Download Screening for Cardiovascular Disease and Risk Factors

Launch of the MOH
Clinical Practice Guidelines on
Screening for
Cardiovascular Disease
and Risk Factors
23rd April 2011
Global Risk Assessment
Dr Low Lip Ping
Low Cardiology Clinic
Global Risk Assessment
•
•
•
•
•
•
Categories of Risk
Absolute (Global) Risk
Multivariable Risk Assessment
Risk Scores
Singapore Coronary Risk Score
Managing Risk Groups
Cardiovascular Risk Assessment
Assessment of a patient's cardiovascular
risk may be used for
• the targeting of preventive treatments
of individual patients who are
asymptomatic but at increased risk for
the development of CVD
• adjustment of the intensity of risk
reduction therapy to the level of risk
Risk Categories
• Appropriate application of preventive
measures requires an understanding of
the categories of risk
• 3 risk categories often referred to viz
 absolute risk
 relative risk
 attributable risk.
Absolute Risk
• Absolute risk is also referred to as
Global risk
• Absolute risk
 defines the probability of developing
disease over a finite period
 can be qualified as high or low
 can be either short-term (eg over 10
years) or long-term or even lifetime
Relative Risk
The relative risk (RR) is a measure of association
between a disease or condition and a factor under
study.
It is calculated by dividing the incidence rate among
those exposed to the factor by the incidence rate
among those not exposed to the factor.
RR = Incidence in the exposed
Incidence in the nonexposed
Attributable Risk
Population attributable risk (PAR): is the portion of
the incidence of a disease in the population
(exposed and nonexposed) that is due to exposure.
It is the incidence of a disease in the population that
would be eliminated if exposure were eliminated.
The PAR is calculated by subtracting the incidence in
the unexposed from the incidence in total
population (exposed and unexposed)
Multivariable risk prediction
Epidemiological studies have identified key risk
factors that account for most CVD burden in the
community, and demonstrated the clustering and
conjoint influences of multiple risk factors in
mediating cardiovascular risk.
Risk of coronary disease by number of associated risk
factors
Multivariable risk prediction
These research findings have been used to devise
multivariable risk prediction tools that synthesize
vascular risk factor information to yield estimates
of absolute (global) CVD risk in individual
patients
These tools are also referred to as
risk scores
Multivariable risk prediction
These risk scores can be used to assess in
individual patients the absolute risk of
developing all atherosclerotic CVD or specific
components of CVD, ie, coronary heart disease,
stroke, peripheral vascular disease, or heart
failure.20
Importance of global CVD risk
assessment
• Cardiovascular prevention strategies may
vary in benefit depending on the
underlying level of cardiovascular risk.
• The absolute reduction in risk is important
to estimate, to adequately assess the risk
versus benefit of any prevention strategy.
Importance of global CVD risk
assessment
• If the relative risk reduction is equal across
risk strata, the absolute reduction would be
greater in a high-risk cohort than in a lowrisk cohort.
• For this reason, it is very important to
accurately estimate the cardiovascular risk
Importance of global CVD risk
assessment
In addition to rendering treatment most costeffective, multivariable risk assessment also
avoids overlooking high risk CVD individuals with
multiple marginal risk factors and avoids
needlessly alarming persons with only 1 isolated
risk factor.
High short-term CHD risk
Might be
• defined as a probability of developing a fatal or
nonfatal myocardial infarction of >20% in the
next 10 years
• identified by the presence of clinical
atherosclerotic disease in other arterial beds, by
the presence of subclinical atherosclerosis, or by
multiple risk factors.
Risk Scores
• Several algorithms or risk scores have been
described to facilitate the assessment of risk in
individual patients.
• Most risk scores have included age, sex, blood
pressure level, smoking status, diabetes
mellitus, and lipid values.
• Although obesity is a risk factor, it is frequently
omitted because its influence is largely
mediated through other cardiovascular risk
factors in the short term (5- to 10-year timeline
of most risk estimation algorithms).
