Latest Hypertension Treatment Guidelines: A JNC 7 Synopsis
Latest Hypertension Treatment Guidelines: A JNC 7 Synopsis
Persons with a systolic blood pressure (BP) of 120 to 139 mm Hg or a diastolic BP of 80 to 89 mm Hg are now considered prehypertensive, according to the latest Joint National Committee (JNC) report on hypertension.1 Another key change to the previous JNC report: thiazide diuretics are now recommended as first-line treatment.
The National Heart, Lung, and Blood Institute decided to update the Sixth Report of the Joint National Committee on the Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC VI), published in 1997, in part because of the many new observational and clinical trials in the area of hypertension and in part because of the awareness that the JNC reports have not been used to their maximum benefit. The updated report-which offers a simplified classification of BP-aims to provide a clear and concise guideline for physicians as they seek to prevent and manage a growing epidemic.Highlightedhere are the principal changes from the JNC VI report.
A NEW URGENCY FOR TREATMENT
Key messages of the new report include the following:
The JNC 7 defines "normal" BP as below 120/80 mm Hg.
Persons with a systolic BP of 120 to 139 mm Hg or a diastolic BP of 80 to 89 mm Hg are at increased risk for progression to hypertension. Those whose BP is 130/80 to 139/89 mm Hg are twice as likely to progress to hypertension as those with lower values.
For hypertensive patients with diabetes or renal disease, the BP goal is less than 130/80 mm Hg.
The prehypertension classification serves to acknowledge the relationship between hypertension and risk of cardiovascular disease.
As the population ages, the prevalence of hypertension will continue to increase. Persons who are normotensive at age 55 have a 90% lifetime risk of hypertension. In persons older than 50 years, systolic BP higher than 140 mm Hg is a much more important risk factor for cardiovascular disease than elevated diastolic BP. In addition, the risk of cardiovascular disease in persons who are between the ages of 40 and 70 doubles with each increment of 20/10 mm Hg.
BP reduction is associated with a mean decreased incidence of 35% to 40% in stroke, 20% to 25% in myocardial infarction (MI), and more than 50% in heart failure.
Lifestyle modification. A healthy lifestyle is crucial for the prevention of high BP; it is also a key component of hypertension management (Algorithm). Lifestyle modifications decrease BP, enhance antihypertensive drug efficacy, and lower cardiovascular risk. Measures include:
Pharmacologic therapy. Results of a number of trials demonstrate that thiazide diuretics are unsurpassed in preventing the cardiovascular complications of hypertension. They enhance the efficacy of multidrug regimens and are less expensive than newer agents. Nevertheless, diuretics remain underused. These agents should be prescribed as initial therapy for most patients with hypertension, either alone or in combination with other medications.
Most patients require 2 or more antihypertensive medications to achieve BP control. If a single drug in adequate doses is ineffective, add a second drug from another class. When BP is more than 20/10 mm Hg higher than the target level, consider initiating therapy with 2 drugs, either as separate prescriptions or fixed-dose combinations. Caution is advised for patients at risk for orthostatic hypotension, such as those with diabetes or autonomic dysfunction.
Have patients return monthly for follow-up and adjustment of therapy until the BP goal is reached. More frequent visits are required for patients with stage 2 hypertension (systolic BP of 160 mm Hg or higher; diastolic BP of 100 mm Hg or higher) or with complicating comorbid conditions. Measure serum potassium and creatinine once or twice a year. Once target BP is stable, have patients return at 3- to 6-month intervals. Low-dose aspirin therapy is appropriate only in patients whose BP is controlled, because of the increased risk of hemorrhagic stroke in those with uncontrolled hypertension.
Compelling indications. High-risk conditions that require treatment with specific antihypertensive drug classes are listed in Table 1. Consultation with a specialist is often warranted.
Ischemic heart disease. This is the most common form of target-organ damage associated with hypertension. First-line therapy for hypertensive patients with stable angina pectoris is usually a β-blocker. Calcium channel blockers may also be used. In patients with acute coronary syndromes (unstable angina or MI), hypertension is treated initially with a β-blocker and an angiotensin-converting enzyme (ACE) inhibitor. Other drugs are added as needed for BP control. ACE inhibitors, β-blockers, and aldosterone antagonists are most effective for patients following MI, along with intensive lipid management and aspirin therapy.
Heart failure. Systolic or diastolic ventricular dysfunction results primarily from systolic hypertension and ischemic heart disease. Tight BP and cholesterol control are the principal preventive measures for patients at high risk for heart failure. ACE inhibitors and β-blockers are recommended for asymptomatic patients with demonstrable ventricular dysfunction. For those with symptomatic ventricular dysfunction or end-stage heart disease, suggested agents include ACE inhibitors, β-blockers, angiotensin-receptor blockers (ARBs), aldosterone blockers, and loop diuretics.
