Hypertension

Hypertension, better known as high blood pressure, is defined as a chronic elevation in systolic blood pressure to greater than 140 millimeters of mercury (mm Hg) or a diastolic blood pressure greater than 90 mm Hg. At the turn of the century, nearly one billion people had hypertension worldwide which is more than 25% of the adult population. By 2025, an estimated 1.56 billion people world-wide will have high blood pressure (1). There is approximately a 90% lifetime risk of developing hypertension.

Over 90% of hypertension is classified as primary hypertension, which is sometimes called essential hypertension. This describes hypertension where no cause can be identified.

Secondary hypertension, a much less common diagnosis, accounts for less than 10% of the cases of hypertension. This is high blood pressure from another disease process. Some examples of disease that cause secondary hypertension include: narrowing of the arteries going to the kidney, narrowing of the aorta, thyroid disease and sleep apnea.

Secondary hypertension is uncommon and not usually worked up for extensively unless your doctor strongly suspects a secondary cause to your high blood pressure. High blood pressure in a young individual, physical exam findings suggestive of a secondary cause of hypertension, drug resistant hypertension, severe hypertension, or previously well-controlled blood pressure would be reasons to look for a secondary cause of hypertension.

The top – or systolic number – is more likely to be elevated in the patient over the age of 60. The systolic reading is a greater risk factor for cardiovascular disease than the bottom or diastolic number. Treatment of isolated systolic hypertension decreases death rates, cardiovascular complications and stroke (2).






Readings

According to the Seventh Report of the Joint National Committee on Detection, Education and Treatment of High Blood Pressure (JVC VII) (3) normal blood pressure is less than 120/80 mmHg. When readings are 120-139/80-89 mmHg, one is considered to be pre-hypertensive. Readings between 159-140/90-99 mm Hg define stage I hypertension and readings greater than 160/100 mm Hg are considered to be stage II hypertension.





Goals

Optimal blood pressure is a reading less than 120/80 mm Hg. While this is a measurable goal, the ultimate goal of blood pressure control is to prevent damage to the organs and death. This includes preventing heart problems such as heart failure, increased size of the heart and heart attack. Other goals are to prevent stroke, kidney failure, eye disease and any blockages in the vessels of the legs. Ultimately, the control of blood pressure reduces death and disability.

Risk Factors

Risk factors for high blood pressure need to be considered. Family history of high blood pressure, advanced age, obesity, a diet high in salt and those who are physically inactive are at greater risk for developing hypertension. The use of certain drugs increases the risk for hypertension including certain hormones, certain pain medicines such as ibuprofen, Naproxen, or Celecoxib and alcohol. Those with kidney disease, diabetes and abnormal cholesterol have higher incidence of high blood pressure.

Risks

Hypertension significantly increases the rates of death and disability. The risk of cardiovascular disease doubles for each 20/10 mm Hg increment of blood pressure over 115/75 mm Hg (3). Sustained elevation in blood pressure leads to changes in the blood vessels and heart. Consequently, hypertension increases risk for stroke, heart attack, heart failure, aortic dissection, retinopathy, peripheral artery disease and kidney failure. Diagnosis

High blood pressure is diagnosed by averaging two or more blood pressure readings on two or more separate office visits. One elevated blood pressure reading with signs or symptoms such as chest pain, shortness of breath, visual changes, sleepiness, confusion, nausea and vomiting is considered a hypertension emergency and should be treated aggressively with strong consideration of hospitalization. The diagnosis of hypertension should be accompanied by a history and physical exam by a health care provider. The doctor needs to evaluate three things when evaluating you for high blood pressure. The first is to evaluate your cardiovascular risk factors and treat if necessary. Secondly, you should be evaluated for any specific cause of high blood pressure. Lastly, your doctor should evaluate and monitor for any damage high blood pressure has done to your body such as damage to the kidneys, eyes or heart.

Laboratory evaluation is done to look for causes of hypertension, cardiovascular risk factors and evidence of target organ damage. Selected laboratory evaluation – a cholesterol test, blood levels of potassium, calcium and kidney function - can help determine damage done to the body by hypertension or suggest secondary causes of hypertension.

