Hypertension

Dr. Mohammad Tanvir IslamAssistant Professor (Medicine)Bangabandhu Sheikh Mujib Medical University

19th and 20th centuries

•Strict sodium restriction (for example the rice diet

•Sympathectomy (surgical ablation of parts of the sympathetic nervous system)

•Pyrogen therapy (injection of substances that caused a fever, indirectly reducing blood pressure)

Chlorothiazide, the first thiazide diuretic

1958 Major breakthrough,1st well tolerated oral agent

Hexamethonium, hydralazine and reserpine 2nd World War Popular and reasonably effective

Sodium thiocyanate

1900 Not well tolerated

Disease burden • Globally 1 billion ( 25% of the adult population) • 50 million people in USA• In Asia, dramatic increase in last 30 years• In China, prevalence has increased from 7.8% in 1980 to 27.2% in 2001

• For every 20 mmHg systolic or 10 mmHg diastolic increase in BP, there is a doubling of mortality from both IHD and stroke

• High BP, the second most important cause of disability adjusted life year (DALY) loss in Asian countries.

• The Framingham Heart study suggests that individuals who are normotensive at 50 years of age have a 90 % lifetime risk for developing hypertension.

HTN in BangladeshHypertension Deaths in Bangladesh reached 18,245 or 1.91% of total deaths

WHO data published in April 2011

•Prevalence rates of systolic and diastolic hypertension in natives > 20 years of age are14.4% and 9.1% respectively• Among the elder individuals, it is 65%

BMRC

Today's topic includes• Understanding hypertension• Basic knowledge on measurement of BP• Common issues in management of hypertension• Treatment of hypertension in community clinics or

hospitals

Topics not included• Hypertensive emergencies• Pregnancy related hypertension• Secondary hypertension

What is Hypertension?

It is the level of blood pressure above which treatment has been shown to reduce the

development or progression of disease There is no natural cut-point above

which "hypertension" definitively exists and below which, it does not

Blood Pressure Classification

According to JNC 7

BP Classification SBP mmHg DBP mmHgNormal <120 and <80Prehypertension 120–139 or 80–89Stage 1 Hypertension 140–159 or 90–99Stage 2 Hypertension >160 or >100

Reduce BP

Decrease progression of BP to hypertensive levels with age

Prevent hypertension entirely

Prehypertension

According to JNC 7

Hea

lthy L

ifest

yle

Systolic 120-139 mmHg

Diastolic 80-89 mmHg

BP Measurement Techniques

Clinic/office BP measurement

Home BP monitoring

Ambulatory BP monitoring

• With a properly calibrated and validated instrument• Patient is seated quietly for at least 5 minutes in a

chair with feet on the floor and arms supported at the heart level

• Appropriate sized cuff (Cuff – bladder encircling 80% of the arm) is used.

• At least two measurements are made at separate occasion at a reasonable interval

Office/ Clinic measurement

According to NICE guideline 2011

Diagnosis

If the clinic blood pressure is 140/90 mmHg or higher

Offer

Ambulatory blood pressure monitoring (ABPM) to confirm the diagnosis of hypertension.

According to NICE guideline 2011

Diagnosis

When using the following to confirm diagnosis, ensure:

ABPM:• at least two measurements per hour during the person’s usual waking

hours, average of at least 14 measurements to confirm diagnosis

HBPM:• two consecutive seated measurements, at least 1 minute apart• blood pressure is recorded twice a day for at least 4 days and

preferably for a week• measurements on the first day are discarded –

average value of all remaining is used.

Hypertension should not be diagnosed nor treatment offered on the basis of a single BP measurement

Essential – 95%

Secondary – 5%• Sleep apnea• Pregnancy • Coarctation of aorta• Renal diseases • Endocrine diseases • Drugs

Types of hypertension

Patient EvaluationIdentify CV risk factors

• Hypertension• Cigarette smoking• Obesity• Physical inactivity• Dyslipidemia• Diabetes mellitus• Microalbuminuria or

estimated GFR <60 ml/min

• Age (older than 55 for men, 65 for women)

• Family history of premature CVD • (men under age 55 or

women under age 65)

Reveal secondary causeds

• Sleep apnea• Drug-induced or related

causes• Chronic kidney disease• Primary aldosteronism• Renovascular disease• Chronic steroid therapy and

Cushing’s syndrome• Pheochromocytoma• Coarctation of the aorta• Thyroid or parathyroid

disease

Asses TOD

• Heart• Left ventricular

hypertrophy• Angina or prior myocardial

infarction• Prior coronary

revascularization• Heart failure

• Brain• Stroke or transient

ischemic attack• Chronic kidney disease• Peripheral arterial disease• Retinopathy

TOD= target organ damage

Look for identifiable causes

• labile or paroxysms of hypertension accompanied by• headache,palpitations, pallor, and perspiration

Pheochromocytoma

• Decreased pressure in the lower extremities or delayed or• absent femoral arterial pulses

Aortic coarctation

• truncal obesity, glucose intolerance,and purple striae

Cushing’s syndrome

Look for identifiable causes

• Facial or leg swelling• H/O oliguria or polyuria

Chronic kidney disease

• Thyroid swelling• Weight loss/gain• Palpitaion/skin thickening etc

Thyroid disorders

• sudden/severe/resistant HTN• H/O flash pulmonary edema

Renal artery stenosis

• Palpable kidney • H/O hematuria

Polycystic kidney disease

CHD,LVH,Heart failure

Stroke Chronic kidney disease

Peripheral vascular disease

Hypertensive retinopathy

Target organ damage

How shall we investigate this patient

Investigation

1.Investigations of all patients

2. Investigation of selected patients

Investigation of all patients• Urinalysis for blood, protein and glucose • Blood urea, electrolytes and creatinine • Blood glucose • Serum total and HDL cholesterol • 12-lead ECG (left ventricular hypertrophy,

coronary artery disease)

Investigation for selected patients• Chest X-ray: to detect cardiomegaly, heart failure, coarctation of the

aorta • Echocardiogram: to detect or quantify left ventricular hypertrophy • Renal ultrasound: to detect possible renal disease • Renal angiography: to detect or confirm presence of renal artery

stenosis • Urinary catecholamines: to detect possible phaeochromocytoma • Urinary cortisol and dexamethasone suppression test: to detect

possible Cushing's syndrome • Plasma renin activity and aldosterone: to detect possible primary

aldosteronism

Do we need to treat ??

