This document summarizes various noninvasive tests for evaluating coronary artery disease (CAD), including stress testing, imaging modalities, and test results. Stress testing can be done with exercise or pharmacologic stress to detect ischemia and evaluate risk. Imaging like radionuclide perfusion, echocardiography, and cardiac MRI can be used during stress testing to localize ischemia. Abnormal test results on ECG, physiologic parameters, or imaging may warrant coronary angiography. Additional tests discussed include assessing myocardial viability and using coronary CT or MR angiography to detect coronary artery stenosis without radiation. A coronary artery calcium score can also estimate plaque burden and risk of CAD.

1. NONINVASIVE EVALUATION OF CAD
POCKET MEDICINE NOTES
ANWER GHANI

2. STRESS TESTING
• Indications: dx obstructive CAD, evaluate Δ in clinical status in Pt w/ known CAD,
risk
stratify after ACS, evaluate exercise tolerance, localize ischemia (imaging required)
• Contraindications:
• Absolute: AMI w/in 48 h, high-risk UA, acute PE, severe AS, uncontrolled HF,
uncontrolled arrhythmias, myopericarditis, acute aortic dissection
• Relative : left main CAD, mod symptomatic valvular stenosis, severe HTN, HCMP,
high-degree AVB, severe electrolyte abnl.

3. EXERCISE TOLERANCE TEST
• Generally preferred if Pt can meaningfully exercise; ECG Δs w/ Se ~65%, Sp
~80%
• Typically via treadmill w/ Bruce protocol (modified Bruce or submax if decond. or
recent
• MI)
• Hold anti-isch. meds (eg, nitrates, βB) if dx’ing CAD but give to assess adequacy
of meds

4. PHARMACOLOGIC STRESS TEST
• Use if unable to exercise, or recent MI. Se & Sp ≈ exercise.
• Coronary vasodilator: diffuse vasodilation : Regadenoson (↓side effects),
dipyridamole, adenosine. Side effects: flushing, ↓ HR, AVB, SOB, bronchospasm.
• Dobuta.: longer test; may precip arrhythmia

5. IMAGING FOR STRESS TEST
• Use if uninterpretable ECG
• Use when need to localize ischemia
• Radionuclide myocardial perfusion imaging w/ images obtained at rest & w/ stress
• Echo (exercise or dobuta): Se ~85%, Sp ~85%; no radiation; operator dependent
• Cardiac MRI (w/ pharmacologic stress) another option with excellent Se & Sp

6. TEST RESULTS
• HR (must achieve ≥85% of max pred HR [220-age] for exer. test to be dx)
• BP response,
• peak double product (HR × BP; nl >20k)
• HR recovery (HR peak – HR1 min later; nl >12)

7. TEST RESULTS
• ECG Δs: downsloping or horizontal ST ↓ (≥1 mm) 60–80 ms after QRS
predictive of CAD (but does not localize ischemic territory); however, STE highly
predictive &
• localizes
• Imaging: radionuclide defects or echocardiographic regional wall motion
abnormalities
• reversible defect = ischemia; fixed defect = infarct; transient isch dilation
→ Severe 3VD

8. HIGH-RISK TEST RESULTS. CONSIDER
CORONARY ANGIO)
• ECG: ST ↓ ≥2 mm or ≥1 mm in stage 1 or in ≥5 leads or ≥5 min in
recovery; ST ↑; VT
• Physiologic: ↓ or fail to ↑ BP, angina during exercise, Duke score
≤–11;↓EF
• Radionuclide: reversible defects, transient LV cavity dilation, ↑
lung uptake

9. MYOCARDIAL VIABILITY
• Goal: identify hibernating myocardium that could regain fxn after
revascularization
MRI (Se ~85%, Sp ~75%),
PET (Se ~90%, Sp ~65%)
Dobutamine stress echo (Se ~80%, Sp ~80%)

10. CORONARY CT/MR ANGIO
CCTA 100% Se, 54% Sp for ACS,
↑ cath/PCI, radiation vs. fxnal study
CCTA vs. fxnal testing → ↑ radiation, cath/PCI early; by 5 y, ↓ CHD
death/MI
• Unlike CCTA, MR does not require iodinated contrast or radiation,
and can assess LV fxn

11. CORONARY ARTERY CALCIUM SCORE
• Quantifies extent of calcium; thus, estimates plaque burden (but not
% coronary stenosis)
• CAC sensitive (91%) but not specific (49%) for presence of CAD
• ACC/AHA guidelines note CAC assessment is reasonable in asx
Pts w/ intermed risk and selected borderline risk.

12. THANKS
• ANWER GHANI