Hypertension & Cardiovascular Risk Factors

Final Year Cardiology Teaching

2003-4

Outline

• Global burden of cardiovascular disease

• Epidemiology of cardiovascular disease

• Hypertension– Epidemiology– Clinical features– Investigation

• Cardiovascular risk assessment

The Global Burden of Disease

The scope of the problem

Leading Causes of Death and Disability (DALY’s)

Rank Cause % Rank Cause %

1 Lower respiratory infections 8.2 1 Ischemic heart disease 5.9

2 Diarrhoeal diseases 7.2 2 Major depression 5.7

3 Perinatal conditions 6.7 3 Road traffic accidents 5.1

4 Major depression 3.7 4 Cerebrovascular disease 4.4

5 Ischemic heart disease 3.4 5 COPD 4.2

6 Cerebrovascular disease 2.8 6 Lower respiratory infections 3.1

7 Tuberculosis 2.8 7 Tuberculosis 3.0

8 Measles 2.7 8 War 3.0

9 Road traffic accidents 2.5 9 Diarrhoeal diseases 2.7

10 Congenital abnormalities 2.4 10 HIV 2.6

1990 2020

Global Burden of Disease Study, 1996

*

**

*

World Health Report 2002

Mortality due to leading global risk factors

Cardiovascular risk factors

Blood pressure

Lipids

Diabetes

Smoking

BP and relative risk of stroke and CHD

Brit Med Bull 1994;50:272-98

Approximate mean usual BP Approximate mean usual BP

12376

12376

13684

13684

14891

14891

16298

16298

175105

175105

4.00

2.00

1.00

0.50

0.25

4.00

2.00

1.00

0.50

0.25

Stroke CHD

Blood Pressure and Risk of Congestive Heart Failure:the Framingham Study

0

20

40

60

80

100

120

140

35-44 45-54 55-64 65-74

Ave

rag

e a

nnu

al r

ate

/ 10

,00

0

Age at examination

NormotensiveBP <140/90 mmHg

HypertensiveBP >160/95 mmHg

Kannel et al. 1972

Systolic BP as a risk factor for renal failure

0

20

40

60

80

100

< 117 117-123 124-130 131-140 > 140

White men 300,645

African-American men 20,222

Systolic BP, mmHg

Inci

denc

e / 1

00,0

00 p

erso

n ye

ars

MRFIT ‘screenees’ Klag MJ, JAMA ‘97; 277: 1293

Cholesterol and risk of CHD & cardiovascular death

Approximate mean usual cholesterol (mmol/l)

4.0 4.5 5.0 5.5 6.0

4.00

2.00

1.00

0.50

0.25

Re

lati

ve

Ris

k

(51652 participants, 310 events)

Approximate mean usual cholesterol (mmol/l)

4.0 4.5 5.0 5.5 6.0

4.00

2.00

1.00

0.50

0.25

Re

lati

ve

Ris

k

Coronary Heart Disease(51652 participants, 310 events)

Re

lati

ve

Ris

k

Cardiovascular Death(9 studies, 49296 participants, 938 events)

Approximate mean usual cholesterol (mmol /l)

4.0 4.5 5.0 5.5 6.0

4.00

2.00

1.00

0.50

0.25

Approximate mean usual cholesterol (mmol /l)

4.0 4.5 5.0 5.5 6.0

4.00

2.00

1.00

0.50

0.25

Eastern Stroke & Coronary Heart Disease Project

Association between cholesterol and ischemic stroke

4.0 4.5 6.05.55.0

Rela

tive

risk

Approximate mean usual cholesterol concentration (mmol/L)

Asia Pacific Cohort Studies Collaboration

0

20

40

60

80

100

120

140

160

Developed Developing World

mil

lio

ns

Worldwide Prevalence of Diabetes1997

0

1

2

3

4

5

6

CH

D

CH

F

Str

oke

All

CV

D

Non

-CV

D

All

caus

e

Oth

er C

VD

Non-diabeticsDiabetics

Asia-Pacific Cohort Studies Collaboration

Risks of death in diabetics and non-diabetics

Smoking

0

50

100

150

200

250

300

350

1 2

Years

Cu

mu

lati

ve d

ea

ths

(in

mil

lio

ns)

Premature Deaths From Tobacco Use

Preventable if adults quit (halving global cigarette consumption by 2020)

Preventable if young adults do not start (halving global uptake by 2020)

Other premature deaths from tobacco-related causes

2000-2024 2025-2049

The World Health Report, 1999: Making a Difference

Blood Pressureor

Hypertension?

Hypertension and alcoholC. Lian, French army physician, 1915

0

5

10

15

20

25

30

Sobres Moyens Buveurs Grands Buveurs

% h

ype

rten

sive

Sobres <1 litre wine/ dayMoyens buveurs: 1-1.5 litres wine/ dayGrands buveurs: 2-2.5 litres wine/ dayTres grands buveurs: 3 litres wine/ day + 4-6 aperitifs

Tres GrandsBuveurs

Blood Pressureor

Hypertension?

