Blood pressure is a beautiful (but imperfect) biomarker of hypertension. The quixotic quest that fuels the hypertension guideline industry

Hypertension is a disease; blood pressure (BP) is a biomarker. However, the 2 terms have become ineluctably bound. Based on BP measurements, the 2017 American College of Cardiology/American Heart Association (ACC/AHA) guideline defines normal BP as 120/80 mm Hg. As a result, the number of individuals in the US classified as hypertensive increased from 72 million in the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7) to over 100 million—45.6% of the population, with 36.2% needing antihypertensive medication.1 This is consistent with the longstanding observation made by the insurance industry actuaries that BP levels above 120/80 mm Hg were associated with increased cardiovascular morbidity and mortality. Nevertheless, they suggest that drug therapy be only recommended for those with BPs above 140/90 mm Hg. However, physicians treat patients, not mm Hg. Thus, caregivers should be discussing BP with their patients to understand the appropriate level for each person.

Sir George Pickering articulated over 40 years ago: “Arterial pressure is a quantity and its adverse effects are related numerically to it. The dividing line (between normal BP and hypertension) is nothing more than an artifact.”2 Epidemiologic data support a continuous, incremental risk of cardiovascular disease, stroke, and renal disease across levels of both systolic and diastolic BP, beginning at BP levels of approximately 120/80 mm Hg. However, this fact has not deterred every organization with interest in hypertension, and many groups of individuals, to promote their own guidelines for definition and treatment. It is time to end this quixotic quest for a one‐size‐fits‐all BP number.

In order to understand the evolution of the definition of hypertension over time, it is necessary to distinguish between the disease called hypertension and BP, the biomarker. Hypertension is a progressive cardiovascular syndrome arising from complex and interrelated etiologies.3 Early markers of the syndrome are often present before BP elevation is sustained; therefore, hypertension cannot be classified solely by discrete BP thresholds. Progression is strongly associated with functional, endocrine, and structural cardiac and vascular abnormalities that damage the heart, kidneys, brain, vasculature, and other organs and lead to premature morbidity and death.

In 1937, Paul Dudley White in the second edition of his book entitled Heart Disease wrote “The treatment of hypertension itself is a difficult and almost hopeless task in the present state of our knowledge, and in fact for aught we know, in advanced cases with permanently narrowed coronary and cerebral arteries the hypertension may be an important compensatory mechanism which should not be tampered with, even were it certain that we could control it.”4 It took 40 years for this opinion to be corrected. In 1977, the first JNC report classified hypertension as diastolic BP > 105 mm HG, and suggested that consideration is only given to actively treating patients with diastolic BP > 90 mm HG. In 1980, the second JNC defined hypertension as diastolic BP > 90 mm HG.5 There were no recommendations for classifying or treating systolic BP in JNC I or II. Subsequent JNC reports have recommended progressively more rigorous criteria for defining and treating hypertension.

To understand the evolution of the definition of hypertension over time, it is necessary to distinguish between the disease called hypertension and BP, the biomarker. Further complicating the use of BP as a means of defining hypertension is the voluminous literature documenting the inaccuracy of BP measurements in clinical settings. In fact, virtually all of the BP data used in the “guidelines” is fatally flawed. Nevertheless, every person who has had any association with the field of hypertension will immediately conclude that only they are privy to the ideal guideline for the diagnosis and treatment of hypertension based on BP, and then will organize all description of groups and publish their thoughts.

It is now evident that the development of hypertension involves genetic, epigenetic factors, autonomic nervous system dysregulation, and alterations in cardiovascular structure and function. It is now time to abandon these expensive attempts to promote BP levels and concentrate on phenotypic refinement.

The SPRINT clinical trial, published in late 2017, showed that in patients at high risk for cardiovascular events treatment to target systolic BP below 120 mm HG is associated with lower mortality and rates of fatal and nonfatal major cardiovascular events.6 The publication of SPRINT created several types of reactions: some raised concern about overmedicating patients rather than an emphasis on cardiovascular disease. They are afraid that otherwise there is a risk that Molière's statement in Malade Imaginaire (The Imaginary Invalid) that nearly all people die of their remedies and not from their illnesses (“Presque tous les hommes meurent de leur remèdes, et non pas de leur maladies”).

The guideline has been criticized on several grounds, including the length of time between hypothesis generation and publication, the short duration of clinical trials, emphasis on a small number of studies and undue emphasis on frequentist statistics (P values), and the lack of similarity between participants in clinical trials and the population at large.

We are reminded of the lecture entitled Existentialism is a Humanism (“L'existentialisme est un humanism”) that Sartre gave at Club Maintenant in Paris on October 29, 1945.7 In this very well attended lecture, he stated that the existence precedes the essence and “man first of all exists, encounters himself, surges up in the world – and defines himself afterwards.” “l'existence précède l'essence” and “Cela signifie que l'homme existe d'abord, se rencontre, surgit dans le monde, et qu'il se définit après.” In keeping with this concept, all those in charge of patients should act today and advise our patients appropriately. In the past, the medical profession was wrong in considering that values above normal are acceptable or even desirable for patients with different pathological conditions (as stated by Dr. Paul Dudley White above). This is also true for cholesterol and blood glucose. Today, we should strive to bring the BP of each patient as close to normal as possible considering individual circumstances; genetic, cultural, physiological, pathological, and psychological differences; interactions of BP with other risk factors; and the adverse effects, expense, and patient labeling as sick because of the use of antihypertensive therapy.

CONFLICT OF INTEREST

The authors declare that there are no conflicts of interest regarding the publication of this article.