Cardiovascular Disease Risk Assessment Tools

Cardiovascular Disease Risk Assessment Tools

Risk assessment is often considered a first step in the clinical management of cardiovascular disease (CVD). The following risk assessment tools are provided for the convenience of the clinician to support the CVD evaluation process and are not intended as a replacement for clinical judgement.

Step 1: In conjunction with patient's fasting lipid results, identify major risk factors and coronary heart disease (CHD) risk equivalents. 1,2

 

Major Risk Factors 1

__ Premature (<55 years) CHD in first-degree male relative

__ Male >45 years

__ Premature (<65 years) CHD in first-degree female relative

__ Female >55 years

__ Untreated hypertension

__ HDL-C <40 mg/dL

__ Treated hypertension

__ Smoker

 

CHD Risk Equivalents 1,3

__ Diabetes

__ Multiple risk factors that confer 10-year risk >20%

__ Peripheral artery disease

__ Abdominal aortic aneurysm

__ Symptomatic carotid artery disease

__ Chronic kidney disease

Step 2: Determine 10-year risk for patients with two or more risk factors using Framingham scoring. 1

See the following Tables 1 and 2.1

Table 1. Estimate of 10-year Risk for Males

 

Age (y)

Points

20-34

-9

35-39

-4

40-44

0

45-49

3

50-54

6

55-59

8

60-64

10

65-69

11

70-74

12

75-79

13

 

Total Cholesterol (mg/dL)

Points

20-39 (y)

40-49 (y)

50-59 (y)

60-69 (y)

70-79 (y)

<160

0

0

0

0

0

160-199

4

3

2

1

0

200-239

7

5

3

1

0

240-279

9

6

4

2

1

≥280

11

8

5

3

1

 

 

Points

20-39 (y)

40-49 (y)

50-59 (y)

60-69 (y)

70-79 (y)

Nonsmoker

0

0

0

0

0

Smoker

8

5

3

1

1

 

HDL (mg/dL)

Points

≥60

-1

50-59

0

40-49

1

<40

2

 

Systolic BP (mm Hg)

Untreated

Treated

<120

0

0

120-129

0

1

130-139

1

2

140-159

1

2

≥160

2

3

 

Point Total

<0

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

≥17

10-Year Risk %

<1

1

1

1

1

1

2

2

3

4

5

6

8

10

12

16

20

25

≥30

 

Table 2. Estimate of 10-Year Risk for Females

Age (y)

Points

20-34

-7

35-39

-3

40-44

0

45-49

3

50-54

6

55-59

8

60-64

10

65-69

12

70-74

14

75-79

16

 

Total Cholesterol (mg/dL)

Points

20-39 (y)

40-49 (y)

50-59 (y)

60-69 (y)

70-79 (y)

<160

0

0

0

0

0

160-199

4

3

2

1

1

200-239

8

6

4

2

1

240-279

11

8

5

3

2

≥280

13

10

7

4

2

 

 

Points

20-39 (y)

40-49 (y)

50-59 (y)

60-69 (y)

70-79 (y)

Nonsmoker

0

0

0

0

0

Smoker

9

7

4

2

1

 

HDL (mg/dL)

Points

≥60

-1

50-59

0

40-49

1

<40

2

 

Systolic BP (mm Hg)

Untreated

Treated

<120

0

0

120-129

1

3

130-139

2

4

140-159

3

5

≥160

4

6

 

Point Total

<9

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

≥25

10-Year Risk %

<1

1

1

1

1

2

2

3

4

5

6

8

11

14

17

22

27

≥30

Step 3: Calculate Reynolds Risk Score

Of all US women who experience coronary events, 20% do not have traditional risk factors.4 Moreover, many women who have traditional risk factors do not experience coronary events.4 Such disparities suggest the need for additional tools to refine risk assessment in certain patient populations.

In 2007, Ridker et al published findings from a study of 24,558 apparently healthy women 45 years of age and older that demonstrated improved accuracy for cardiovascular risk prediction.4 By evaluating the study population with an algorithm that incorporated smoking status, blood pressure, parental history of myocardial infarct before age 60, total cholesterol, HDL cholesterol, and hsCRP, risk categories for 40% to 50% of participants were reclassified.4 The Reynolds Risk Score calculation is as follows and is also available at www.reynoldsriskscore.org:4

10-year cardiovascular disease risk (%) = [1-0.98634(exp[B-22.325])] x 100%

Where:

B = 0.0799 x age + 3.137 x ln(systolic blood pressure) + 0.180 x ln(hsCRP) + 1.382 x ln(total cholesterol) – 1.172 x ln(HDL-C) + 0.134 x hemoglobin A1c (%) (if diabetic) + 0.818 (if current smoker) + 0.438 (if positive family history of premature MI)

Reynolds Risk Score

___ Yes

___ No

Mother / father having MI <60 years

___ Yes

___ No

Smoker

___ mm Hg

Systolic blood pressure

___ mg/dL

Total cholesterol

___ mg/L

hsCRP

___ mg/dL

HDL-C

Step 4: Using the results of Steps 1-3, define CVD risk.

