2023 ACC AUC Multimodality Imaging for CCD

Overview & Key Changes

The 2023 ACC Appropriate Use Criteria (AUC) for multimodality imaging in chronic coronary disease (CCD) provides evidence-based recommendations for selecting diagnostic and prognostic tests. This update focuses on:

What's New in 2023

"No Test" Option Added: Acknowledges that not all patients require imaging; clinical judgment and patient preferences matter
ASCVD Risk-First Approach: Risk stratification (low, borderline, intermediate, high) precedes test selection for asymptomatic patients
Simplified Clinical Scenarios: 20% fewer scenarios vs. 2013; reduced complexity with maintained clinical coverage
Risk-Enhancing Factors: Non-traditional risk factors (Lp(a), hsCRP, metabolic syndrome, CKD) now guide testing in intermediate-risk patients
CAC Score Elevated: Increased recognition of coronary artery calcium for risk prediction in asymptomatic patients

Core Assumptions

Each test is performed, interpreted, and reported per published standards (ECG, stress echo, PET, SPECT, CMR, CCTA, CAC, invasive angiography)
Tests are locally available with appropriate equipment and expertise
Patient baseline imaging and clinical status are established before test selection
These criteria apply to stable CCD; not acute coronary syndromes or unstable angina
Clinician judgment supersedes AUC in individual cases with unusual presentations

Clinical Decision Tree: Start with patient symptom status (Yes/No) → Clinical scenario category → Select appropriate test from scenario table.

AUC Rating Scale

All imaging recommendations in this guideline are rated on a three-point scale reflecting overall appropriateness for a given clinical scenario:

Rating	Score	Interpretation	Clinical Meaning
Appropriate	A	Median score 7–9	Test is generally acceptable and beneficial; benefits outweigh risks. Reasonable choice for most patients in this scenario.
May Be Appropriate	M	Median score 4–6	Test is sometimes useful; appropriateness depends on clinical judgment, patient preferences, local expertise, and availability.
Rarely Appropriate	R	Median score 1–3	Test lacks clear benefit for this scenario; risks likely outweigh benefits. Generally not recommended unless extenuating circumstances exist.

Note: Specific clinical features (e.g., renal function, body habitus, inability to exercise) may modify appropriateness. Always integrate test results with clinical judgment.

Imaging Modalities Comparison

Each diagnostic modality offers distinct advantages and limitations. Selection depends on clinical scenario, patient factors, local expertise, and availability:

Modality	Strengths	Limitations
Stress Echocardiography	Wall motion assessment, valvular disease, chamber function, no radiation, cost-effective	Acoustic windows (obesity, COPD), operator-dependent, limited in certain physiques
Stress Nuclear (SPECT)	Perfusion imaging, pharmacologic options, extensive outcome data	Radiation exposure, attenuation artifacts, motion artifacts, lower specificity in women
Stress PET	Superior image quality, quantifiable flow, lower radiation than SPECT	Limited availability, higher cost, requires tracer availability
Coronary CTA (CCTA)	High sensitivity for CAD, anatomic visualization, rules out alternate diagnoses, excellent NPV	Radiation, iodine allergy risk, calcification artifacts, decreased specificity with high CAC
Stress CMR	Ischemia + myocardial viability, no radiation, tissue characterization, wall motion	Contraindications (pacemakers, metallic implants), claustrophobia, cost
Coronary Artery Calcium (CAC)	Risk prediction, low radiation, rapid, reproducible, well-validated prognostic value	No assessment of stenosis, artifact from stents/dense calcification, limited therapy guidance

Pearl: No single modality is "best" for all scenarios. Combine imaging with clinical judgment, patient factors (age, renal function, ability to exercise), and local expertise.

Risk-Enhancing Factors for CCD Detection

In addition to traditional risk factors (age, sex, LDL, smoking, family history), these conditions may warrant consideration of testing in borderline- or intermediate-risk patients:

Risk Category	Specific Factors
Lipid Abnormalities	LDL-C ≥160 mg/dL (untreated); elevated Lp(a) (≥50 mg/dL or ≥125 nmol/L); hypertriglyceridemia (≥175 mg/dL)
Metabolic Disorders	Metabolic syndrome; elevated waist circumference; elevated triglycerides; elevated blood glucose; elevated LDL particle number
Renal Disease	CKD stage 3b–5 (eGFR 15–59 mL/min/1.73m²); proteinuria
Inflammatory/Autoimmune	RA, SLE, psoriasis, HIV/AIDS; history of preeclampsia or gestational diabetes
Biomarkers	Elevated hsCRP (≥2.0 mg/L); elevated Lp(a)
Vascular/Other	Non-coronary atherosclerosis (PAD, carotid disease, aortic disease); high-risk race/ethnicity; prior coronary calcifications on imaging

Use the PREVENT-ASCVD Calculator or ACC/AHA ASCVD Risk Calculator to integrate risk factors and guide testing decisions.

