Hypertension treatment and management

RATIONALISING HYPERTENSION

Many guidelines exist for the management of hypertension. Two of the most widely used recommendations are those from the American Diabetes Association (ADA) and the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7). The Eighth Report of the JNC (JNC 8) was released in December 2013.^{[10, 11]}

2013 updated JNC 8 guidelines

Two key recommendations in the JNC 8 guidelines that differ from the JNC 7 guidelines are (1) less aggressive targeting of blood pressures (BPs) and treatment-initiation thresholds for elderly patients and for those younger than age 60 years with diabetes and kidney disease and (2) no longer recommending only thiazide-type diuretics as the initial therapy in most patients (angiotensin-converting enzyme [ACE] inhibitors, angiotensin receptor blockers [ARBs], calcium channel blockers [CCBs], or diuretics are recommended).

The JNC 8 recommendations include the following

• In patients aged 60 years or older, initiate therapy in those with systolic BP levels at 150 mm Hg or greater or whose diastolic BP levels are 90 mm Hg or greater; treat to below those thresholds
• In patients younger than 60 years as well as those older than 18 years with either chronic kidney disease (CKD) or diabetes, the BP treatment initiation and goals should be 140/90 mm Hg
• In non black hypertensive patients, begin treatment with either a thiazide-type diuretic, CCB, ACE inhibitor, or ARB
• In hypertensive black patients, initiate therapy with a thiazide-type diuretic or CCB
• Regardless of race or diabetes status, in patients 18 years or older with CKD, initial or add-on therapy should consist of an ACE inhibitor or ARB
• Do not use an ACE inhibitor in conjunction with an ARB in the same patient
• If a patient's goal BP is not achieved within 1 month of treatment, increase the dose of the initial agent or add an agent from another of the recommended drug classes; if 2-drug therapy is unsuccessful for reaching the target BP, add a third agent from the recommended drug classes
• In patients whose goal BP cannot be reached with 3 agents from the recommended drug classes, use agents from other drug classes and/or refer the patients to a hypertension specialist

Collaborative AHA/ACC/CDC advisory recommendations

A science advisory on the treatment of hypertension, issued in November 2013 via a collaborative effort by the American Heart Association (AHA), the American College of Cardiology (ACC), and the Centers for Disease Control and Prevention (CDC), describes criteria for successful hypertension management algorithms and advocates the creation of algorithms that can be incorporated into a system-level approach to high BP, as well as modified to accommodate different practice settings and patient populations.^{[58, 59]}

A joint AHA/ACC/CDC algorithm in the report includes the following recommendations^{[58, 59]} :

• BP: Recommended goal of 139/89 mm Hg or less
• Stage 1 hypertension (systolic BP 140-159 mm Hg or diastolic BP 90-99 mm Hg): Can be treated with lifestyle modifications and, if needed, a thiazide diuretic
• Stage 2 hypertension (systolic BP >160 mm Hg or diastolic BP >100 mm Hg): Can be treated with a combination of a thiazide diuretic and an ACE inhibitor, an angiotensin receptor blocker, or a calcium channel blocker
• Patients who fail to achieve BP goals: Medication doses can be increased and/or a drug from a different class can be added to treatment

Joint ESH and ESC guidelines

In June 2013, the European Society of Hypertension (ESH) and the European Society of Cardiology (ESC) released new guidelines for the management of hypertension, recommending that all patients, except special populations such as patients with diabetes and the elderly, be treated to below 140 mm Hg systolic BP.^{[8, 9]} The guidelines advise that physicians should make decisions on treatment strategies based on the patient's overall level of cardiovascular risk.

Recommendations of the new ESH and ESC guidelines include^{[8, 9]} :

• In patients younger than 80 years, the systolic BP target should be 140 to 150 mm Hg, but physicians can go lower than 140 mm Hg if the patient is fit and healthy; the same advice applies to octogenarians—however, the patient's mental capacity and physical heath should also be considered if targeting to less than 140 mm Hg
• Patients with diabetes should be treated to below 85 mm Hg diastolic BP
• Salt intake should be limited to approximately 5 to 6 g per day
• Body-mass index (BMI) should be reduced to 25 kg/m² and waist circumferences should be reduced to less than 102 cm in men and less than 88 cm in women
• Ambulatory BP monitoring (ABPM) should be incorporated into the assessment of risk
• Effective combination therapies include thiazide diuretics with ARBs, calcium-channel antagonists, or ACE inhibitors; or, calcium-channel antagonists with ARBs or ACE inhibitors
• Dual renin-angiotensin system blockade (ie, ARBs, ACE inhibitors, and direct renin inhibitors) is not recommended because of the risks of hyperkalemia, low BP, and kidney failure
• Although additional data is needed, renal denervation is a promising therapy in the treatment of resistant hypertension

