SEVENTH JOINT NATIONAL COMMITTEE REPORT ON HIGH BLOOD PRESSURE EASIER TO READ AND IMPLEMENT THAN PREVIOUS DOCUMENTS
The Joint National Committee on the Prevention, Detection, Evaluation, and Treatment of High Blood Pressure in collaboration with the Coordinating Committee of the National High Blood Pressure Education Program recently released their seventh report (JNC 7). Presented in two separate publications, this first short version was generated to provide a succinct and practical guide to the current updated recommendations from the previous report last issued in 1977. A more comprehensive report will be published in the near future to provide a broader discussion of and justification for these current recommendations. Some initial comments about this report were presented in The JCH—Vol. 5, No. 3, pages 187–190.
The report reviewed all the available English‐language, peer‐reviewed scientific literature from January 1997 through April 2003. Recognizing that a physician's judgment remains paramount for the management of his or her patients, the document recommended the following:
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• A new classification scheme for the prevention and management of hypertension. “Normal” blood pressure is now defined as systolic blood pressure (SBP) <120 mm Hg and diastolic blood pressure (DBP) <80 mm Hg. This was previously considered optimal blood pressure. Persons with SBP of 120–139 mm Hg or DBP of 80–89 mm Hg should now be considered “prehypertensive.” Stage 1 hypertension remains SBP of 140–159 mm Hg or DBP of 90–99 mm Hg. Stage 2 hypertension remains SBP at or above 160 mm Hg or DBP at or above 100 mm Hg. There is no longer a stage 3 hypertension designation as in the previous document.
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• For persons older than age 50 years, SBP is a more important risk factor for cardiovascular disease (CVD) than DBP.
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• For persons aged 40 to 70 years, the risk of CVD begins at 115/75 mm Hg and doubles with each 20/10 mm Hg incremental increase up to 185/115 mm Hg.
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• Persons who are normotensive at age 55 years have a 90% lifetime risk for developing hypertension. Thiazide diuretics are recommended as initial therapy for most patients with uncomplicated hypertension, either alone or combined with drugs from other classes.
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• Certain high‐risk conditions are compelling indications for the initial use of other antihypertensive drug classes including angiotensin‐converting enzyme inhibitors, angiotensin‐receptor blockers, β blockers, or calcium channel blockers.
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• There are only two targets for blood pressure control. The minimum goal for blood pressure control is <140/90 mm Hg. In those with diabetes or chronic kidney disease, the goal is <130/80 mm.
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• Most persons with hypertension will require two or more antihypertensive medications to achieve blood pressure control. When the initial blood pressure is more than 20/10 mm Hg above goal, for example >160/100 mm Hg, practitioners should consider initiating therapy with two agents, one of which should be a thiazide‐type diuretic.
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• The most effective therapy prescribed by the most effective clinician will control hypertension only if the patient is motivated. The importance of the physician‐patient relationship builds trust and improves patient motivation and medication adherence.—The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure: The JNC 7 Report. JAMA. 2003;289:2560–2572.
Comment
Hypertension remains the most common primary office diagnosis in the United States with more than 35 million visits per year. More people today are aware of and are on therapy for their hypertension than in previous years, but control rates, which are improving, are still achieved in only one in three persons.
The new blood pressure classification system is somewhat controversial. A new category, prehypertension, replaces two former blood pressure categories used in JNC VI, normal blood pressure (SBP <130 mm Hg and DBP <85 mm Hg) and high normal blood pressure (SBP 130–139 mm Hg or DBP 85–89 mm Hg). Normal blood pressure is now considered SBP <120 mm Hg and DBP <80 mm Hg, and the term “optimal blood pressure” used in JNC VI has been abandoned. The term “prehypertension” has been coined because research findings suggest that 90% of persons who are prehypertensive (fall into this new category) at age 55 years will develop hypertension a decade later. In fact, adults at the upper end of the prehypertension blood pressure range (130/80–139/89 mm Hg) are twice as likely to progress to hypertension than those with lower blood pressure levels. Furthermore, many CVD events occur in the prehypertensive blood pressure group. Accordingly, this new term, analogous to the term “prediabetes,” tries to be action oriented in educating patients to understand that more healthful lifestyles, but not necessarily antihypertensive therapy, are recommended to keep them from becoming hypertensive. This has been done in an effort to be informative rather than to create undue anxiety.
