Hypertension: Which guidelines are appropriate?

Cardiology Review® Online, January 2004, Volume 21, Issue 1

ypertension:

Which guidelines are appropriate?

Daniel R. Montellese, MD

From the Department of Internal Medicine, Stony Brook University Hospital,

Stony Brook, New York

For the past decade, the recommendations of the Joint National Committee (JNC) on the Prevention, Detection, Evaluation, and Treatment of High Blood Pressure have been the accepted guidelines for the general physician’s approach to the classification and management of hypertension in the United States. The European medical community, however, has followed the guidelines of the European Society of Hypertension (ESH) since 1989.1 JNC 7 recommendations2 are now being called into question, especially in light of the recent publication of the ESH 2003 recommendations. There is a clear difference of opinion reported in these two documents regarding the most appropriate approach to the classification and treatment of the hypertensive patient. Because of this dissimilarity, a closer examination of the JNC 7 and ESH guidelines is warranted.

Comparing the guidelines

ESH was created in the vacuum of its downsizing predecessor, the International Society of Hypertension. The goals of ESH are similar to those of JNC, which are to formulate a set of basic guidelines by which the general health care community may classify and treat hypertension based on scientific data and the current literature.

Defining and classifying hypertension. ESH and JNC 7 guidelines differ on the definition and classification of hypertension. The ESH recommendations state that the optimal range of systolic blood pressure is below 120 mm Hg, and the optimal range of diastolic blood pressure is below 80 mm Hg. They also state that normal systolic blood pressure ranges from 120 to 129 mm Hg, normal diastolic blood pressure ranges from 80 to 84 mm Hg, high-normal systolic blood pressure ranges from 130 to 139 mm Hg, and high-normal diastolic blood pressure ranges from 85 to 89 mm Hg. The high-normal category includes values that would be considered hypertensive in high-risk patients but that are acceptable in lower risk populations. A different approach is taken by JNC.

JNC 7 has included the new category of “prehypertensive” in its classification of blood pressure. This designation is given to patients (without renal disease or diabetes) with systolic blood pressures of 120 to 139 mm Hg or diastolic blood pressures of 80 to 89 mm Hg. The treatment recommendation for this group is lifestyle modification. The classifications of blood pressure ranges set forth in the JNC 7 and ESH 2003 guidelines are shown in table 1.

The ESH 2003 position statement states the “committee is aware that it is easier to prepare guidelines on a medical condition in general than to deal with individual patients with that condition requiring medical advice and intervention.”1 Although JNC 7 acknowledges the responsible physician’s judgment as “paramount” in their position statement, their recommendations reflect a less au-

tonomous and more rigid thought process compared with their European counterparts. This is clearly illustrated if one compares the two committees’ algorithms for the pharmacologic treatment of hypertension.

Pharmacologic treatment. Based mostly on the findings of the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT), JNC 7 recommends thiazide therapy alone or in combination with other antihypertensive agents as the initial intervention for patients with uncomplicated, untreated hypertension. ESH, however, clearly states that numerous possible combinations of therapies as initial treatment are acceptable based on the individual clinical situation and the patient’s tolerance of that medication. Their guidelines state “emphasis on identifying the first class of drugs to be used is probably outdated.”1 Both JNC 7 and ESH recognize there are certain compelling indications for initiating the use of a particular antihypertensive, for example, angiotensin-converting enzyme (ACE) inhibitors, for patients with diabetes or renal insufficiency.

Assessing risk. In assessing cardiovascular risk, ESH included increased high-sensitivity C-reactive protein (CRP) level as a risk factor in its 2003 guidelines. The guidelines state “C-reactive protein has been added as a marker of increased cardiovascular risk because of the mounting evidence that it is a predictor of cardiovascular events at least as strong as low-density lipoprotein cholesterol and because of its association with the metabolic syndrome.”2 Because of the increased volume of testing and the recent surge in research focusing on cardiovascular disease risk and CRP, the American Heart Association and Centers for Disease Control and Prevention released a set of guidelines in the January 23, 2003, issue of Circulation.3 These guidelines cited high-sensitivity CRP as the only inflammatory marker that can be recommended for use as an independent cardiovascular disease risk factor. They also recommended the following cutoff points of serum CRP levels for determining a person’s risk of developing cardiovascular disease: below 1 mg/L is considered low risk, 1 to 3 mg/L is considered average risk, and above 3 mg/L is considered high risk. Despite this recent accumulating evidence, CRP is not mentioned in the JNC 7 guidelines as an independent cardiovascular risk factor.

Sorting out clinical

implications

Although JNC 7 is the source primarily referred to by American physicians, the ESH 2003 recommendations should also be viewed as an additional source that can provide an alternate approach to the classification, evaluation, and treatment of hypertensive patients. The highlights of the JNC 7 and ESH position statements are shown in tables 2 and 3.

Both sets of guidelines are limited because they provide advice for lifelong therapy, which, in middle-aged hypertensive patients, denotes a period ranging from 20 to 30 years. Current recommendations are based exclusively on evidence accumulated from trials that lasted only 3 to 5 years. Most trials were not effective in evaluating the long-term consequence of changes in intermediate end points, such as new-onset diabetes, microalbuminuria, and left ventricular hypertrophy.

Conclusion

Both the JNC 7 and ESH 2003 guidelines are excellent resources for clinicians to use for the identification, classification, and treatment of hypertensive patients. The comparatively progressive approach outlined in the ESH guidelines, how-ever, may be the nidus for a new paradigm. In this model, today’s physicians have a less prescriptive and a more flexible construct in which to treat their hypertensive patients.