ADA 2011 standard of medical care

The ADA 2011 standard of medical care states that in individuals with diabetes and mild hypertension, it may be reasonable to begin treatment with a trial of nonpharmacologic therapy (diet, exercise, and other lifestyle modifications.) Mild hypertension as defined by the ADA guideline (systolic BP 130-139 mm Hg or diastolic BP 80-89 mm Hg) may be classified as prehypertension by other organizations.^[60]

The ADA 2011 standards of medical care in diabetes also indicate that a majority of patients with diabetes mellitus have hypertension. In patients with type 1 diabetes, nephropathy is often the cause of hypertension, whereas in type 2 diabetes, hypertension is one of a group of related cardiometabolic factors.^{[60, 61]}Hypertension remains one of the most common causes of congestive heart failure (CHF). Antihypertensive therapy has been demonstrated to significantly reduce the risk of death from stroke and coronary artery disease.

Other studies have demonstrated that a reduction in BP may result in improved renal function. Therefore, earlier detection of hypertensive nephrosclerosis (using means to detect microalbuminuria) and aggressive therapeutic interventions (particularly with ACE inhibitor drugs) may prevent progression to end-stage renal disease.^[13]

JNC 7

Key messages of the JNC 7 were as follows^[4] :

• The goals of antihypertensive therapy is the reduction of cardiovascular and renal morbidity and mortality, with the focus on controlling the systolic BP, as most patients will achieve diastolic BP control when the systolic BP is achieved
• Prehypertension (systolic 120-139 mm Hg, diastolic 80-89 mm Hg) requires health-promoting lifestyle modifications to prevent the progressive rise in BP and cardiovascular disease
• In uncomplicated hypertension, a thiazide diuretic, either alone or combined with drugs from other classes, should be used for the pharmacologic treatment of most cases
• In specific high-risk conditions, there are compelling indications for the use of other antihypertensive drug classes (eg, angiotensin-converting enzyme [ACE] inhibitors, angiotensin receptor blockers [ARBs], beta blockers, calcium channel blockers)
• Two or more antihypertensive medications will be required to achieve goal BP (< 140/90 mm Hg or < 130/80 mm Hg) for patients with diabetes and chronic kidney disease
• For patients whose BP is more than 20 mm Hg above the systolic BP goal or more than 10 mm Hg above the diastolic BP goal, initiation of therapy using 2 agents, one of which usually will be a thiazide diuretic, should be considered
• Regardless of therapy or care, hypertension will be controlled only if patients are motivated to stay on their treatment plan

Lifestyle modifications

Lifestyle modifications are essential for the prevention of high BP, and these are generally the initial steps in managing hypertension. As the cardiovascular disease risk factors are assessed in individuals with hypertension, pay attention to the lifestyles that favorably affect BP level and reduce overall cardiovascular disease risk. A relatively small reduction in BP may affect the incidence of cardiovascular disease on a population basis. A decrease in BP of 2 mm Hg reduces the risk of stroke by 15% and the risk of coronary artery disease by 6% in a given population. In addition, a prospective study showed a reduction of 5 mm Hg in the nocturnal mean BP and a possibly significant (17%) reduction in future adverse cardiovascular events if at least one antihypertensive medication is taken at bedtime.

Surgical intervention

Aortorenal bypass using a saphenous vein graft or a hypogastric artery is a revascularization technique for renovascular hypertension that has become much less common since the advent of renal artery angioplasty with stenting. Surgical resection is the treatment of choice for pheochromocytoma and for patients with a unilateral solitary aldosterone-producing adenoma, because hypertension is cured by tumor resection. In patients with fibromuscular renal disease, angioplasty has a 60-80% success rate for improvement or cure of hypertension. A promising therapy for resistant hypertension is renal denervation via a percutaneous approach. This catheter-based intervention is currently in the clinical trial phase.

Consultations

Consultations with a nutritionist and exercise specialist are often helpful in changing lifestyle and initiating weight loss. Consultations with an appropriate consultant are indicated for management of secondary hypertension attributable to a specific cause.