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When Guidelines Cause Hypertension

The 2017 ACC/AHA Hypertension Guidelines1 lowered the threshold for diagnosing hypertension from a blood pressure of ≥140/90 mm Hg to ≥130/80 mm Hg. In the United States, this effectively increases the number of adults diagnosed as “hypertensive” from 72 to 103 million.2 It has been stated that “by reclassifying people formerly considered to have pre-hypertension as having hypertension, the Guidelines create a new level of disease affecting people previously deemed healthy.”2

The fundamental problem with this approach is that the Guidelines treat high blood pressure as a disease rather than a major cause of diseases, such as stroke and myocardial infarction. The distinction between a cause of disease and the disease itself is important. Setting an arbitrary blood pressure cut-off to distinguish “healthy” from “diseased” individuals is a flawed concept. Blood pressure in older adults is endemically high and, if lowered, reduces the incidence of blood pressure–related diseases. Acknowledging this would avoid falsely classifying millions of people as “patients” when virtually all older adults stand to benefit from lower blood pressure. Requiring measurement of blood pressure to determine who should receive preventive medication needlessly medicalizes millions of people and simultaneously denies potentially life-saving blood pressure reduction to millions more.

Setting an arbitrary blood pressure cut-off for diagnosing hypertension distracts attention from the value of broadly lowering blood pressure, thereby reducing the population burden of blood pressure–related diseases such as stroke, myocardial infarction, and kidney failure—all leading causes of death and disability worldwide.

A population-based preventive medicine approach to reducing blood pressure would avoid labeling people as “hypertensive” while simultaneously preventing many from becoming patients. It is already widely accepted that population-wide dietary salt reduction to lower blood pressure is beneficial. Notwithstanding rare contraindications, nearly everybody middle aged and over would benefit from a daily blood pressure–lowering medication by preventing a heart attack or stroke, provided, of course, that they do not die of a noncardiovascular disorder first. Ample evidence supports this approach.

Clinical trials have found that low-dose, combination blood pressure medication is effective.3 The rare side effects it causes can easily be managed through symptom reporting. The benefits are substantial: for example, in patients aged 50 years or older, lowering blood pressure by 10 mm Hg diastolic (or 20 mm Hg systolic) roughly halves the incidence of stroke.3, 4 In light of these facts, the goal for people above a specified age should be to lower blood pressure in all and measure it in some rather than measure blood pressure in all and reduce it in some, as is currently practiced. Of course, blood pressure measurement can be easily carried out when requested by people on medication, or when prompted by symptoms such as dizziness. However, measurement of blood pressure should not be required to determine eligibility for preventive treatment.

In addition to substantially reducing the incidence of heart attack and stroke, adopting an age-based population strategy would markedly lower health care costs.5 Individuals would no longer be required to undergo a physical examination, risk assessment, pretreatment screening, and serial blood testing to determine their eligibility for preventive medication. Countless families, and society at large, would be spared the expense of hospital admission, long-term care, and premature death from preventable heart attacks, strokes, and hypertensive kidney disease. This age-based population strategy is not conceptually different from advising women to take folic acid supplements periconceptionally to prevent neural tube defects, or prophylactically administering antimalarials to travelers and local citizens in parts of the world where the disease is endemic.

Asserting that blood pressure reduction should not be determined by an individual’s blood pressure may strike many as counterintuitive, but it is based on 3 observations: 1) the relationship between blood pressure and cardiovascular disease is a continuous function, increasing in a log-linear manner from the lowest levels of blood pressure recorded in a population;4, 6 2) there is, from a practical perspective, no threshold below which lowering blood pressure does not confer some reduction in risk; and 3) the magnitude of benefit from lowering blood pressure depends on an individual’s underlying level of risk, which is predominantly determined by age rather than initial blood pressure level. In fact, from about age 20 years on, an individual’s risk of sustaining a first heart attack or stroke approximately doubles every 7 years7 (Figure). We cannot reduce age, but we can lower blood pressure.

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-Nicholas Wald, FRS, FRCP, David Wald, FRCP, Arthur L. Kellermann, MD

This article originally appeared in the December issue of The American Journal of Medicine.

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