New guidelines redefine what classes as high blood pressure

By Sally Robertson, B.Sc.Nov 14 2017

New guidelines have been released redefining the parameters for high blood pressure so that the condition can be treated earlier.

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The new American College of Cardiology and American Heart Association (AHA) guidelines state that a blood pressure measurement of 130/80 mm Hg will now class as hypertension, rather than the previous measurement of 140/90 mm Hg.

The updated recommendations, which are the first comprehensive set since 2003, were developed by a panel of 21 scientists and health experts who assessed more than 990 published articles. The changes have been made in order to account for the complications that can occur at this lower limit and allow for earlier intervention.

The new definition will see almost half (46%) of the U.S. adult population classing as hypertensive, with the impact expected to be largest among young people. Hypertension prevalence is expected to triple among men aged under 45 and double among women aged under 45.

However, treatment approaches will mainly involve lifestyle changes and only a small number of people are expected to need medication.

Lead author of the guidelines, Paul Whelton, says that at a blood pressure of between 130-139/80-89 mm Hg, people have already doubled their risk of cardiovascular complications, compared with people who have a normal blood pressure.

We want to be straight with people – if you already have a doubling of risk, you need to know about it. It doesn't mean you need medication, but it's a yellow light that you need to be lowering your blood pressure, mainly with non-drug approaches,"

Paul Whelton, Lead Author.

According to the guidelines, which are published in the American Heart Association journal, Hypertension, and the Journal of the American College of Cardiology, the term “prehypertension” is eliminated and the new categories are as follows:

• Normal: Less than 120/80 mm Hg
• Elevated: Systolic (top number) between 120-129 and diastolic (bottom number) less than 80
• Stage 1: Systolic between 130-139 or diastolic between 80-89
• Stage 2: Systolic at least 140 or diastolic at least 90 mm Hg
• Hypertensive crisis: Systolic over 180 and/or diastolic over 120, with patients needing prompt changes in medication if there are no other indications of problems, or immediate hospitalization if there are signs of organ damage.

The guidelines also advise the following:

• Medication should only be prescribed for stage 1 hypertension if a patient has already experienced a cardiovascular event or is at high risk of doing so, based on age, the presence of diabetes or atherosclerosis risk.
• Recognising that two or more types of medication may be required to manage blood pressure and that adherence to medication may be more likely if the two drugs are combined into one pill.

Identifying socioeconomic and psychosocial stress as risk factors that should be taken into account for a patient’s’ healthcare plan. In a corresponding analysis, epidemiologist Paul Munter from the University of Alabama at Birmingham, states: "The 2017 ACC/AHA hypertension guideline has the potential to increase hypertension awareness, encourage lifestyle modification and focus antihypertensive medication initiation and intensification on US adults with high CVD risk."