Diabetic hypertension. Patients with diabetes usually require 2 or more agents to attain the target BP goal of less than 130/80 mm Hg. Thiazide diuretics, β-blockers, ACE inhibitors, ARBs, and calcium channel blockers reduce the incidence of cardiovascular disease and stroke in these patients. Regimens based on ACE inhibitors or ARBs slow the progression of diabetic nephropathy and reduce albuminuria. ARBs also slow the progression to macroalbuminuria.
Chronic kidney disease. Therapeutic goals are to slow deterioration of renal function and prevent cardiovascular disease. Most patients with kidney disease have hypertension and should be treated aggressively-with 3 or more drugs, if needed-to achieve a target BP level of less than 130/80 mm Hg.
ACE inhibitors and ARBs are effective for patients with diabetic and nondiabetic renal disease. Increasing doses of loop diuretics are usually needed in combination with other agents for patients with advanced renal disease.
Cerebrovascular disease. The risks and benefits of aggressive lowering of BP during an acute stroke are unclear. Control of BP at intermediate levels (about 160/110 mm Hg) is appropriate until the patient's condition has stabilized or improved. The combination of an ACE inhibitor and a thiazide diuretic reduces the rate of recurrent stroke.
Left ventricular hypertrophy. This independent risk factor increases the risk of cardiovascular disease. Regression of left ventricular hypertrophy can be achieved with aggressive BP control, including weight loss, sodium restriction, and treatment with antihypertensive agents (except hydralazine and minoxidil).
Peripheral arterial disease. This condition carries the same risk as ischemic heart disease and may be treated with any class of antihypertensives. Aspirin therapy and aggressive monitoring of other risk factors are indicated.
Obesity and the metabolic syndrome. Obesity (body mass index of 30 or more) is an increasingly prevalent risk factor for hypertension and cardiovascular disease. The metabolic syndrome is defined as the presence of 3 or more of the following conditions:
Abdominal obesity (waist circumference of more than 102 cm [40 in] in men and 89 cm [35 in] in women).
Glucose intolerance (fasting glucose level of 110 mg/dL or more).
BP of at least 130/85 mm Hg.
High triglyceride levels (more than 150 mg/dL) or low high-density lipoprotein cholesterol levels (lower than than 40 mg/dL in men and 50 mg/dL in women).
Intensive lifestyle modification is indicated for persons with the metabolic syndrome, along with appropriate drug therapy for each of its components as indicated.
Dementia. Dementia and cognitive impairment are common in patients with hypertension. Progression of cognitive impairment may be slowed with effective antihypertensive therapy.
Minority populations. Socioeconomic and lifestyle factors may be significant obstacles to BP control in some groups. BP control rates are lowest in Mexican Americans and Native Americans. The prevalence, severity, and impact of hypertension are elevated in African Americans. In these patients, monotherapy with β-blockers, ACE inhibitors, or ARBs is somewhat less effective than treatment with diuretics or calcium channel blockers. Effective therapy can be achieved with combination therapy that includes adequate doses of a diuretic. ACE inhibitor-induced angioedema occurs 2 to 4 times more frequently in hypertensive African Americans than in other groups.
IMPROVING BP CONTROL
Adherence. Even the best antihypertensive regimens will be effective only if patients are motivated to take their medication as prescribed and maintain healthy lifestyles. Motivation improves when patients have good relationships with and trust their physicians. Such factors as cultural differences, beliefs, and previous experiences with the health care system greatly affect patients' attitudes. Physician empathy and understanding foster trust and communication.
The patient and clinician must agree on BP goals. A patient-centered strategy and an estimate of time needed to reach the goal are important.
The risk of nonadherence to therapy may be increased by a patient's lack of understanding of the condition or treatment, denial of illness, lack of involvement in the care plan, or unanticipated side effects from medication. Encourage patients to discuss their concerns about medication side effects.
Decision support systems, feedback reminders, and the involvement of nurse clinicians and pharmacists can be helpful. All members of the health care team must work together to reinforce patient adherence to the treatment plan.
Resistant hypertension. The reasons for failure to reach goal BP (Table 2) must be carefully explored in patients who are adhering to full doses of an appropriate 3-drug regimen that includes a diuretic. Pay particular attention to diuretic type and dosage in relation to renal function. Consultation with a hypertension specialist may be indicated if goal BP cannot be achieved.
1. Chobanian AV, Bakris GL, Black HR, et al, and the National High Blood Pressure Education Program Coordinating Committee. 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.