The specific lifestyles identified as being critical for the prevention of high blood pressure include weight reduction in those persons who are overweight or obese, adoption of the Dietary Approaches to Stop Hypertension (DASH) diet, which is high in potassium and calcium and low in dietary fat, as well as a reduction in dietary sodium, increasing physical exercise, and limiting alcohol consumption. JNC 7 cites studies showing that adoption of these interventions, if followed rigorously, can reduce blood pressure as much as single‐drug therapy. For instance, a 10 kg loss in weight can produce a 5–20 mm Hg drop in SBP, while adopting the DASH diet could reduce SBP by 8–14 mm Hg. Combining two or more lifestyles may achieve even better results.
When pharmacologic therapy is necessary, thiazidetype diuretics are recommended as the treatment of choice for most persons with hypertension. This new focus on thiazide‐type diuretics for the initial treatment of Stage 1 hypertension derives from the recently published Antihypertensive and Lipid‐Lowering Treatment to Prevent Heart Attack Trial (ALLHAT), suggesting that diuretics are as or more effective than other single drug therapies in the treatment of hypertension. On the other hand, if the patient has a compelling indication for other antihypertensive therapy (heart failure, post‐myocardial infarction, high coronary disease risk, diabetes, chronic kidney disease, or recurrent stroke prevention), those evidence‐based agents should be used as needed. When blood pressure is at or above 160/100 mm Hg (20/10 mm Hg above the minimum target for blood pressure control), clinicians should consider initiating therapy with two agents, usually including a thiazide diuretic. This is a reemphasis of the JNC VI recommendation for the use of combination therapy as an initial strategy in an effort to improve the control of blood pressure. In certain situations, combinations such as an angiotensin converting enzyme inhibitor combined with a calcium channel blocker may be appropriate.
One area where this report differs from its predecessor is the removal of a comprehensive risk stratification tool. While trying to keep this document an easy guide for clinicians to use, JNC 7 places less emphasis on individual cardiovascular risk for a patient with hypertension. This is in contrast to the guidelines most recently issued by the European Society of Cardiology, and the previous guidelines of the World Health Organization/international Society of Hypertension (WHO/ISH). It is hoped that this will be added to the formal and larger document to be published in a subsequent publication.
Hypertension affects approximately 50 million US adults and the number is expected to grow as our population ages. Despite more than 30 years of guidelines and six previous JNC reports, hypertension remains poorly controlled. The importance of the physician‐patient relationship in fostering trust and improving patient motivation and medication adherence is of extreme importance for the overall improvement in blood pressure control. Physicians should read this document and follow its guidelines.
STATIN‐BASED THERAPY BENEFICIAL IN REDUCING CORONARY EVENTS IN THOSE WITH HYPERTENSION AND HYPERCHOLESTEROLEMIA
Hypertension and hypercholesterolemia are independent risk factors for the development of coronary heart disease (CHD) and when they occur together lead to an even greater CHD risk than when either risk factor occurs alone. Well‐designed clinical trials have not previously been performed to evaluate the benefits of lipid‐lowering therapy for the primary prevention of CHD in persons with both hypertension and elevated serum cholesterol.
The Anglo‐Scandinavian Cardiac Outcomes Trial (ASCOT) enrolled 19,342 patients with hypertension from 718 centers, including 686 general practices in Scandinavia, Iceland, Ireland, and the United Kingdom. To be eligible for this multicenter, international study, hypertensive men and women 40–79 years of age could not have any history of CHD and had to have at least three prespecified cardiovascular risk factors. Baseline blood pressure without antihypertensive medication had to be either a SBP of 160 mm Hg or greater and/or DBP of >100 mm Hg; or SBP >140 mm Hg and/or DBP 90 mm Hg on antihypertensive medication. Subjects were randomized to one of two open‐label antihypertensive regimens: either the calcium channel blocker amlodipine, with or without the angiotensin‐converting enzyme (ACE) inhibitor perindopril as needed, or a regimen consisting of the β blocker atenolol, with or without the thiazide‐diuretic bendrofluazide. The study's 2×2 factorial design included a lipid‐lowering arm (LLA) in which 10,305 of the hypertensive participants were randomized in a double‐blind manner to either 10 mg/d atorvastatin or placebo. Inclusion criteria for the LLA included a nonfasting total serum cholesterol level below 250 mg/dL and a fasting serum triglyceride level of no more than 400 mg/dL. Although the antihypertensive arm of the trial is still ongoing with the results not due to be reported before 2005, the results of the LLA of the trial were dramatic enough to warrant the study's early termination after a median of 3.3 years, sooner than the planned 5‐year follow‐up.
ASCOT‐LLA was a primary prevention trial designed to compare the effects of atorvastatin 10 mg vs. placebo on the combined primary outcome of nonfatal myocardial infarction (including silent myocardial infarction) and fatal CHD in patients with hypertension and total cholesterol levels of 250 mg/dL or less (those who would not normally have been treated for their lipid abnormalities). At baseline, mean age was 63 years, 81% were men, and 95% were white. The mean blood pressure was 164/95 mm Hg at baseline and 138/80 mm Hg on antihypertensive therapy. Lipid values on entry included total cholesterol of 213 mg/dL, low‐density lipoprotein cholesterol of 131 mg/dL, high‐density lipoprotein cholesterol of 50 mg/dL, and triglyceride level of 146 mg/dL. Risk factors (average number of 3.7) in addition to hypertension (100%) included age 55 years or older (84%), male gender (81%), microalbuminuria/proteinuria (62%), smoking (33%), family history of CHD (26%), type 2 diabetes (24%), left ventricular hypertrophy (14%), previous cerebrovascular event (10%), and peripheral vascular disease (5%). Based on an intention‐to‐treat analysis, the 5168 subjects who took atorvastatin had a 36% reduction in the primary end point compared with the 5137 subjects treated with placebo. In addition, those on active therapy had a 27% reduction in fatal and nonfatal stroke, a 21% reduction in total cardiovascular events including revascularization, and a 29% reduction in total coronary events. Atorvastatin subjects sustained a 19% reduction in total cholesterol, 29% reduction in low‐density lipoprotein cholesterol, and a 14% reduction in triglyceride level. The mean low‐density lipoprotein cholesterol at the conclusion of the trial was 87 mg/dL.
The number of noncardiovascular deaths was similar between the two treatment groups with no differences in the incidence of fatal cancers, serious adverse events, or liver function abnormalities.
Conclusions of This Study
Cardiovascular risk reduction should be based on an assessment of global risk and not on an arbitrary lipid cut point as presently endorsed by the National Cholesterol Education Program. Patients with hypertension who are at higher than average cardiovascular risk benefit from statin‐based lipid‐lowering therapy. Lipid‐lowering treatment thresholds in patients with hypertension need to be reduced.—Sever P, Dahlof B, Poulter NR, et al. for the ASCOT investigators. Prevention of coronary and stroke events with atorvastatin in hypertensive patients who have average or lower‐than‐average cholesterol concentrations, in the Anglo‐Scandinavian Cardiac Outcomes Trial‐Lipid Lowering Arm (ASCOT‐LLA): a multicentre randomized controlled trial. Lancet. 2003;361:1149–1158.