Low potassium levels may suggest secondary causes of high blood pressure. Decreased kidney function points to damage done to the kidney due to the effects of hypertension. Urine analysis should be done to check for any damage to the tubules of the kidney. Fasting blood sugar evaluates for the presence of diabetes which, when combined with hypertension, significantly increases the risk of kidney damage and cardiovascular disease. Red blood cell count with hemoglobin and hematocrit levels will detect an underlying anemia. Electrocardiogram is done to assess for abnormal heart rhythms, increased size of the heart or evidence of an old heart attack.

Hypertension is typically a disease without symptoms. Patients are unaware they have hypertension until they are tested for it. Occasionally, headaches, dizziness, vision changes, chest pain may be a manifestation of hypertension. Secondary hypertension is more often associated with signs and symptoms.

Treatment



Treatment of hypertension involves a combination of lifestyle changes and/or medications. The decision to start medication therapy versus recommending lifestyle changes is determined by evaluating your overall medical profile. Lifestyle interventions are appropriate in all patients though its use as a solo therapy is not always effective. Lifestyle modification alone is appropriate in patients with no risk factors, no evidence of organ damage or heart disease and blood pressure less than 160/100 mm Hg. When there is evidence of organ damage or cardiovascular disease drug therapy is indicated. Lifestyle changes: Lifestyle modification has a profound impact on hypertension control. Important lifestyle changes in reducing blood pressure include a healthy diet, exercise, weight loss and moderate alcohol consumption.Diet: Diet is an essential component in controlling blood pressure. Weight control is paramount; a weight loss of 10 kilograms can result in a reduction in blood pressure of approximately 5-20 mm Hg (3). Reducing the number of calories eaten in a day and increasing the number of calories expended are the best way to reduce weight.

Free Health Ebook: Superfoods






Dietary approaches to controlling hypertension include eating a diet high in fruits, vegetables, low fat dairy, fish and nuts while limiting saturated fats, red meat, sweets and salt (5). Not only will this aid in a weight loss, it will help the individual to get the proper nutrients in his or her body to optimally control blood pressure. Diets high in potassium, calcium, folic acid and magnesium can reduce blood pressure. Maintaining a diet with 2.4 grams of sodium or lower has the potential to lower blood pressure 2-8 mm Hg (3).

Moderate alcohol consumption, no more than one to two drinks a day, is also important in blood pressure control. Controlling alcohol intake has been shown to lower blood pressure 2-4 mm Hg (3). In addition, alcohol is full of empty calories and is a potential source of weight gain. Exercise: To control blood pressure it is important to increase your activity level. Exercising 20-30 minutes a day at a moderately intense level at least 3-4 days a week is recommended.

Exercise can be broken up into two or three, ten-minute sessions each day with equal effectiveness on blood pressure control. Exercise has been shown to reduce the systolic blood pressure 4-9 mm Hg (3). Medicines: Medicines are the most effective way to lower blood pressure. Different classes of medicines work at different targets in the body. Because each medicine has a different mechanism of action, individuals respond differently to medicine classes. This section looks at common classes of medicines to control blood pressure: angiotensin converting enzyme inhibitors, angiotensin receptor blockers, beta-blockers, calcium channel blockers and diuretics. There are other classes of blood pressure medicines but these are the most common medicines and each group will be addressed. Angiotensin converting enzyme inhibitors (ACE-I): Angiotensin II is a hormone, which constricts blood vessels, increases the amount of sodium and water retention, and consequently raises blood pressure. ACE-I interrupt the production of angiotensin II and prevents the formation of angiotensin II and therefore dilates blood vessels and lowers blood pressure. ACE-I, for example, quinapril (Accupril), captopril (Capoten) and ramipril (Altace), are more effective in younger white patients in treating high blood pressure. ACE-I are useful in treating blood pressure especially in those afflicted with other conditions (Table 15).

