A New Definition for Hypertension

Categories of Blood Pressure

A new analysis shows no harm in diastolic blood pressure higher than 80 mmHg, but 2017 AHA/ACC guidelines could cause millions to be considered hypertensive and possibly treated inappropriately, authors assert.

Isolated diastolic hypertension is now more prevalent, owing to the definition of hypertension used in the most recent US blood pressure guidelines, but the condition does not appear to be associated with increased risk for cardiovascular outcomes, a new study suggests.

The findings and recommendations are controversial. 

Association of Isolated Diastolic Hypertension as Defined by the 2017 ACC/AHA Blood Pressure Guideline With Incident Cardiovascular Outcomes

Importance  In the 2017 American College of Cardiology (ACC)/American Heart Association (AHA) guideline, the definition of hypertension was lowered from blood pressure (BP) of greater than or equal to 140/90 to greater than or equal to 130/80 mm Hg. The new diastolic BP threshold of 80 mm Hg was recommended based on expert opinion and changes the definition of isolated diastolic hypertension (IDH). 

McEvoy, who is professor of preventive cardiology at the National University of Ireland, Galway, added: "Our data suggest there is no harm of having a diastolic pressure above 80 mmHg if the systolic is below 130 mmHg and that the new 80 mmHg diastolic threshold means that 12 million adults in the US will be labeled as hypertensive but will not benefit from the diagnosis and may be given unnecessary treatment."

The recommendation to lower the diastolic threshold for hypertension from 90 mmHg to 80 mmHg was based on expert opinion, not on trial data. This change has major implications with respect to isolated diastolic hypertension, now defined as a systolic blood pressure <130 mmHg with a diastolic pressure ≥80 mmHg, the authors write.

McEvoy said he is a strong proponent of the new 130 mmHg threshold for systolic pressure. "But the lowering of the diastolic threshold from 90 to 80 was just based on expert opinion. There is no solid evidence behind this recommendation. Our data suggest there is no harm of having a diastolic over 80, and I do not believe it is appropriate to use diastolic pressure for defining hypertension and treatment targets."

Controversy Now Moves to New Diastolic BP Threshold: