Stress testing choices: exercise ECG, stress echo and perfusion imaging

• This page compares the exercise ECG, stress echocardiography, nuclear perfusion imaging with SPECT or PET, and stress CMR: what each detects, who should have which, how to read a high-risk result and when not to test.^[1]
• Anatomical testing with CCTA is compared here only where the guidelines set it against stress testing; resting echocardiography is covered in Echocardiography: EF quantitation and diastology basics, CMR tissue characterisation in Cardiac MRI: LGE patterns and clinical questions, and treatment after the diagnosis in Chronic coronary syndrome: antianginal therapy, event prevention and where revascularisation fits.

How a stress test shows ischaemia

The four tests differ in the stress they apply and in what they record.^[1]

• The exercise ECG records ECG changes, stress echocardiography wall thickening, SPECT relative tracer uptake, PET relative uptake plus absolute blood flow, and CMR the first pass of gadolinium.^[1]

• ESC 2024 explains stress echocardiography this way: it relies on inducing myocardial ischaemia by increasing myocardial oxygen demand beyond the myocardial blood supply, and because ischaemia starts in the subendocardium, which contributes to more than 50% of systolic myocardial wall thickening, stress precipitates wall-thickening abnormalities in the perfusion territory of narrowed coronary arteries.^[1]

• Myocardial perfusion SPECT images regional tracer retention, which reflects relative regional myocardial blood flow; hypoperfusion shows as relatively reduced uptake and retention during vasodilatation or stress compared with rest.^[1]

• Because SPECT (and stress CMR) needs a normally perfused reference territory to show relative hypoperfusion, ESC 2024 calls this the main limitation, particularly in multivessel CAD.^[1]

• PET-CT produces similar relative images, with superior image quality and at much lower radiation dose exposure, but its unique strength is robust absolute quantitative measures of myocardial blood flow (MBF).^[1]

CMR perfusion relies on the first-pass myocardial perfusion of gadolinium-based contrast agents.^[1]

Stressors and what they do

^[1]

ESC 2024 Table 6 (overview of first-line tests in suspected CCS): the functional imaging rows

^{[1] [1]}

Exercise ECG

• ESC 2024 describes the classical exercise ECG as graded exercise until fatigue, limiting chest pain or discomfort, significant ischaemic ECG changes, arrhythmias, excessive hypertension, a BP drop, or after reaching 85% of the maximal predicted heart rate.^[1]
• AHA/ACC 2021 defines the symptom-limited exercise ECG as graded exercise until physical fatigue, limiting chest pain (or discomfort), marked ischemia, or a drop in blood pressure occurs.^[2]
• The test is low cost, uses no ionizing radiation, is widely accessible, and remains an alternative for diagnostic testing depending on local resources and individual characteristics.^[1]

Why it is no longer the default diagnostic test

• ESC 2024 says exercise ECG testing has a lower diagnostic performance for obstructive CAD than modern functional imaging and CCTA, which should therefore be preferred as a first-line test in suspected CCS.^[1]
• It gives the reason in numbers: a low sensitivity (58%) and specificity (62%), so exercise ECG testing has low diagnostic performance for obstructive CAD and should mainly be used for risk stratification.^[1]
• AHA/ACC 2021 puts the diagnostic accuracy of the exercise ECG lower than stress imaging (sensitivity and specificity range, 60%–77%), but says prognostication remains a useful goal.^[2]
• ESC 2024 adds that two randomized trials showed fewer anginal complaints during follow-up when patients with stable chest pain were randomized to CCTA rather than exercise ECG as the index investigation.^[1]

Who can and cannot have a diagnostic exercise ECG

• ESC 2024 says an exercise ECG is of no diagnostic value when resting ECG abnormalities prevent interpretation of ST-segment changes during stress: LBBB, paced rhythm, Wolff-Parkinson-White syndrome, ≥0.1 mV ST-segment depression on the resting ECG, or treatment with digitalis.^[1]
• AHA/ACC 2021 describes candidates as those without disabling comorbidity (for example frailty, marked obesity [body mass index >40 kg/m²], peripheral artery disease, chronic obstructive pulmonary disease or orthopedic limitations) who can perform activities of daily living or achieve ≥5 METs.^[2]
• Its candidates also have no rest ST-T abnormalities (for example >0.5-mm ST depression, left ventricular hypertrophy, paced rhythm, left bundle branch block, Wolff-Parkinson-White pattern or digitalis use).^[2]

ESC 2024 rows for exercise ECG in suspected CCS

ESC 2024: exercise ECG

^[1]

• ESC 2024 says that in regions with limited access to functional imaging or CCTA, or with a low (>5%–15%) pre-test likelihood of obstructive CAD, exercise ECG remains useful for risk stratification and prognostication.^[1]
• Particularly, with a low (>5%–15%) likelihood, a negative exercise ECG may help to down-classify patients into the very low likelihood (<5%) class, in whom further testing can be deferred.^[1]
• In patients with known CAD, exercise ECG may be considered in selected patients to complement clinical evaluation of symptoms, ST-segment changes, exercise tolerance, arrhythmias, BP response and event risk.^[1]

AHA/ACC 2021 rows for exercise ECG

AHA/ACC 2021: exercise ECG

^[2]

What the exercise ECG still tells you

• ESC 2024 says people exercising >10 metabolic equivalents with a negative exercise ECG and a low-risk Duke Treadmill Score have a good prognosis, with limited need for downstream testing and revascularization.^[1]

Marked ischaemia at a low workload with a high-risk Duke Treadmill Score may justify further anatomical or functional testing.^[1]

• AHA/ACC 2021 makes the same points in its own terms: failure to complete the first stage of the Bruce protocol (or <5 METs) or to achieve 85% of age-predicted fitness level increases CAD event risk, and exercising to Bruce stage III or >10 METs with a negative ECG carries a low risk of CAD events.^[2]
• It adds that with submaximal exercise or an ischemic ECG with ≥1.0 mm ST depression, additional stress imaging may improve risk detection, and that marked ischemia (for example ≥2.0 mm at reduced workloads) or high Duke or Lauer scores signify increased risk among women and men, who may benefit from additional anatomic or stress testing.^[2]
• ESC 2024 reports a SCOT-HEART post hoc analysis that suggested abnormal exercise ECG results remain a specific indicator of obstructive CAD and are associated with future coronary revascularization and risk of MI.^[1]

