What is the recommended age range for a calcium coronary scan?

Recommended Age Range for Coronary Artery Calcium Scanning

Coronary artery calcium (CAC) scanning is generally recommended for asymptomatic adults aged 40-75 years with intermediate cardiovascular risk, with selective use in younger individuals who have significant risk factors. 1

General Age Guidelines

• Standard recommendation: 40-75 years 1, 2
• Lower age limit: Generally not recommended for men <40 years and women <50 years due to low prevalence of detectable calcium 1
• Upper age limit: Limited utility after age 75, with caution advised for routine use in adults >70 years 1

Risk-Based Age Recommendations

CAC scanning is most appropriate for:

1. Intermediate risk individuals (40-75 years):

   • 10-year ASCVD risk of 7.5-19.9% (ACC/AHA) 1
   • 10-year ASCVD risk of 5-20% (SCCT) 1
   • Used to guide decisions about preventive interventions, especially statins 1

2. Borderline risk individuals (40-75 years):

   • 10-year ASCVD risk of 5-7.5% 1
   • CAC can help with shared decision-making about preventive therapies

3. Low risk individuals with specific risk enhancers:

   • Strong family history of premature CAD 1
   • Genetic dyslipidemias
   • Smoking history
   • Diabetes

Sex-Specific Considerations

• Women: Generally develop CAC approximately 10 years later than men 1

  • Optimal age for first scan in women without risk factors: ~57.6 years 3
  • Optimal age for first scan in women with diabetes: ~50.3 years 3

• Men: Develop CAC earlier than women

  • Optimal age for first scan in men without risk factors: ~42.3 years 3
  • Optimal age for first scan in men with diabetes: ~36.8 years 3

Risk Factor-Based Age Adjustments

Certain risk factors warrant earlier CAC testing 3:

• Diabetes: Accelerates CAC development by approximately 6.4 years
• Smoking, hypertension, dyslipidemia, family history: Each accelerates CAC development by 3.3-4.3 years

Repeat Testing Intervals

If CAC testing is performed, follow-up intervals should be 1, 2, 4:

• CAC = 0: Repeat in 5-7 years
• CAC = 1-99: Repeat in 3-5 years
• CAC = 100-400: Repeat in 3 years
• CAC > 400: May not require repeat scanning as these patients often require aggressive treatment

Important Caveats

1. Testing should only be performed if results will influence treatment decisions 4
2. Radiation exposure: While low (typically 1.5 mSv), this is still a consideration 1
3. Cost-effectiveness: Currently limited data on cost-effectiveness in Australia and New Zealand 4
4. Not recommended for patients with established ASCVD 1
5. USPSTF position: Differs from other guidelines, stating evidence is insufficient for CAC addition to traditional CV risk assessment 1

Clinical Decision Algorithm

1. Determine baseline 10-year ASCVD risk using Pooled Cohort Equations
2. Consider CAC if:
   • Age 40-75 AND
   • Intermediate risk (7.5-19.9%) OR
   • Borderline risk (5-7.5%) with risk enhancers OR
   • Low risk (<5%) with strong family history of premature CAD
3. Consider earlier testing (age 30-39) only for:
   • Type 1 diabetes >20 years duration
   • Type 2 diabetes >10 years duration
   • Multiple major ASCVD risk factors
   • Strong family history of premature ASCVD

CAC scoring provides valuable risk stratification beyond traditional risk calculators and can guide decisions about preventive therapies, particularly statins, in appropriate age groups.