For more than a century, clinicians have pondered the significance of elevated blood pressure (BP) and its contribution to cardiovascular disease (CVD). While it is widely understood that high BP increases CVD events, and that treatment lowers that risk, the most appropriate BP goal continues to be a subject of debate.
This article briefly summarizes the evidence to support lower BP goals for patients with hypertension who are commonly seen in family practice, including those needing primary prevention, as well as those with, or at high risk for, atherosclerotic cardiovascular disease (ASCVD), patients with diabetes, and those with chronic kidney disease (CKD). Detailed information regarding specific lifestyle and medication treatment recommendations and thresholds for drug therapy is beyond the scope of this review.
A brief history: ACC/AHA guidelines vs JNC 7 and 8
The most recent comprehensive, evidence-based guideline on the prevention, detection, evaluation, and management of high BP in adults was released in late 2017 by the American College of Cardiology (ACC) and the American Heart Association (AHA).1 It was the first comprehensive BP guideline since the Seventh Report of the Joint National Committee (JNC 7) in 2003.2 The new guideline includes several changes, notably in how BP is classified, the threshold for initiation of antihypertensive drug therapy, and target BP.
While widely viewed as positive, the changes in classification, thresholds, and targets for BP therapy have generated controversy and disagreement. Common reasons cited include concern about the data supporting lower thresholds for treatment, the applicability of trial findings to broad patient populations, and the risk of harm with lower BP goals.3 The American Academy of Family Physicians (AAFP) declined to endorse the ACC/AHA guidelines and continues to support the 2014 report by the panel members appointed to the Eighth Joint National Committee (JNC 8) by the National Heart Lung and Blood Institute (NHLBI).4 A primary reason cited for the lack of support for the 2017 guideline is that the majority of recommendations made in the ACC/AHA guideline were not “based on a systematic evidence review.”4 However, there are significant differences in purpose, structure, and scope between the ACC/AHA and JNC 8.
In 2013, the NHLBI announced that it would cease involvement in creating guidelines and transferred responsibility for development to professional organizations.5 Of the 5 guidelines that were in the process of creation (cholesterol, lifestyle intervention, obesity, risk assessment, and high BP), all but the high BP guideline were transferred to the ACC/AHA for completion. The panel members appointed to the JNC 8 elected to publish their recommendations independently and focused only on 3 “critical questions” related to hypertension therapy (eg, therapy initiation, BP goals, and choice of initial agent).6
The JNC 8 report generated significant controversy with the recommendation to relax the BP goal for patients ≥60 years of age to <150/90 mm Hg. Members of the JNC 8 panel who disagreed with this goal published a "minority view" citing concerns about the negative impact the goal would have on CVD and public health, and the "insufficient and inconsistent" evidence supporting relaxed goals.7 The dissenting group cited additional drawbacks of the recommendation, noting that it was highly focused, included data only from randomized controlled trials (RCTs; no meta-analyses or observational data), and did not address or provide guidance on numerous other issues of importance in the care of hypertension.
While the 2017 ACC/AHA guideline also includes formal systematic evidence reviews on major critical questions (ie, optimal BP targets, preferred antihypertensives, the role of home and ambulatory BP monitoring),8 it was designed to be comprehensive and useful for clinicians, providing 106 graded recommendations on commonly encountered questions. It would have been unrealistic to do a formal systematic evidence review and meta-analysis on all clinically relevant questions seen in practice. However, available systematic reviews, meta-analyses, and observational data were scrutinized and used to support the recommendations wherever possible.
Continue to: Say "goodbye" to prehypertension; say "hello" to elevated BP