The new magic number will be 130/80 mm Hg. That's the blood pressure goal that many hypertension experts say will be the centerpiece of an update to U.S. guidelines.
The new guideline will be introduced next month in Anaheim during the annual meeting of the American Heart Association (AHA). The guideline is now (ACC).
Previous national hypertension guidelines were produced by the Joint National Commission (JNC) under the auspices of the NIH. In 2013, the NIH announced that it would no longer be responsible for developing influential guidelines like the JNC guideline for hypertension and the Adult Treatment Panel (ATP) guideline for cholesterol.
The last "official" U.S. hypertension guideline was JNC 7, . That guideline established a target systolic blood pressure of less than 140 mm Hg. (For people with diabetes or kidney disease, the target was even lower, less than 130 mm Hg.)
initially appeared to support a radically more aggressive systolic target below 120 mm Hg. The trial tested an antihypertensive strategy using the conventional goal of less than 140 mm Hg against the more aggressive goal of less than 120 mm Hg in high-risk patients. The results favored the more aggressive treatment, but many hypertension experts were critical of the trial and said the under-120 goal should not be broadly adopted.
One of the main arguments against SPRINT was that the method used to measure blood pressure in SPRINT differed in important ways from the methods used in other clinical trials and, equally important, from the methods commonly used in clinical practice. Many experts believe the under-120-mm Hg goal in SPRINT needs to be adjusted upward by at least 10 mm Hg in clinical practice. Another important issue is the high number of side effects created by aggressive treatment.
The systolic blood pressure goal of less than 130 in the forthcoming AHA/ACC guideline -- confirmed by multiple experts within the hypertension community -- suggests that the writing committee found a middle ground or compromise between the previous goal and the far more aggressive goal suggested by the SPRINT trial.
For now it is unclear how the new target will apply to patients who fall outside the SPRINT population, such as those at lower risk than the SPRINT population or those who were excluded from that trial, such as people with diabetes.
A recently-published (ADA) may offer a preview of the AHA/ACC guideline. The ADA recommends that most patients with diabetes and hypertension be treated to a goal of less than 140 mm Hg, but that a lower target under 130 mm Hg "may be appropriate for individuals at high risk of cardiovascular disease if they can be achieved without undue treatment burden." The document also recommends that people with an initial blood pressure between 140/90 mm Hg and 160/100 mm Hg be started with one antihypertensive agent. People with higher initial blood pressure should be started on two agents.
An important lingering question is how the guideline will resolve the ongoing controversy over how best to measure blood pressure, both in clinical trials and in clinical practice.
Most hypertension experts I contacted said they thought the new goal was reasonable. But one expert said he believed it will be difficult, no matter what the guideline recommends, to convince most doctors to treat blood pressure between 130 and 140 mm Hg or to initiate combination treatment in people with blood pressure over 140/90 mm Hg. The lower goal will also not satisfy critics who have expressed concerns about overtreatment. One questioned pushing for new goals while at the same time "we have continually failed to reach the old ones for so many people."
The next update to the European hypertension guideline is expected to come out next year. Much of the criticism of SPRINT has stemmed from European experts, and it is widely anticipated that the European guideline will be more critical of SPRINT.
Two Guesses
Erin Michos (Johns Hopkins) was a co-author of the ADA guideline but has not seen the forthcoming AHA/ACC guideline. She shared two "quick guesses" about the forthcoming guideline:
"(1) I believe there may be an endorsement for the use of automated BP cuff (AOBP) readings obtained while a patient rests quietly alone in the room. This was mentioned as the preferred method in the Canadian guidelines, and we also mentioned it as an alternative method in the ADA guidelines. Importantly, AOBP was used in both SPRINT and ACCORD – two very large impactful guidelines that likely will shape the U.S. hypertension guidelines. And AOBP can also be helpful for diagnosing white-coat hypertension if readings are taken when the patient is alone. It is important to note that AOBP generally provides BP values that are 5 to 10 mm Hg lower than conventional office based semiautomated oscillometric blood pressures. So when considering 'lower targets', the method of blood pressure ascertainment is very important to factor in. There will be lower cutpoints when using AOBP versus conventional methods. Which is why it may be hard and not appropriate to achieve 'SPRINT-like' BPs using conventional office readings.
"(2) Most importantly, in light of SPRINT, I also anticipate that the new guidelines might inch towards a 'Risk Based' treatment approach to BP management, similar to what the 2013 ACC/AHA Guidelines have done for lipids. I anticipate they might support lower blood pressure targets for higher-risk individuals (such as those that meet the inclusion criteria for SPRINT), if this can be achieved without undue burden and side effects (such as drug adverse effects, hypotension, falls, adversely-low diastolic BPs, etc).
"The benefits and risks of more intensive BP targets will vary for an individual patient, so it really needs to be an individualized decision and the patient should be part of the conversation. Therefore, similar to the lipid guidelines, I think there will be an endorsement for a 'Clinician-Patient Risk Discussion' when deciding target goals, where patients and clinicians engage in a shared decision-making process that takes into account their absolute risk for ASCVD [atherosclerotic cardiovascular disease] events (particularly stroke) or risk for progressive kidney disease/albuminuria, but also factor in the burden of more intensive therapy, potential for adverse side effects, patients' life expectancy, and patients' attitude and personal preferences regarding more intensive treatment, etc.
"We talked a lot about this shared decision-making process in the ADA guidelines. As we said in the ADA guidelines, patients who are at higher risk for cardiovascular events, heart failure, or albuminuria and who also can achieve blood pressure control relatively easily without significant side effects might be the type of patients who are recommended for more intensive BP control. On the other hand, intensive therapy may not be desired in patients with anticipated less favorable risk/benefit ratio such as those with extensive polypharmacy and risk for drug/drug interactions, have significant functional limitations, or at risk for other adverse events. Again, this should be part of a shared decision-making conversation between clinicians and their individual patients. I don't see a 'one-size-fits-all' approach to targets."