Stress echocardiography

Stress echocardiography detects ischaemia as regional systolic wall-thickening abnormalities (RWTA) during exercise, dobutamine or vasodilator stress.^[1] ESC 2024 says demand stress echocardiography has provided diagnostic accuracy and risk-stratification capabilities similar to other contemporary functional imaging modalities.^[1]

• Its listed advantages: widely available, low-cost, can be performed and interpreted at the bedside, rapid, free of ionizing radiation, and can be repeated without safety concerns.^[1]

Limits of wall-motion reading

• ESC 2024 notes that stress echocardiography is operator-dependent, which may compromise reproducibility, and that compromised image quality, especially in obese people and those with chronic obstructive pulmonary disease, is a significant limitation.^[1]
• RWTA may not occur if the oxygen demand increase is inadequate or the induced perfusion abnormality is not large enough (<10% of the myocardium), such as in mild atherosclerotic CAD or single-vessel obstructive CAD.^[1]

Because it relies on RWTA, stress echocardiography may under-estimate ischaemia in microvascular disease that does not affect the subendocardium, as in ANOCA/INOCA.^[1]

Contrast, perfusion and flow reserve

• Ultrasound contrast agents (microbubbles) opacify the left heart chambers, and the better image quality and endocardial border definition markedly improve the accuracy of stress echocardiography.^[1]
• ESC 2024 says contrast may be required with obesity and chronic obstructive pulmonary disease, and must be used in all cases if it is evident at baseline that all segments may not be visible during stress.^[1]
• Contrast passing through the myocardium also allows perfusion assessment simultaneously with wall motion, improving sensitivity (better detection of single-vessel and microvascular disease) and risk stratification beyond RWTA.^[1]

The agents are generally safe, but rare cases of anaphylactic reactions have been reported.^[1]

• Doppler coronary flow velocity reserve (CFVR) in the LAD and B-lines on lung ultrasound can easily be added; in a prospective observational multicentre study, reduced CFVR showed independent value over RWTA in predicting an adverse outcome.^[1]

ESC 2024: stress echocardiography

^[1]

• AHA/ACC 2021 says that after ACS has been ruled out, stress echocardiography can be used to define ischemia severity and for risk stratification, and that ultrasound-enhancing agents help left ventricular opacification when ≥2 contiguous segments or a coronary territory is poorly visualized.^[2]
• The EACVI 2023 clinical consensus statement describes an ABCDE protocol: regional wall motion (step A, when regional perfusion may also be assessed with ultrasound contrast), diastolic function and B-lines (B), contractile and preload reserve (C), LAD coronary flow velocity reserve (D) and ECG-based heart rate reserve (E).^[16]
• Only its PubMed abstract is held, so no class is quoted from it; the abstract calls stress echo low cost, versatile and universally available, without ionizing radiation exposure.^[16]

Nuclear perfusion imaging: SPECT and PET

SPECT

ESC 2024 says technetium-99m (99mTc)-based tracers are the most commonly used, whereas thallium 201 (201Tl) should be avoided because of higher radiation exposure.^[1] Ischaemia can be shown with exercise, pharmacological stressors such as dobutamine, or vasodilators such as dipyridamole, adenosine or regadenoson.^[1] Exercise and pharmacological stress options, wide availability and no absolute contraindications make myocardial perfusion SPECT highly versatile in clinical routine.^[1] SPECT is associated with good accuracy for flow-limiting coronary lesions, provides prognostic information and improved patient management in a randomized controlled trial.^[1]

• Calcium scoring from the non-contrast CT acquired for attenuation correction, transient ischaemic dilatation (TID) and reduced post-stress ejection fraction are important non-perfusion predictors of severe obstructive CAD.^[1]
• Newer cadmium–zinc–telluride (CZT) cameras cut radiation dose and acquisition time, increase diagnostic accuracy and allow absolute MBF quantification, and diagnostic performance for multivessel CAD has improved substantially.^[1]

ESC 2024 adds a reminder: non-obstructive atherosclerosis not linked with ischaemia generally remains undetected by functional testing.^[1]

PET

• PET radionuclides (13N-ammonia, 15O-water and 82Rubidium) are short-lived, with half-lives in the range of minutes, so they must be produced ad hoc for every investigation.^[1]

Attenuation correction is mandatory, so PET is routinely combined with non-contrast CT, and scans are done at rest and during pharmacological stressors or vasodilators.^[1]

• Measuring MBF with cardiac PET does not increase radiation or imaging time; hyperaemic and rest MBF, MBF reserve and relative MBF reserve add diagnostic and prognostic value beyond relative perfusion.^[1]

Quantitative MBF helps in known or suspected diffusely impaired flow, for example multivessel CAD or microvascular dysfunction.^[1]

• In head-to-head comparisons PET-CT outperformed other functional imaging modalities, but whether this superiority in diagnostic accuracy improves clinical effectiveness and post-test management remains to be elucidated.^[1]

Its limits are limited availability, methodological heterogeneity (particularly thresholds for abnormality of quantitative measurements) and the difficulty of performing physical exercise.^[1]

• If available, ESC 2024 particularly recommends PET-CT perfusion in obese patients (high photon energy), young patients (low radiation dose) and those with known or suspected diffusely impaired MBF.^[1]
• ESC 2024 says an MFR of less than 2.0 (2.5 for non-obstructive CAD) is often considered abnormal for PET, but no definitive references are available across imaging modalities because different MBF estimates correlate only moderately.^[1]

ESC 2024: SPECT, PET and stress CMR

^[1]

AHA/ACC 2021: stress imaging and nuclear technique

^[2]