Table 1 Characteristics of the Various Cardiovascular Risk Scores
Study
FRS
Variables
Included
Outcomes
Age, sex, BP, CHD (angina,
smoking, use of MI, sudden
HTN
death)
medications,
TC, and HDL
Population
Derived
Population
Validated
ROC
Limitations
U.S. white men Men, women, 0.7744 (w)
and women,
blacks, Europe, 0.7598 (m)
ages 30–62 yrs Mediterranean,
and Asia
Age <30 yrs,
>65 yrs,
JapaneseAmerican men,
Hispanic men,
NativeAmerican
women, LVH,
DM, and severe
HTN
0.793 (w) 0.763 Mainly white
(m)
Global
Age, sex, SBP, CHD, stroke, U.S. white men Framingham
cardiovascular smoking, TC, CHF, or PVD and women,
offspring
risk
HDL, DM, and
ages 30–74 yrs
use of HTN
medications
BMI = body mass index; BP = blood pressure; CABG = coronary artery bypass graft surgery; CHD = coronary
heart disease; CVD = cardiovascular disease; DM = diabetes mellitus; FRS = Framingham risk score; HDL =
high-density lipoprotein; hgb = hemoglobin; hsCRP = high-sensitivity C-reactive protein; HTN = hypertension;
LVH = left ventricular hypertrophy; m = men; MI = myocardial infarction; PTCA = percutaneous transluminal
coronary angiography; ROC = receiver-operating characteristic; TC = total cholesterol; TIA = transient ischemic
attack; w = women.
Study
SCORE
ASSIGN
Reynolds
QRISK
Reynolds, men
Variables Included
Outcomes
Population Derived Population Validated
ROC
Limitations
Age, sex, smoking, Fatal CV events
European men and Europe
either TC or TC/HDL
women, ages 45–64
ratio, broken up into
yrs
areas of high and low
CVD risk
Age, sex, SBP, TC, CV death, CHD
Scotland men and
Scotland
HDL, +family
admission, CABG, or women, ages 30–74
history, social
PTCA
yrs
deprivation
Age, SBP, smoking, MI, stroke, coronary U.S. women, age >45 U.S. women
total cholesterol,
revascularization, or yrs
HDL, hsCRP,
CV death
+family history,
hgbAIc if DM
0.71–0.84
No nonfatal events,
"single" risk factor
measurements made,
rather than "usual"
0.7841 (w) 0.7644
(m)
Age, sex, SBP,
smoking, ratio of
TC/HDL, +family
history, use of HTN
medications, BMI,
social deprivation
Age, sex, SBP,
smoking, total
cholesterol, HDL,
hsCRP, +family
history, hgbAIc if
DM
0.7879 (w) 0.7674
(m)
Marginally better
than Framingham,
still overestimated
risk
Mainly white, all
women,
socioeconomic status
not generalizable, BP,
weight, and family
history, all taken by
self-report
"Home advantage,"
data validated from
same population it
was originally
derived
MI, CHD, stroke,
TIA
United Kingdom men United Kingdom
and women, ages 35–
74 yrs
MI, stroke, coronary U.S. men, ages 50–80 U.S. men
revascularization, or yrs
CV death
0.808 (w)
0.7–0.714 (m)
Mainly white,
middle-aged,
socioeconomic status
and access to care not
generalizable, selfreported with family
history
ASSIGN = Assessing Cardiovascular Risk to Scottish Intercollegiate Guidelines Network/SIGN to Assign Preventative Treatment; BMI = body mass index; BP = blood pressure; CABG = coronary artery bypass graft surgery;
CHD = coronary heart disease; CVD = cardiovascular disease; DM = diabetes mellitus; FRS = Framingham risk score; HDL = high-density lipoprotein; hgb = hemoglobin; hsCRP = high-sensitivity C-reactive protein; HTN =
hypertension; LVH = left ventricular hypertrophy; m = men; MI = myocardial infarction; PTCA = percutaneous transluminal coronary angiography; ROC = receiver-operating characteristic; QRISK = QRESEARCH
Cardiovascular Risk Algorithm; SBP = systolic blood pressure; SCORE = Systematic Coronary Risk Evaluation; TC = total cholesterol; TIA = transient ischemic attack; w = women.
