1. Coronary Artery Disease **CAD Risk Stratification**
Dr. Joseph A Akamah
2016

2. OBJECTIVES To describe the burden of CAD
To discuss the risk factors for CAD
To discuss the role of global risk scores
To discuss the role of clinical, stress testing, calcium score and CTA in risk stratification

3. Worldwide Causes of Mortality
World Health Organization

4. Distribution of CVD deaths: Males vrs Females

5. Chart 22-2
The 16 leading diagnoses for direct health expenditures, United States, 2007 (in billions of dollars)
Roger, V. L. et al. Circulation 2011;123:e18-e209

7. AHA Heart Disease and Stroke Statistics — 2008

8. Breakdown of Deaths Due to Cardiovascular Disease
Focus on problem areas to maximize preventive measures
Circulation. 2011;123:e18-e209

9. It is all about Atherosclerosis!
Lipid accumulation and modification.
Endothelial dysfunction.
Inflammation.

10. The biology of the artery wall in the atherogenesis.
O’Brien KD, Chait A.
Med Clin North Am 1994;78:41-67.

11. The Endothelium

12. Endothelial Dysfunction

13. Inflammation: Concept of Vulnerable and Stable Plaques
Characteristics of Vulnerable Plague
Large Lipid Core
High Macrophage Density/Activity
Low SMC Density
Thin Cap-Disorganized Collagen
High TF Content

15. CAD Risk Factors Modifiable Nonmodifiable Increasing Age Male gender
Tobacco Use
Elevated LDL cholesterol
Low HDL cholesterol
High Triglycerides
High blood pressure
Diabetes
Physical Inactivity
Obesity
Diet high in Saturated fat
Social Stress: Poverty, Social Isolation, Stressful life
Alcohol 1 to 2 drinks may lead to 30% (reduce)
Medications
Increasing Age
Male gender
Family history of premature CHD
Ethnic Group/Race

16. INTERHEART Study Included population in 52 countries
Identified 9 risk factors responsible for 90% of the CVD risk:
Smoking
Dyslipidemia
Hypertension
Diabetes
Obesity
Diet
Physical activity
Alcohol consumption
Psychosocial factors.
Lancet. 2004;364: l

17. Natural History of Coronary Artery Disease
Death MI
Unstable Angina
Stable angina
Atherosclerosis
Risk Factors
PREVENTION

19. Comparison of risk factors considered in the overall cardiovascular risk scores
Framingham
SCORE
PROCAM (Men)
Reynolds (Men)
Risk factors
Age, sex, total cholesterol,
HDL, smoking, sBP,
antihypertensive medication
Age, sex, total
cholesterol – HDL ratio, smoking, sBP
Age, LDL, HDL, smoking,
diabetes, sBP, triglycerides,
family history
Age, total cholesterol,
CRP, family history of
MI at age <60 years
Electronic address
iii/calculator.
heartscore.org
m/coronary_risk_assessme
nt.html
score.org/

21. CAD Pathophysiology 2 asymptomatic stable angina progressive angina
The patient’s risk is usually a function of four types of patient characteristics
CAD typically cycles in and out of clinically defined phases
asymptomatic
stable angina
progressive angina
unstable angina
acute MI
Functioning of the LV. (EF)
Anatomic extent and severity of atherosclerotic involvement of the coronary tree.
Evidence of a recent coronary plaque rupture (ACS)
General health and noncoronary comorbidity.

23. Clinical Classification of Chest Pain
Typical angina (definite)
Substernal chest discomfort with a characteristic quality and duration of 3-15 minutes
Provoked by exertion or emotional stress(Predictable)
Relieved by rest or NTG or absence of stressor
Atypical angina (probable)
Meets 2 of the above characteristics.
NonAngina chest pain
Meets one or none of the typical anginal characteristics.
Sharp pain, Pricking, lasting seconds, hours, days

24. Pretest Probability of Coronary Artery Disease by Age, Gender, and Symptoms
Age (Y)
Gender
Typical/
Definite Angina Pectoris
Atypical/
Probable Angina Pectoris
Nonanginal Chest Pain
Asymptomatic
30-39
Men
Women
Intermediate
Very low
Low
40-49
High
50-59
60-69