• AHA/ACC 2021 says rest/stress PET or SPECT, after ACS has been ruled out, detects perfusion abnormalities, measures left ventricular function and shows high-risk findings such as transient ischemic dilation.^[2]
• For PET, myocardial blood flow reserve (MBFR, the ratio of peak hyperemia to resting myocardial blood flow) adds diagnostic and prognostic information over MPI data.^[2]
• It gives average effective doses of about 3 mSv for rest/stress PET with Rb-82 and about 10 mSv for Tc-99m SPECT, and says dual-isotope SPECT using thallium is not recommended.^[2]
• It also says PET has improved diagnostic and prognostic performance over SPECT, especially when MBF can be quantified, and cites a trial (n=475) with higher diagnostic accuracy for stress PET MPI than other stress test modalities.^[2]

Stress CMR

• ESC 2024 says stress CMR perfusion combines high spatial resolution with no ionizing radiation and has shown high diagnostic accuracy for flow-limiting lesions, prognostic value and improved patient management.^[1]

Vasodilators (adenosine or regadenoson) or dobutamine are commonly used, because physical exercise is challenging to perform.^[1]

• Quantitative CMR MBF methods vary extensively in diagnostic performance and lack standardized protocols and software, so visual assessment of perfusion defects is used in clinical practice.^[1]
• A multiparametric protocol, with LV function and LGE assessment alongside perfusion, increases the ability to rule in or rule out obstructive CAD in suspected CCS.^[1]
• Limits include availability, claustrophobia, acquisition time, and contraindications to CMR (for example non-conditional pacemakers and ICDs) or to gadolinium (for example renal failure, because of the potential risk of nephrogenic systemic fibrosis).^[1]

Unlike SPECT/CT or PET-CT, stress CMR does not currently provide information on coronary calcification.^[1]

• ESC 2024 says that, if available and if no contraindications are met, stress CMR is recommended as an option in patients with suspected CCS with moderate or high (>15%–85%) pre-test likelihood of obstructive CAD or known CCS, particularly if additional information on cardiac function and tissue characterization is warranted.^[1]

AHA/ACC 2021 says CMR can accurately assess global and regional ventricular function, detect and localize ischemia and infarction, and determine myocardial viability.^[2]

Choosing the first test in suspected chronic coronary syndrome

ESC 2024: likelihood, patient and local expertise

• ESC 2024 says further testing after the pre-test likelihood estimate depends on the clinical scenario, general condition, quality of life, comorbidities, local availability and expertise, and patient expectations and preferences.^[1]

Further diagnostic testing can be deferred with a very low (≤5%) likelihood of obstructive CAD.^[1]

• People with a very low and low (≤15%) likelihood make up about 85% of those with de novo symptoms suspected of CCS, and most can be treated conservatively without further testing.^[1]
• Those with a moderate or high (>15%–85%) likelihood should be referred for non-invasive anatomical or functional imaging to establish the diagnosis and assess the risk of future cardiac events.^[1]

ESC 2024: selecting the initial test

^[1]

ESC 2024 says functional imaging should be selected as a first-line test if information on myocardial ischaemia, viability or microvascular disease is desired.^[1]

• Tests for ischaemia have better rule-in power than CCTA, so ESC 2024 says they should be selected with a moderate-high (>15–85%) likelihood of obstructive CAD.^[1]
• Functional imaging overcomes the limits of CCTA in older patients with more extensive calcification, AF and other irregular or fast heart rates, renal insufficiency or iodinated contrast allergy, and avoids ionizing radiation in young people and those suspected of ANOCA/INOCA.^[1]
• CCTA has its own resolution limits, which can hinder precision in adjudicating stenosis severity; ESC 2024 says this is most problematic in older patients with heavily calcified arteries, in whom functional testing may be more appropriate.^[1]

On the other side, ESC 2024 notes growing support for CCTA as a first-line test at low or moderate (15%–50%) likelihood.^[1]

• It frames the rationale for any first-line test as assessing the anatomical severity and functional consequences of coronary disease, obstructive or not, and says PET-CT should be considered more often because it combines calcium scoring with operator-independent detection of ischaemia and CMD at low dose.^[1]

^[1]

Sequential testing

In the moderate likelihood group, except older men with all three CCS symptom characteristics, ESC 2024 puts the likelihood of obstructive CAD around 20%.^[1]

• At that level anatomical and functional testing each give an intermediate positive predictive value with many false positives, especially with CCTA easily overestimating stenosis severity.^[1]
• Sequential testing (functional testing after CCTA, or vice versa) will therefore be needed in many people to establish an accurate diagnosis of obstructive, ischaemia-inducing CAD.^[1]
• ESC 2024 gives a worked example: a 69-year-old man with four risk factors and all three anginal symptom characteristics has an adjusted pre-test likelihood of 60%; a positive DSE alone gives a high post-test likelihood (± 90%), a negative DSE leaves 32%, and sequential CCTA would allow ruling out obstructive CAD (<5%).^[1]
• With a very high (≥85%) likelihood, symptoms unresponsive to medical therapy or angina at a low level of exercise, and an initial evaluation (including echocardiogram and, in selected patients, exercise ECG) indicating high event risk, ESC 2024 says proceeding directly to ICA is a reasonable option.^[1]

AHA/ACC 2021: risk groups instead of likelihood bands

• AHA/ACC 2021 sorts stable chest pain without known CAD into low risk and intermediate-high risk, and says intermediate-high risk patients have modest rates of obstructive CAD (∼10%–20%) and risk of clinical events (∼1%–2% per year).^[2]
• Its stable chest pain pathway says test choice is guided by exercise capacity and resting ECG abnormalities, with CCTA preferable under 65 years of age and not on optimal preventive therapies, and stress testing favored at ≥65 years (with a higher likelihood of ischemia).^[2]

AHA/ACC 2021: anatomic and stress testing together

^[2]

• AHA/ACC 2021 supports the stress-imaging row with observational and trial data: the prognostic value of stress echocardiography in large observational series with low event rates after normal results, particularly with good exercise tolerance.^[2]