3.2 Global cardiovascular risk assessment
In asymptomatic individuals it is recommended
that the risk of cardiovascular disease first be
estimated based on the global assessment of risk
Grade C, Level 2+
S
The Framingham Risk Score adapted to the
Singapore population should be used to give
an estimate of an individual’s risk of major
coronary artery disease events.
Grade D, Level 4
Singapore CHD Risk Score
• 10-Year CHD Risk Score for Chinese, Malay and Indian
males and females in Singapore derived from the
Framingham-based NCEP ATP III 10-Year Risk Score
Tables which have been modified taking into account the
Singapore cardiovascular epidemiological data.
• The score gives an estimate of an individual’s risk of
major coronary artery disease events, including
myocardial infarction and coronary death
Singapore CHD Risk Score
These risk scores are derived from the Framingham-based NCEP ATP
III 10-Year Risk Score Tables which have been modified taking into
account the Singapore cardiovascular epidemiological data.
This modification was carried out as part of a collaboration between
investigators at the Singapore Ministry of Health, Singapore General
Hospital, National University of Singapore and Prof. Ralph B
D’Agostino from the Framingham Heart Study, USA.
Table 2A-1 Estimation of 10-year
coronary artery disease risk for
men
Allocate points based on person’s
•
•
•
•
age,
total and HDL cholesterol levels,
smoking status and
systolic blood pressure (BP).
Check the total points against Table for
estimate of that person’s 10-year CHD risk.
Stratification for cardiovascular
disease risk
From the global cardiovascular assessment,
asymptomatic individuals can be categorised into
3 risk group categories viz:
• High risk (10-year CHD risk >20%)
• Intermediate risk (10-year CHD risk 10-20%)
• Low risk (10-year CHD risk <10%)
For the purpose of risk assessment, the 10-year CHD risk
refers to the risk of having myocardial infarction or
coronary death in the next 10 years.
Low risk asymptomatic individuals
In low risk individuals (<10% 10year risk of coronary artery disease)
further testing for coronary artery
disease is not routinely
recommended
Grade C, Level 2++
Intermediate risk asymptomatic
individuals
Further testing for coronary artery disease to
reclassify asymptomatic individuals in the
intermediate risk group to high risk group needs
to be considered because interventions to reduce
cardiovascular risk is intensified as the risk
category increases from low to high risk
individuals
Limitations of Singapore Coronary
Risk Score
• Substantial underestimation of lifetime risk,
when only a 10-year risk model is used
• Diabetes and family history not included
• Only coronary risk estimated not all
atherosclerotic disease eg stroke, peripheral
arterial disease, heart failure
Limitations of Singapore Coronary
Risk Score
• Misclassification of high-risk subjects as low or
intermediate risk and of very low-risk subjects
into higher strata of risk
• Minority of patients with coronary heart
disease have none of the traditional risk factors
• In a large proportion of patients with >1 risk
factors, coronary heart disease does not
develop
Change in risk status
Periodic monitoring is needed to assess
whether risk status has changed because
absolute risk rises with advancing age,
emergence of additional risk factors or
development of atherosclerotic disease
Original Singapore CHD Risk Score
Step 1
Identify the following individuals who automatically fall
into the High Risk Group:
(1) Individuals with established CHD
(2) Individuals with CHD Risk Equivalents defined as:
(a) diabetes mellitus
(b) atherosclerotic cerebrovascular disease,
peripheral artery disease or abdominal aortic
aneurysms
(Estimation of the 10-Year CHD Risk Score in these
individuals is not necessary).
