For a patient with a positive stress test and scheduled CT (Computed Tomography) calcium score, should I cancel the CT calcium score and instead refer them to cardiology for a CT (Computed Tomography) angiogram to further evaluate for coronary artery disease?

Yes, Cancel the CT Calcium Score and Proceed Directly to CT Angiography or Invasive Coronary Angiography

In a patient with a positive stress test, a CT calcium score provides no additional diagnostic value and should be cancelled—proceed directly to either CT angiography (CCTA) or invasive coronary angiography (ICA) based on the severity of ischemia and clinical risk factors. 1

Why CT Calcium Scoring is Inappropriate After a Positive Stress Test

• CT calcium scoring is a screening tool for asymptomatic patients or those with low-to-intermediate pre-test probability of coronary artery disease (CAD), not a diagnostic test for patients with already-established ischemia. 1

• A positive stress test has already demonstrated functional evidence of obstructive CAD, making anatomic confirmation the next logical step—not risk stratification with calcium scoring. 1

• The 2021 ACC/AHA Chest Pain Guidelines explicitly recommend against layered testing and emphasize moving directly to anatomic assessment (CCTA or ICA) when ischemia is documented. 1

Decision Algorithm: CCTA vs. Invasive Coronary Angiography

Proceed Directly to Invasive Coronary Angiography if:

• The stress test shows moderate-to-severe ischemia 1
• The patient has high-risk features: left main disease suspected, three-vessel disease, or proximal LAD involvement 1, 2
• The patient has ongoing or frequent angina despite medical therapy 1, 2
• The patient has hemodynamic instability or high-risk clinical features 1

Consider CT Angiography (CCTA) if:

• The stress test shows mild or inconclusive ischemia 1
• The patient is at intermediate risk with no prior CAD documentation 1
• CCTA can define coronary anatomy and guide decisions about ICA, particularly when combined with FFR-CT for intermediate stenoses (50-90%) 1
• The patient has adequate heart rate control, low body weight, and minimal expected coronary calcification (younger patients) 1

Practical Management Steps

• For patients with moderate-to-severe ischemia on stress testing, refer directly to cardiology for invasive coronary angiography with capability for FFR assessment of intermediate lesions. 1, 2

• For patients with mild or inconclusive ischemia, CCTA is reasonable to define coronary anatomy and determine if obstructive CAD (≥50% stenosis) is present. 1

• Optimize guideline-directed medical therapy (high-intensity statin, beta-blocker, antiplatelet therapy, ACE inhibitor/ARB) while awaiting the anatomic assessment. 2

• Do not repeat stress testing in patients who already have a positive test—this represents unnecessary layered testing and delays definitive diagnosis. 1, 2

Common Pitfalls to Avoid

• Do not order CT calcium scoring after a positive stress test—this adds no diagnostic value and delays appropriate care. 1

• Do not repeat stress testing when the initial test was positive and clinical characteristics suggest significant CAD. 1, 2

• Do not delay invasive angiography in high-risk patients (moderate-to-severe ischemia, ongoing symptoms, high-risk clinical features) by ordering CCTA first. 1, 2

• Be aware that CCTA has limitations in patients with extensive coronary calcification, high heart rates, obesity, or inability to cooperate with breath-holding—in these cases, proceed directly to ICA or stress imaging. 1