Absolute Risk Categories According to National Cholesterol Education Program Update, 2004

10-Year Absolute Risk Category

Definition of Risk

*In 2004, the National Cholesterol Education Program (NCEP) further divided the "intermediate risk" category into "moderately high risk" and "moderate risk."

From Greenland P, Bonow RO, Brundage BH, et al. ACCF/AHA 2007 Clinical Expert Consensus Document on Coronary Artery Calcium Scoring by Computed Tomography in Global Cardiovascular Risk Assessment and in Evaluation of Patients With Chest Pain: A report of the American College of Cardiology Foundation Clinical Expert Consensus Task Force developed in collaboration with the Society of Atherosclerosis Imaging and Prevention and the Society of Cardiovascular Computed Tomography. J Am Coll Cardiol. 2007; 49(3):378-402.

High risk

CHD, CHD equivalents including two or more major risk factors plus 10-year risk for hard CHD (ie, CHD death, MI) >20%

Moderately high risk*

Two or more major risk factors plus 10-year risk for hard CHD 10% to 20%

Moderate risk*

Two or more major risk factors plus 10-year risk for hard CHD <10%

Low risk

None or one major risk factor (10-year risk for hard CHD usually <10%)

Step 5: Use additional tools to refine CVD risk.

Option A: Identify presence of metabolic syndrome

A secondary target of risk reduction is metabolic syndrome − a constellation of lipid and nonlipid risk factors. Metabolic syndrome enhances risk for CHD regardless of LDL-C level and is closely related to insulin resistance,1 which is promoted by physical inactivity and excess body fat (particularly abdominal fat). The presence of three or more of the following metabolic risk factors constitutes a diagnosis of metabolic syndrome. 1,5

Risk Factors for Metabolic Syndrome

___ Male: >40" waist circumference (Asian >35")

___ Male: HDL cholesterol <40 mg/dL

___ Female: >35" waist circumference (Asian >31")

___ Female: HDL cholesterol <50 mg/dL

___ Triglycerides ≥150 mg/dL

___ Fasting glucose ≥100 mg/dL

___ Elevated blood pressure ≥130/85 mm Hg

 

Option B: Consider noninvasive imaging to identify subclinical vascular disease.

Since a majority of heart attacks occur in people who are in the low risk or moderate or moderately high (formerly intermediate) risk categories,6 it has been suggested that traditional risk assessment methods (eg, Framingham scoring) may need enhancement. Noninvasive imaging studies may strengthen the predictive power of traditional approaches.

Coronary Arterial Calcium (CAC)

As part of the atherosclerotic process, coronary arterial calcium (CAC) occurs almost exclusively in atherosclerotic arteries and is absent in normal vessels. It occurs in small amounts in early lesions, which usually begin to appear when people are in their 20s and 30s. It is found more frequently in advanced lesions and in older age.7

Patients with calcified plaque are also more likely to have noncalcified or “soft” plaque that is prone to rupture and acute coronary thrombosis.7 This co-occurrence provides a means of more completely estimating the risk of coronary events by CAC scoring. Currently, electron-beam computed tomography (EBCT) and multi-detector computed tomography (MDCT) are the main, fast CT methods used to measure CAC.7

In a consensus document, the American College of Cardiology Foundation (ACCF) and the American Heart Association (AHA) concluded it is reasonable to use CAC scores in asymptomatic patients with intermediate risk (10% to 20% estimated 10-year risk for cardiovascular events), because CAC scores may add incremental risk prediction resulting in reclassification of this patient population into a higher risk category with concomitant therapy modification.7 With respect to CAC scores in low-risk patients (10-year risk <10%) and high-risk patients (10-year risk >20%), the ACCF/AHA consensus reported that currently available data indicate limited clinical utility in assessing the former and insufficient incremental discrimination to alter recommended aggressive treatment in the latter.7

 

Summary Relative Risk Ratios
 

CAC Score

Relative Risk

Note: Higher CAC scores are associated with higher relative risk, event rates.

From Grundy SM, Cleeman JI, Daniels SR, et al, "Diagnosis and Management of the Metabolic Syndrome: An American Heart Association/National Heart, Lung, and Blood Institute Scientific Statement," Circulation, 2005, 112(17):2735-52.