25. Prevalence (%) of Coronary Artery Disease According to Sex, Age, and Symptom
Age Range
Symptoms
None
Nonanginal Chest Pain
Atypical Angina
Typical Angina
Male
30-39 2 5 22 70
40-49 6 14 46 87
50-59 10 59 92
60-69 12 28 67 94
Female
<1 1 4 26 3 13 55 8 32 79 19 54 91
Diamond GA, Forrester JS. N Engl J Med 1979;300:

26. Nomogram showing the probability of severe (three-vessel or left main) coronary disease based on a five-point score.
One point is awarded for each of the following variables:
male gender
typical angina
history and ECG evidence of MI
diabetes and
use of insulin
Each curve shows the probability of severe coronary disease as a function of age
Hubbard BL, Gibbons RJ, et alArch Intern Med 1992;152:

27. Clinicals: EPIDEMIOLOGY
CHEST PAIN
Typical Angina, Atypical Angina or Nonanginal
Age
Gender
BAYES’ THEOREM
Past Experience + Present Observation = Future Interpretation
DIAMOND AND FORRESTER
1 mm ST-Segment Depression Varies According To Type of Chest Pain and Pretest Probability
Information Gained is 5X more In Atypical Angina Than Patients Without Symptoms and 2.5X that of Patients with Typical Angina
SENSITIVITY AND SPECIFICITY
PREDICTIVE VALUE AND RELATIVE RISK

28. Sensitivity and Specificity
Sensitivity: among those with disease, the proportion with a positive test (true positive)
Specificity: among those without disease, the proportion with a negative test (true negative)
Positive Predictive Value: among those with a positive test, the proportion that has the disease
Negative Predictive Value: among those with a negative test, the proportion that does not have the disease
Likelihood Ratio: the ratio of the probability of a certain test result in people with the disease to the probability in people without the disease

30. Brown KA, Rowen M. Impact of antianginal medications, peak heart rate and stress
level on the prognostic value of a normal exercise myocardial perfusion imaging study.
J Nucl Med 1993;34:

31. Incremental Prognostic Value of Clinical, Exercise, Myocardial Perfusion Imaging, and Cardiac Catheterization Data
Iskandrian AS, et al. J Am Coll Cardiol 1993;22: Independent and incremental prognostic value of exercise single-photon emission computed tomographic (SPECT) thallium imaging in coronary artery disease.

32. Hachamovitch R, Hayes SW, Friedman JD, Cohen I, Berman DS
Hachamovitch R, Hayes SW, Friedman JD, Cohen I, Berman DS. Comparison of the short-term survival benefit associated with revascularization compared with medical therapy in patients with no prior coronary artery disease undergoing stress myocardial perfusion single photon emission computed tomography. Circulation 2003;107:

34. DECISIONS

36. Three Groups based on Cardiac Mortality
High Risk >3% per year
Intermediate Risk 1-3% per year
Low Risk <1% per year

37. Non-Invasive Risk Stratification

39. Low risk

40. STRESS TEST: REAL WORLD
Why do you STRESS about Stress Testing?
Is the stress test necessary?
Is the reason
purpose of Diagnosis?
effectiveness of Therapy?
risk stratification?
To begin exercise program?
Help define what treatment plan?
Is any form of imaging required for localization of Ischemic segment?
Which imaging modality?
Which stress test modality is better for your px: exercise or pharmacology?
What type of (exercise) stress works better for a given form of imaging?

41. Stress Testing
An exercise ECG may be considered for cardiovascular risk assessment in intermediate-risk asymptomatic adults (including sedentary adults considering starting a vigorous exercise program), particularly when attention is paid to non-ECG markers such as exercise capacity
Stress echocardiography is not indicated for cardiovascular risk assessment in low- or intermediate-risk asymptomatic adults

42. Stress Testing
Stress MPI may be considered for advanced cardiovascular risk assessment in asymptomatic adults with diabetes or symptomatic adults with a strong family history of CHD or when previous risk assessment testing suggests high risk of CHD, such as a CAC score of 400 or greater
Stress MPI is not indicated for cardiovascular risk assessment in low- or intermediate-risk asymptomatic adults. (Exercise or pharmacologic stress MPI is primarily used and studied for its role in advanced cardiac valuation of symptoms suspected of representing CHD and/or estimation of prognosis in patients with known CAD.)

