22
Diagnosis
Table 10. Noninvasive Risk Stratification
High risk (>3% annual death or MI)
Severe resting LV dysfunction (left ventricular ejection fraction [LVEF] <35%) not
readily explained by noncoronary causes
Resting perfusion abnormalities ≥10% of the myocardium in patients without prior
history or evidence of MI
Stress ECG findings including ≥2 mm of ST-segment depression at low workload or
persisting into recovery, exercise-induced ST-segment elevation, or exercise-induced
VT/VF
Severe stress-induced LV dysfunction (peak exercise LVEF <45% or drop in LVEF with
stress ≥10%)
Stress-induced perfusion abnormalities encumbering ≥10% myocardium or stress
segmental scores indicating multiple vascular territories with abnormalities
Stress-induced LV dilation
Inducible wall motion abnormality (involving >2 segments or 2 coronary beds)
Wall motion abnormality developing at low dose of dobutamine (≤10 mg/kg/min) or
at a low heart rate (<120 beats/min)
Coronary artery calcium (CAC) score >400 Agatston units
Multivessel obstructive CAD (≥70% stenosis) or le main stenosis (≥50% stenosis) on
CCTA
Intermediate risk (1%-3% annual death or MI)
Mild/moderate resting LV dysfunction (LVEF 35%-49%) not readily explained by
noncoronary causes
Resting perfusion abnormalities in 5%-9.9% of the myocardium in patients without a
history or prior evidence of MI
≥1 mm of ST-segment depression occurring with exertional symptoms
Stress-induced perfusion abnormalities encumbering 5%-9.9% of the myocardium or
stress segmental scores (in multiple segments) indicating one vascular territory with
abnormalities but without LV dilation
Small wall motion abnormality involving 1-2 segments and only one coronary bed
CAC score 100-399 Agatston units
One vessel CAD with ≥70% stenosis or moderate CAD stenosis (50%-69% stenosis) in
≥2 arteries on CCTA
Low risk (<1% annual death or MI)
Low-risk treadmill score (≥5) or no new ST segment changes or exercise-induced chest
pain symptoms when achieving maximal levels of exercise
Normal or small myocardial perfusion defect at rest or with stress encumbering <5% of
the myocardium*
Normal stress or no change of limited resting wall motion abnormalities during stress
CAC score <100 Agaston units
No coronary stenosis >50% on CCTA
*Although the published data are limited; patients with these findings will probably not be at low
risk in the presence of either a high-risk treadmill score or severe resting LV dysfunction
(LVEF <35%).
