Stress testing choices — structured viva

Stem

Practice viva. The examiner asks how you would choose a stress test, what makes a result high risk, who should not be stress tested, and how you would test a patient with known coronary disease.^[1][2][3]

Branch A — Choosing the test

Examiner: A 58-year-old man has suspected chronic coronary syndrome, with constricting retrosternal chest discomfort brought on by exertion and relieved by rest within 5 minutes. He smokes and has hypertension, dyslipidaemia and diabetes. On ESC 2024 Figure 4 (men aged 50–59, symptom score 3, 4–5 risk factors) his risk factor-weighted clinical likelihood of obstructive CAD is 33%. Which functional tests would you consider, and where does the exercise ECG fit?^[1]

Strong answer:

• ESC 2024: select the initial non-invasive test on pre-test likelihood, patient characteristics that influence test performance (ability to exercise, likelihood of good image quality, expected radiation exposure, risks or contraindications) and local expertise and availability (Class I, Level C).^[1]
• In suspected CCS at moderate or high (>15%–85%) pre-test likelihood, if available and supported by local expertise, stress echocardiography is recommended to diagnose myocardial ischaemia and to estimate the risk of MACE; stress SPECT or, preferably, PET perfusion imaging to diagnose and quantify myocardial ischaemia and/or scar, estimate the risk of MACE and (PET) quantify myocardial blood flow; and stress CMR perfusion imaging to diagnose and quantify myocardial ischaemia and/or scar and estimate the risk of MACE (each Class I, Level B). ESC 2024 text (no class or level given) says functional imaging should be selected as a first line test if information on myocardial ischaemia, viability or microvascular disease is desired.^[1]
• The exercise ECG is not recommended to rule out CAD at low or moderate (>5%–50%) likelihood if CCTA or functional imaging tests are available (Class III, Level C); with a low sensitivity (58%) and specificity (62%) it should mainly be used for risk stratification.^[1]

Follow-up: How does the American guidance frame the same decision?^[2]

• AHA/ACC 2021 sorts stable chest pain without known CAD into low and intermediate-high risk; at intermediate-high risk, stress imaging is effective for diagnosis of ischemia and estimating MACE risk (COR 1, LOE B-R), and exercise ECG is reasonable with an interpretable ECG and ability to achieve ≥5 METs (COR 2a, LOE B-R).^[2]
• Its pathway favours stress testing at ≥65 years (with a higher likelihood of ischemia) and CCTA under 65 years when not on optimal preventive therapies.^[2]

Branch B — Reading the result

Examiner: Which stress results tell you the patient is at high risk, and what would you do?^[1]

• ESC 2024 recommends using one or more of these test results to identify individuals at high risk of adverse events (Class I, Level B): Duke Treadmill Score < −10 on exercise ECG; an area of ischaemia ≥10% of the LV myocardium on stress SPECT or PET; ≥3 of 16 segments with stress-induced hypokinesia or akinesia on stress echocardiography; ≥2 of 16 segments with stress perfusion defects or ≥3 dobutamine-induced dysfunctional segments on stress CMR. The row also includes a CCTA item.^[1]
• In individuals at high risk of adverse events (regardless of symptoms), ICA, complemented by invasive coronary pressure (FFR/iFR) when appropriate, is recommended to refine risk stratification and improve symptoms and cardiovascular outcomes by revascularization (Class I, Level A).^[1]
• ESC 2024 calls the evidence on the prognostic impact of inducible myocardial ischaemia by functional stress imaging conflicting: large observational studies consistently show a robust prognostic value for the extent of inducible ischaemia detected by functional imaging, but post hoc analyses of the randomized COURAGE and ISCHEMIA trials showed that only CAD severity, not ischaemia severity, was independently predictive of long-term mortality and MI risk. When assessing event risk, ESC 2024 advises an integrative approach, considering risk factors, comorbidities, LV dysfunction, the severity of myocardial ischaemia, the number of functionally significantly stenotic coronary arteries, and the coronary plaque burden and characteristics, as all of these are likely interrelated factors that affect overall prognosis.^[1]

Follow-up: And a man who exercises beyond 10 METs with a negative ECG?^[1]

• ESC 2024: exercising >10 metabolic equivalents with a negative exercise ECG and a low-risk Duke Treadmill Score carries a good prognosis, with limited need for downstream testing and revascularization.^[1]
• AHA/ACC 2021: patients exercising to Bruce stage III or >10 METs with a negative ECG have a low risk of CAD events.^[2]

Branch C — Who should not be stress tested

Examiner: Name contraindications that would stop you booking an exercise test or a vasodilator perfusion scan.^[2]

• AHA/ACC 2021 exercise ECG column includes: abnormal ST changes on resting ECG, digoxin, LBBB, Wolff-Parkinson-White pattern or ventricular paced rhythm (unless the test is to establish exercise capacity); inability to achieve ≥5 METs or unsafe to exercise; high-risk unstable angina or AMI (<2 d); uncontrolled heart failure; severe symptomatic aortic stenosis; acute illness such as acute PE, myocarditis/pericarditis or aortic dissection.^[2]
• Its stress nuclear column includes high-risk unstable angina, complicated ACS or AMI (<2 d), and contraindications to vasodilator administration, which include significant arrhythmias (for example VT, second- or third-degree AV block) or sinus bradycardia <45 bpm; SBP <90 mm Hg; known or suspected bronchoconstrictive or bronchospastic disease; methylxanthines (for example caffeine) within 12 h; and known hypersensitivity to adenosine, regadenoson.^[2]
• ACC/AHA 2020: in symptomatic severe AS (Stage D1), exercise testing should not be performed because of the risk of severe hemodynamic compromise (COR 3: Harm, LOE B-NR).^[13]

Branch D — Known coronary disease

Examiner: A patient with a stent has new symptoms that persist despite GDMT. How would you test him, and would you test him routinely once he is stable?^[3]

• AHA/ACC 2023: in CCD with a change in symptoms or functional capacity that persists despite GDMT, stress PET/SPECT MPI, CMR or stress echocardiography is recommended to detect the presence and extent of myocardial ischemia, estimate risk of MACE and guide therapeutic decision-making (COR 1, LOE B-NR); when rest/stress nuclear MPI is selected, PET is reasonable in preference to SPECT, if available, to improve diagnostic accuracy and decrease the rate of nondiagnostic test results (COR 2a, LOE B-R).^[3]
• ESC 2024: risk stratification is recommended for new or worsening symptoms, preferably using stress imaging (Class I, Level C); functional imaging is preferred after revascularization because of the high frequency of extensive CAD.^[1]
• Once stable: AHA/ACC 2023 does not recommend routine periodic testing with coronary CTA or stress testing with or without imaging to guide therapeutic decision-making in CCD without a change in clinical or functional status on optimized GDMT (COR 3: No benefit, LOE B-R). ESC 2024 text (no class or level given) says routine functional testing is not recommended for asymptomatic post-PCI patients, as it has not been shown to improve outcomes compared with standard care after 2 years.^[3][1]