East West Study: Patients with Diabetes
at Similar Risk to No Diabetes with MI
p<0.001
7-year incidence rate of MI (%)
50
40
30
p<0.001
No prior MI
MI
20
10
0
No diabetes
(n=1373)
Diabetes
(n=1059)
Adapted from Haffner SM et al. N Engl J Med 1998;339:229–234
Diabetic Patients
The results of studies by Haffner which concluded
that diabetes is a coronary artery disease risk
equivalent because it is associated with an
absolute risk equivalent to that for recurrent major
coronary events in patients with established
coronary artery disease have been accepted
worldwide for a decade now.
Diabetics have therefore been automatically
assigned to the high risk category
Diabetic Patients
This view is now questioned by a metaanalysis by Bulugahapitiya et al.
DIABETICMedicine 26, 142–148 (2009)
Is diabetes a coronary risk equivalent?
Systematic review and meta-analysis
U. Bulugahapitiya, S. Siyambalapitiya, J.
Sithole* and I. Idris
DIABETICMedicine 26, 142–148 (2009)
Is diabetes a coronary risk equivalent?
Systematic review and meta-analysis
A meta-analysis of 45,108 patients showed that
patients with diabetes without prior myocardial
infarction had a 43% lower risk of developing
total coronary artery disease events compared
with patients without diabetes with previous
myocardial infarction (summary odds ratio 0.56,
95% confidence interval 0.53-0.60).
Diabetic Patients
• Their meta-analysis did not support the
hypothesis that diabetes is a ‘coronary heart
disease equivalent
• The explanation for this discrepancy is likely
to be that diabetic patients now receive
optimal aggressive treatment strategy
including, the use of statins and
antihypertensive agents.
Diabetic Patients
People with diabetes should no longer be
automatically assigned to the high risk category
for cardiovascular risk. They should therefore
be based on appropriate patients’ coronary
artery disease risk estimates
Grade A, Level 1++
Limitations of Singapore Coronary
Risk Score
• Only coronary risk estimated not all
atherosclerotic disease eg stroke, peripheral
arterial disease, heart failure
General Cardiovascular Risk Score
• Primary care physicians engaged in preventive
health maintenance may want to assess risk of
developing any major atherosclerotic CVD event
using a general CVD risk assessment tool.
Ralph B. D’Agostino, Sr, PhD; Ramachandran S. Vasan, MD;
Michael J. Pencina, PhD; Philip A. Wolf, MD; Mark Cobain,
PhD; Joseph M. Massaro, PhD; William B. Kannel, MD
General Cardiovascular Risk Profile for
Use in Primary Care
The Framingham Heart Study
Ralph B. D’Agostino, Sr, PhD; Ramachandran S. Vasan, MD;
Michael J. Pencina, PhD; Philip A. Wolf, MD; Mark Cobain, PhD;
Joseph M. Massaro, PhD; William B. Kannel, MD
Circulation. 2008;117:
743-753
General Cardiovascular Risk Profile for Use in
Primary Care
The Framingham Heart Study
General Cardiovascular Risk Profile for Use in
Primary Care
The Framingham Heart Study
A sex-specific multivariable risk factor
algorithm can be conveniently used to
assess general CVD risk and risk of
individual CVD events (coronary,
cerebrovascular, and peripheral arterial
disease and heart failure).
Interactive Risk Calculator
From The Framingham Heart Study
CHD(MI and Coronary Death) Risk Prediction
Enter Values Here
National Cholesterol Education Program
Adult Treatment Panel III
Units
(Type Over
Placeholder Values in
Each Cell)
male (m) or female (f)
years
mg/dL
mg/dL
mmHg
yes (y) or no (n)
yes (y) or no (n)
f
70
130
60
119
n
y
10 years
10
0.03
3%
Risk Factor
Gender
Age
Total Cholesterol
HDL
Systolic Blood Pressure
Treatment for Hypertension {Only if SBP>120}
Current Smoker
Time Frame for Risk Estimate
Your Risk (The risk sco re sho wn is derived o n the basis o f an equatio n.