Multicenter registries support risk stratification with rest/stress MPI and left ventricular function, with recent evidence on the prognostic value of stress PET.^[2] In CE-MARC 2 (n=1,202), CMR and SPECT MPI strategies had similar rates (7.1%–7.5%) of unnecessary invasive angiography, compared with 28.8% for standard testing (p<0.001).^[2]

• In MR-INFORM, 918 patients with typical angina and multiple risk factors or a positive exercise ECG were randomized to a CMR or invasive FFR strategy; the CMR strategy was associated with less coronary revascularization (p=0.005) and a similar event rate (death, AMI, or target vessel revascularization; p=0.91).^[2]

^[18]

• ESC 2024 reports PROMISE as showing that CCTA, mainly by detecting non-obstructive CAD, outperformed functional testing in predicting outcomes, in patients more representative of an all-comer population.^[1]
• It adds that adding the Framingham Risk Score to the functional test result made the difference from anatomical testing insignificant, so both modalities are equivalent for detecting CCS symptoms and predicting outcomes when risk factors are considered.^[1]

Contraindications and safety

AHA/ACC 2021 tabulates contraindications by imaging modality and stress protocol; the lists below include its entries for each stress column.^[2] For every imaging modality, it says the inability to achieve high-quality images should be considered, in particular in obese patients.^[2]

Contraindications by stress protocol (AHA/ACC 2021)

^[2]

• The same table footnote says screening for potential pregnancy by history and/or pregnancy testing should be done according to local imaging policies before tests that involve ionizing radiation in women of child-bearing age.^[2]
• The ESC 2024 overview of first-line tests (Table 6, set out at the top of this page) lists the matching limitations for each functional test.^[1]

The ESC 2026 cardiac rehabilitation guideline lists clinical conditions that should be considered as contraindications to exercise testing and training.^[12]

• ESC 2026 conditions that should be considered as contraindications to exercise testing and training: early phase after acute coronary syndrome (up to 2 days); untreated life-threatening cardiac arrhythmias; decompensated heart failure (during the initial period of haemodynamic instability); uncontrolled hypertension; advanced atrioventricular block.^[12]
• The same column continues: acute myocarditis and pericarditis; symptomatic aortic stenosis; hypertrophic cardiomyopathy with severe obstruction; acute systemic illness; intracardiac thrombus.^[12]

^[2]

Reading the result: who is at high risk

• ESC 2024 defines high event risk as a cardiac mortality rate of >3% per year, intermediate as ≥1% to ≤3% per year and low as <1% per year, based on large registries and historical RCTs.^[1]
• On the exercise ECG, ST-segment depression at a low workload with exertional angina or dyspnoea, low exercise capacity, complex ventricular ectopy or other arrhythmias, and an abnormal BP response mark a high risk of cardiac mortality.^[1]

ESC 2024: test results that identify high risk of adverse events

^[1]

• The row is phrased as the use of one or more of these test results; ESC 2024 also recommends an initial stratification of risk based on basic clinical assessment (for example age, ECG, anginal threshold, diabetes, CKD, LVEF) (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 says patients can be referred for ICA if functional imaging shows moderate or severe ischaemia encompassing an extensive perfusion territory, or if CCTA shows left main stenosis ≥50%, or three-vessel or two-vessel disease including the proximal LAD with ≥70% stenosis.^[1]

^[1]

Does the amount of ischaemia predict outcome?

ESC 2024 calls the evidence conflicting.^[1]

• Large observational studies consistently link the extent of inducible ischaemia with prognosis (for example ≥3/16 abnormal segments on stress echo, ≥10% LV ischaemia on nuclear or MR perfusion, or decreased hyperaemic flow or flow reserve on quantitative PET).^[1]
• Post hoc analyses of COURAGE and ISCHEMIA found that only CAD severity, not ischaemia severity, independently predicted long-term mortality and MI risk; ESC 2024 says selection and entry biases between registries and RCTs may explain the difference.^[1]
• It concludes that event risk should be judged with an integrative approach: risk factors, comorbidities, LV dysfunction, severity of ischaemia, number of functionally significant stenoses, and plaque burden and characteristics.^[1]

^[19]

• ESC 2024 reads ISCHEMIA as showing no short-term survival benefit from early revascularization in patients without left main disease or reduced LVEF who had moderate-severe ischaemia at non-invasive testing, suggesting most such patients should initially be treated conservatively with optimized GDMT.^[1]

Known coronary disease, recurrent symptoms and follow-up

ESC 2024: established chronic coronary syndrome

^[1]

• ESC 2024 says that for obstructive CAD or previous cardiac events, non-invasive functional imaging is the preferred method to detect and quantify ischaemia and/or scar, and that it is preferred after revascularization because of the high frequency of extensive CAD.^[1]
• With severely limiting angina and known severe ischaemia on functional testing or high-risk CAD on CCTA, direct referral to ICA for revascularization is preferred because of the very high risk of recurrent CAD events.^[1]
• For known non-obstructive CAD, ESC 2024 says CCTA can help detect new obstructive stenoses, evaluate disease progression and identify high-risk plaque features, while functional imaging is reasonable for detecting myocardial ischaemia and guiding further management.^[1]
• Exercise ECG may be considered to confirm symptoms and evaluate functional capacity if it alters management, but routine functional testing is not recommended for asymptomatic post-PCI patients, because it has not been shown to improve outcomes compared with standard care after 2 years.^[1]

When symptoms are uncertain, functional testing may help clarify the presence and extent of ischaemia.^[1]

AHA/ACC 2023: testing in chronic coronary disease

^[3]

The four 2023 diagnostic rows above are footnoted as modified from the 2021 AHA/ACC chest pain guideline.^[3]

AHA/ACC 2021: nonobstructive CAD and prior CABG

^[2]

AHA/ACC 2023 defines chronic coronary disease as including obstructive and nonobstructive CAD, with or without previous MI or revascularization.^[3]