The ‘normal’ distribution of diastolic BP within a population

0

5

10

15

20

50 60 70 80 90 100 110 120 130

Diastolic BP, mmHg

% o

f sc

reen

ed p

opul

atio

n

Hypertension: a practical definition

That level of blood pressure at which investigation and treatment

do less harm than good

Rose

Assessment of the Hypertensive Patient

History+

Examination

Hypertension risk factorsWeight

Family historySalt, Alcohol,Stress

Target organ damageHeartBrainEyes

Kidneys

Clues to 2o HTSymptoms

DrugsSigns

Other CV risk factorsLipids

SmokingDiabetesExercise

Concurrent conditionsAsthma

GoutPregnancy

Investigations• Urine• Blood• ECG

? Specialised investigations• Renal USS• 24-hour ABPM• Echocardiography• Angiography• Hormone assays• CT / MRI scanning

Indications for further investigations

• Clinical features of an underlying cause• Early onset (< 30 y)• Rapid progression• Proteinuria, haematuria, glycosuria• Severe hypertension, difficult to control• Vascular disease: peripheral, coronary, carotid• Heart failure, ‘flash’ pulmonary oedema• Lack of nocturnal dip on ABPM

Secondary causes of hypertension…

…. comprise a small proportion of overall cases, probably < 5%

The Heinz guide to hypertension

Renal artery stenosis

Pyelonephritis

Obstruct nephropathy

Vesico-ureteric reflux

Ask-Upmark kidney

Renal dysplasia

Renin JGA tumor

Glomerulonephritis

Polycystic disease

Analgesic kidney

Systemic sclerosis

ITT purpura

Haemolytic uremic

1o Aldosteronism

Cushing’s syndrome

Phaeochromocytoma

DOC excess

Cong adrenal h’plasia

Gluc remediable

Diabetes

Amyloidosis

Carbenoxalone

Obstruct sleep apnoea

Alcohol

MAO-I inhibitors

Pre-eclampsia

Liquorice

Sympathomimetics

Chronic renal failure

Poliomyelitis

11- OH-St dehyd def

Porphyria

Acromegaly

Aortic coarctation

intracranial pressure

Oral contraceptive

Endothelinoma

Lead poisoning

Corticosteroids

Renal artery stenosis

Secondary causes of hypertension

Polycystic kidney

Secondary causes of hypertension

Phaeochromocytoma

Phaeochromocytoma

MIBG scan

Target Organ Damage&

Complications of Hypertension

Target organ damage: left ventricular hypertrophy

Target organ damage: hypertensive retinopathy

Grade 4 hypertensive retinopathy

Intra-cerebralhaemorrhage

Complications of hypertension

Myocardial infarction inhypertrophied left ventricle

Management of Hypertension

Non-pharmacological/ lifestyle

Pharmacological

Measures that lower blood pressure: weight salt intake alcohol consumption physical exercise fruit & vegetable consumption

Measures to reduce cardiovascular risk: Stop smoking saturated fat, poly- & mono-unsaturates oily fish consumption total fat intake

Non-pharmacological interventions

BHS Guidelines 1999

The Mediterranean Diet

BP lowering treatment and cardiovascular risk

Brit Med Bull 1994;50:272-98

Tot

al n

umbe

r of

indi

v idu

als

affe

cted

Stroke CHD All vasculardeaths

All otherdeaths

1200

1000

800

600

400

200

% reductionin odds

38%SD 4

16%SD 4

T C

T C

T CT C

Fatal events

Non-fatal events

T=treatmentC=control

Drug treatment of hypertension

Diuretic

Beta-blocker

Calcium-channel blocker

ACE-inhibitor

(Alpha-blocker)

Angiotensin receptorblocker

Most hypertensives will need 2 drugs to control BP Drug combinations may be synergistic

How to choose anti-hypertensive therapy

ACE inhibitor (AII antagonist) Aor-blocker B

Calcium antagonist C Diuretic D

One drug: Younger, non-black A or BOlder, black C or D

Two drugs: (A or B) + (C or D)

Three drugs: (A or B) + C + D

Target blood pressure

< 140/90 mmHg

…. except in those with diabetes or chronic renal disease

< 130/80 mmHg

Cholesterol & cardiovascular disease

“Large randomised trials demonstrate lowering LDL- cholesterol by 1 mmol/l reduces non-fatal MI and fatal CHD by about 25% ( about half the the effect predicted from epidemiological studies for a similar reduction in long term cholesterol lowering in people without vascular disease ) “ Collins 2002With greater reductions in cholesterol there are correspondingly larger reductions in CHD endpoints.

Landmark Statin Trials: LDL-C Levels vs Events at 5 Years

Follow-up

5.4 (210)2.3 (90) 2.8 (110) 3.4 (130) 3.9 (150) 4.4 (170) 4.9 (190)

0

5

10

15

20

25

AFCAPS-S

WOSCOPS-S

WOSCOPS-PCARE-S

LIPID-P

4S-P

LIPID-S

CARE-P

4S-S

AFCAPS-P

Modified from Kastelein JJP. Atherosclerosis. 1999;143(suppl 1):S17-S21.

Per

cen

tag

e w

ith

CH

D e

ven

t

LDL-C, mmol/L (mg/dL)

S=statin treated; P=placebo treated* Extrapolated to 5 Years

Secondary preventionPrimary preventionSimvastatin

Pravastatin

Lovastatin

ASCOT-S*

ASCOT-P*Atorvastatin

HPSl-S

HPSh-S

HPSl-P

HPSh-P