From 1977 to 2003, seven Joint National Committees (JNC), sponsored by the National Heart, Lung, and Blood Institute (NHLBI), produced consensus multi-specialty guidelines on the diagnosis and management of hypertension. In 2013, well into the development of JNC8, the NHLBI abruptly turned the process over to the American College of Cardiology/American Heart Association (ACC/AHA). The JNC8 committee independently published an
evidence-based guideline in
JAMA that raised the blood pressure treatment threshold in most older adults from 140/90 to 150/90 mm Hg. Concerned about conflicts of interest and other deviations from
Institute of Medicine-recommended practices for developing trustworthy guidelines, primary care groups, including the American Academy of Family Physicians (AAFP), declined to participate in the ACC/AHA guideline panel. And the longstanding edifice of hypertension guidelines fractured.
In 2017, the ACC/AHA
released its clinical practice guideline, which most notably re-defined hypertension as sustained blood pressure over 130/80 mm Hg and recommending, based largely on the controversial
SPRINT trial, that treatment should aim to reduce blood pressure below this new threshold. The AAFP
decided against endorsing the guideline and advised its members to continue following the JNC8 report and its own
2017 practice guideline, co-authored with the American College of Physicians, that largely reiterated JNC8’s treatment thresholds for adults aged 60 years and older.
Last month,
American Family Physician published an
updated AAFP hypertension guideline, written by a panel of family physicians (including me), which focuses on updated evidence for optimal blood pressure targets in adults. Based on a
Cochrane systematic review of randomized controlled trials that compared higher and lower blood pressure targets for primary prevention of cardiovascular disease (76% of study participants did not have preexisting CVD), the AAFP strongly recommends treating to a standard blood pressure target of less than 140/90 mm Hg to reduce all-cause and cardiovascular mortality. Since a lower blood pressure target of less than 135/85 mm Hg further reduces the risk of myocardial infarction (number needed to treat = 137 over 3.7 years) but not mortality, the AAFP recommends that clinicians consider treating to this lower target with shared decision-making. Notably, although the lower target did not increase serious adverse events compared to the standard target, it required patients to take one more anti-hypertensive medication on average and increased non-serious adverse events (number needed to harm = 33).
The AAFP guideline also applies to adults with hypertension and existing CVD, as another
recent Cochrane review comparing standard to lower blood pressure targets in this population found no differences in total or cardiovascular mortality, conclusions that were unchanged from
an earlier version. The AAFP guideline is mostly consistent with
guidelines from the International Society of Hypertension that recommend a treatment threshold of 140/90 in office settings and lower thresholds for blood pressures obtained with
home monitoring or
24-hour ambulatory monitoring.
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