Graded exercise stress test
Indications for testing
  • Selected asymptomatic adults with CVD risk factors especially those who are embarking on a vigorous exercise program
  • Selected adults in the intermediate-risk category
Frequency for testing
  • If symptoms develop
Normal range
Duke Score*
  • Low-risk: ≥+5
  • Moderate-risk: -10 to +4
  • High-risk: ≤-11
*CAD risk is also increased in subjects with low exercise capacity (<6 METS achieved on GXT)
Carotid ultrasound imaging
Indications for testing
  • Selected asymptomatic adults not candidates for statin Rx based on conventional risk factors
  • Only in centres with clear expertise
Frequency for testing
  • Every 5-10 years as indicated for reassessment of risk
Normal range
  • CIMT <1.0 mm
  • No visible plaque. Each 0.1 mm increase in CIMT is associated with a 10% increased risk for MI and a 13% increased risk for stroke – visible arterial wall plaques defined as a CIMT ≥1.5 mm or in the absence of plaque, CIMT values >75% for age and sex are considered as evidence of subclinical atheroslcerosis – a CIMT ≥1.5 mm is an indication for statin therapy
Ankle brachial index (ABI)
Indications for testing
  • Selected asymptomatic adults not candidates for statin Rx based on conventional risk factors (particularly smokers, patients with diabetes)
Frequency for testing
  • Every 5-10 years as indicated for reassessment of risk or if symptoms develop
Normal range
  • ABI 1.0-1.3 (an ABI <0.90 is associated with at least a 50% stenosis in a peripheral artery and a high probability of concomitant coronary artery disease and is an indication for intensive statin therapy)
Coronary artery calcium (CAC)
Indications for testing
  • Selected asymptomatic adults who are not candidates for statin Rx based on conventional risk factors
Frequency for testing
  • CAC=0, every 10 years where clinically indicated
  • CAC=0-100, every 3-5 years if Rx is deferred
Normal range
  • Low-risk: 0
  • Increased risk: 0-99
  • High-risk: 100-299. CAC >100 is generally considered high-risk.
  • Very high-risk: >300. CAC >300 places patients in very high-risk category (10 year risk of MI/CV death=28%.)

ABI: ankle brachial index; CAC: coronary artery calcium; CAD: coronary artery disease; CIMT: carotid intimal media thickness; CV: cardiovascular; CVD: cardiovascular disease; GXT: graded exercise stress test; MI: myocardial infarction; METS: metabolic equivalents.