Hypertension affects
approximately 75 million adults in the United States and is a major risk factor
for stroke, myocardial infarction, vascular disease, and chronic kidney
disease.
Essential update: Increased long-term stroke risk in
hypertensive patients with retinopathy
In a recent report of
2907 adults with hypertension participating in the Atherosclerosis Risk in
Communities (ARIC) study, hypertensive retinopathy was associated with an
increased long-term risk of stroke, independent of vascular risk factors.
Of the 2907 patients,
1406 (48.4%) had no retinopathy, 1354 (46.6%) had mild retinopathy, and 146
(5.0%) had moderate retinopathy. The one patient with severe hypertensive
retinopathy was included in the moderate hypertensive retinopathy group (5.1%).
After an average follow-up of 13 years, there were 165 incident strokes,
including 146 cerebral infarctions. Increasing severity of hypertensive
retinopathy was associated with an increased risk of stroke. The stroke risk
was 1.35 (95% confidence interval, 0.96-1.89) in the mild retinopathy group and
2.37 (1.39-4.02) in the moderate/severe group. Corresponding figures for
cerebral infarction were 1.52 (1.06-2.19) and 2.01 (1.10-3.70).
Signs and symptoms
Hypertension is
defined as a systolic blood pressure (SBP) of 140 mm Hg or more, or a diastolic
blood pressure (DBP) of 90 mm Hg or more, or taking antihypertensive medication
Based on
recommendations of the Seventh Report of the Joint National Committee on
Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC7),
the classification of BP for adults aged 18 years or older is as follows
·
Normal: Systolic lower
than 120 mm Hg, diastolic lower than 80 mm Hg
·
Prehypertension:
Systolic 120-139 mm Hg, diastolic 80-89 mm Hg
·
Stage 1: Systolic
140-159 mm Hg, diastolic 90-99 mm Hg
·
Stage 2: Systolic 160
mm Hg or greater, diastolic 100 mm Hg or greater
Hypertension may be
primary, which may develop as a result of environmental or genetic causes, or
secondary, which has multiple etiologies, including renal, vascular, and
endocrine causes. Primary or essential hypertension accounts for 90-95% of
adult cases, and secondary hypertension accounts for 2-10% of cases.
Diagnosis
The evaluation of
hypertension involves accurately measuring the patient’s blood pressure,
performing a focused medical history and physical examination, and obtaining
results of routine laboratory studies A
12-lead electrocardiogram should also be obtained. These steps can help
determine the following
·
Presence of end-organ
disease
·
Possible causes of
hypertension
·
Cardiovascular risk
factors
·
Baseline values for
judging biochemical effects of therapy
Other studies may be
obtained on the basis of clinical findings or in individuals with suspected
secondary hypertension and/or evidence of target-organ disease, such as CBC,
chest radiograph, uric acid, and urine microalbumin.
Management
Many guidelines exist
for the management of hypertension. Most groups, including the JNC, the
American Diabetes Associate (ADA), and the American Heart Association/American
Stroke Association (AHA/ASA) recommend lifestyle modification as the first step
in managing hypertension.
Lifestyle
modifications
JNC7 recommendations
to lower BP and decrease cardiovascular disease risk include the following,
with greater results achieved when 2 or more lifestyle modifications are
combined
·
Weight loss (range of
approximate systolic BP reduction [SBP], 5-20 mm Hg per 10 kg)
·
Limit alcohol intake
to no more than 1 oz (30 mL) of ethanol per day for men or 0.5 oz (15 mL) of
ethanol per day for women and people of lighter weight (range of approximate
SBP reduction, 2-4 mm Hg)
·
Reduce sodium intake
to no more than 100 mmol/day (2.4 g sodium or 6 g sodium chloride; range of
approximate SBP reduction, 2-8 mm Hg)
·
Maintain adequate
intake of dietary potassium (approximately 90 mmol/day)
·
Maintain adequate
intake of dietary calcium and magnesium for general health
·
Stop smoking and
reduce intake of dietary saturated fat and cholesterol for overall cardiovascular
health
·
Engage in aerobic
exercise at least 30 minutes daily for most days (range of approximate SBP
reduction, 4-9 mm Hg)
The AHA/ASA recommends
a diet that is low in sodium, is high in potassium, and promotes the
consumption of fruits, vegetables, and low-fat dairy products for reducing BP
and lowering the risk of stroke. Other recommendations include increasing
physical activity (30 minutes or more of moderate intensity activity on a daily
basis) and losing weight (for overweight and obese persons).
The 2013 European
Society of Hypertension (ESH) and the European Society of Cardiology (ESC)
guidelines recommend a low-sodium diet (limited to 5 to 6 g per day) as well as
reducing body-mass index (BMI) to 25 kg/m2 and waist
circumference (to < 102 cm in men and < 88 cm in women).
Pharmacologic
therapy
If lifestyle
modifications are insufficient to achieve the goal BP, there are several drug
options for treating and managing hypertension. Thiazide diuretics are the
preferred agents in the absence of compelling indications.
Compelling indications
may include high-risk conditions such as heart failure, ischemic heart disease,
chronic kidney disease, and recurrent stroke, or those conditions commonly
associated with hypertension, including diabetes and high coronary disease
risk. Drug intolerability or contraindications may also be factors. An angiotensin-converting enzyme (ACE)
inhibitor, angiotensin receptor blocker (ARB), calcium channel blocker (CCB),
and beta-blocker are all acceptable alternative agents in such compelling
cases.
The following are drug
class recommendations for compelling indications based on various clinical
trials
·
Heart failure:
Diuretic, beta-blocker, ACE inhibitor, ARB, aldosterone antagonist
·
Postmyocardial
infarction: Beta-blocker, ACE inhibitor, aldosterone antagonist
·
High coronary disease
risk: Diuretic, beta-blocker, ACE inhibitor, CCB
·
Diabetes: Diuretic,
beta-blocker, ACE inhibitor, ARB, CCB
·
Chronic kidney
disease: ACE inhibitor, ARB
·
Recurrent stroke
prevention: Diuretic, ACE inhibitor