• So when a change in symptoms or functional capacity persists despite GDMT in these patients, the newer 2023 row applies: 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).^[3]
• Separately, in patients with CCD undergoing stress PET MPI or stress CMR imaging, the addition of MBFR can be useful to improve diagnostic accuracy and enhance risk stratification (COR 2a, LOE B-NR).^[3]
• In patients with CCD and a change in symptoms or functional capacity that persists despite GDMT who have had previous coronary revascularization, the 2023 guideline adds that CCTA is reasonable to evaluate bypass graft or stent patency (for stents ≥3 mm) (COR 2a, LOE B-NR).^[3]

^{[3] [1]}

Angina with non-obstructive coronary arteries

ESC 2024 says myocardial ischaemia on functional imaging without obstructive CAD on CCTA or ICA should always raise the suspicion of ANOCA/INOCA.^[1]

• PET-CT quantifies MBF (millilitres per minute per gram) and myocardial flow reserve (MFR), which reflects the increase in MBF achievable by maximal coronary vasodilation with vasodilators such as adenosine or regadenoson, and represents small vessel function.^[1]

There is only a modest correlation between MBF reserve values measured by different techniques and modalities.^[1]

• In known ANOCA/INOCA, stress SPECT or PET, stress CMR or stress echocardiography remain first-line, although the diagnostic yield may be low, and the current standard remains invasive coronary functional testing.^[1]
• Sequential or combined anatomical and functional testing is also useful for non-invasive diagnosis of ANOCA/INOCA, and combined testing (for example CCTA with PET) may improve prognostication in CCS patients.^[1]

Flow reserve and coronary function testing in ANOCA/INOCA

^{[1] [2]}

• Because AHA/ACC 2023 counts nonobstructive CAD as chronic coronary disease, its MBFR row also covers patients with nonobstructive CAD: in patients with CCD undergoing stress PET MPI or stress CMR imaging, the addition of MBFR can be useful to improve diagnostic accuracy and enhance risk stratification (COR 2a, LOE B-NR), the same class as the 2021 PET and CMR MBFR rows.^[3][2]

Acute chest pain and NSTE-ACS

• ESC 2023: in patients with suspected ACS, non-elevated (or uncertain) hs-cTn levels, no ECG changes and no recurrence of pain, incorporating CCTA or a non-invasive stress imaging test as part of the initial workup should be considered (Class IIa, Level A).^[4]

AHA/ACC 2021: acute chest pain

^[2]

• AHA/ACC 2021 also gives a warranty period for prior testing: a normal stress test (given adequate stress) for 1 year, against 2 years for a normal coronary angiogram or CCTA with no stenosis or plaque.^[2]
• For recent prior testing with normal findings, it says no further testing is indicated if adequate exercise or pharmacologic stress was achieved, imaging was of sufficient quality, and symptom frequency and stability are unchanged.^[2]
• In patients with NSTE-ACS at low risk of ischemic events, ACC/AHA 2025 recommends either a routine invasive or selective invasive approach to help identify those who may require revascularization and to reduce MACE (COR 1, LOE A).^[5]
• Its supportive text says some low-risk patients, particularly those with normal cardiac biomarkers in whom a diagnosis of ACS is suspect, may have improved outcomes with a selective invasive approach.^[5]
• These patients should preferentially undergo noninvasive stress testing or coronary CT angiography before discharge to help determine the need for coronary angiography, and patients with suspected ongoing ischemic symptoms should be considered for coronary angiography.^[5]

Special populations

Heart failure

• ESC 2024 says exercise or pharmacological stress echocardiography can assess inducible ischaemia and help in the differential diagnosis of HFpEF, and that stress SPECT or PET can also detect inducible ischaemia.^[1]

Non-invasive stress testing can be difficult in heart failure because of possible exercise intolerance.^[1]

Stress testing in heart failure

^{[1] [9] [8] [15]}

Women, younger patients and radiation

• ESC 2024 reports that in the WOMEN trial, in low-risk symptomatic women, exercise ECG was as effective as exercise myocardial perfusion scintigraphy, with a similar 2-year incidence of MACE and significant diagnostic cost savings.^[1]
• AHA/ACC 2021 gives the WOMEN trial as 824 symptomatic women with similar 2-year CAD event rates (2.0% versus 2.3%; p=0.59) for exercise ECG and exercise SPECT MPI.^[2]
• If available, ESC 2024 particularly recommends PET-CT in young patients because of the low radiation dose exposure, and its first-line test overview lists irradiation, especially in young women, as a limitation of SPECT and PET.^[1]

Stress echocardiography and stress CMR use no ionizing radiation.^[1]

Pregnancy

• ESC 2025 says that if new-onset CVD is suspected during pregnancy, submaximal exercise testing (at 80% of predicted maximal heart rate) can be useful to assess the cardiovascular response to exercise, with no evidence that exercise testing increases the risk of spontaneous miscarriage.^[10]

Stress echocardiography with bicycle ergometry may improve diagnostic specificity, and pharmacologic stress agents such as dobutamine should be avoided.^[10]

• ESC 2025 recommends limiting exposure to all medical ionizing radiation to ALARA levels (Class I, Level C), and says CMR without gadolinium contrast should be considered for a definitive, clinically relevant diagnosis during pregnancy if other non-invasive diagnostic measures are not sufficient (Class IIa, Level C).^[10]
• AHA/ACC 2021 text (no class or level given) says that for elective and urgent cardiac testing, imaging using ionizing radiation during pregnancy or postpartum while breast feeding should generally be avoided, and that gadolinium with CMR should be discouraged and used only when necessary to guide clinical management and expected to improve fetal or maternal outcome.^[2]

Atrial fibrillation, older patients and kidney disease

ESC 2024 says diagnostic assessment of CAD, by CCTA or non-invasive tests, may be difficult in AF with a high ventricular rate.^[1]

• ACC/AHA 2023 says that in newly diagnosed AF, protocolized testing for ischemia, ACS and PE should not routinely be performed to assess its etiology unless additional signs or symptoms indicate those disorders (COR 3: No benefit, LOE B-NR).^[14]

In older patients with heavily calcified arteries, ESC 2024 says functional testing may be more appropriate than CCTA.^[1]