Side effects of ACE-I include: low blood pressure, dizziness, high potassium, dry hacking cough, GI upset, headache, renal impairment and occasionally swelling of the face and lips. Angiotensin Receptor Blockers (ARBS): ARBS, e.g. candesartan (Atacand), losartan (Cozaar) and valsartan (Diovan), work very similarly to ACE-I and dilate blood vessels resulting in lower blood pressure.

Side effects of ARBS include: dizziness, high potassium, fatigue, headache and facial and lip swelling. This class of medicine does not suffer from the side effect of cough, which is common with ACE-I.

Like ACE-I, the main use of these medications is to control blood pressure but they are particularly helpful in those with co-existing high blood pressure with heart failure, diabetes, and renal failure.

Beta Blockers (BB): Beta-blockers control blood pressure and lower heart rate. This class of medicine works by blocking chemical messengers to the heart. This drug sits in the beta receptor and stops chemicals from interacting with this receptor. Consequently, there is lower blood pressure and heart rate. BB have names ending in the suffix "lol" including atenolol (Tenormin), metoprolol (Lopressor) and propranolol (Inderal).

Side effects include fatigue, dizziness, depression, stomach upset, slow heart rate, low blood pressure, bronchospasm, heart failure and insomnia.

BB remain a decent first line treatment choice for uncomplicated hypertension. Health care providers often start this class of medicine when hypertension is complicated by fast heart rates, coronary heart disease, congestive heart failure, diabetes, migraine and previous heart attacks. Diabetics need to use caution when using these medicines because it may mask the signs and symptoms of low blood sugar. BB should be used with caution in patients with peripheral vascular disease, depression, and COPD as it may worse these conditions.

Calcium Channel Blockers (CCB): CCB lower blood pressure by inhibiting vessel constriction. Blacks and older patients respond better to this class of drug when compared to beta-blockers and ACE-I. This difference is minimized when drug combinations include adequate doses of diuretics (3).

The CCB verapamil (Calan) and diltiazem (Cardizem) slow the heart rate and decrease its pumping action therefore caution must be used when combined with beta-blockers. The CCB amlodipine (Norvasc), felodipine (Plendil), nicardipine (Cardene), and nifedipine (Procardia) dilate the blood vessels and can increase the heart rate.

Side effects vary by individual drug but common side effects include headache, edema, fatigue, dizziness, low blood pressure, constipation, GI upset and slow heart rate.

CCB are effective in preventing death, myocardial infarction and stroke in patients with stable heart disease who need BP control. In addition to heart disease they are used to control blood pressure in a variety of patients. Patients whose high blood pressure is complicated by renal failure, a fast heart rate and diabetes are good candidates for CCB.

Diuretics: Diuretics are equal or superior to other (more expensive) blood pressure medications as first line treatment for hypertension. This class of drugs works initially by ridding the body of excess fluid, but as therapy is continued there is a decrease in the constriction of blood vessels. Thiazide diuretics are used as first line therapy for uncomplicated hypertension. Compelling indications for the use of diuretics include congestive heart failure, those at high-risk for cardiovascular disease, diabetes and secondary stroke prevention.

Patients on diuretics need to be monitored for side effects. Dehydration, low blood pressure and drops in blood pressure with standing are common and increase the risk of falls. This class of medicine is recommended in the elderly population as first line treatment. Caution must be used when prescribing this drug to younger patients as the long-term use of thiazide diuretics can increase the risk for the development of diabetes. Patients with gout or a predisposition to gout are at increased risk for a gout flare while on some diuretics.

Drug interactions can occur with diuretics with drugs such as digoxin, ACE-I, ARBS and certain pain medicines such as ibuprofen, naproxen or celecoxib. Eating a diet high in sodium increases the risk for low potassium while on diuretics.

Diuretics incorporate a broad range of drugs from a variety of classes. Thiazide diuretics, such as hydrochlorothiazide, are widely used and are effective in controlling hypertension. They have a relative long duration of action – meaning they are dosed one time a day – and work well to control patient’s blood pressure without renal dysfunction. Those with renal failure do not respond as well to thiazides and more powerful diuretics known as loop diuretics are required.

