Coronary Artery Calcium Vimal Ramjee, MD FACC The Chattanooga Heart Institute
Disclosures I have no conflicts of interest to disclose.
Objectives Recognize the utility of coronary artery calcium scoring in CV risk stratification Understand the diagnostic modality of CACS and how results affect patients Implement appropriate diagnostic and therapeutic steps with CACS results
Outline I. CAD and calcific plaquing II. CV risk reclassification III. Coronary artery calcium score IV. Therapeutic implications
CAD and Calcific Plaquing CHD remains the leading cause of death worldwide CHD accounts for 1 out of 3 deaths in US adults > 35 years 41% increase in CV related deaths since 1990 Total CV Death Rate per 100,000 CDC, 2013-2015.
Murabito, Circulation. CAD: Diagnosis often comes too late
Fuster & Sanz, JACC. High Prevalence of Subclinical Plaque
Sandfort, Circulation. CAD and Calcific Plaquing
Cardiovascular Risk Stratification Global risk factor scores address only conventional factors Age, diabetes, elevated LDL, low HDL, HTN, tobacco use, family history CACS demonstrates a very high NRI when compared to other risk markers High NRI - % patients with FRS estimate that were correctly reclassified by CACS: 52 to 66% in intermediate risk group 34 to 36% in high risk group 12 to 15% in low risk group Hecht, JACC.
CACS Adds Value Regardless of Other Risk Factors
Hecht, JACC. Cardiovascular Risk Stratification
Hecht, JACC. Cardiovascular Risk Stratification
Cumulative Survival CACS Strongly Associated with CV Death 1.00 0.95 0 (n=11,044) 1-10 (n=3,567) 11-100 (n=5,032) 101-299 (n=2,616) 0.90 300-399 (n=561) 0.85 0.80 400-699 (n=955) 700-999 (n=514) 0.75 0.70 2 =1363, p<0.0001 for variable overall and for each category subset. 1,000+ (n=964) Budoff, JACC. 0.0 2.0 4.0 6.0 8.0 10.0 12.0 Time to Follow-up (Years)
Indications for CAC Assessment Asymptomatic adults with intermediate risk (10-20% 10 year risk) Class IIA, LOE B Asymptomatic adults with low to intermediate risk (6-10% 10 year risk) Class IIB, LOE B Asymptomatic adults with diabetes Class IIA, LOE B Low risk (< 6% 10 year risk) should not undergo CAC measurement Class III, LOE B ACCF/AHA Guidelines, 2010 & 2013
Coronary Artery Calcium Scan Ambulatory non-contrast CT scan with limited FOV 3 to 5 second breath hold Low radiation exposure < 1 msv (<< 1 msv with newer systems) Nearly equal to radiation from a mammogram Approximate radiation from living in a big city x 3 months Costs less than most tests that are covered ($59 out of pocket) Immediate printed results given to patient Printed report tells referring provider what percentile via MESA
Blaha, JACC.
Coronary Artery Calcium Scan 0 = No identifiable calcium 1-99 = Mild disease 100-399 = Moderate disease 400 = Severe disease
Coronary Artery Calcium Scan Calcium = presence of atherosclerosis, but atherosclerotic lesions do not always contain calcium Calcium may occur early in life, and not necessarily in functionally significant lesions (i.e. significant stenosis) CAC of 0 = very protective = < 1-2% chance of CV event next 10 yrs CAC > 0 CAD is unequivocally present Even low score of 1-10, confers a significant risk of CV events High (>100) and very high (>400) are proportionally associated with more risk
Berman, JACC. CAC Score and MPI Result
Hecht, JACC.
Therapeutic Implications CACS > 0 confers greater risk of CV events, therefore ideal to initiate: Aspirin 81mg PO daily Statin therapy *Irrespective of lipid level CAC > 100 confers high risk of CV events Careful clinical assessment Consider stress testing (? Functional stenosis) If initial CACS = 0, consider repeat scan no earlier than 5 years
Thank You Email: vramjee@chattanoogaheart.com Phone: (973) 960-7188 Don t hesitate to reach out!
Likelihood of CAD based on Risk Factor
DIAGNOSTIC SENSITIVITY NON-INVASIVE MODALITIES STRESS ECG $300 STRESS ECHO $900 STRESS THALLIUM $1600 PET SCANNING $2200 Coronary Calcium with CT $295 $59 INTRAVASCULAR ULTRASOUND $3,000 INVASIVE MODALITIES CORONARY ANGIOGRAPHY $5,000 0% 20% 45% 60% 70% 90% DATA TAKEN FROM THE DAWN OF A NEW ERA - NON-INVASIVE CORONARY IMAGING R. ERBEL HERZ 1996; 21, 75-77