Should we base treatment decisions on short-term or lifetime CVD risk? Rod Jackson University of Auckland New Zealand

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1 Should we base treatment decisions on short-term or lifetime CVD risk? Rod Jackson University of Auckland New Zealand

2 Presentation outline Strengths & weaknesses of short-term risk approach Strengths & weaknesses of lifetime risk approach A model incorporating the strengths of both approaches

3 Presentation outline Strengths & weaknesses of short-term risk approach Strengths & weaknesses of lifetime risk approach A model incorporating the strengths of both approaches

4 Why inform treatment decisions by estimating short-term (5 or 10 yr) CVD risk 1. Treatment works rapidly within 1-2 years

5 Blood pressure lowering & stroke Progress Lancet 2001; 358:

6 Lipid lowering & CVD HPS Lancet 2002; 360: 7 22

7 Why inform treatment decisions by estimating short-term (5 or 10 yr) CVD risk 1. Treatment works rapidly within 1-2 years 2. Treatment rapidly reverses most excess risk

8 Relative Risk Reduction Effects in cholesterol lowering trials mostly explained by amount of cholesterol reduction Regression line from intervention studies: 1 mmol/l 21% CHD ; cohort studies 30% (but will be more after first few years) 40% 30% 20% 10% 0% -10% -20% Net cholesterol difference (mmol/l) Statin (3 groups of trials) Dietary & other Fibrate Anthony Rogers (unpublished)

9 Relative Risk Reduction Effects in BP lowering trials mostly explained by amount of BP reduction Regression line: 10 mmhg 32% stroke ; cohort studies 35% 40% 30% 20% 10% 0% -10% Net SBP difference (mmhg) -20% Drug vs.. Placebo Drug vs.. Drug More vs.. Less Anthony Rogers (unpublished)

10 Why inform treatment decisions by 5 yr rather than 10 yr CVD risk? 1. Treatment works rapidly within 1-2 years 2. Treatment rapidly reverses most excess risk 3. Evidence of BP and lipid-lowering treatment benefit comes from RCTs 5 years duration 4. Re-measuring risk 5 yearly would identify most patients who change risk categories 5. Early GP feedback predicting 10 year risk (& benefits) was too distant to inform current treatment decisions

11 Presentation outline Strengths & weaknesses of short-term risk approach Strengths & weaknesses of lifetime risk approach A model incorporating the strengths of both approaches

12 35 yr old male Overweight smoker Non diabetic BP 140/ 80 mmhg TC 6.0 mmol/l HDLC 1.0 mmol/l TC/HDL = yr CVD risk = 4% but long-term risk

13 Preventing a CVD event in a young person must save more life-years than preventing an event in an older person????? 35 yrs old: 10% 5 yr CVD risk 75 yrs old: 10% 5 yr CVD risk

14 Does preventing a CVD event in a young person save more life-years than preventing an event in an older person? Su May Liew et al. (unpublished) Estimating potential life-years gained from treatment at different ages 1. Case fatality increases exponentially with age 2. Time preferences: we value time in the near future more than in the distant future 3. Competing risk from other causes of death

15 Potential years of life lost by men with a 10% five-year CVD risk by delaying treatment for 5 years Liew et al. unpublished

16 Predicted 5-year CVD risk ranks patients aged years by their potential life years lost due to a CVD event

17 Presentation outline Strengths & weaknesses of short-term risk approach Strengths & weaknesses of lifetime risk approach A model incorporating the strengths of both approaches

18 Lifetime risk of CVD to age 95 yrs: Framingham 3.2% of men 4.5% of women Lloyd-Jones et al. Circ 2006;113:

19 Life-time CVD risk chart No Diabetes Diabetes Nonsmoker Smoker Ratio of Total Cholesterol:HDL Nonsmoker Smoker Ratio of Total Cholesterol:HDL / /95 140/85 120/75 AGE / /95 140/85 120/75 180/ /95 140/85 120/75 AGE / /95 140/85 120/75 180/ /95 140/85 120/75 AGE / /95 140/85 120/75 180/ /95 140/85 120/75 AGE / /95 140/85 120/ Ratio of Total Cholesterol:HDL Ratio of Total Cholesterol:HDL

20 Lifetime risk of CVD to age 95 yrs: Framingham 10 yr 5 yr 5 yr 10 yr 3.2% of men 4.5% of women Lloyd-Jones et al. Circ 2006;113:

21 62% 72% 54 yr old European female, nonsmoker, BMI = 33.2, SBP = 150 mm Hg; TC:HDL ratio = 5.3, 31 yr old Indian female, nonsmoker, BMI = 27.2, SBP = 128 mm Hg, TC:HDL ratio = 5 QRISK. BMJ 2010

22 Presentation outline Strengths & weaknesses of short-term risk Strengths & weaknesses of lifetime risk A model incorporating the strengths of both approaches

23 35 yr old male Overweight smoker Non diabetic BP 140/ 80 mmhg TC 6.0 mmol/l HDLC 1.0 mmol/l TC/HDL = yr CVD risk = 4% but long-term risk

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32 Recommendation Inform current treatment decisions on current short-term (5 or 10-yr) risk but Inform long-term prevention by estimating heart age & forecasting future short-term risk