Average risk

1-112

1.9

Moderate risk

100-400

4.3

High risk

400-999

7.2

Very high risk

1000

10.8

Carotid Intima-media Thickness (CIMT)

Initial clinical CVD symptoms frequently arise when atherosclerosis has progressed; however, during the presumably long period of subclinical progression, arterial wall changes occur that are characterized by endothelial dysfunction and intima thickening. CIMT progression is closely related to major risk factors, and it is a well-validated predictor of cardiovascular disease.8,9 It is also associated with prevalent and incident CHD and stroke.10,11

Investigators from the Atherosclerosis Risk in Communities (ARIC) study followed a group of 13,145 patients for approximately 15 years and found the addition of CIMT along with plaque information improved CHD risk prediction.10 In addition, they concluded both CIMT and plaque information should be considered in patient populations with an estimated 10-year risk of 5% to 20% (intermediate risk).10 A consensus statement from the American Society of Echocardiography (ASE) underscores this study and findings from several others: CIMT measurement and plaque information can be useful in refining CVD risk assessment in patients without established CHD or risk equivalents and with an estimated 10-year risk of 5% to 20% (intermediate risk).11 The ASE further indicates CIMT might also be considered in:11

• Patients with a family history of premature CVD in a first-degree relative (male <55 years, female <65 years)

• Individuals <60 years of age with severe abnormalities in a single risk factor (eg, genetic dyslipidemia) who would otherwise not be candidates for pharmacotherapy

• Women <60 years of age with at least two CVD risk factors

Step 6: Based on clinical judgment, refine risk as necessary.

CHD Risk Classification12

Very High Risk (high-risk criteria + presence of additional risk factor)

High-risk criteria (any one of the following:

• Known CHD or cerebrovascular disease, or

• Clinically silent atherosclerosis as indicated by coronary calcium score (CAC) or intima-media thickness (CIMT), or

• CHD risk equivalent (type II diabetes mellitus, chronic kidney disease, peripheral vascular disease, abdominal aortic aneurysm, or >20% estimated 10-year risk)

PLUS any one of the following additional factors

• Two or more major risk factors (male >45 years of age, female >55 years of age, HDL-C <40 mg/dL, current smoker, hypertensive, family history of CHD <55 years of age male or <65 years of age female)

• One or more severe or poorly-controlled risk factors (type II diabetes mellitus or metabolic syndrome)

• Acute coronary syndrome

High Risk (one of the following)

• Known CHD or cerebrovascular disease, or

• Clinically silent atherosclerosis as indicated by coronary calcium score (CAC) or intima-media thickness (IMT), or

• CHD risk equivalent (type II diabetes mellitus, chronic kidney disease, peripheral vascular disease, abdominal aortic aneurysm, or >20% 10-year risk)

Moderate High Risk

• Two or more major risk factors (male >45 years of age, female >55 years of age, HDL-C <40 mg/dL, current smoker, hypertensive, family history of CHD <55 years of age male or <65 years of age female, 10% to 20% estimated 10-year risk)

Moderate Risk

• Two or more major risk factors (male >45 years of age, female >55 years of age, HDL-C <40 mg/dL, current smoker, hypertensive, family history of CHD <55 years of age male or <65 years of age female, <10% estimated 10-year risk)

Low Risk

• None or one major risk factor (male >45 years of age, female >55 years of age, HDL-C <40 mg/dL, current smoker, hypertensive, family history of CHD <55 years of age male or <65 years of age female)

Step 7: Establish therapy targets - actionable events that can be measured.

To optimize efficacy, safety, and cost-effectiveness, a generally accepted principle of CVD prevention is that the intensity of intervention should be adjusted to the level of risk.1

Therapy Target Goals

Risk

LDL-C (mg/dL)

LDL Particle Number* (nmol/L)

ApoB* (mg/dL)

Non-HDL-C† (mg/dL)

HDL-C (mg/dL)

Triglycerides (mg/dL)

*According to W. Cromwell (written communication, May 2011), more aggressive lowering may be needed based on clinical judgment.

†Calculated as total cholesterol minus HDL cholesterol (if triglyceride target >200 mg/dL)

From Cromwell W, Dayspring T, Richman M, eds. Lipid and Lipoprotein Disorders: Current Clinical Solutions. Baltimore, Md: International Guidelines Center; 2009.

Very high

<100 (consider <70)

<1000

<80

<130 (consider <100)

Male: >40; Female: >50

<150

High

<100 (optional <70)

<1000

<80

<130 (optional <100)

Male: >40; Female: >50

<150

Moderately high

<130 (optional 100)

<1300 (optional <1000)

<100 (optional <80)

<160 (optional <130)

Male: >40; Female: >50

<150

Moderate

<130

<1300

<100

<160

Male: >40; Female: >50

<150

Low

<160

<1600

<120

<190

Male: >40; Female: >50

<150

Step 8: Initiate clinical interventions.

Therapeutic lifestyle changes (TLC) are recognized to reduce LDL-C, LDL-P, and triglycerides as well as increase HDL-C. If TLC modifications do not achieve established therapy targets, consideration may need to be given to lipid altering medications. TLC components and lipid altering medications are generally well known and discussed in detail elsewhere.

Step 9: Evaluate response to therapy.

Based on clinical judgment, treatment efficacy should be assessed utilizing tools appropriate to established therapy targets and modifications made as required.

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