Other NCEP materials, such as A TP III print pro ducts, use a po int-based system
to calculate a risk sco re that appro ximates the equatio n-based o ne.)
Notes
If value is < the minimum for the field, enter the minimum value.
If value is > the maximum for the field, enter the maximum value.
0.04
0.03
0.05
age
Lowest
Low
age
32
37
42
47
52
57
62
67
0
0
0
0.01
0.02
0.03
0.05
0.07
0
0.01
0.01
0.02
0.04
0.06
0.08
0.1
32
37
42
47
52
57
62
67
77
0.12
0.16
77
0.10
0.15
0.20
0.25
Comparative Risks for
Same Age and Gender
Lowest=Total Chol<160,
HDL>60, Optimal SBP, No Trt
for Htn, Non-Smoker;
Low=Total Chol 160-199, HDL
50-59, Normal SBP, No Trt for
Htn, Non-Smoker
0.30
Tables for Graph
Lowest
0.02
0.09
0.01
These functions and programs were prepared by Ralph B. D'Agostino, Sr., Ph.D. and Lisa M. Sullivan, Ph.D., Boston University and The Framingham Heart
0.09
Study and Daniel Levy, M.D., Framingham Heart Study, National Heart, Lung and Blood Institute.
Your Risk Estimate,
WOMEN
Lowest=Total Chol<160,
HDL>60, Optimal SBP, No Trt
for Htn, Non-Smoker;
Low=Total Chol 160-199, HDL
50-59, Normal SBP, No Trt for
Htn, Non-Smoker
0.02
0.00
MEN
Lowest = Total Chol<160, HDL>60, Optimal SBP (<120), No Trt for Htn, Non-Smoker
Low = Total Chol 160-199, HDL 50-59, Normal SBP (<130), No Trt for Htn, Non-Smoker
Low
0.02
0
0.02
Summary
•
Cardiovascular prevention strategies may vary in benefit
depending on the underlying level of cardiovascular risk.
•
Assessment of a patient's cardiovascular risk may be used for

the targeting of preventive treatments of individual
patients who are asymptomatic but at increased risk
for the development of CVD

adjustment of the intensity of risk reduction
therapy to the level of risk
Summary
• The absolute reduction in risk is important to
estimate, to adequately assess the risk versus benefit
of any prevention strategy.
• Several algorithms or risk scores have been described
to facilitate the assessment of risk in individual
patients.
• Most risk scores have included age, sex, blood
pressure level, smoking status, diabetes mellitus, and
lipid values.
Summary
People with diabetes should no longer be
automatically assigned to the high risk
category for cardiovascular risk.
They should therefore be based on appropriate
patients’ coronary artery disease risk estimates
Summary
In asymptomatic individuals it is recommended that the
risk of cardiovascular disease first be estimated based on
the global assessment of risk
Grade C, Level 2+
The Framingham Risk Score adapted to the Singapore
population should be used to give an estimate of an
individual’s risk of major coronary artery disease events.
Grade D, Level 4
Summary
From the global cardiovascular assessment,
asymptomatic individuals can be categorised into
3 risk group categories viz:
• High risk (10-year CHD risk >20%)
• Intermediate risk (10-year CHD risk 10-20%)
• Low risk (10-year CHD risk <10%)
For the purpose of risk assessment, the 10-year
CHD risk refers to the risk of having myocardial
infarction or coronary death in the next 10 years.
Grade C, Level 2++
Summary
In low risk individuals (<10% 10-year risk of coronary
artery disease) further testing for coronary artery
disease is not routinely recommended
Grade C, Level 2++
Further testing for coronary artery disease to reclassify
asymptomatic individuals in the intermediate risk group
to high risk group need to be considered because
interventions to reduce cardiovascular risk is intensified
as the risk category increases from low to high risk
individuals
Summary
• Periodic monitoring is needed to assess
whether risk status has changed.
• Suggested improvements in risk score
application include development of a general
CVD risk score, incorporation of dabetes and
family history and development of an online
interactive risk calculator