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Good reasons not to lower the definition of high blood pressure in adults
Clinical Question
Is the new definition of hypertension valuable to patients?
Bottom line
After the publication of guidelines from the American College of Cardiology and the American Heart Association that redefined the definition of high blood pressure to be higher than 130/80 mm Hg, placing an additional 31 million American adults under the hypertension tent, the authors of this commentary stopped to ask, "What makes a disease a disease?" They point out that using a new definition of 130/80 mm Hg will now identify many people (80%) as hypertensive, but they will not need treatment. Those patients who qualify for treatment only under the new definition will be exposed to the risk of medication side effects though they are at low risk of cardiovascular disease and do not stand to benefit from treatment. Two US groups—the American College of Physicians and the American Academy of Family Physicians—have stated that they'll keep their existing definition of 140/90 mm Hg, thank you very much, consistent with most of the rest of the world. 5
Reference
Study design: Other
Funding: Self-funded or unfunded
Setting: Not applicable
Synopsis
What makes a disease a disease? Can mere mortals change disease definitions? To paraphrase Humpty Dumpty, a "disease" means just what we choose it to mean, neither more nor less. In 2017, two US cardiology societies decided to change the definition of hypertension, lowering the threshold to 130/80 mm Hg, largely based on the results of a single study (SPRINT) that did not measure blood pressure in the typical way. To evaluate the risk of overdiagnosis occurring as a result, the authors of this commentary used a checklist for redefining disease (JAMA Intern Med 2017;177(7):1020-1025). Here it is: (1) What is the difference between definitions? The new definition elevates the status of pre-hypertension (> 80/130 mm Hg) to hypertension and suggests drug treatment in patients at high risk. (2) How will the new definition change the prevalence of the disease? It adds 31 million more US adults to the roles and qualifies 4.2 million for treatment. (3) Why change the definition? The authors presume it's because of the results of the SPRINT trial. (4) How well does the new definition predict clinically important outcomes? Observational data suggest cardiovascular mortality doubles with every 20-mm Hg increase in systolic blood pressure, starting at 115 mm Hg. (5) How reproducible is the measurement of blood pressure? Systolic blood pressure can easily vary 10 mm Hg over repeated measures in the same person, So, not very good. (6) What are the additional benefits of including more people? It all depends on the patients' baseline risk. One estimate suggests 80% of people with newly diagnosed hypertension will not benefit (Circulation 2018;137(2):109-118). (7) What harms can come from the new definition? Fear and anxiety over having a disease; inability to get health insurance due to a pre-existing condition; risks of treatment, (8) What are the net benefits and harms to the new definition? For patients at low risk, there is no benefit to the change and some increased risk. At patients at high risk, it may be beneficial. In patients older than 80 years, those with diabetes, and those with renal disease, the benefits and risks are offsetting.
Reviewer
Allen F. Shaughnessy, PharmD, MMedEd
Professor of Family Medicine
Tufts University
Boston, MA
Comments
Thank-you, thank-you, thank-you - we must not let fear-mongering rule, and not let one organization override the evidence-based research that the rest of the world uses.
I am with the Family Docs on this one. Can't help but wonder about conflict of interest in the latest guidelines esp since in the US they result an an additional 31 million people being diagnosed with hypertension. That's almost all of Canada! Ka-ching!!!!
stick to the current guidelines for hypertension especially relevant for people at older age !
Perhaps more than another study about which group more accurately defines hypertension and then again which hypertensive category of patient requires treatment, we should focus more on treating systemic obesity and inactivity. On a recent rare holiday, I came across sturdy exercise equipment anchored in a circle surrounding a children’s playground. Here in Canada! If the Scandinavian countries can do it, we can too: we need to insist on the transformation of our society from a sedentary one to an active one and address once and for all the culture of consistent overeating. Those should be our and policy-makers’ prime objectives.
The familiar malodorous whiff of Big Pharma.
A sensible response.
Good to know that there is support for my usually target of 140/90. There needs to be a sensible risk/benefit when defining a disease.
The new ACC & AHA guidelines represent a reckless endangerment for our present and future patients. The authors of this new review are to be congratulated for their searching and fearless review of the facts and their conclusions.
This adds to the confusion around what is an appropriate cut-off for diagnosis but this highlights the importance of treating our patients as individuals - discussing what the various recommendations are and why, what their own risk seems to be and the benefits and drawbacks for them personally of using pharmaceuticals vs. not.
I do not agree with the criteria changes. They are potentially harmful, not beneficial.
Good poem
I have kept the approaches taken to not change the BP and avoid side-effects from medications, especially as maximum doses and all available anti-hypertensives in combination, need to be used. Hypokalemia may be a risk, as is hyperkalemia, when some of these meds are pushed to a maximum dose.
Not sure. I am confused with the recommendations and the comments. What does the Insurance industry say and what do their figures show? Mosts of the time, in medicine I think we discounted the date from the insurance indurstry but they must mean something.