The recent changes to the American College of Cardiology/American Heart Association high blood pressure (BP) guidelines have been controversial, with some groups claiming the new guidelines are not evidence based. An editorial published in JAMA Internal Medicine explained the decision process behind the change, the benefits and harms to patients, and treatment recommendations under the new definitions.
An 8-item checklist was used to consider both benefits and harms in the context of changing the definition of high BP and is described here.
1) What are the differences between the new definition and the previous definition?
Hypertension diagnostic criteria were lowered to systolic BP >130 mm Hg from 140 mm Hg, and drug treatment is recommended for “high-risk” people with hypertension.
2) How will the new disease definition change the incidence and prevalence of the disease?
The new changes are expected to result in hypertension diagnoses for 31 million more US adults (14%); 4.2 million more US adults (2%) will be recommended for immediate drug treatment.
3) What is the trigger for considering the modification of the disease definition?
The SPRINT trial (ClinicalTrials.gov Identifier: NCT01206062) showed benefit with a lower BP target (systolic BP 120 mm Hg).
4) How well does the new definition predict clinically important outcomes compared with the old definition?
Evidence suggests that the relative risk for cardiovascular disease (CVD) mortality doubles with every 20-mm Hg increase in systolic BP.
5) What are the repeatability, reproducibility, and accuracy of the new definition?
The new guidelines place more emphasis on averaging out-of-office BP measurements, which may improve, but not necessarily solve, the reproducibility issue.
6) What is the incremental benefit for patients classified by the new definition but not by the previous definition?
Evidence suggests 80% of people newly classified will have no expected benefit to CVD risk reduction by lowering BP. An additional 11% will have a small benefit of 1.4% risk reduction over 5 years. Finally, 9% may exhibit larger benefits in CVD risk reduction of 2% to3.8%.
7) What is the incremental harm for patients classified by the new definition but by not the previous definition?
The hypertension label may increase anxiety and depression. In addition, it may compound barriers to treatment, as the label would be a pre-existing condition for insurance purposes. Finally, people being treated may experience treatment-related adverse effects.
8) What are the net benefits and harms for patients classified by the new definition but not by the previous definition?
People at high risk for a CV event or who have a history of CVD may experience incremental benefits that outweigh the incremental harms. The net effects for others are not as clearly beneficial.
The authors wrote, “Some people are willing to accept a moderate increased risk of a cardiovascular event to avoid taking daily medications, increased doses, or more medications, and others are not.”
They added, “In this situation, informed and shared decision making is essential.”
Bell KJL, Doust J, Glasziou P. Incremental benefits and harms of the 2017 American College of Cardiology/American Heart Association high blood pressure guideline [published online April, 16 2018]. JAMA Intern Med. doi:10.1001/jamainternmed.2018.0310