hypertension 2012

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Hypertension Dr Uday Prashant CARE Hospitals

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Hypertension lecture prepared for B Soma Raju lecture incorporating major current concepts of Hypertension

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Page 1: Hypertension 2012

HypertensionDr Uday Prashant

CARE Hospitals

Page 2: Hypertension 2012

Hypertension

• Introduction & Definition.• How to measure?• Etiology• Treatment• Complications

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Global Mortality 2000: Impact of hypertension and other health risk factors

Adapted from Ezzati et al. Lancet 2002;360:1347–60

Attributable mortality (in millions (total: 55,861,000)

Developing regionDeveloped region

0 87654321

High BP

Tobacco

High cholesterol

Unsafe sex

High BMI

Physical inactivity

Alcohol

Underweight

Page 5: Hypertension 2012

Hypertension

Definition: the force exerted by the blood against the walls of the bleed vessels

Adequate to maintain tissue perfusion during activity and rest

Arterial blood pressure: primary function of cardiac output and systemic vascular resistance

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04/10/2023 6

Hypertesnion

• Hypertension currently is defined as a usual BP of 140/90 mm Hg or higher, for which the benefits of drug treatment have been definitively established in randomized placebo-controlled trials.

• For certain high-risk patients, especially those with CAD, the recommended medical treatment threshold recently has been lowered to 130/80 mm

.

Page 7: Hypertension 2012

Hypertension• The major factors which help maintain blood

pressure (BP) include the sympathetic nervous system and the kidneys.

• Optimal healthy blood pressure is a systolic blood pressure of <120 mmHg and a diastolic blood pressure of <80 and cardiovascular risk increases from BP >115/75 mm Hg

Page 8: Hypertension 2012

HypertensionCategory Systolic Blood

PressureDiastolic Blood Pressure

Normal < 120 <80

Pre-hypertension 120-139 80-89

Hypertension – Stage 1 140-159 90-99

Hypertension – Stage 2 >160 >100

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04/10/2023 9

Blood Pressure

• Exhibits a normal or Guassian distribution within the population

• Increasing blood pressure is associated with a progressive increase in the risk of stroke and cardiovascular disease

• Risk however rises exponentially and not linearly with pressure

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04/10/2023 10

Page 11: Hypertension 2012

Measurement

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The force of the blood in its vessels is continually varying according to...the various distances of time after taking food...also from exercise, rest, different states of vigour or vivacity of the animal and many other circumstances.”

Stephen Hales

The first observer of mammalian blood pressure, summarizing his remarkable observations in dogs 277 years ago.

Page 13: Hypertension 2012

How BP was measured first

d

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Complex methods of BP measurement before sphygmomanometer discovered

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Modern methods

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BP measurement• BP should be measured at least twice after 5 minutes of rest, with the patient

seated in a chair, the back supported, and the arm bare and at heart level.

• A large adult-sized cuff should be used to measure BP in overweight adults because the standard-sized cuff can spuriously elevate readings.

• Tobacco and caffeine should be avoided for at least 30 minutes.

• BP should be measured in both arms and both patient & doctor should not be talking during BP measurement

• after 3 minutes of standing, the latter to exclude a significant postural fall in BP, particularly in older persons and in those with diabetes or other conditions (e.g., Parkinson's disease) that predispose to autonomic insufficiency.

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Assessment of hypertension

NICE BP confirmationIf Initial BP > 140/90 repeat monthly for 2 months

How often should BP be measured

• 5 yearly - adults up to 80 years

• Annually - high normal (130-139 or 85-89)

& anyone with high readings at any time

Confirmation of hypertension

• If BP high – repeat monthly over 4-6 months. (Unless BP very high, then measure more frequently)

• Do not treat on basis of one isolated readingBHS guidelines

Page 19: Hypertension 2012

Indications for ABPM24 hour BP monitoring

• Possible ‘white coat’ hypertension

• Informing equivocal treatment decisions

• Evaluation of nocturnal hypertension

• Determining efficacy of drug treatment over 24 hours

• Evaluation of symptomatic hypotension

• Unusual BP variability

• Diagnosis & treatment of hypertension in pregnancy

• Evaluation of drug resistant hypertension

Page 20: Hypertension 2012

Kieran McGlade Nov 2001 Department of General Practice QUB

Aetiology of Hypertension• Primary – 90-95% of cases – also termed “essential” of

