory was that this was beneficial, because aging vessels are stiffer, and thus might require higher pressure to get blood to the brain and body. But studies showing positive effects of BP-lowering medications handedly disproved that theory.

Yet another question is if patients with HTN should be treated more like those with high cholesterol. For the latter patients, doctors typically take into account the patient s family history as well as factors such as the presence of comorbidities like diabetes, and overweight or obesity. But typically HTN patients treatments hinge on just the one number systolic blood pressure. Perhaps that should change as well.

ACSH s Dr. Ruth Kava commented We often think, the lower the better when it comes to BP, but we don t really know that the new study will be likely to help answer that question. It s not clear yet if it will also provide information on whether other risk factors should be taken into account perhaps another study will have to elucidate that information.