Hypertension Guidelines in the United States and Canada: Are We Getting Closer?
See related article, pp e13–e115
The American College of Cardiology/American Heart Association (ACC/AHA) with 9 other organizations recently released new guidelines for the prevention, detection, evaluation, and management of hypertension in adults, including new blood pressure (BP) treatment thresholds and targets.1 The previous US guidelines released in 2014 caused some controversy by recommending relaxed treatment goals for several high-risk subgroups, including patients aged ≥60 years and those with diabetes mellitus or kidney disease.2 Instead, the new ACC/AHA guidelines provide a single, more intensive BP target for BP management, regardless of age or comorbid conditions. Overall, these new guidelines are more aligned with the 2017 Hypertension Canada guidelines3 and share similar key messages given that both sets of guidelines were derived from the same clinical evidence. However, some differences between ACC/AHA and Hypertension Canada are notable and warrant further discussion.
First, diagnosis of hypertension. In the ACC/AHA guidelines, hypertension diagnosis is set as BP ≥130/801 versus ≥140/90 mm Hg in Hypertension Canada and other international guidelines.3,4 However, most people in the BP bracket of 130 to 139/80 to 89 mm Hg (stage 1 hypertension according to the new ACC/AHA guidelines) will have low cardiovascular risk, and both guidelines encourage health behavior modification for low-risk patients.
Although observational studies demonstrate a doubling in cardiovascular risk in patients with pressures of 130 to 139/80 to 89 mm Hg compared with optimal readings, the absolute 10-year cardiovascular risk increase is relatively small. In a recent meta-analysis of 74 trials (n=306 273 participants),5 BP lowering for primary prevention was associated with decreased risk for cardiovascular disease and mortality only if baseline systolic BP was ≥140 mm Hg. The benefits for BP lowering when systolic BP was below a threshold of 140 mm Hg were only experienced in …