“idiopathic”• Secondary – about 5% -10% of cases

– Renal or renovascular disease– Endocrine disease

• Phaeochomocytoma• Cusings syndrome• Conn’s syndrome• Acromegaly and hypothyroidism

– Coarctation of the aorta– Iatrogenic

• Hormonal / oral contraceptive• NSAIDs

Page 21: Hypertension 2012

Causes of Secondary HTN

• Common– Intrinsic renal

disease– Renovascular

disease– Mineralocorticoid

excess – Sleep Breathing

disorder

• Uncommon– Pheochromocytoma– Glucocorticoid

excess– Coarctation of Aorta– Hyper/

hypothyroidism

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04/10/2023 22

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RISK FACTORS FOR HYPERTENSION

• Age• Weight• Race, Genetics• Diet (High Sodium)• Smoking• Excess Alcohol• Sleep apnea• Stress – Mental and emotional• Hormonal disorders – Hypothyroidism, POCD, Syndrome X,

Cushings• Drugs – Cyclosporine, Steroids , NSAIDS etc

Page 24: Hypertension 2012

• Overweight

• Excess alcohol Men 3 units/day; Women 2 units/days

• Excess salt intake

• Lack of exercise

• Environmental stress

Contributory factors

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Examination

• Appropriate measurement of BP in both arms• Optic fundi• Calculation of BMI ( waist circumference also may be

useful)• Auscultation for carotid, abdominal, and femoral

bruits • Palpation of the thyroid gland.

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Examination-contd.

• Thorough examination of the heart and lungs • Abdomen for enlarged kidneys, masses, and

abnormal aortic pulsation• Lower extremities for edema and pulses • Neurological assessment

Page 27: Hypertension 2012

Kieran McGlade Nov 2001 Department of General Practice QUB

Investigation of the New Hypertensive

• History and examination• Exclude secondary Hypertension• Urea and electrolytes• FBP and ESR• ECG• Lipid profile• Urine CUE• Chest x-ray

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Kieran McGlade Nov 2001 Department of General Practice QUB

Clinical clues to renal vascular disease• History Onset of hypertension before 30 years or after 50 years of age

Abrupt onset of hypertension Severe or resistant hypertension Symptoms of atherosclerotic disease elsewhere Negative family history of hypertension Smoker Worsening renal function after renin-angiotensin inhibition Recurrent “flash” pulmonary edema

Examination Abdominal bruits Other bruits Advanced fundal changes

Laboratory Findings Secondary aldosteronism Higher plasma renin level Low serum potassium level Low serum sodium level Proteinuria, usually moderate Elevated serum creatinine level Unilateral small (atrophic) kidney size by ultrasound examination.

Page 30: Hypertension 2012

Etiology of Primary HT

• Age <40 yrs; IDH (Isolated Diastolic HT) increased CO. High RAAS & sympathetic activation

• Age 40-60 yrs SDH (Systolic & Diastolic HT); increased PVR

• Age >60 yrs ISH (Isolated Systolic HT); 1)Increased arterial stiffness - widened pulse pressure. 2)Reduced GFR, Na & water retention

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<40 40-49 50-59 60-69 70-79 80+Age (y)

17% 16% 16% 20% 20% 11%

Distribution of Hypertension Subtype in the untreated Hypertensive Population in NHANES III by Age

ISH (SBP ³140 mm Hg and DBP <90 mm Hg) SDH (SBP ³140 mm Hg and DBP ³90 mm Hg)IDH (SBP <140 mm Hg and DBP ³90 mm Hg)

0

20

40

60

80

100

Numbers at top of bars represent the overall percentage distribution of untreated hypertension by age. Franklin et al. Hypertension 2001;37: 869-874.

Frequency of hypertensionsubtypes in all

untreated hypertensives

(%)

Page 32: Hypertension 2012

Classification Important because

• Younger Hypertensive patients drugs which act on RAAS & Beta Blockers are important.

• Older patients CCB`s first choice and evidence of volume overload present diuretics

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Pulse Pressure

• Increase in pulse pressure (PP) indicates greater stiffness in large conduit arteries, primarily the thoracic aorta.

• PP, therefore, is a surrogate measure of dynamic, cyclic stress during systole.

• PP may be a better marker of increased CV risk than either systolic BP or diastolic BP alone in older persons.