43. Perform if Indicated
Use a Global Risk Assessment Instrument (Global risk scores) (I)
Family history of atherothrombotic CVD should be obtained for cardiovascular risk assessment in all asymptomatic adults (I)
Measurement of hemoglobin A1C may be reasonable for cardiovascular risk assessment in asymptomatic adults without a diagnosis of diabetes (IIa)
Urinary Albumin Excretion IIa for DM/HTN, IIb for Intermediate risk

44. Perform if Indicated
Measurement of ABI is reasonable for cardiovascular risk assessment in asymptomatic adults at intermediate risk IIa
Measurement of carotid artery IMT is reasonable for cardiovascular risk assessment in asymptomatic adults at intermediate risk (IIa)
ECG: IIa for HTN/DM and IIb if no HTN/DM
ECHO: IIb for HTN and III if no HTN

45. Do Not Perform if Asymptomatic (Class III)
Genotype testing for CHD risk assessment in asymptomatic adults is not recommended
Lipoprotein and Apolipoprotein Assessments: No benefit
Measurement of natriuretic peptides is not recommended for CHD risk assessment in asymptomatic adults
Coronary CT Angiogram
Cardiac MRI

46. Recommendations for Measurement of C-Reactive Protein
Class IIa
In men 50 years of age or older or women 60 years of age or older with LDL cholesterol less than 130 mg/dL; not on lipid-lowering, hormone replacement, or immunosuppressant therapy; without clinical CHD, diabetes, chronic kidney disease, severe inflammatory conditions, or contraindications to statins, measurement of CRP can be useful in the selection of patients for statin therapy.
Class IIb
In asymptomatic intermediate-risk men 50 years of age or younger or women 60 years of age or younger, measurement of CRP may be reasonable for cardiovascular risk assessment.22,115 (Level of Evidence: B)
Class III: No Benefit
In asymptomatic high-risk adults, measurement of CRP is not recommended for cardiovascular risk assessment.116 (Level of Evidence: B)
In low-risk men younger than 50 years of age or women 60 years of age or younger, measurement of CRP is not recommended for cardiovascular risk assessment.22,115 (Level of Evidence: B)

47. Computed Tomography for Coronary Calcium
Measurement of CAC is reasonable for cardiovascular risk assessment in
Asymptomatic adults at intermediate risk (10% to 20% 10-year risk). (Class IIa)
Asymptomatic adults with diabetes, 40 years of age and older (Class IIa)
Measurement of CAC may be reasonable for cardiovascular risk assessment in persons at low to intermediate risk (6% to 10% 10-year risk) (Class IIb)
Class III: No Benefit
Persons at low risk (<6% 10-year risk) should not undergo CAC measurement for cardiovascular risk assessment.18,348,351 (Level of Evidence: B)

48. Coronary angiography –stable CAD
Chronic CAD who have lifestyle-limiting angina despite medical therapy
Markedly positive results on noninvasive stress testing
Successful resuscitation from sudden cardiac death
Documented ventricular tachycardia
Maybe considered
patients with nonspecific chest pain who have had recurrent hospitalizations, in order to completely exclude CAD as a cause for the current symptoms.

49. KEY MESSAGES Concept of Risk Stratification: Dynamic Process
Pre-Op Risk Stratification
New Angina
Chronic stable Angina
Assess Effectiveness of Therapy
Assess Progression
ACS: NSTEMI and UA
STEMI
Other Considerations
Females
Diabetics
Presence or absence of Co-morbidities

50. Strategies used for CAD Risk Stratification
KEY MESSAGES
Clinical
Noninvasive Tests
Electrocardiography
Echocardiography
Stress ECG
Stress Test + Echocardiography
Stress Test + Nuclear Myocardial Imaging
Viability Studies
MPI SPECT (Single Isotope or Dual Isotope)
PET
Cardiac MR
Cardiac CT Angiography
Invasive

51. KEY MESSAGES
The decision to order a specific stress test is based upon:
The pretest probability of CAD;
The ability of the patient to exercise;
The findings on the resting electrocardiogram (ECG)
The presence of comorbid conditions such as reactive airways disease

52. Diagnosis of Coronary Artery Disease

53. THANK YOU