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Cardiac CT Calcium Scoring

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Cardiac CT Calcium Scoring, Coronary Calcium Score, CT Coronary Calcium

  • Definitions
  1. Coronary Calcium Score
    1. Non-Contrast CT-based quantification of coronary Calcium deposits (Agatson Score)
    2. Score sums the products of attenuation (Hounsfield Units) and area (mm3) of all lesions at coronary arteries
    3. Calcium deposits correlate with atherosclerotic Plaque
  • Indications
  1. CAD Risk stratification of asymptomatic patients
    1. Intermediate risk patients who have not undergone stress testing
    2. Intermediate risk patients with equivocal stress testing
    3. May direct preventive strategies (Aspirin, Statin) with better predictive power than risk factors and serum markers
  • Efficacy
  1. Increased Calcium scoring is an indepedent predictor of CAD event (RR >2.6)
  2. Increased Calcium scoring is associated with an increase in all cause mortality (RR >5.6)
  3. Calcium score does not predict focal stenosis severity
  • Equipment
  1. Electron beam tomography or
  2. Multidetector CT
  • Interpretation
  1. Calcium Score 0: Low risk
  2. Calcium Score 1-99: CAD event Relative Risk = 2.1
  3. Calcium Score 100-299 (or mild Coronary ArteryCalcium incidental on non-cardiac CT)
    1. CAD Risk >75th percentile (CAD event Relative Risk = 3.1)
    2. Threshold indicating further evaluation with stress testing in symptomatic patients
    3. Indicates moderate intensity Statin and LDL target <100 mg/dl
  4. Calcium Score 300-999 (or moderate to severe Coronary ArteryCalcium incidental on non-cardiac CT)
    1. CAD Risk Severe (CAD event Relative Risk = 4.6)
    2. Indicates high intensity Statin and LDL target <70 mg/dl
  5. Calcium Score >1000
    1. CAD risk extensive (CAD event Relative Risk = 8.3)
    2. Indicates high intensity Statin and LDL target <55 mg/dl
  • Adverse Effects
  1. Radiation Exposure: 0.89 mSv (similar to Mammogram)