PP = SBP – DBP

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Renal mechanisms

• Many forms of experimental and human hypertension, the fundamental abnormality is an acquired or inherited defect in the kidneys' ability to excrete the excessive sodium load imposed by a modern diet high in salt.[22]

• As humans evolved in a low-sodium/high-potassium environment, the human kidney is ill-equipped to handle the current exposure to high sodium and low potassium – Hence low salt diet is important

Page 35: Hypertension 2012

Neural mechanisms

• Sympathetic overactivity has been demonstrated in early primary hypertension and in several other forms hypertension, associated with obesity, sleep apnea etc

• deactivation of inhibitory neural inputs (e.g., baroreceptors) & activation of excitatory neural inputs (e.g., carotid body chemoreceptors, renal afferents),

• an implantable carotid baroreceptor pacemaker and

• catheter-based radiofrequency ablation of the renal sympathetic nerves

Page 36: Hypertension 2012

Hypertension Treatment

• If the lifestyle modifications described are not adequate to bring the blood pressure to goal

• <140/90 mm Hg for most individuals;• <130/80 mm Hg for those with diabetes or

renal insufficiency),

Start drug therapy

Page 37: Hypertension 2012

Lifestyle Recommendations for the Treatment of Hypertension

1. Healthy diet; High in fresh fruits, vegetables and low fat dairy products, low in saturated fat and salt in accordance with the DASH diet

2. Regular physical activity: optimum 30-60 minutes of moderate cardiorespiratory activity 4-7/week

3. Low risk alcohol consumption (≤2 standard drinks/day and less than 14/week for men and less than 9/week for women)

4. Maintenance of ideal body weight (BMI 18.5-24.9 kg/m2)Weight loss (> 5 Kg) in those who are over weight (BMI>25)

5. Waist Circumference< 102 cm for men< 88 cm for women

6. Restriction of salt intake to less than 100 mmol/day in individuals considered salt-sensitive, such as: Canadians of African descent, age over 45, individuals with impaired renal function or with diabetes.

7. Smoke free environment

Page 38: Hypertension 2012

Lifestyle Recommendations for Hypertension Dietary

• Fresh Fruits• Vegetables• Low Fat dairy

products• Low saturated fat

diet in accordance with the DASH diet

http://www.hc-sc.gc.ca/hpfb-dgpsa/onpp-bppn/food_guide_rainbow_e.html

Dietary SodiumRestrict to target range of 65-100 mmol/day

(Most of the salt in food is hidden and comes from processed food)

Dietary PotassiumIf required, daily dietary intake

>80 mmol

Calcium supplementationNo conclusive studies for hypertension

Magnesium supplementationNo conclusive studies for hypertension

Page 39: Hypertension 2012

Exercise should be prescribed as adjunctive to pharmacological therapy

Lifestyle Recommendations for Hypertension Physical Activity

Should be prescribed to reduce blood pressure

Type Dynamic exercise- Walking, jogging- Cycling- Non-competitive swimming

Time - 30-60 minutes

Intensity - Moderate

Frequency - Four to seven days per weekF

I

T

T

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Lifestyle Recommendations for Hypertension Alcohol

Low risk alcohol consumption

• Women: maximum of 9 standard drinks/week

• Men: maximum of 14 standard drinks/week

• 0-2 standard drinks/day

A standard drink is about 43 mL or 1.5 oz of spirits (40% alcohol), 341 mL or 12 oz of beer (5% alcohol) or 142 mL or 5 oz of wine (12% alcohol).

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Lifestyle Recommendations for Hypertension Stress Management

Hypertensive patientsin whom stress appears to be an important issue

Individualized cognitive behavioral interventions are more likely to be effective when relaxation techniques are employed.

