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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.
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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) 1990 2020 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 depression3.74 Cerebrovascular disease 4.4 5 Ischemic heart disease3.45 COPD 4.2 6 Cerebrovascular disease2.86 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 Global Burden of Disease Study, 1996
* * * * Mortality due to leading global risk factors World Health Report 2002
Cardiovascular risk factors Blood pressure Lipids Diabetes Smoking
4.00 4.00 2.00 2.00 1.00 1.00 0.50 0.50 0.25 0.25 123 76 136 84 148 91 162 98 175 105 123 76 136 84 148 91 162 98 175 105 Approximate mean usual BP Approximate mean usual BP BP and relative risk of stroke and CHD Stroke CHD Brit Med Bull 1994;50:272-98
Normotensive BP <140/90 mmHg Average annual rate/ 10,000 Hypertensive BP >160/95 mmHg Age at examination Blood Pressure and Risk of Congestive Heart Failure:the Framingham Study Kannel et al. 1972
Systolic BP as a risk factor for renal failure Incidence / 100,000 person years Systolic BP, mmHg MRFIT ‘screenees’ Klag MJ, JAMA ‘97; 277: 1293
Cholesterol and risk of CHD & cardiovascular death Coronary Heart Disease (51652 participants, 310 events) Cardiovascular Death (9 studies, 49296 participants, 938 events) 4.00 4.00 4.00 4.00 (51652 participants, 310 events) 2.00 2.00 2.00 2.00 Relative Risk Relative Risk Relative Risk 1.00 1.00 1.00 1.00 0.50 0.50 0.50 0.50 0.25 0.25 0.25 0.25 4.0 4.0 4.5 4.5 5.0 5.0 5.5 5.5 6.0 6.0 4.0 4.0 4.5 4.5 5.0 5.0 5.5 5.5 6.0 6.0 Approximate mean usual cholesterol ( Approximate mean usual cholesterol ( mmol mmol /l) /l) Approximate mean usual cholesterol ( Approximate mean usual cholesterol ( mmol mmol /l) /l) Eastern Stroke & Coronary Heart Disease Project
Relative risk 4.0 4.5 5.0 5.5 6.0 Approximate mean usual cholesterol concentration (mmol/L) Association between cholesterol and ischemic stroke Asia Pacific Cohort Studies Collaboration
Non-diabetics Diabetics CHF CHD Stroke All CVD All cause Non-CVD Other CVD Risks of death in diabetics and non-diabetics Asia-Pacific Cohort Studies Collaboration
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
Hypertension and alcoholC. Lian, French army physician, 1915 30 25 20 15 % hypertensive 10 5 0 Tres Grands Buveurs Sobres Moyens Buveurs Grands Buveurs Sobres <1 litre wine/ day Moyens buveurs: 1-1.5 litres wine/ day Grands buveurs: 2-2.5 litres wine/ day Tres grands buveurs: 3 litres wine/ day + 4-6 aperitifs
The ‘normal’ distribution of diastolic BP within a population % of screened population 50 60 70 80 90 100 110 120 130 Diastolic BP, mmHg
Hypertension: a practical definition That level of blood pressure at which investigation and treatment do less harm than good Rose
Hypertension risk factors Weight Family history Salt, Alcohol,Stress History+Examination Concurrent conditions Asthma Gout Pregnancy Clues to 2o HT Symptoms Drugs Signs Target organ damage Heart Brain Eyes Kidneys Other CV risk factors Lipids Smoking Diabetes Exercise
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
Secondary causes of hypertension Renal artery stenosis
Secondary causes of hypertension Polycystic kidney Phaeochromocytoma
Phaeochromocytoma MIBG scan
Complications of hypertension Intra-cerebral haemorrhage Myocardial infarction in hypertrophied left ventricle
Management of Hypertension Non-pharmacological/ lifestyle Pharmacological
Non-pharmacological interventions 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 BHS Guidelines 1999
Non-fatal events 1200 Fatal events 1000 T=treatment C=control 800 Total number of individuals affected 600 T T T T C C C C 400 200 Stroke CHD All vascular deaths All other deaths 38% SD 4 16% SD 4 % reduction in odds BP lowering treatment and cardiovascular risk Brit Med Bull 1994;50:272-98
Drug treatment of hypertension Diuretic ACE-inhibitor • Most hypertensives will need 2 drugs to control BP • Drug combinations may be synergistic Angiotensin receptor blocker Calcium-channel blocker Beta-blocker (Alpha-blocker)