Stress testing choices — practice case: dobutamine stress echocardiography in suspected chronic coronary syndrome

Presentation

Practice case (not a real patient). A 64-year-old woman in Australia has four months of constricting retrosternal chest discomfort brought on by exertion and relieved by rest within 5 minutes, and is assessed for suspected chronic coronary syndrome. She has hypertension, dyslipidaemia and diabetes and is a former smoker.^[1] With all three chest pain characteristics (symptom score 3) and four risk factors, her risk factor-weighted clinical likelihood of obstructive CAD on ESC 2024 Figure 4 (women aged 60–69, symptom score 3, 4–5 risk factors) is 19%.^[1] Her resting ECG shows sinus rhythm with no Q waves or ST-segment/T-wave changes, she can walk briskly but has knee osteoarthritis limiting treadmill exercise, and her echo windows are good. Stress echocardiography, SPECT, PET and CMR are available locally and supported by local expertise.^[1]

Step 1 — Which first test?

Discussion:

• ESC 2024: in symptomatic patients with a pre-test likelihood of obstructive CAD >5% by clinical assessment, CCTA or non-invasive functional imaging for myocardial ischaemia is recommended as the initial diagnostic test (Class I, Level B), selected on pre-test likelihood, patient characteristics that influence test performance such as ability to exercise, and local expertise and availability (Class I, Level C).^[1]
• At 19% she is in the moderate or high (>15%–85%) band, where stress echocardiography is recommended to diagnose myocardial ischaemia and to estimate the risk of MACE (Class I, Level B); stress SPECT or, preferably, PET and stress CMR perfusion rows also apply.^[1]
• Her exercise is limited: ESC 2024 says pharmacological agents are indicated in patients who cannot exercise adequately (SPECT section) and lists i.v. dobutamine, or vasodilators with atropine, besides exercise as the stress modalities for stress echocardiography.^[1]

Step 2 — Before the test

Discussion:

• Check the AHA/ACC 2021 stress echocardiography contraindications, which include inability to reach target heart rate, uncontrolled heart failure and high-risk unstable angina, active ACS or AMI (<2 d); because she needs a pharmacologic test, also check its contraindications to dobutamine, which include AV block, uncontrolled atrial fibrillation and haemodynamically significant LV outflow tract obstruction.^[2]
• If two or more contiguous segments are not visualized, ESC 2024 recommends ultrasound contrast agents to improve diagnostic accuracy (Class I, Level B), and notes that they are generally safe but that rare anaphylactic reactions have been reported.^[1]

Step 3 — The result

Her dobutamine stress echocardiogram shows stress-induced hypokinesia in four of 16 segments in the anterior and septal walls.^[1]

Discussion:

• ESC 2024 lists ≥3 of 16 segments with stress-induced hypokinesia or akinesia on stress echocardiography as a result that identifies high risk of adverse events (Class I, Level B).^[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 reports that the ISCHEMIA trial (Initial Invasive or Conservative Strategy for Stable Coronary Disease) showed that an early revascularization strategy did not yield a short-term survival benefit in patients without left main disease or reduced LVEF who had moderate-severe ischaemia at non-invasive testing, suggesting that most such patients should initially be treated conservatively with optimized GDMT.^[1]

Step 4 — Two years later

Two years after ICA confirmed obstructive coronary disease, she has chronic coronary disease, is stable on optimized GDMT with no change in clinical or functional status, and asks for a yearly stress test.^[3]

Discussion:

• AHA/ACC 2023: routine periodic testing with coronary CTA or stress testing with or without imaging is not recommended 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).^[3]
• If new or worsening symptoms appear, ESC 2024 recommends risk stratification, preferably using stress imaging (Class I, Level C).^[1]

Examiner criteria

• Pass: reads 19% from ESC 2024 Figure 4, places it in the moderate or high band and names the ESC 2024 stress echocardiography, SPECT/PET and CMR rows with their classes; chooses a pharmacological stress when exercise is limited; checks contraindications, including those to dobutamine, and the contrast row; recognises ≥3 of 16 abnormal segments as high risk and gives the ICA row; and declines routine yearly stress testing, citing the AHA/ACC 2023 row.^[1][2][3]
• Fail: orders an exercise ECG to rule out CAD although functional imaging is available (ESC 2024 Class III, Level C), or misses the high-risk threshold.^[1]