Stress management

Behaviour Modification

Page 42: Hypertension 2012

Impact of Lifestyle Therapies on Blood Pressure in Hypertensive Adults

Intervention Amount SBP/DBP

Reduce foods with added sodium 1.8g or 78 mmol/d -5.0 / -2.7

Weight loss per kg lost -1.1 / -0.9

Alcohol intake - 3.6 drinks/day -3.9 / -2.4

Aerobic exercise 120-150 min/week -4.9 / -3.7

Dietary patterns

DASH dietHypertensiveNormotensive

-11.4 / -5.5-3.6 / -1.8

Applying the 2005 Canadian Hypertension Education Program recommendations: 3. Lifestyle modificationsto prevent and treat hypertension Padwal R. et al. CMAJ ・ SEPT. 27, 2005; 173 (7) 749-751

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Lifestyle Therapies in Hypertensive Adults: Summary

Intervention Target

Reduce foods with added sodium

< 100 mmol/day

Weight loss BMI <25 kg/m2

Alcohol restriction Less or equal to 2 drinks/day

Exercise at least 4 times/week

Dietary patterns DASH diet

Smoking cessation Smoke free environment

Waist Circumference

< 102 cm for men< 88 cm for women

Page 44: Hypertension 2012

DEVELOPMENT OF ANTIHYPERTENSIVE THERAPIES

Directvasodilators

Alphablockers

DRIs

Peripheralsympatholytics

Ganglion blockers

Veratrumalkaloids

Central alpha2 agonists

Non-DHPCCBs

Beta blockers

Thiazidediuretics

DHP CCBs

ARBsACEinhibitors

Effectiveness

Tolerability

1940s 1950 1957 1960s 1970s 1980s 1990s 2007

DHP, dihydropyridine; CCB, calcium channel blocker; ARB, angiotensin II receptor blocker; DRI, direct renin inhibitors

Page 45: Hypertension 2012

Clinical Trials in Patients With Disorders Related to Hypertension

Renal disease

DyslipidemiaDiabetes

LVHCVA/DementiaHeart failure/

LIFE

Atherosclerosis

Post-MI

IDNT

RENAAL

IRMA2

ACCORDDREAM

CAPTOPRILUKPDS

IDNT

RENAAL

IRMA2

AASK

1990-1995 1996-1999 2000 2001 2002 20032004-2008

HOPE

EUROPA/

PEACE ON-TARGET/

TRANSCEND

ALLHAT ASCOT

PROGRESS

SCOPE

SOLVD

RALES

I-PRESERVE

ELITE-2 CHARM

EPHESUSVALIANT

VAL-HeFTSAVE

EPHESUSVALIANTINVEST

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HypertensionAntihypertensive Drug Therapy

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Landmark Trials in treatment of Hypertension

• HOT, STOP, SHEP – Blood pressure lowering benefits all including elderly pts.

• ALLHAT – largest hypertensive trial by any drug achieving target BP is most important

• ASCOT-BPLA – ACE inhibitors with CCB`s better than Beta Blockers with diuretics

• ON TARGET, ROADMAP – ARB`s better• SIMPLICITY – Renal denervation in Resistant

Hypertension

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Combinations should be initiated early

• BP is maintained by complex regulatory and counter regulatory mechanisms.

• Blocking of one pathway causes excess activation of other system and offsets BP reduction achieved by single drug.

• Therefore combination therapy should be initiated first line instead of waiting for maximally tolerated dose of single drug

Page 51: Hypertension 2012

Combination therapy• Most trials showed that use of standard doses of any class of

anti HT caused 8 mm Hg reduction Syst BP and 4 mm in Diastolic and increasing to max tolerated dose 9-10 mm reduction 5-6 mm in diastolic

• Whereas low dose combination drugs caused 14-20 mm Hg reduction in BP with less side effects

• Some meta analysis showed 5 times BP reduction more when combination drugs used than doubling the dose of single BP drug.

Page 52: Hypertension 2012

What Hypertensive drugs are best?• Young start with ARB and add on Beta Blockers or Diuretics

• Old start with CCB and combine with ARB or Diuretics

• B blockers are no longer first line drugs for BP unless they had IHD.

• After 2006 ON TARGET results ARB score over ACEI

• IHD pts Beta Blockers should be preferred unless contra indicated.

• Diabetics and also with LV dysfunction - ACEI/ARB`s evaluate renal function.

• Stroke & PVD pts CCB`s better

Page 53: Hypertension 2012

Slow approach is better

• Many physicians control a patient's hypertension rapidly and completely.

• Regardless of which drugs are used, this approach often leads to undue fatigue, weakness, and postural dizziness,

• which many patients find intolerable, particularly when they felt well before therapy was begun.