Benefits of Lowering BP

Average Percent Reduction

Stroke incidence 35–40%

Myocardial infarction 20–25%

Heart failure 50%

Benefits of Lowering BP

In stage 1 HTN and additional CVD risk factors, achieving a sustained 12 mmHg reduction in SBP over 10 years will

prevent 1 death for every 11 patients treated

Treating hypertension

Non pharmacologic• Major life - style modification

• Decreases BP• Increase a drug efficacy• Decrease cardiovascular risks

Drug treatment• Effective treatment reduces

• CVD – 30%• CAD – 20%

Life style Modifications

Modification Recommendation Approximate SBP Reduction

Weight Reduction BMI 18.5 – 24.9 5 – 20 mmHg/ 10 kg wt loss

Adopt DASH eating plan ↑ fruits, vegetables, ↓saturated and total fat

8 – 14 mmHg

Dietary sodium reduction 2.4 gm Na+ or 6 gm NaCI 2 – 8 mmHg

Physical activity Brisk walking, 30 min/day 4 – 9 mmHg

Alcohol (moderate) 10 oz or 30 ml ethanol for men not more than 1 drink/ day.

2 – 4 mmHg

DASH (Dietary Approaches to Stop Hypertension)Type of food Number of servings for

1600 - 3100 Calorie dietsServings on a 2000 Calorie diet

Fruits 4-6 4-5

Vegetables 4-6 4-5

Low fat or non fat dairy foods

2-4 2-3

Lean meat, fish, poultry 1.5-2.5 2 or less

Nuts, seeds, and legumes 3-6 per week 4-5 per week

Fats and sweets 2-4 limited

Grains and grain products (include at least 3 whole grain foods each day)

6-12 7-8

Initiating treatmentDrug should be given to -

Any age with stage 2 HTN

< 80 yr with stage 1 HTN who have target organ damage (TOD) -

Established cardiovascular disease Renal disease

Diabetes 10 yr cardiovascular risk ≥ 20%

Initiating treatment

• If possible, offer drugs taken only once a day• Prescribe non-proprietary drugs if these are appropriate

and minimise cost• Offer people with isolated systolic hypertension (systolic

blood pressure 160 mmHg or higher)the same treatment as people with both raised systolic and diastolic blood pressure

• Offer people aged over 80 years the same antihypertensive drug treatment as people aged 55–80 years, taking into account any comorbidities.

• Do not combine an angiotensin-converting enzyme (ACE) inhibitor with an angiotensin II receptor blocker (ARB)

General principles

Choosing antihypertensive

Step 1 treatment:

• ACE inhibitor 1st choice, If not tolerated , then ARB

age< 55 yr

• calcium-channel blocker is 1st choice for

age over 55 yr or black people of any age

Choosing antihypertensive

• If a CCB is not suitable, or • if heart failure

Thiazide-like diuretic (chlortalidone or indapamide)

Who already having thiazide and BP is well controlled, treatment should be continued

Choosing antihypertensive

people with increased sympathetic drive

or

women of child-bearing potential

or

those with an intolerance to ACE inhibitors & ARB

Beta-blockers may be considered in younger

Choosing antihypertensive

Step 2 treatment

• If BP is not controlled , a CCB is added with either an ACE inhibitor or an ARB

• If a CCB is not tolerated, or there is heart failure thiazide-like diuretic is the choice

• For black people, consider an ARB in preference to an ACE inhibitor, in combination with a CCB

Choosing antihypertensive

Step 3 treatment• Before considering step 3 , medication

should be reviewed to ensure step 2 treatment is at optimal or best tolerated dose

• If treatment with three drugs is required, thiazide-like diuretic should be used as 3rd drug

Choosing antihypertensive

Step 4 treatment

• If BP not controlled with 3 drugs• A 4th drug is added and/or • Expert advice is needed• As a 4th drug, further diuretic with low-dose

spironolactone , if the blood K+ < 4.5 mmol\l

Choosing antihypertensive

If further diuretic at step 4 is not tolerated, an alpha- or beta-blocker should be used

Blood Na+ and K+ and renal function should be monitored within 1 month and repeat as required

Higher-dose thiazide-like diuretic is considered if the blood K+ level is higher than 4.5 mmol/l

Step 4

Summary of antihypertensive drug treatment

Aged over 55 years or black person of African or Caribbean family origin of any age

Aged under55 years

CA

A +C

A + C + D

Resistant hypertension

A + C + D + consider further diuretic or alpha- or

beta-blocker

Consider seeking expert advice

Step 1

Step 2

Step 3

KeyA – ACE inhibitor or low-cost angiotensin II receptor blocker (ARB)C – Calcium-channel blocker (CCB) D – Thiazide-like diuretic

Additional recommendations

Patient education and adhere

nce

•Crucial part of patient management

Provide:

•information about benefits of drugs and side effects

•details of patient organisations

•an annual review of care.

Follow-up visits

Useful links

www.nice.org.uk

www.nhlbi.nih.gov/guidelines/hypertension

http://www.nhlbi.nih.gov/health/public/heart/hbp/dash/new_dash.pdf

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