Coronary Artery Calcium Scoring Mirvat Alasnag FACP, FRCP, FSCCT, FSCAI, FASE King Fahd Armed Forces Hospital, Jeddah March 2017
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Referrals 62 year old female CT chest and abdomen following an endoscopy for a suspicious mass No cardiac symptoms CAC score moderate Now what? CACS 100-300 then risk factor modification CACS > 300 ETT or CCTA Arterial calcification on mammography is a predictor >> recommend CAC score
1. Younger patients with family history of premature coronary heart disease, have significantly higher CACS.
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2. CAC scoring has consistently been associated with a greater precision than individual and combination of risk factors.
3. Second hand smoking & pollution from smoking has been associated with increased risk of coronary artery calcification, but not coronary artery disease.
4. Radiation exposure from a CAC scoring is higher than average annual background radiation in the USA, but less than that for a mammogram.
5. MESA reports the prevalence of CAC among intermediate risk individuals is 10% and very low risk individuals is 5%.
MESA SCORE: Multi-Ethnic Study of Atherosclerosis >300 Risk Equivalent (LDL < 70mg/dl) 100-300 Intermediate <100 Low
6. CAC scoring is highly predictive of coronary heart disease events across all age groups.
7. Men tend to have higher levels of calcium than women and the amount of calcium tends to increase with age. This difference is eliminated by age 75.
8. A CAC score higher than the 50 th percentile for one s age and sex is indicative of high risk clinically significant plaque and premature atherosclerosis.
9. Patients with a CAC score > 100 were 7-10x more likely to experience a coronary event over a median follow up of 3.9 years.
10. The value of a CAC score of ZERO has been confirmed in multiple high risk groups.
11. The annual rate of a coronary event in a patient with a CAC score of 0 is 0.11%.
12. A CAC score of 0 translates into a low 10-year risk of coronary heart events irrespective of risk factors.
13. In Diabetic patients, CAC scoring cannot identify those who are at low risk within this high risk population.
14. Higher CAC scores have only been associated with coronary heart events and not an increased risk of atrial fibrillation, heart failure or stroke.
15. CAC scoring is a stronger predictor of cardiovascular disease and coronary heart disease than carotid ultrasound measures.
Controversies with CAC: 1. A positive CAC score does not imply obstructive disease (+ ETT, MPI suggest high likelihood of stenosis ) Often CAC score is referrerd to as a test of atherosclerosis and not stenosis > > risk factor modification 2. CAC score of 0 Over 40 years risk of event/year is <1/1000 Soft plaque is not concerning & event rates higher with mixed or calcified plaque.
3. Who to screen for CAC? Low risk with FH of premature CAD, Lupus, HIV Intermediate risk: (5-20%/10 year event rate by 2013 pooled cohort equation) High risk: None >> test won t alter their risk as assessed by other calculators except in statin intolerant 4. De-escalation of therapy for 0 CAC score?
Warranty: Normal Coronary angiogram >>10 years CAC score 0 >> 15 years 5 easily 10 probably safe 15 years unless develop in the interim DM/HTN 9715 stratified by age, FRS, NCEP ATP III RESULTS: 4864 CAC 0 >>229 deaths CAC score strongest predictor of death CAC 0 associated with a low vascular age CONCLUSION: Mean follow up 14.6 yrs (12.9-16.8 ) A score of 0 confers a 15 year warranty in those at low intermediate risk unaffected by age and sex. High risk w CAC 0 confers better survival than those w lowintermediate risk & any score more than 0.
American College of Cardiology Foundation Amir A. Mahabadi et al. JIMG 2017;10:143-153
American College of Cardiology Foundation Amir A. Mahabadi et al. JIMG 2017;10:143-153
5 Trials for Primary Prevention of CVS Disease: 1. DIAD (Diagnostic Imaging in Asymptomatic Diabetics) 2. St Francis Heart Study 3. PACC (Prospective Army Coronary Calcium) 4. EISNER (Early Identification of Subclinical Atherosclerosis by Noninvasive Imaging Research) 5. FACTOR-64 6. KEEPS -Underpowered -Short follow up