Risk Stratification in CVD Prevention How to Identify Cardiovascular Risk in the Office

1. Risk Stratification in CVD PreventionHow to Identify Cardiovascular Risk in the Office Dr. Thomas G. Allison Cardiovascular Diseases and Internal Medicine Mayo Clinic Rochester, MN

2. Clinically-Based CVD Prevention • Risk assessment for all patients • Set evidence- and guideline-based goals for specific risk factors • Lifestyle management • Pharmacologic intervention for selected risk factors in appropriate patients

3. Levels of Risk in Primary Prevention • Highest: the patient has evidence of CVD • High: the patient has high immediate risk (a probability of > 20% in the next 10 years) for having a CVD event • 2 or more major risk factors BP > 160/100 Diabetes Cigarette smoking LDL cholesterol > 160 mg/dL HDL cholesterol < 35 mg/dL men, < 45 mg/dL women Family history of premature CVD

4. Levels of Risk in Primary Prevention • Intermediate: the patient will not likely have a CVD event in the next 10 years, but has a high lifetime risk • 1 major risk factor or • > 2 minor risk factors BP 140-159/90-99 mmHg Blood glucose 100-129 mg/dL LDL cholesterol 130-159 mg/dL HDL cholesterol 35-39 mg/dL men, 45-49 mg/dL women

5. Levels of Risk in Primary Prevention • Low: the patient may develop CVD at older ages without lifestyle adjustment • 1 or 2 minor risk factors • Minor risk factors are generally correctable with lifestyle change • Diet change, exercise, weight loss • Very low: the patient will not likely develop CVD during his or her lifetime • No major or minor risk factors

6. What Do We Do with Risk? • Highest risk patient • Use secondary prevention guidelines to manage risk factors • Further evaluation: exercise test ± imaging or angiography • High risk patient • Treat all major risk factors pharmacologically • Provide appropriate lifestyle counseling • Exercise test

7. What Do We Do with Risk? • Intermediate risk patient • Lifestyle counseling • Pharmacologic treatment of any major risk factors • Initial follow-up in 3-6 months, annually thereafter • Consider exercise test

8. Stress Testing for Risk Stratification in Primary Prevention • Look for clinical disease • Evaluate symptoms • Establish prognosis • Prior to prescribing exercise • Intermediate-high risk patients • High threshold of disease

9. What Do We Do with Risk? • Low risk patient • Recommend appropriate lifestyle change • Re-evaluate in 3-12 months • Very low risk patient • Reassure • Suggest additional evaluation in 3-5 years

10. Prediction of Lifetime Risk for Cardiovascular Disease by Risk Factor Burden at 50 Years of Age Donald M. Lloyd-Jones et al Circulation 2006;113:791-798

11. High Intermediate Low Very Low

12. Identifying Risk in the OfficeStep 1 • Symptoms: Angina, TIA, claudication • Physical exam: bruits, AAA, diminished peripheral pulses, reduced ABI (0.90 for men and 0.85 for women), xanthomas • ECG: Q-waves, ST-T wave abnormalities, LVH

13. Angina has 3 characteristics • Feels like tightness, pressure, squeezing, or burning (not generally a sharp pain) • Starts in the center of the chest, behind or underneath the sternum (breast bone) – may radiate to the neck and jaw, around the back, down the arms (left more common than right) • Increased by physical activity, relieved by rest (or nitroglycerine)

14. Rose Angina Questionnaire • 1. Do you get pain or discomfort in your chest when walking up hills, stairs or hurrying on level ground? (Yes or no) Positive = “yes” • 2. If you get pain or discomfort in the chest when walking, do you usually stop? Slow down? Carry on at the same pace? (Mark the alternative best fitting) Positive = “stop” or “slow down” • 3. If you stop or slow down, does the pain disappear after less than 10 minutes? Or after 10 minutes or more? (Mark the alternative best fitting) Positive = “after less than 10 minutes”

15. Other symptoms that might represent coronary heart disease include • Fatigue • Reduced exercise tolerance • Shortness of breath • Symptoms suggesting other vascular disease • TIA • Claudication

16. Assessing CVD Risk in the OfficeStep 2 • Measure height, weight, waist circumference, calculate BMI • Measure blood pressure and pulse • Discuss family history of premature CVD • Review lifestyle: smoking, physical activity, diet (servings of fruits/vegetables per day)

17. Non-Fasting Blood Sugar, Lipids • Physicians in developing countries (or in low income populations in developed countries) may not have the luxury of scheduled visits for measurement of fasting blood sugar and lipids • Inexpensive, fingertip, glucometer • Opportunities for measuring these factors in non-fasting states will present

18. Non-Fasting Blood Sugar • In routine cases where patient is not fasting but not acutely ill, FBG > 150 mg/dL may serve to identify patients with diabetes or impaired fasting glucose • Consider measuring hemoglobin A1C • Reflects status prior to acute illness • May underestimate prevalence of diabetes • Elevated A1c indicates need to begin therapy

19. When to Add a Lipid ProfileStep 3 • Positive family history of CVD • BMI > 28 kg/m2 or prominent waist circumference (> 102 cm men, 89 cm women) • High non-fasting glucose • Improper dietary habits • Elevated blood pressure • Cigarette smoking • Consider for all patients if resources available

20. Honduras versus US Statistics • Total expenditure on health per capita • Honduras: $241 US: $6,714 • Gross national income per capita • Honduras: $3,240 US: $44,070 • Total expenditure on health as % of GDP • Honduras: 7.4% US: 15.3% World Health Statistics 2008 Financial data from 2006

21. Fasting Lipid Profile?Non-HDL Cholesterol • Easy to calculate: Total-C – HDL-C • Predicts CVD risk as well as LDL-C • Goals = LDL-C goals + 30 mg/dL • Not much affected by non-fasting samples • Can be used opportunistically

22. More Tools for Assessing CHD Risk in Asymptomatic Adults • Novel risk factors (CRP, Lp(a), Lp-PLA2, etc.) • Advanced lipid testing • LDL particle concentrations, apolipoproteins • Non-invasive imaging • EBCT, CIMT, CTA, MRI • Arterial function studies • Brachial reactivity, ENDO-PAT, arterial stiffness

23. Framingham Risk Score

24. Framingham Risk Score • Very age dependent • Short-term (10-year) risk projections • Ignores many factors that likely contribute to cardiovascular risk • Developed in USA with people of (western) European descent • Does it have to be modified for developing nations or different racial or ethnic groups?

25. Framingham 10-year risk by age for a male or female ●smokes 1 ppd ●TC = 212 (5.5), HDL-C = 42 (1.1) ●No DM, normal BP

26. Three Options for Preventing CVD in Asymptomatic Individuals • Wait until the patient has had a CVD event • Wait until the patient has signs of atherosclerosis • Requires expensive imaging procedures • Treat factors that lead to an increased lifetime risk of CV disease • How do we know when it is time to start? • Likely 10-20 years earlier than current practice

27. Rochester, MN early fall

28. Comments? • Questions?