• For kidney disease, AHA/ACC 2021 lists reduced GFR (<30 mL/min/1.73 m²) as a stress CMR contraindication, while ESC 2024 gives renal failure (due to the potential risk of nephrogenic systemic fibrosis) as an example of a possible contraindication to gadolinium-based contrast agents, and lists haemodialysis as a limitation of contrast CMR.^[2][1]

Before non-cardiac surgery

• ESC 2022 says stress imaging is appropriate for risk assessment in patients with clinical risk factors and poor functional capacity, and is not recommended before urgent surgery or with an unstable clinical condition.^[7]
• ESC 2022 says an exercise stress test detects ischaemia through ST-segment changes with poor sensitivity (61–73%) and specificity (60–80%), while also estimating functional capacity and the BP and heart rate response.^[7]
• It says an exercise stress test alone should only be considered a valuable alternative to diagnose obstructive CAD if non-invasive imaging tests are unavailable, or to assess functional capacity when the history is ambiguous.^[7]
• Normal stress imaging without resting abnormalities has high negative predictive value, but positive predictive value for peri-operative events is relatively low and needs confirmation by other tests.^[7]
• On DSE, the strongest predictors of post-operative events so far are significant ischaemia (more than four segments), an ischaemic threshold of 60% of age-predicted maximal heart rate, and a history of congestive heart failure.^[7]

Myocardial perfusion imaging is particularly suitable when acoustic windows are poor for DSE.^[7]

ESC 2022: stress imaging before non-cardiac surgery

^[7]

• Only the PubMed abstract of the 2026 AHA/ACC/ACS/ASNC/HRS/SCA/SCCT/SCMR/SVM Guideline for Perioperative Cardiovascular Management for Noncardiac Surgery (PMID 42804570) is held; its full text is not held and was not checked for this topic.
• The held abstract is that of its JACC co-publication (PMID 42813718), and it does not name stress testing.
• The 2024 AHA/ACC perioperative guideline (PMID 39316661) is held, but the 2026 edition replaces it, so its stress-testing text is not used here.

Stress testing in aortic stenosis and other valve disease

• ESC/EACTS 2025 says patients with slowly progressive valve lesions may gradually limit their activity and deny symptoms that exercise testing can unmask, and that this is particularly important in AS because once symptoms occur there is a sharp increase in the risk of sudden cardiac death unless a valve intervention is performed.^[11]
• It says exercise testing can unmask symptoms and haemodynamic intolerance (fall in BP >20 mm Hg) and is recommended for risk stratification in asymptomatic patients with severe AS.^[11]
• Exercise echocardiography assesses LV global and segmental function, pulmonary artery pressure and aortic and mitral gradients, and documents exercise-induced increases in MR and TR, especially in secondary disease.^[11]
• In low-flow, low-gradient AS with reduced LVEF, DSE can help discriminate between pseudo-severe and true severe AS in the presence of flow reserve (increase in stroke volume of ≥20%).^[11]

ACC/AHA 2020: exercise and dobutamine testing in aortic stenosis

^[13]

Pitfalls

• Using the exercise ECG to rule out CAD when imaging is available: ESC 2024 does not recommend it at low or moderate (>5%–50%) likelihood if CCTA or functional imaging is available (Class III, Level C).^[1]
• Ignoring the resting ECG: LBBB, paced rhythm, Wolff-Parkinson-White, ≥0.1 mV resting ST depression or digitalis make the exercise ECG non-diagnostic (ESC 2024).^[1]
• Reading a normal stress echo as excluding microvascular disease: wall-motion reading may under-estimate ischaemia that does not affect the subendocardium, as in ANOCA/INOCA (ESC 2024).^[1]
• Relying on relative perfusion in multivessel disease: the need for a normally perfused reference territory is the main limitation of SPECT (and stress CMR), particularly in multivessel CAD; PET quantifies absolute flow (ESC 2024).^[1]
• Caffeine before a vasodilator stress nuclear or stress CMR study: AHA/ACC 2021 lists methylxanthines (for example caffeine) within 12 h among the contraindications to vasodilator administration in its stress nuclear column, and caffeine use within 12 h in its stress CMR column.^[2]
• Exercising a patient with symptomatic severe AS (Stage D1, aortic velocity ≥4.0 m/s or mean pressure gradient ≥40 mm Hg): ACC/AHA 2020 says exercise testing should not be performed because of the risk of severe hemodynamic compromise (COR 3: Harm, LOE B-NR).^[13]
• Routine surveillance stress tests: AHA/ACC 2023 says routine periodic testing with coronary CTA or stress testing with or without imaging is not recommended to guide therapeutic decision-making in chronic coronary disease without a change in clinical or functional status on optimized GDMT (COR 3: No benefit, LOE B-R), and ESC 2024 text (no class or level given) says routine functional testing is not recommended for asymptomatic post-PCI patients.^[3][1]
• Treating the amount of ischaemia as the whole risk picture: ESC 2024 calls the prognostic evidence conflicting and asks for an integrative approach.^[1]

Evidence, guidelines and regional differences

^{[1] [7] [2] [3]}

• The difference to explain at the viva is framing: ESC 2024 selects the initial test based on pre-test likelihood of obstructive CAD, other patient characteristics that influence test performance, and local expertise and availability, while AHA/ACC 2021 sorts stable chest pain into low and intermediate-high risk and adds an age split of 65 years.^[1][2]
• ESC 2024 text (no class or level given) says exercise ECG testing has a lower diagnostic performance for obstructive CAD than modern functional imaging and CCTA, which should therefore be preferred as a first-line test in suspected CCS.^[1]
• For intermediate-high risk patients with stable chest pain and no known CAD, AHA/ACC 2021 says stress imaging (stress echocardiography, PET/SPECT MPI or CMR) is effective for diagnosis of myocardial ischemia and for estimating risk of MACE (COR 1, LOE B-R), and that exercise electrocardiography is reasonable for those with an interpretable ECG and ability to achieve maximal levels of exercise (≥5 METs) (COR 2a, LOE B-R).^[2]
• For nuclear perfusion imaging, ESC 2024 recommends, in individuals with suspected CCS and moderate or high (>15%–85%) pre-test likelihood of obstructive CAD, if available and supported by local expertise, stress SPECT or, preferably, PET to diagnose and quantify myocardial ischaemia and/or scar, estimate the risk of MACE and quantify myocardial blood flow (PET) (Class I, Level B), while AHA/ACC 2021 says that for intermediate-high risk patients with stable chest pain and no known CAD for whom 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).^[1][2]

