Preclinical Detection of CAD: Is it worth the effort? Michael H. Crawford, MD

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1 Preclinical Detection of CAD: Is it worth the effort? Michael H. Crawford, MD 1

2 Preclinical? No symptoms No physical findings No diagnostic ECG findings No chest X-ray X findings No diagnostic events 2

3 Detection of CAD? Visualization of coronary or other arterial plaques. NOT: Risk of CAD CAD equivalents diabetes Biomarkers 3

4 Techniques of Interest Coronary calcium detection by CT Carotid intima-media media thickness (CIMT) by ultrasound Insufficient Data: CT coronary angiography MRI/A Major current use is in symptomatic patients 4

7 CIMT at the Carotid Bifurcation 7

8 CIMT in the RCCA 8

9 Ideal Screening Test High sensitivity to detect the disease Early detection will alter management and improve outcomes Negative results will reassure that risk of disease is low Low false positive rate Motivates patient compliance Lee TH, Brennen TA. N Engl J Med 2002;345:

10 CT Coronary Calcium Detection Specificity for plaque near 100% Coronary angiography gold standard Sensitivity 80% Specificity 75%, frequent false positives Issues Ability to predict events? Outcomes influenced by early detection? Compliance motivated? 10

11 Six New Observational Studies of Event Risk 27,622 subjects RR any calcium detected 4.3 ( ) 5.2) Zero calcium, event risk <1% Independent risk factor Risk increases with the extent of calcium Conclusion Most useful in patients with intermediate clinical risk where treatment decisions would be impacted. 11

12 Seven-year risk of nonfatal myocardial infarction (MI) or death from coronary heart disease (CHD) based on Framingham Risk Score, stratified by CAC score Kramer, C. M. Circulation 2008;117: Copyright 2008 American Heart Association 12

13 Hypothetical Case 47 y/o asymptomatic man with a postive famly hx of CAD Metabolic syndrome Hypertension, treated HDL 35, LDL 130 Calcium score = zero Would you put him on statins? 13

14 Does CT Calcium Improve Outcomes? 450 asymptomatic y/o subjects Routine exam in Army, with CT Ca score Randomized to 4 groups: intensive case management vs. usual care; Ca score results given or withheld. Primary end-point was change in Framingham risk score at one year O Malley, FG, et al. JAMA 2003;289:

15 Results 15% had a positive Ca score Ca score given or withheld, p=ns ICM vs. usual care, p=0.003 Improvement or no change in Framingham score related to number of risk factors and ICM, not Ca score. Conclusion: Ca score not associated with significant changes in Framingham risk score. ICM superior to usual care. 15

Severely Calcified Left Anterior Descending Artery Gottlieb, I. et al.

17 Does CT Ca Score Motivate Lifestyle Changes? 703 asymptomatic subjects without known CAD, self referred for CT Ca score Lifestyle questionaire before and years later. Ca score positive in 59% men and 43% women. Wong ND, et al. Am J Cardiol 1996;78:

18 Results At baseline Ca score related to sex, age, smoking, dyslipidemia,, hypertension and family history. At follow-up Ca score related to MD visit, new medications, reduced dietary fat and increased worry about health. Not related to smoking cessation, weight loss or increased exercise. 18

19 Psychology Literature People change health behaviors if : They believe they can change the behavior and if They believe that the disease can be positively effected by the change. 19

20 CIMT Simple, inexpensive screening test for atherosclerotic vascular disease. Abnormal CIMT associated with MI, stroke and CAD death independent of clinical risk factors in 9 large propective studies. Presence of carotid plaque even more predictive of events. 20

21 CIMT Guidelines - Indications Family hx of premature CAD in a first degree relative Age <60 with a severe abnormality of one risk factor Women <60 with two risk factors No prospective therapy trials using CIMT. No data on value of serial studies for following patient progress. 21

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23 Does CIMT Motivate Patients? OPACA study of 263 men >age 45, women >55, but <70, with one risk factor, but not on lipid lowering therapy. CIMT positive if plaque or thickness >75 th percentile for age, sex and race. Surveys before and after screening about changes in management and lifestyle. Wong ND, et al. Am J Cardiol 1996;78:

24 Results 59% had a positive study, many had plaque. Related to number of risk factors. MDs changed Rx more ASA, more LDL lowering Rx and more control of SBP. Patients increased their perception that they had CVD, and planned to take there medications and change their diet. No change in exercise habits planned 24

25 Conclusion CT Calcium score or CIMT adds risk information to the FRS in intermediate risk patients. Thus, it is reasonable to perform these studies if the results would alter therapy in such patients. 25

MPS and Calcium Score in asymptomatic patient F. Mut, J. Vitola

MPS and Calcium Score in asymptomatic patient F. Mut, J. Vitola Nuclear Medicine Service, Asociacion Española Montevideo, Uruguay Quanta Diagnostico Nuclear Curitiba, Brazil Clinical history Male 63 y.o.,