Comment
Up to 40% of hypertensive patients are also hypercholesterolemic. Although it has been observed in previous trials that reducing both blood pressure and lipids leads to an improvement in vascular outcome, the LLA of the ongoing ASCOT hypertension trial is the first large primary prevention clinical hypertension trial to show the benefit of cholesterol reduction. The group treated with a statin experienced a markedly improved outcome in all end points evaluated; hypertensive patients who achieved an average blood pressure of 138/80 mm Hg and a favorable reduction in low‐density lipoprotein cholesterol had a beneficial reduction in both CHD and stroke. This translated into 3.4 fewer nonfatal myocardial infarctions or CHD deaths and two fewer strokes per 1000 patient‐years of treatment. The reduction in both stroke and CHD incidence was seen within the first year of the trial suggesting an early benefit from both antihypertensive and statin‐based therapy.
Current lipid‐lowering guidelines are based on baseline low‐density lipoprotein cholesterol values. As in the Heart Protection Study, this study enrolled hypertensive patients with at least three additional risk factors. Benefit was noted regardless of baseline lipid values. This occurred even in those with low‐density lipoprotein cholesterol levels of <100 mg/dL on entry.
This study supports the initiation of statin‐based therapy in patients at high‐risk for vascular disease. The threshold for initiating statin‐based therapy needs to be readdressed.
GUIDELINES FOR HYPERTENSION MANAGEMENT IN AFRICAN AMERICANS
In an effort to improve blood pressure control in African Americans, a 16‐member working group writing for the International Society of Hypertension in Blacks issued first time guidelines suggesting an up‐to‐date approach to managing hypertension in this special population. Highlighting the well‐known greater likelihood for blood pressure elevation, as well as the poorer cardiovascular and renal outcomes in this population, the guidelines attempt to help physicians improve control rates in the African American with hypertension through improved lifestyle as well as drug therapy.
Lifestyle modification should include physical activity, cessation of smoking, and weight loss. The Dietary Approaches to Stop Hypertension (DASH) diet is especially beneficial for African Americans with hypertension. Including a diet rich in fruits, vegetables, and low‐fat dairy products that is also high in potassium and low in salt is recommended.
African Americans do not usually respond as well to monotherapeutic agents that block the renin‐angiotensin system (RAS) as to either thiazide‐type diuretics or calcium channel blockers. Drugs that block the RAS, including angiotensinconverting enzyme (ACE) inhibitor, angiotensin receptor blocker (ARB), and β‐blocker therapy, combined with a thiazide‐type diuretic, or combining an ACE inhibitor with a calcium channel blocker will be more effective in African‐American patients.
When patients have more than a 15/10 mm Hg elevation in blood pressure above their targeted goal, 140/90 mm Hg in those with uncomplicated hypertension, and 130/80 mm Hg in patients with diabetes or renal disease, the guidelines suggest that initial treatment with dual‐drug combination therapy is recommended. Additional combinations include a β blocker and diuretic.—Douglas JG, Bakris GL, Epstein M, et al. Management of high blood pressure in African Americans: consensus statement of the Hypertension in African American Working Group of the International Society on Hypertension in Blacks. Arch Intern Med. 2003;163:525–541.
Comment
The current guidelines are an initial attempt by the leaders of the ISHIB (International Society on Hypertension in Blacks) to improve outcomes for African Americans with hypertension. This consensus opinion from 16 leaders within the hypertension community recommends combination therapy as first‐line therapy to more effectively control blood pressure in this population. As noted within the Joint National Committee's Seventh Report on the Prevention, Detection, Evaluation, and Treatment (JNC 7) guidelines, most practitioners fail to up‐titrate the dose of medication or use additional drug therapy as necessary to control blood pressure. Although this recommendation can be broadened to all patients with hypertension, those within the African‐American community may benefit significantly from this more aggressive approach to management.
The guidelines emphasize that African‐American patients respond well to ACE inhibitor, ARB, and β blocker therapy when these drugs are used in combination with a thiazide diuretic. Nevertheless, when a compelling indication exists for an RAS blocker, they should be used to improve outcome.
These guidelines reflect an approach to the treatment of hypertension for all of our patients, and are in agreement with the current JNC 7 recommendations. Hopefully following these guidelines will improve the control of blood pressure in African Americans as well as all patients with hypertension.