Clinical practice guidelines are an important established resource in medicine and public health. Clinical practice guidelines are particularly well suited to conditions such as high blood pressure (BP) that are common, result in a substantial disease burden and utilization of health care resources, incur individual and societal cost, demonstrate large variation in practice patterns, and have enough high-quality evidence to guide decision-making. Although many BP-related clinical practice guidelines have been developed by individual countries and professional societies, few would dispute that 2 such reports released during the past 12 months鈥攖he 2017 American College of Cardiology (ACC)/American Heart Association (AHA)¹ and 2018 European Society of Cardiology (ESC)/European Society of Hypertension (ESH)² guidelines鈥攈ave substantial influence beyond their immediate regions of origin.

Presentation and publication of these 2 comprehensive guidelines have resulted in comparisons and vigorous debate, with an emphasis on differences³ rather than how their core recommendations can be implemented to improve the health of the public. This may lead to an impression that experts cannot agree or that the evidence is flawed or insufficient, providing support for those who are content with the status quo of lamentable hypertension control globally.⁴ Against this backdrop, it is important to recognize that the convergence of the 2017 ACC/AHA (US) and 2018 ESC/ESH (European) guidelines is greater now than ever before.

The 2 guidelines have much in common (eTable in the Supplement), including recommendations to (1) base diagnosis and management of hypertension on accurate BP measurements; (2) perform out-of-office BP readings to confirm high office readings and to recognize 鈥渨hite coat鈥� and 鈥渕asked鈥� hypertension; (3) use cardiovascular disease (CVD) risk estimation, in addition to BP levels, for therapeutic decision-making; (4) utilize a similar array of drug treatment and nonpharmacological lifestyle interventions as the core strategy for BP lowering; (5) add antihypertensive drug treatment to nonpharmacological therapy at lower BP thresholds than previously recommended; (6) use combination drug therapy, preferably in the form of a single combination pill, to improve treatment adherence; (7) utilize combinations of the same classes of antihypertensive drugs for treatment of most adults with hypertension (thiazide/thiazide-like diuretics, calcium channel blockers, angiotensin-converting enzyme inhibitors, and angiotensin receptor blockers), reserving combinations with 尾-blockers for specific clinical conditions; (8) use lower BP treatment targets than those previously recommended, including lower BP targets in older adults, adults with diabetes, and adults with a variety of comorbid conditions; (9) emphasize functionality rather than chronological age in managing high BP in older adults; and (10) use strategies known to improve the control of hypertension. In addition, both guidelines identify evidence gaps for which additional research is needed to resolve areas of current uncertainty.

The guidelines vary in the details of their commonality but generally encourage greater use of out-of-office BP measurements, lower BP thresholds for initiating antihypertensive drug therapy, and lower BP treatment targets, which collectively should lead to a lower BP and fewer BP-related complications.⁵ Other recent comprehensive BP clinical practice guidelines from Canada⁶ and Australia⁷ have also recommended lower BP treatment targets than in previous guidelines.

A key change in both guidelines is the approach to treatment of BP in older adults, which is closer than ever to that proposed for younger adults. Emerging evidence that lowering BP seems to protect against cognitive decline⁸ may help reinforce the importance of improving BP treatment and hypertension control rates, with no age-related end date and cessation of therapy only when it is poorly tolerated or the patient experiences functional decline to the point at which treatment is futile.

Despite their similarities, the guidelines take a different position in several areas. The most apparent is in classification of BP. The definition of hypertension in the European guideline is unchanged, reflecting the level of BP (鈮�140/90 mm Hg) at which drug treatment is recommended for all patients. In the US guideline, hypertension is defined by an average systolic BP of at least 130 mm Hg or diastolic BP of 80 mm Hg or higher, based on an interpretation of risk and treatment effect. This results in a different approach to treatment of adults with a systolic BP of 130 through 139 mm Hg or diastolic BP of 80 through 89 mm Hg, who are classified as having stage 1 hypertension in the US guideline and high-normal BP in the European guideline. The US guideline recommends nonpharmacological therapy for all adults with stage 1 hypertension and additional antihypertensive drug therapy for the approximately 30% in this highly prevalent BP category who are deemed to be at high risk for atherosclerotic CVD (10-year risk of atherosclerotic CVD鈮�10%). In contrast, the European guideline predominantly recommends lifestyle interventions, with consideration of antihypertensive drug therapy only in adults at very high risk, ie, with established CVD, especially coronary artery disease.