Loop diuretics – furosemide (Lasix), torsemide (Demadex), and bumetanide (Bumex) – are more robust in their action to off load fluid and result in more electrolyte (such as potassium and magnesium) disturbances.

Aldosterone antagonists are another class of diuretics and include the drugs aldactone (Spironolactone) and eplerenone (Inspra). Potassium sparing diuretics including triamterene (Dyazide) are more expensive but less commonly associated with low potassium levels.

Side effects of diuretics consist of dehydration, abnormal electrolytes (low potassium or low sodium), sunburns, GI upset, and high blood sugars.

These drugs are recommended as the first drugs prescribed for uncomplicated hypertension and as part of the initial combination of blood pressure medicines to treat blood pressure 20/10 mm Hg over goal.

Compelling indications for the use of diuretics include heart failure, history of stroke, heart disease and diabetes. Other agents

The five classes of medications listed above are the most commonly prescribed antihypertensive medicines but other medications are used.

Alpha-blockers such as doxazosin (Cardura) and prazosin (Minipress) are centrally acting agents and dilate blood vessels. These drugs enter the brain and have their effects through regulation of receptors in the brain. Side effects include sleepiness, dizziness, headache, fatigue, and low blood pressure.

Central alpha agonists, which reduce blood vessel constriction, such as clonidine (Catapres), guanfacine (Tenex) and methyldopa (Aldomet) have significant side effects including sedation, dry mouth, and depression and are not used commonly.

Clonidine comes in a patch form (Catapres patch). It is changed one time a week and can be beneficial in those with compliance issues because the oral form requires three times a day dosing.

The newest drug to treat high blood pressure is Aliskiren (Tekturna). The most common side effects are diarrhea and cough. The medication is dosed once a day between 150-300 mg.


Compelling indications

Patients with high blood pressure often have other diseases. Health care providers consider other diseases when prescribing drugs to control blood pressure. Studies have shown that certain blood pressure medications have favorable effects, not only on blood pressure, but other disease processes. If you are afflicted with any of the diseases listed below and are being treated for high blood pressure you should be on one of the recommended drugs. If not, discuss this with you doctor – there may be a very good reason why not, but it may have been an oversight.

• Congestive heart failure – ACE-I, ARBS, aldosterone agonists, beta blockers, and thiazide diuretics
• A history of a heart attack – ACE-I, aldosterone agonists and beta blockers
• Diabetes – ACE-I, ARBS, BB, thiazide diuretics, and CCB
• After a stroke – ACE-I and diuretics together
• Chronic renal failure – ACE-I and ARBS
• Osteoporosis – Thiazide diuretics

Combination therapy

Combination therapy is the use of more than one drug to treat high blood pressure. It is used in patients who are 20/10 mm Hg over goal or those who do not reach blood pressure goals with one drug. Many patients need combination therapy to control blood pressure.

Studies suggest many effective and safe combinations of medications. ACE-I or ARBS with diuretics, especially thiazide diuretics, work well together to lower blood pressure. Caution needs to be taken as these medicines can precipitate large drops in blood pressure, renal failure and electrolyte imbalance.

ACE-I or ARBS with CCB are another combination that works well together. BB and thiazide diuretics also work well together to lower blood pressure.

Certain medications do not work as well together. Beta-blockers and ACE-I both block the same hormonal system and are not as effective as other combinations. Thiazide diuretics and CCB do not work well together. The use of BB, ACE-I, alpha-blockers, and alpha agonists are not additive in the ability to lower blood pressure.

Some drug combination can be potential dangerous to use together and extreme caution must be exercised. Older individuals have a higher propensity to have significant drops in blood pressure when initiating multiple antihypertensive medicines. This increases the risk of falls and fracture. CCB and alpha-blockers can precipitate a large drop in blood pressure. The use of beta-blockers and CCB can trigger a large drop in heart rate or congestive heart failure.

