Risk Factors for CHD

1
Risk Factors for CHD
Introduction to Cardiac Care Course4th September
2007
Dr Neil Chapman International Centre for
Circulatory Health, Imperial College St Marys
Hospital
2
Outline

• Epidemiology of CHD
• Overview of risk factors
• Ethnic differences in CHD risk factors
• Benefits of treating risk factors
• How do we do
• Conclusions

3
Selected major global risk factors for death
disability

• Alcohol
• Childhood sexual abuse
• High BMI
• High BP
• High cholesterol
• Illicit drugs
• Indoor smoke
• Iron deficiency
• Lack of contraception
• Lead exposure

• Low fruit vegetable intake
• Occupational injury
• Physical inactivity
• Tobacco
• Underweight
• Unsafe injections
• Unsafe water, sanitation
• Unsafe sex
• Vitamin A deficiency
• Zinc deficiency

World Health Report 2002
4
Global mortality due to leading risk factors
High blood pressure gt 115 mmHg systolic High
cholesterol gt 3.8 mmol/L
World Health Report 2002
5
Cause of death, UK
Men
Women
9
16
13
BHF Statistics Database, 2005
6
Deaths in UK 2001
7
Standardised mortality ratio for CHD by sex
country of birth, 1989/92, England Wales
SMR
www.heartstats.org
Wild S, McKeigue P (1997)
8
Death rates from CHD, men and women aged 35-74,
1998, selected countries
9
Changes in CHD death rates, men and women aged
35-74, 1989 - 1999, selected countries
10
All cardiovascular deaths, UK 1970 - 2001 (men
women, lt75y)
11
Why are CHD rates so high?Statistically proven
risk factors include

• Snoring
• Not having siesta
• Non - English mother tongue
• Slow beard growth
• No varsity athletics at college
• Poor church attendance

12
Risk Factors for CHD

• Modifiable
• High LDL cholesterol
• High blood pressure
• Smoking
• Low HDL cholesterol
• Lack of exercise
• Diabetes and glucose intolerance
• Left ventricular hypertrophy
• Central obesity
• Homocysteine
• Clotting factors
• Oral contraceptives

Non-modifiable Age Sex Family
history Genetic Other Birth weight
13
CARDIOVASCULAR DEATH
Why is the UK a World Title Contender?

• Bad luck? X
• Genetics? X
• Unidentified factor? X
• High levels of known risk factors? ?
• Low levels of intervention? ?

14
9 risk factors explain 90 of PAR of MI15152
cases AMI 14820 controls in 52 countries
Smoking ApoB/ApoA Hypertension Diabetes Abdominal
Obesity Psychosocial stress Fresh fruit
vegetables Alcohol Physical activity
Interheart, Lancet 2004
PAR population attributable risk
15
Major risk factors for coronary heart disease
16
Cholesterol and cardiovascular disease
Eastern Stroke Coronary Heart Disease Project
Asia Pacific Cohort Studies Collaboration
17
Cholesterol CV risk some facts

• Total cholesterol gt 3.8 mmol/L accounts for an
  estimated
• 56 of ischaemic heart disease
• 18 of cerebrovascular disease
• Overall, estimated to account for
• 4.4 million deaths (7.9 of total)
• 40.4 million DALYs

World Health Report 2002
18
BP risk of stroke
BP risk of IHD
Asia Pacific Cohort Studies Collaboration J
Hypertens 2003
19
BP cardiovascular risk - facts

• 10-12 / 5-6 mmHg higher usual BP associated
  with
• 25 higher risk of CHD
• 40 higher risk of stroke
• MacMahon et al. Lancet 1990
• SBP gt 115 mmHg accounts for an estimated
• 49 of ischaemic heart disease
• 62 of cerebrovascular disease
• World Health Report 2002

20
Most MIs strokes occur in individuals with
normal or near normal levels of BP
World Health Report 2002
21
HDL (high density lipoprotein) cholesterol CHD
T Chol (mmol/l)

CHD/1000 per year
HDL cholesterol (mmol/l)
22
CHD mortality by smoking status
Annual death rate/ 100,000 men
Daily cigarette consumption
23
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
24
but weve only just banned smoking in public
places
25
Interaction of cardiovascular risk factors
DBP ? 95 mmHg
Pardell J Hypertens 2005
26
Worldwide prevalence of diabetes 1997
27
Projected prevalence of diabetes in 2025
28
CV mortality in diabetics non-diabetics
3-fold increase in CHD mortality
6
Non-diabetics
5
Diabetics
4
Relative Risk
3
2
1
0
CHF
CHD
Stroke
All CVD
All cause
Non-CVD
Other CVD
Asia-Pacific Cohort Studies Collaboration
29
Risk factors in type 2 diabetic non-diabetic
populations
SBP
LDL
HDL
T Chol
Trigs
BMI (kg/m2)
Nathan DM, Lancet 1997
30
Lifestyle coronary heart disease risk
31
Obesity
6 year old boy - 15 stone (95 kg)
32
BESITY

• Obesity levels in UK have tripled in the past 2
  decades
• A fifth of men and a quarter of women are now
  obese.
• Obesity is rising among children.
• Maturity-onset diabetes is emerging in childhood.
  