Page 54: Hypertension 2012

Circumstances Requiring Rapid Treatment of Hypertension

Accelerated-malignant hypertension with papilledema Cerebrovascular Hypertensive encephalopathy Atherothrombotic brain infarction with severe hypertension Intracerebral hemorrhage Subarachnoid hemorrhage

Cardiac Acute aortic dissection Acute left ventricular failure Acute or impending myocardial infarction After coronary bypass surgery

Renal Acute glomerulonephritis Renal crises from collagen-vascular diseases Severe hypertension after kidney transplantation

Excessive circulating catecholamines Pheochromocytoma crisis Food or drug interactions with monoamine oxidase inhibitors Sympathomimetic drug use (cocaine) Rebound hypertension after sudden cessation of antihypertensive drugs

Eclampsia Surgical Severe hypertension in patients requiring immediate surgery Postoperative hypertension Postoperative bleeding from vascular suture lines

Severe body burns Severe epistaxis Thrombotic thrombocytopenic purpura

Page 55: Hypertension 2012

Diuretics

• Until now, hydrochlorothiazide (HCTZ) in doses of 12.5 to 25 mg has been the overwhelming choice and is the diuretic combined with various beta blockers, ACEIs, ARBs, and DRIs

• However, HCTZ in these doses has not been shown to reduce morbidity or mortality.

• Conversely, chlorthalidone, 12.5 to 25 mg, has shown benefit in National Institutes of Health (NIH)–sponsored trials (HDFP, MRFIT, SHEP, ALLHAT).

• After many years of not being prescribed, chlorthalidone is now being recommended as an appropriate diuretic.[44,45]

Page 56: Hypertension 2012

Resistant Hypertension

• This is diagnosed when blood pressure can not be reduced to below 140/90 mmHg despite a triple drug regimen.

• Patients with resistant hypertension are often referred to a hypertension specialist and the cause for the resistance is often found and overcome.

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Hypertensive Crises

• Accelerated Hypertension is used BP readings are greater than 180/120.

• If there is end-organ damage, but no intracranial pressure increases, this is called hypertensive emergency.

• Lastly, if there is end-organ damage and papilledema (due to raised intracranial pressure), the term Malignant hypertension is used.

Page 59: Hypertension 2012

Indications for specialist referral(Part 1)

Urgent treatment needed

• Accelerated hypertension (severe hypertension and grade III-IV retinopathy)

• Particularly severe hypertension (>220/120mmHg)

• Impending complications (e.g. TIA, LVF)

Page 60: Hypertension 2012

Possible underlying cause Any clue in history or examination of a secondary cause, eg. low potassium with increased or high normal plasma sodium (Conn’s syndrome)

• Raised serum creatinine

• Proteinuria or haematuria

• Sudden onset or worsening of hypertension

• Resistant to multi-drug regimen (> 3 drugs)

• Young age (any hypertension <20 years; needing treatment <30 years)

Indications for specialist referral Part 2

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ComplicationsA) Acute B) Chronic

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Acute complications

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04/10/2023 66

Hypertension chronic complications

• Major risk factor for:– cerebrovascular disease– myocardial infarction– heart failure– peripheral vascular disease– renal failure

Page 67: Hypertension 2012

Complications of chronic hypertension

Heart• Pressure Overload Hypertrophy, arrythmias• Heart Failure ( Systolic & Diastolic)• Accelerated atherosclerotic disease - UA, MI• Arterial (Aortic) aneurysm, dissection, and rupture.

Kidney • Glomerulosclerosis -Reduction GFR, Albuminuria, ESRD• Renal artery stenosis – shrunken kidney.

Retina• Hemorrhages, retinopathy, vitreous hemorrhage, retinal detachment CVS• Stroke, intracerebral and subaracnoid hemorrhage.• Cerebral atrophy and dementia

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Retina Normal and Hypertensive Retinopathy

Normal Retina Hypertensive Retinopathy A: HemorrhagesB: Exudates (Fatty Deposits)C: Cotton Wool Spots (Micro Strokes)

A B

C

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Benefits of Lowering BP

Average Percent Reduction

Stroke incidence 35–40%

Myocardial infarction 20–25%

Heart failure50%

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Future Perspectives

• The measurement of BP will become more accurate for diagnosis and cardiovascular risk stratification with the greater use of out-of-office measurements (ABP) and assessments of vascular health by measures of vascular compliance (Pulse pressure), central aortic pressure, and inflammatory biomarkers.

• Future research on underlying mechanisms of primary hypertension should aim to make treatment less empiric and more effective than current practice.

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THANK YOU