The decision in the US guideline to reclassify hypertension and base treatment of stage 1 hypertension on CVD risk estimation has important implications for older adults, many of whom would meet the risk threshold for drug treatment. Even though BP thresholds for treatment in older adults have been reduced in the European guideline, they remain higher than the US recommendations at BP levels of 140/90 mm Hg or higher for patients older than 65 years and 160/90 mm Hg or higher for patients older than 80 years who have not previously been treated.

Both guidelines recommend lower BP targets during combined lifestyle and antihypertensive drug therapy. In the US guideline, the target is lower than 130/80 mm Hg in almost all patient groups, except older adults, among whom the target is systolic BP lower than 130 mm Hg. In the European guideline, the first objective is to reduce BP to less than 140/90 mm Hg, with a target of 130/80 mm Hg or lower, if tolerated, in adults younger than 65 years but not in adults 65 years and older, for whom the target is below 140 to 130/80 mm Hg, if tolerated.

Another difference in BP targets relates to patients with chronic kidney disease (CKD). The European guideline recommends a target of less than 140/90 mm Hg, with flexibility for individualized management depending on treatment tolerance and impact on renal function and electrolyte levels. The US guideline recommends a target below 130/80 mm Hg, largely based on the favorable CVD and all-cause mortality experience in SPRINT participants with CKD at baseline.⁹ Both guidelines recommend management of additional CVD risk factors, but the US guideline generally defers to other ACC/AHA guidelines, whereas the European guideline provides recommendations for concomitant treatment with statins in many patients who have hypertension with a low-moderate or high risk of CVD. It also recommends antiplatelet therapy and aspirin for secondary but not primary prevention of CVD.

Two final differences relate to the process used for guideline development. The US writing committee had no BP-related commercial relationships and used an independent evidence review committee, in addition to literature review, to analyze the data for key questions. The European guideline task force considered the latter option unnecessary because many relevant systematic reviews had been published recently in high-quality journals. Both processes resulted in similar outputs, raising an important question regarding the value and need for rigorous independent assessments when high-quality systematic reviews are already in the public domain. Interpretation of the results and considerations of local factors, policies, and feasibility of implementation was what led to the guideline differences.

Adoption of the ACC/AHA and ESC/ESH guideline recommendations will be challenging for patients, clinicians, and health care systems. The fundamental issue is that too many adults have unhealthy lifestyles that put them at risk for adverse consequences including stroke, myocardial infarction, heart failure, and CKD.¹⁰ The best solution is a change to healthier lifestyles but dissemination, acceptance, and implementation of the ACC/AHA and ESC/ESH core recommendations for diagnosis and treatment of hypertension will likely result in substantially better public health.⁵ It seems unlikely that current models of care can respond adequately to meet the guideline recommendations. Potential solutions include minimizing barriers to accurate diagnosis and management of hypertension, a progressive shift to team-based care, better application of strategies for enhanced therapeutic adherence, and greater involvement of patients in their own care. The latter could also reduce the burden for primary care clinicians.

Corresponding Author: Paul K. Whelton, MB, MD, MSc, 1440 Canal St, Room 2015, New Orleans, LA 70112 (pkwhelton@gmail.com).

Conflict of Interest Disclosures: Dr Whelton reports having served as chair of the 2017 ACC/AHA blood pressure guideline committee. Dr Williams reports receiving grants and personal fees from Vascular Dynamics Inc, fees from Novartis for serving on a study advisory board, fees from Daiichi Sankyo for educational lectures, fees from Servier for educational lectures, fees from Boehringer Ingelheim for educational lectures, and fees from Pfizer for educational lectures outside the submitted work; and served as chair of the 2018 ESC-ESH Guidelines on Arterial Hypertension Guideline Task Force, and chair of the ESC Council on Hypertension, 2016-2018.

Additional Contributions: We thank Robert M. Carey, MD, and Giuseppe Mancia, MD, PhD, for valuable suggestions that improved the text.