• Obesity reduces life expectancy by 9 years.

33
(No Transcript)
34
The Danish advertising campaign promoting fresh
fruit vegetable consumption, 6-a-day .. and
exercise
35
Exercise
36
Physical fitness predicts CV mortality1960 men
followed for 16 years (baseline fitness by
bicycle ergometry)
Risk ratio for CV mortality, quartile 4 vs.
quartile 1 0.41, p0.013
Sandvik, NEJM 1993
37
Hypertension and alcohol
30
25
20
15
hypertensive
10
5
0
Increasing alcohol intake
C. Lian, French army physician, 1915
38
Hypertension and alcohol
30
25
20
15
hypertensive
10
5
0
Sobres lt1L wine/day
Grands buveurs
Moyens buveurs
Tres grands buveurs ?3L wine 4-6 aperitifs
C. Lian, French army physician, 1915
39
Ethnic differences in CHD risk factors
40
Standardised mortality ratio for CHD by sex
country of birth, 1989/92, England Wales
SMR
www.heartstats.org
Wild S, McKeigue P (1997)
41
Relative risk of hypertension and diabetes by UK
ethnic group
Relative risk
Whitehall II Whitty et al 1999
42
CVD risk factors (London men) by ethnicity
In one observational study in women, SBP 17
mmHg greater in blacks than whites
43
Risk factors in African-Caribbean and European
men UK, aged 40-64
plt0.05
Chaturvedi et al, 1993
44
African-Caribbean Blacks

• Lower risk of CHD death than whites
• But hypertension common (50 in gt 40 year olds)
• High risk of complications of hypertension
  (stroke, renal failure, LVH)
• Sensitive to salt restriction, diuretics, CCBs
• Less responsive than whites to ACE-i and
  ß-blockers
• 2-fold increased risk of diabetes

45
British South Asians

• Hypertension common
• High prevalence of type II diabetes
• Insulin resistance common
• Central obesity
• Diabetes, elevated fasting glucose
• Low HDL cholesterol
• High triglycerides
• High CVD risk (1.5 x risk calculated using charts)

46
Who should receive cardiovascular risk factor
treatment?Primary vs. Secondary prevention?
47
Facts about coronary artery disease

• Only 20 of coronary events are preceded by
  long-standing angina
• 57 of men 64 of women who die suddenly of CHD
  have had no prior symptoms
• In 62 of men and 46 of women the first sign of
  CAD is MI or death
• Only 70 survive their first CAD event

48

• The difference between primary and secondary
  cardiovascular disease prevention is about
• 2 minutes

49
Benefits of treating known coronary risk factors
50
BP lowering treatment and cardiovascular
riskMeta-analysis of trials of BP lowering in
mild-moderate hypertension
Collins et al, Lancet 1990
51
Benefits of BP lowering on CHD ? BP differences
in trials of BP lowering
1.50
1.25
1.00
Relative risk of CHD
0.75
0.50
0.25
2
4
-10
-8
-6
-4
-2
0
SBP difference between randomised groups (mmHg)
Lancet 2003
52
Lipid lowering - statins CHD preventionAnglo-Sc
andinavian Cardiac Outcomes Trial
Lipid-Lowering Arm
Lancet 2003 361 1149-58
53
Statins CHD preventionHeart Protection Study


HPS, Lancet 2002
54
Effect of smoking cessation on myocardial
re-infarction
Continued to smoke (n174) Stopped smoking (n
231)
Cumulative percentage of non-fatal reinfarction
Months
55
Lifestyle interventions risk factors

• Weight loss reduces BP
• Short-term studies of diet, exercise or both
• 5.1kg weight loss ? 4.4/3.6 mmHg BP ?
• Long-term studies (?2 years)
• 10kg weight loss ? 6.0/4.6 mmHg BP ?
• Alcohol moderation reduces BP
• Meta-analysis of 15 trials, n2234
• Reduced intake ? 3.3/2.0 mmHg BP ?
• Dose-response relationship

Neter et al. Hypertension 2003 Aucott et al.
Hypertension 2005
Xin. Hypertension 2001
56
. but a little alcohol is good for the heart
Relative risk of CHD by alcohol intake
Relative risk of CHD
Units /week
57
Dose-response relationship between physical
activity health benefit
Haskell, Med Sci Sports Exerc 1994
58
CHD risk factor management

• How do we do?

59
Secondary prevention in high risk (CHD)
patientsEUROASPIRE I II
Prevalence of risk factors ()
Obesity
Diabetes
Smokers
BP ? 140/90
TC ? 5mmol/l
Lancet 2001
60
Secondary prevention in high risk (CHD)
patientsEUROASPIRE I, II III
Prevalence of risk factors ()
Obesity
Diabetes
Smokers
BP ? 140/90
TC ? 5mmol/l
European Society of Cardiology 2007
61
Conclusions

• Major risk factors for CHD are known
• Treating these risk factors is possible
• Treating risk factors reduces risk of
• CHD events mortality
• Other cardiovascular events
• We can do better

62
(No Transcript)