Take home points for blood pressure control your patients should understand

• When initiating blood pressure treatment, follow up with the health care provider should occur on a monthly basis until blood pressure is stabilized. Follow ups every six months is reasonable after blood pressure is stabilized to monitor the blood pressure and any side effects of the treatment regime.
• Blood pressure is only lowered while taking medicines. Medicines need to be taken everyday to be effective and many drugs need to be taken life-long.
• Medicines can be changed. If too many side effects occur providers can switch medicines to reduce side effects.
• Know your blood pressure goal – ideally it is less than 120/80 mm Hg.
• Understand what lifestyle changes need to be implemented to maximize blood pressure control.
• Know your medical diagnoses and talk to their health care provider as to why or why not you are on certain blood pressure medicines based on other diseases.
• Know what monitoring needs to be done based on your medicines.
• Carry a blood pressure log to record blood pressure and heart rate readings at intervals recommended by the primary health care provider.

 Health Care Responsibility

1. Know the answers to the questions listed below.
2. Track your blood pressure with the form in appendix
3. Practice lifestyle interventions helpful in maintaining well controlled blood pressure.
4. Attain a blood pressure of less than 120/80 mmHg

   The following is a list of questions that each patient should be able to answer about their hypertension. A worksheet is available in the appendix.

   How often should I monitor my blood pressure?

   What is my blood pressure goal? Most people have a blood pressure goal of less than 120/80 mm Hg

   Do I need any routine labs to follow up on my high blood pressure or high blood pressure medicine? Many hypertensive medications require periodic monitoring of certain labs.

   What is a good weight for me? Is there a diet that will help me achieve this weight?

   What are the side effects of my medicines?

   When should I take my medicines?

   Should I take my blood pressure pills with food or on an empty stomach?

   What should I do if I forget to take my blood pressure medicine?

   Do I need an electrocardiogram (EKG)? A baseline EKG may be helpful in those with hypertension. It can detect problems with the heart rhythm, with the size of the heart or detect a prior heart attack.

   Do I need an echocardiogram? Some individuals with hypertension benefit from an echocardiogram that evaluates valve problems, heart function and helps tailor therapy.

   Should I be on aspirin? It is recommended that most people with multiple risk factors for vascular disease be on aspirin unless there is a contraindication such as a bleeding disorder or a stomach ulcer.

   What is my kidney function? Periodic evaluations of kidney function can detect one of the complications of high blood pressure - kidney failure.

   Do I have protein in my urine? This is not a common test in those with high blood pressure but protein in the urine is an early marker of kidney damage.

   What is my cholesterol? Those with hypertension are at increased risk for vascular disease. Monitoring cardiovascular risk factors can prevent cardiovascular disease. Ask the health care provider if cholesterol readings are at goal.

   Have I been checked for diabetes? It is important to assess for all cardiovascular risk factors in those with hypertension.

   What lifestyle changes should I make to help control my blood pressure? Most health care providers recommend exercise, a healthy diet, moderate to no alcohol consumption and stress reduction.

   Do I need a stress test? Many individuals get a stress test to assess for cardiovascular disease. For most with hypertension it is important to obtain a stress test prior to starting an exercise program.

   References

   1. Kearney PM, Whelton M, Reynolds K, Munter P, Whelton PK & He J. Global burden of hypertension: analysis of worldwide data. Lancet 2005; 365: 217-223.
   2. Chobanian AV, Bakris GL, Black HR, Cushman WC, Green LA, Izzo JL Jr, et al. Seventh report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. JAMA 2003; 289(19): 2560-2572.
   3. 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. NEJM. 2001; 344: 3-10.
   4. Joint National Committee on detection, education, and treatment of high blood pressure. The sixth report on the joint national committee on detection, education, and treatment of high blood pressure. Archives of Internal Medicine 1997; 157: 2413-2446
   5. Wassertheil-Smoller S, Psaty B, Greenland P, et al. Association between cardiovascular outcomes and antihypertensive drug treatment in older women. JAMA 2004; 292(23): 2849-2859.