New hypertension guidelines: One size fits most?

ADDITIONAL TOPICS IN JNC 8

A supplemental report covered some additional topics for which formal evidence review was not conducted but which the panel considered important.

Measuring and monitoring blood pressure

The panel recommended measuring the blood pressure with an automated oscillometric device that is properly calibrated and validated, or carefully measuring it manually.

Blood pressure should be measured in a quiet and relaxed environment with the patient seated comfortably for at least 5 minutes in a chair (rather than on an examination table) with feet flat on the floor, back supported, and arm supported at heart level. Blood pressure should be taken on the bare upper arm with an appropriate-sized cuff whose bladder encircles at least 80% of the mid-upper arm circumference, and patients should avoid caffeine, smoking, and physical activity for at least 30 minutes before measurement. In addition, patients should be asked about the need to empty the bladder (and encouraged to do so if they have to).

To establish the diagnosis of hypertension and to assess whether blood pressure goals are being met, two or three measurements should be taken at each visit as outlined above, and the average recorded.

At the first visit, blood pressure should be measured in both arms, and the arm with the higher pressure should be used for subsequent measurements.

Appropriate dosing of antihypertensive medications

Dosing should be individualized for each patient, but in general, target doses can be achieved within 2 to 4 weeks, and generally should not take longer than 2 months.

In general, to minimize potential adverse effects, treatment is started at a lower dose than the target dose and is then titrated up. This is especially important in older patients and patients on multiple medications with other comorbidities, and if two antihypertensive medications are being started simultaneously.

The panel reviewed evidence-based dosing of antihypertensive medications that were shown to improve cardiovascular outcomes from the studies that were selected for review. Hydrochlorothiazide gets a special mention: although doses up to 100 mg were used in some studies, the panel recommended an evidence-based dose of 25 or 50 mg daily to balance efficacy and safety.

Three strategies for dosing antihypertensive medications that were used in the selected randomized controlled trials were provided. These strategies were not compared with each other, nor is it known if one is better than the others in terms of health outcomes. In all cases, avoid combining an ACE inhibitor and an ARB.

• Start one drug from the four classes in Recommendation 6, titrate to the maximum dose, then add a second drug and titrate, then add a third drug and titrate to achieve the goal blood pressure.
• Start one drug from the four classes in Recommendation 6 and add a second drug before increasing the initial drug to its maximal dose. Titrate both to maximal doses, and add a third drug if needed and titrate to achieve the goal blood pressure.
• Start with two drugs at the same time from the four classes in Recommendation 6, either as separate pills or in a fixed-dose combination. Add a third drug if needed to achieve the goal blood pressure.

Lifestyle modification

The panel did not extensively review the evidence for lifestyle modification but endorsed the recommendations of the Lifestyle Work Group, which was convened by the NHLBI to focus on the effects of diet and physical activity on cardiovascular disease risk factors.¹⁸

Diet. The Lifestyle Work Group recommends combining the Dietary Approaches to Stop Hypertension (DASH) diet with reduced sodium intake, as there is evidence of a greater blood-pressure-lowering effect when the two are combined. The effect on blood pressure is independent of changes in weight.

The Lifestyle Work Group recommends consuming no more than 2,400 mg of sodium per day, noting that limiting intake to 1,500 mg can result in even greater reduction in blood pressure, and that even without achieving these goals, reducing sodium intake by at least 1,000 mg per day lowers blood pressure.

Physical activity. The Lifestyle Work Group recommends moderate to vigorous physical activity for approximately 160 minutes per week (three to four sessions a week, lasting an average of 40 minutes per session).

Weight loss. The Lifestyle Work Group did not review the blood-pressure-lowering effect of weight loss in those who are overweight or obese. The JNC 8 panel endorsed maintaining a healthy weight in controlling blood pressure.

Alcohol intake received no specific recommendations in JNC 8.

JNC 8 IN PERSPECTIVE

JNC 8 takes a rigorous, evidence-based approach and focuses on a few key questions. Thus, it is very different from the earlier reports: it has a narrower focus and does not address the full range of issues related to hypertension.

Strengths of JNC 8

The panel followed a rigorous process of review and evaluation of evidence from randomized controlled trials, adhering closely to standards set by the Institute of Medicine for guideline development. In contrast, JNC 7 relied on consensus and expert opinion.

The JNC 8 guidelines aim to simplify recommendations, with only two goals to remember: treat to lower than 150/90 mm Hg in patients age 60 and older, and lower than 140/90 mm Hg for everybody else. The initial drug regimen was simplified as well, with any of four choices for initial therapy in nonblacks and two in blacks.

Relaxing the blood pressure goals in elderly patients (although a cutoff of age 60 vs age 80 is likely to be debated) will also allay concerns about overtreating hypertension and causing adverse events in this population that is particularly susceptible to orthostatic changes and is at increased risk of falls.