The recently updated guidelines of the Joint National Committee on the Detection, Evaluation and Treatment of High Blood Pressure (JNC8) recommended greater leniency in treating hypertension in individuals over the age of 60. They recommended treatment only if the blood pressure is above 150/90 rather than the decades-old standard of 140/90. This guideline could affect the treatment of millions, as most people over 60 have hypertension.
Many hypertension specialists, myself included, disagree with this new recommendation. Aside from concern that it will open the door to more lax treatment of hypertension by physicians, I believe the evidence upon which JNC8 bases this recommendation, to leave untreated a blood pressure in the 140s, is open to question.
JNC8 relied exclusively on evidence from large randomized controlled trials (RCTs) that compared the effect on cardiovascular event rate (strokes, heart attacks, etc.) of treatment vs. no treatment (placebo), or of treatment to two different target blood pressure levels. Although RCTs are considered the most reliable form of evidence, the problem is that the RCTs that JNC8 relied on followed patients for only 3-5 years. That is long enough to observe benefit when treating severe hypertension and reducing systolic blood pressure from 160-200 down to 140. But it usually isn't long enough to observe or prove benefit when lowering systolic pressure only 10 millimeters from 150 to 140. Here a longer period of observation is needed to document the benefit.
This runs parallel to what we do in the clinical setting. When I treat a 62-year-old patient whose systolic pressure is 145, I don't expect him to suffer a stroke in that time frame. I am treating to reduce his risk of stroke over the next five or 10 or more years.
It is interesting that JNC8 cited the ACCORD trial as showing that lowering systolic pressure to 120 did not reduce the event rate any more than lowering it to 130. Yet even within the 4.7 years of that study, there was a large and statistically significant 41 percent reduction in stroke, the complication most closely associated with hypertension. That benefit would grow year after year. The ACCORD report did not focus on that finding.
To demonstrate the benefit of lowering systolic pressure by 10 mm would require a study that randomly assigned patients to two different levels of treatment and then followed them for 10 years or more. For many, many reasons, studies like that are very difficult to do, and are unlikely to ever be done. Meanwhile, it is misleading to argue against treatment of mild hypertension because benefit was not seen in studies limited to 3-5 years.
Treating mild hypertension in the middle years of life likely also confers other benefits that cannot be shown in a 3-5 year RCT. Many studies suggest that hypertension contributes to development in later life of problems such as cognitive deficit and dementia, not to mention erectile dysfunction. Some studies suggest that treatment of hypertension in midlife can reduce the risk of developing those problems. Starting treatment at a much older age when the problems are evident is too late; at that point the cow is already out of the barn.
What about patients over the age of 80? There is substantial proof that getting the systolic pressure under 160 is beneficial, but the benefit of reducing it below 140 is unproven; we frankly don't know if that is helpful or harmful, or what blood pressure target is optimal. And the optimal blood pressure likely differs from one person to another. So we don't feel compelled to get the systolic pressure under 140 in someone over 80.
What about the individual whose systolic pressure, with medication, has been maintained at 130 for years, but is now 80? Would I reduce medication to allow the pressure to increase to 150? If he or she is doing well, I'd leave the medication as is; if there are any side effects, I'd reduce it.
To sum up, decades of witnessing the enormous benefits of treating hypertension aiming at the traditional target below 140, particularly reduction in the incidence of stroke by at least 40 percent and possibly much more than that, argue strongly against easing up on treatment. Also supporting aggressive drug therapy, as I discuss in Hypertension and You, are the excellent and now less expensive generic drugs that when prescribed correctly can lower blood pressure without side effects in most patients. We shouldn't withhold treatment because of 3-5 year RCTs that predictably could not prove the benefit of long-term treatment. As per the old adage, the absence of proof of benefit is not proof of the absence of benefit.
That said, I also believe that there IS an epidemic of overtreatment of hypertension, but not because we are aiming for too low a blood pressure. In many cases doctors increase medication because of a temporary increase in blood pressure that usually would resolve on its own. Hypertension is often overtreated because of incorrect measurement of blood pressure. Or because patients are on medications that don't fit the cause of their hypertension. And many whose blood pressure is elevated only in the doctor's office ("white coat hypertension") are on medication that they don't need.
I believe there is an epidemic of overtreatment, but not because the blood pressure level that we aim for is too low. The current targets have a fabulously successful track record; they should not be abandoned.