Symptomatic Patients Without Known CCD — Initial Detection

For patients with ischemic symptoms (chest discomfort, dyspnea with exertion, or fatigue) and no prior testing, imaging is selected based on symptom likelihood and pretest probability. This section provides ratings for the most common clinical scenarios:

Table 1.1: Common Symptomatic Scenarios

Clinical Scenario	ECG Treadmill	Stress Nuclear MPI	Stress Echo	Stress CMR	CAC	CCTA	Cath	No Test
Low pretest probability (<15%) Atypical symptoms, normal exam	A	M	M	M	A	A	R	A
Intermediate pretest probability (15–50%) Typical or atypical symptoms, risk factors	M	A	A	A	M	A	M	M
High pretest probability (>50%) Typical angina, multiple risk factors, old age	M	A	A	A	M	A	A	R

Key Concept — Pretest Probability: Estimate using patient age, sex, symptom character (atypical vs. typical angina), and risk factors. Higher pretest probability favors functional imaging (stress echo, SPECT, CMR) or anatomy (CCTA); very low probability may favor no testing or CAC alone.

Interpreting Prior Test Results

If a patient has had prior testing (abnormal/normal ECG, inconclusive stress study, prior MI, or revascularization), additional scenarios apply. Use the flowchart in the introduction to navigate to the correct table.

Key considerations:

Normal stress imaging: Low event rate; sequential testing rarely warranted; consider CAC if further risk stratification needed
Inconclusive stress imaging: Poor windows, suboptimal heart rate response, uninterpretable ECG → CCTA or CMR may clarify
Abnormal stress imaging (mild ischemia): Risk-stratify and consider referral if extensive ischemia or high-risk features

Symptomatic Patients With Prior MI or Revascularization

Patients with a history of MI, PCI, or CABG presenting with new or recurrent symptoms require careful risk stratification. Imaging helps distinguish new ischemia from scar or other causes:

Clinical Scenario	Stress Echo	SPECT	CMR	CCTA	Cath
Incomplete revascularization New symptoms after PCI with residual CAD	A	A	A	A	A
Prior PCI, typical symptoms Similar angina to prior episode	A	A	A	M	M
Prior CABG, new symptoms Atypical symptoms, concern for graft patency	A	A	A	A	M
Post-PCI silent ischemia assessment High-risk baseline; periodic screening	M	M	M	R	R

Post-Revascularization Testing Principles

Imaging is appropriate for recurrent symptoms: Distinguish recurrent/new ischemia from scar
Viability assessment: CMR excels at identifying viable myocardium in territories with prior MI
Graft patency (CABG): CCTA can visualize saphenous vein and internal mammary grafts; consider for symptomatic post-CABG
Routine surveillance: Generally not recommended unless high-risk features or new symptoms emerge

Asymptomatic Patients — Risk-Stratified Detection

For asymptomatic patients without known CCD, testing is guided by estimated 10-year ASCVD risk. Use the PREVENT-ASCVD Calculator or Pooled Cohort Equations to estimate risk. Risk-enhancing factors may influence testing decisions in borderline-risk patients.

Risk Category & ASCVD Risk	ECG Treadmill	Stress Nuclear	Stress Echo	CAC	CCTA	No Test
Low Risk <5% 10-year ASCVD risk	R	R	R	M	R	A
Borderline Risk 5–7.5% ASCVD risk (consider risk enhancers)	M	M	M	A	M	A
Intermediate Risk 7.5–20% ASCVD risk	M	M	M	A	M	M
High Risk >20% 10-year ASCVD risk	M	A	A	A	A	R

Pitfall: Do not order routine stress testing for low-risk asymptomatic patients. Risk assessment should precede test selection. CAC is preferred for risk refinement in borderline-risk patients.

