Hypertension 2001: How Will JNC VII be Different From JNC VI?

BEGINNING IN 1977 and occurring every 4 years since then, the Joint National Committee INC) has published a consensus document for the clinician caring for patients with high blood pressure. Originally scheduled to be published in 2001, the National Heart, Lung, and Blood Institute suspended organization of the 7th JNC report until the results of the Antihypertensive and Lipid Lowering Treatment to Prevent Heart Attack (ALLHAT) Trial is concluded in 2002. [1] This paper will highlight some of the recent advances that have occurred since the Sixth Report of the JNC on the Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC VI) published in 1997. [2]

The most recent NHANES III [3] data reveals that only 27% of adults are controlled at [less than]140/90 mm Hg. Almost 50% of the 42 million hypertensive patients ([greater than]140/90 mm Hg) are either unaware (13 million) or are aware and untreated (7 million). Of those treated, 58% are uncontrolled. Of those uncontrolled, 73% have systolic blood pressure (BP) between 140 and 160 mm Hg with diastolic BP [less than]90 mm Hg. Dispelling some of the recent stereotypes of those patients in the uncontrolled group, most of the patients had health insurance, averaged 4.3 visits to a physician over the past year, were approximately 60 years of age, and were as likely to be non-Hispanic whites as being black or Mexican-American. This suggests that more needs to be done to control hypertension in all demographic groups, since patients have access to the physician and actually see their physician for their health care, yet blood pressure still remains uncontrolled.

The importance of non-adherence with antihypertensive therapy as a barrier to more effective blood pressure control will be highlighted. Approximately 50% of patients discontinue their antihypertensive agent within the first year of therapy and of those remaining on treatment, more than one-half take less than 80% of the medication prescribed. A recent VA study [1] in over 800 hypertensive men where blood pressure was measured at least 6 times in a year showed increases in therapy in only 7% of visits when blood pressure was [greater than]140/90 mm Hg. This emphasizes the importance of up-titrating the dose of drug therapy in order to "get-to-goal."

Life-style modification will continue to be emphasized. The Dietary Approaches to Stop Hypertension (DASH)-sodium trial established the importance of encouraging a diet low in salt and high in fruits, vegetables, and low-fat dairy products. [5] Although pulse pressure (systolic blood pressure/diastolic blood pressure) is a stronger predictor of vascular risk, [6] a systolic blood pressure (SBP) goal of [less than]140 mm Hg will be recommended for SBP control. [7]

Diuretics and [beta]-blockers will continue to be recommended as first-line therapy for the treatment of uncomplicated hypertension but JNC VII will consider angiotension-converting enzyme (ACE) inhibitors worthy of this recommendation. [8,9] In those with isolated systolic hypertension, who remain at increased risk of stroke, the initial use of calcium-channel blocker (CCB) therapy continues to be supported by trial-based evidence. [10] For the diabetic, where two or more drugs are sometimes needed to achieve the [less than]130 mm Hg systolic blood pressure goal, ACE inhibitor or Angiotensin Receptor Blocker (ARB) with or without a diuretic, and additive CCB and [beta]-blocker treatment will be recommended.

The initial use of selective [[alpha].sub.1]-blocker therapy will be discouraged. [11] In those at high risk for myocardial infarction or congestive heart failure, CCB therapy will be recommended with caution [12,13] while an ACE inhibitor, as in the HOPE study, will be used in those with a history of cerebral vascular, peripheral vascular, or cardiovascular disease who are at high risk for these events. [14]

ARBs reduce proteinuria and BP to a similar degree as ACE inhibitors but do not have the published trial-based evidence supporting ACE inhibitors. [14,15] While awaiting outcome data presented at the American Society of Hypertension meeting in May 2001 to be published, because of superior tolerability, ARBs will often be used instead of an ACE inhibitor, especially in those with an ACE-induced cough.

A diuretic should be included in most regimens to enhance the efficacy of other blood pressure lowering agents [16]; however, the serum potassium level should remain [greater than] 3.5 mEq/L to achieve a favorable outcome when diuretics are used. [17]

As most patients require more than one medication to achieve target levels of BP control, the first agent chosen will assume less importance. Combination therapy, as initial therapy, may allow better BP control and adherence to therapy. A baby aspirin should be added to the antihypertensive regimen as it has been shown to improve cardiovascular outcome over that expected with effective BP control. [18].

From the Department of Primary Care, Ralph H. Johnson VA Medical Center, and the Department of Medicine, Division of General Internal Medicine/Geriatrics, Medical University of South Carolina, Charleston.

References

(1.) Grimm RH, Margolis KL, Papademetriou VV, et al, for the ALLHAT collaborative Research Group: Baseline characteristics of participants in the Antihypertensive and Lipid Lowering Treatment to Prevent Heart Attack Trial (ALL-HAT). Hypertension 2001; 37:19-27

(2.) The Sixth Report of the Joint National committee on prevention, detection, evaluation, and treatment of high blood pressure. Arch Intern Med 1997; 157:2413-2446

(3.) Hyman D, Pavlik V: Characteisttics of patients with uncontrolled hypertension in the United States. N Engl J Med 2001; 345:479486

(4.) Berlowitz DR, Ash AS, Hickey EC, et al: Inadequate management of blood pressure in a hypertensive population. N Engl J Med 1998; 339:1957-1963

(5.) Sacks FM, Svetkey LP, Vollmer WM, et al: Effects on blood pressure of reduced dietary sodium and the Dietary Approaches To Stop Hypertension (DASH) diet. N Engi J Med 2001; 344:3-10

(6.) Franklin SS, Khan SA, Wong ND, et al: Is pulse pressure useful in predicting risk for coronary heart disease? The Framingham Heart Study. Circulation 1999; 100:354-360

(7.) Izzo J, Levy D, Black HR: Importance of systolic blood pressure in older Americans. Hypertension 2000; 35:1021-1024

(8.) Hansson L, Lindholm LH, Niskanen L, et al, for the Captopril Prevention Project (CAPPP) study group: Effect of angiotensin-converting-enzyme inhibition compared with conventional therapy on cardiovascular morbidity and mortality in hypertension. Lancet 1999; 353:611-616

(9.) Hansson L, Lindholm LH, Ekbom T, et al, for the STOP-Hypertension-2 study group: Randomized trial of old and new antihypertensive drugs in elderly patients: cardiovascular mortality and morbidity in the Swedish Trial in Old Patients with Hypertension-2 (STOP-2) study. Lancet 1999; 354:1751-1756

(10.) Staessen JA, Fagard R, Thijs L, et al: Randomised doubleblind comparison of placebo and active treatment for older patients with isolated systolic hypertension. the Systolic Hypertension in Europe (Syst-Eur) trial investigators. Lancet 1997; 350:757-764

(11.) The ALLHAT Officers and coordinators for the ALLHAT Collaborative Research Group: Major cardiovascular events in hypertensive patients randomized to doxazosin vs chiorthalidone. the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT). JAMA 2000; 283:1967-1975

(12.) Pahor M, Psaty BM, Alderman MH, et al: Health outcomes associated with calcium antagonists compared with other first-line antihypertensive therapies: a meta-analysis of randomised controlled trials. Lancet 2000; 356:1949-1954

(13.) Effects of ACE inhibitors, calcium antagonists, and other blood-pressure-lowering drugs: results of prospectively designed overviews of randomised trials. Blood Pressure Lowering Treatment Trialists' Collaboration. Lancet 2000; 355:1955-1964

(14.) The Heart Outcomes Prevention Evaluation Study Investigators: Effects of an ACE inhibitor (ramipril) on cardiovascular events in high risk patients. N Engl J med 2000; 342:145-153

(15.) Mogensen CE, Neldam 5, Tikkanen I, et al, for the CALM study group: Randomised controlled trial of dual blockade of renin-angiotensin system in patients with hypertension, microalbuminuria, and non-insulin dependent diabetes: the Candesartan And Lisinopril Microalbuminuria (CALM) study. BMJ 2000; 321:1440-1444

(16.) Klungel OH, Heckbert SR. Longstreth wTJr, et al: Antihypertensive drug therapies and the risk of ischemic stroke. Arch Intern Med 2001; 161:37-43

(17.) Franse LV, Pahor M, DiBari M, et al: Hypokalemia associated with diuretic use and cardiovascular events in the Systolic Hypertension in the Elderly program. Hypertension 2000; 35:1025-1030

(18.) Hansson L, Zanchetti A, Carruthers SG, et al: Effects of intensive blood-pressure lowering and low-dose aspirin in patients with hypertension: principal results of the Hypertension Optimal Treatment (HOT) randomized trial. Lancet 1998; 351:1755-1762