In Australia and New Zealand

• The 2025 NHFA/CSANZ ACS guideline, through its Med J Aust summary, says that in NSTEACS not at high or very high risk, testing for inducible ischaemia (for example stress testing) may guide the need for invasive coronary angiography (strength of recommendation weak; certainty of evidence moderate).^[6]

It also says invasive or non-invasive inpatient testing is recommended for people at intermediate risk with elevated hs-cTn above the sex-specific 99th percentile.^[6]

• The NHFA/CSANZ 2018 heart failure guideline gives the weak, very-low-quality recommendation for functional testing in heart failure with established CAD shown in the heart failure table above.^[15]

• The NHFA/CSANZ Comprehensive Australian Clinical Guideline for Diagnosing and Managing Acute Coronary Syndromes 2025 (PMID 40180468) is not held as text in its version of record, so it was not checked for this topic.

• Its Med J Aust summary (PMID 41693087) is quoted instead.^[6]

• The Noninvasive coronary artery imaging: current clinical applications: Cardiac Society of Australia and New Zealand guidelines (PMID 21530393) is not held as text in the evidence caches, so it was not checked for this topic.

• Only the PubMed abstract of the 2023 Australian guideline for assessing and managing cardiovascular disease risk (PMID 38623719) is held; its full text is not held and was not checked for this topic.

• The 2024 CSANZ Position Statement on Indications, Assessment and Monitoring of Structural and Valvular Heart Disease With Transthoracic Echocardiography in Adults (PMID 38749800) is not held as text in its version of record, so it was not checked for this topic; only its PubMed abstract is quotable.

Guidelines checked for this topic

• Rows on this page come from the ESC 2024 chronic coronary syndromes, ESC 2023 acute coronary syndromes, ESC 2022 non-cardiac surgery, ESC 2025 pregnancy and ESC 2026 heart failure guidelines, with narrative text from the ESC/EACTS 2025 valvular heart disease and ESC 2026 cardiac rehabilitation guidelines.^{[1][4][7][10][9][11][12]}

• AHA/ACC rows come from the 2021 chest pain, 2023 chronic coronary disease, 2025 ACS, 2022 heart failure (AHA/ACC/HFSA), 2020 valvular heart disease and 2023 atrial fibrillation (ACC/AHA/ACCP/HRS) guidelines.^{[2][3][5][8][13][14]}

• Two society documents are quoted from their PubMed abstracts only: the EACVI 2023 stress echocardiography consensus statement (PMID 37798126) and the 2026 ASNC guideline for stress testing in SPECT and PET myocardial perfusion imaging (PMID 42710612), whose held abstract describes its scope (patient selection and preparation, stress modalities and protocols, safety, and interpretation and reporting) without recommendations.^[16][17]

• Rows marked "History, dated", and rows with a note naming a newer row for a subgroup, have a newer row from the same body beside them; for the other rows, the same-month and newer guidelines of the same body in the census below were checked and give no revising row (census 2026-10-09).

• The documents in this list are not used; each line gives the held status recorded in the census for this topic.

• The 2018 ESC/EACTS Guidelines on myocardial revascularization (PMID 30165437) are not held as text in the evidence caches, so they were not checked for this topic.

• The 2021 ACC/AHA/SCAI Guideline for Coronary Artery Revascularization (PMID 34882435) is not held as text in the evidence caches, so it was not checked for this topic.

• The 2019 ESC Guidelines for the diagnosis and management of chronic coronary syndromes (PMID 31504439) are not held as text in the evidence caches, so they were not checked for this topic.

• The 2020 ESC Guidelines for the management of acute coronary syndromes in patients presenting without persistent ST-segment elevation (PMID 32860058) are not held as text in the evidence caches, so they were not checked for this topic.

• The 2021 ESC Guidelines for the diagnosis and treatment of acute and chronic heart failure (PMID 34447992) are not held as text in the evidence caches, so they were not checked for this topic.

• The 2023 Focused Update of the 2021 ESC Guidelines for the diagnosis and treatment of acute and chronic heart failure (PMID 37622666) are not held as text in the evidence caches, so they were not checked for this topic.

• The 2021 ESC/EACTS Guidelines for the management of valvular heart disease (PMID 34453165) are not held as text in the evidence caches, so they were not checked for this topic.

• The 2020 ESC Guidelines for the diagnosis and management of atrial fibrillation (PMID 32860505) are not held as text in the evidence caches, so they were not checked for this topic.

• The 2022 ESC Guidelines on cardio-oncology (PMID 36017568) are not held as text in the evidence caches, so they were not checked for this topic.

• The JCS/JPCPHS 2025 Guideline on Pulmonary Hypertension and Pulmonary Embolism/Deep Vein Thrombosis (PMID 42386545) is not held as text in the evidence caches, so it was not checked for this topic.

• The 2026 ESC Guidelines for the management of cardiovascular disease and chronic kidney disease, in collaboration with the European Renal Association (ERA) (PMID 42661426) are not held as text in their version of record, so they were not checked for this topic.

• The NHFA/CSANZ Australian Clinical Guidelines for the Diagnosis and Management of Atrial Fibrillation 2018 (PMID 30077228) are not held as text in their version of record, so they were not checked for this topic.

• Only the PubMed abstract of the European Respiratory Society clinical practice guidelines update for the treatment of pulmonary arterial hypertension (PMID 42705705) is held; its full text is not held and was not checked for this topic.

• Only the PubMed abstract of the 2024 ACC/AHA/AACVPR/APMA/ABC/SCAI/SVM/SVN/SVS/SIR/VESS Guideline for the Management of Lower Extremity Peripheral Artery Disease (PMID 38743805) is held; its full text is not held and was not checked for this topic.