CAC Scoring Strategy

Coronary Artery Calcium (CAC) is Appropriate for risk refinement:

CAC = 0: Lowest short-term event risk; reassurance; defer preventive interventions unless other high-risk features
CAC 1–99: Mild-moderate disease; mild risk increase; consider preventive therapy and repeat imaging in 5–10 years
CAC 100–299: Moderate-to-severe calcification; intermediate risk; consider aggressive risk factor modification and functional testing if further risk stratification desired
CAC ≥300: Extensive calcification; higher risk; consider functional imaging (stress echo, SPECT, CMR) or CCTA to assess stenosis

Use the MESA CAC Risk Calculator to integrate CAC with other risk factors.

Asymptomatic Patients With Prior MI or Revascularization

Patients with established coronary disease but no current symptoms represent a special population. Routine surveillance is generally not recommended, but selected cases benefit from assessment of myocardial viability or silent ischemia:

Scenario	Stress Echo	SPECT	CMR	CCTA	No Test
Incomplete revascularization Multiple risk factors; borderline EF	M	M	M	R	A
High-risk PCI Complex lesion; elevated risk features	M	M	M	R	A
Viability assessment Prior MI, reduced EF, no symptoms	M	M	A	R	M

Pearl — Viability Testing: CMR is superior for assessing myocardial viability in post-MI patients with reduced EF. Presence of viable myocardium may support consideration of revascularization; extensive scar suggests limited benefit from intervention.

Clinical Pearls & Pitfalls

Best Practices

Calculate ASCVD Risk First: Use a validated calculator (PREVENT, Pooled Cohort Equations) before ordering tests on asymptomatic patients. Risk stratification guides modality selection.
Consider Patient Preferences: Discuss radiation exposure (SPECT, CCTA, CAC), test duration (CMR), and likelihood of inconclusive results (echo with poor windows). Shared decision-making improves outcomes.
Functional vs. Anatomic: Stress imaging (echo, SPECT, CMR, PET) assesses ischemia; CCTA visualizes anatomy. In intermediate-probability patients, either approach is reasonable; tailor to patient factors.
Serial CAC: CAC score is reproducible and prognostically useful. Interval progression (5–10 years) refines risk; consider repeat CAC if baseline is 1–299 and lifestyle/medication adherence needs reassessment.
Viability in Systolic Dysfunction: CMR with late gadolinium enhancement accurately identifies viable myocardium in post-MI patients with low EF; findings inform revascularization candidacy.
Renal Function Matters: Avoid CCTA and gadolinium-based CMR in severe CKD (eGFR <30); consider alternative modalities or non-contrast CAC.

Avoid These Pitfalls

Routine Surveillance After Normal Test: Normal stress imaging confers low event risk; routine repeat testing is rarely appropriate within 3–5 years absent new symptoms or major risk factor change.
Ordering Imaging Without ASCVD Risk Calculation: Asymptomatic patients require risk stratification. Low-risk patients (ASCVD <5%) rarely benefit from imaging; no-test is often appropriate.
Ignoring "No Test" Column: The 2023 guideline explicitly rates "no test" as appropriate in many scenarios. Clinical judgment and patient preference matter as much as test availability.
Misinterpreting Inconclusive Results: Poor echo windows, motion artifact, or uninterpretable ECG do not mean the test failed—they predict lower test accuracy. Consider alternative modality (e.g., CCTA, CMR) for diagnostic certainty.
Over-testing Post-Revascularization: Asymptomatic post-PCI or post-CABG patients do not require routine surveillance. Test only if recurrent symptoms emerge or significant interval risk factor change occurs.

Special Populations & Modality Contraindications

Severe Renal Disease (eGFR <30): Avoid CCTA (contrast nephropathy risk), gadolinium-enhanced CMR (gadolinium retention), and high-radiation SPECT; favor CAC, echo, PET.
Pacemaker/ICD: Contraindication for standard CMR; consider low-field CMR if available, or alternative modality (SPECT, CCTA, echo).
Claustrophobia or Inability to Lie Flat: CMR not feasible; choose CCTA, echo, SPECT, or stress testing.
Extensive Coronary Calcification: Decreased specificity of CCTA; functional imaging (stress echo, SPECT, CMR) or PET may be superior.
Allergy to Iodine: Avoid CCTA and diagnostic coronary angiography; use stress imaging or non-invasive alternatives.

Related Calculators

Use these SattiMD calculators to support risk assessment and test selection decisions: