America and its Blood Pressure
The American Heart Association (AHA) just recently published new guidelines on when a blood pressure is defined as too high – with the purpose to prevent the population from suffering more damage. However, more people are now classified as diseased. This results in conflicts and discussions.
Undoubtedly, high blood pressure or hypertension damages the cardiovascular system significantly. It contributes to the pathogenesis of numerous disease processes including but not limited to stroke, myocardial infarction, dementia, kidney failure, and peripheral vascular disease. But when is high blood pressure too high? This is where now opinions differ since a recent nationwide guideline revision. On the occasion of their annual meeting, the AHA – the major US cardiologic association – revised their definitions of hypertension and corrected the cutoff values downwards (AHA Press Release and JACC Article).
Hypertension is now defined as a minimum systolic blood pressure of 130 mm Hg and a minimum diastolic pressure of 80 mm Hg (130/80 mm Hg). The prior limits were 140/90 mm Hg. In addition, the old term of “prehypertension” which ranged between 120/80 and 139/89 mm Hg is abolished. In contrast, a new area of “elevated pressure” is introduced with a range of 120-129/<80 mm Hg.
With these massive modifications, the prevalence of Americans with a hypertensive disorder will increase significantly to roughly 46%. The AHA estimates that the younger generations will be affected most. Prevalence will triple in men under 45 and double in women under 45. Including the range of “elevated pressure”, it will now become hard to find any adult without a pathological diagnosis.
So what has urged the AHA to take this radical step? The newest scientific evidence is demonstrating an additional decrease in adverse outcomes, such as those mentioned above, when blood pressure is further reduced to values below 130/80. These findings originate from a large randomized clinical trial named “SPRINT” that was published in the distinguished New England Journal of Medicine back in 2015 (NEJM Link).
Nevertheless, there is some skepticism in the medical community about these measures taken by the AHA. The SPRINT trial evauated patients’ blood pressure in an exam room after the patient was seated quietly for 5 min to avoid a so-called white coat syndrome where people would get nervous and hypertensive upon the sight of a doctor. However, the automatic external device used to capture the blood pressure on a patient’s upper extremity is somewhat prone to inaccuracy related to the user. Previous guidelines across the world were usually based on traditional measurements that included the utilization of a stethoscope and an experienced medical professional performing the reading. In addition, the above article did report that certain side effects, such as serious hypotension, syncope, or kidney injury, were statistically more likely to occur in the cohort subjected to the more aggressive treatment.
The AHA does emphasize that no medical intervention is necessary in the new stage 1 of hypertension of 130-139/80-89 mm Hg unless significant medical comorbidities exist which would require pharmacological treatment. However, in our aging population, I personally have no doubt that these guideline reforms will increase the use of antihypertensive drugs, as healthcare providers will see more and more people with pathological blood pressure values who will subsequently qualify for medications. These latest news must be music to the ears of the big pharmaceutical companies.
While these guideline revisions may increase the public awareness about hypertension and its associated risks – after all, high blood pressure is called the “silent killer”, it may also turn previously healthy people into regular patients in doctors’ offices dependent on their medications.