• Only the PubMed abstract of the Pulmonary hypertension associated with left heart disease (PMID 39209478) is held; its full text is not held and was not checked for this topic.

• Only the PubMed abstract of the A summary of the 2023 Society of Obstetric Medicine of Australia and New Zealand (SOMANZ) hypertension in pregnancy guideline (PMID 38763516) is held; its full text is not held and was not checked for this topic.

• The held guidelines below were checked, and no row from them is used here; each line gives the reason.

• 2017-2022 arrhythmia and pacing guidelines: ACC/AHA/HRS 2018 bradycardia (PMID 30412709; exercise ECG testing for suspected chronotropic incompetence), ESC 2021 pacing (PMID 34455430; exercise testing for symptoms suspicious of bradycardia), ESC 2019 SVT (PMID 31504425) and ESC 2022 ventricular arrhythmias (PMID 36017572) use exercise testing for rhythm questions, outside this topic.

• ESC 2024 atrial fibrillation (PMID 39210723): exercise ECG appears for rate control and drug effects, outside this topic; the ACC/AHA 2023 AF row on ischaemia testing is given above.^[14]

• ESC 2023 cardiomyopathies (PMID 37622657) and AHA/ACC 2024 HCM (PMID 38718139): exercise and stress echocardiography for outflow obstruction and functional capacity in cardiomyopathy, outside this topic.

• ESC 2020 (PMID 32860028) and ACC/AHA 2025 (PMID 41411375) adult congenital heart disease, and ESC 2020 sports cardiology (PMID 32860412): exercise testing in congenital heart disease and in athletes, populations outside this topic.

• ESC 2019 (PMID 31504429) and AHA/ACC 2026 (PMID 41712677) pulmonary embolism, ESC/ERS 2022 pulmonary hypertension (PMID 36017548) and the 2024 pulmonary hypertension definition and treatment documents (PMIDs 39209475, 39209476): cardiopulmonary exercise testing and lung perfusion scanning, outside this topic.

• ESC 2023 endocarditis (PMID 37622656): white-cell SPECT/CT for infection, outside this topic; ESC 2025 myocarditis and pericarditis (PMID 40878297): exercise testing in myocarditis follow-up, outside this topic.

• ESC 2023 diabetes (PMID 37622663): a maximal exercise stress test before a structured exercise programme in type 2 diabetes with CVD, an exercise-prescription question outside this topic; ESC 2021 prevention (PMID 34458905): exercise testing named only for exercise prescription.

• ESC 2024 peripheral arterial and aortic diseases (PMID 39210722) and ACC/AHA 2022 aortic disease (PMID 36322642): exercise testing for claudication, coarctation and hypertension, and CAD evaluation in PAD without evidence that systematic screening improves outcomes, outside this topic.

• Fifth (2026, PMID 42661425) and Fourth (2018, PMID 30571511, superseded) Universal Definitions of MI: SPECT and PET to support the diagnosis of MI, a definition question outside this topic.

• ESC 2024 hypertension (PMID 39210715), AHA/ACC 2025 blood pressure (PMID 40811497), 2019 ESC/EAS dyslipidaemias (PMID 31504418) and its 2025 focused update (PMID 40878289), ACC/AHA 2026 dyslipidemia (PMID 41824552) and the 2026 cardiovascular-kidney-metabolic guideline (PMID 42263157): no stress-testing row.

• NHFA/CSANZ 2018 heart failure summary in Med J Aust (PMID 30067937): the Heart Lung Circ guideline (PMID 30077227) is quoted instead.^[15]

Exam pearls

• Exercise ECG: sensitivity 58% and specificity 62% (ESC 2024); mainly for risk stratification.^[1]
• High-risk thresholds (ESC 2024): Duke < −10; ≥10% LV ischaemia on SPECT/PET; ≥3/16 segments on stress echo; ≥2/16 perfusion segments or ≥3 dobutamine segments on stress CMR.^[1]
• PET: absolute MBF; MFR <2.0 (2.5 for non-obstructive CAD) often considered abnormal; if available, particularly recommended in obese and young patients and in those with known or suspected diffusely impaired MBF (ESC 2024).^[1]
• Radiation (AHA/ACC 2021): about 3 mSv for rest/stress Rb-82 PET and about 10 mSv for Tc-99m SPECT; thallium dual-isotope SPECT is not recommended.^[2]
• Before a vasodilator stress nuclear study, check the AHA/ACC 2021 contraindications to vasodilator administration, which include known or suspected bronchoconstrictive or bronchospastic disease, significant arrhythmias (for example VT, second- or third-degree AV block) or sinus bradycardia <45 bpm, SBP <90 mm Hg and methylxanthines (for example caffeine) within 12 h.^[2]
• Prior normal stress test (given adequate stress): warranty period 1 year (AHA/ACC 2021).^[2]

References19ShowHide

1. [1]Vrints C, et al. 2024 ESC Guidelines for the management of chronic coronary syndromes. Eur Heart J, 2024.PMID 39210710
2. [2]Gulati M, et al. 2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines. J Am Coll Cardiol, 2021.PMID 34756653
3. [3]Virani SS, et al. 2023 AHA/ACC/ACCP/ASPC/NLA/PCNA Guideline for the Management of Patients With Chronic Coronary Disease: A Report of the American Heart Association/American College of Cardiology Joint Committee on Clinical Practice Guidelines. J Am Coll Cardiol, 2023.PMID 37480922
4. [4]Byrne RA, et al. 2023 ESC Guidelines for the management of acute coronary syndromes. Eur Heart J, 2023.PMID 37622654
5. [5]Rao SV, et al. 2025 ACC/AHA/ACEP/NAEMSP/SCAI Guideline for the Management of Patients With Acute Coronary Syndromes: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines. J Am Coll Cardiol, 2025.PMID 40013746
6. [6]Brieger DB, et al. National Heart Foundation of Australia and Cardiac Society of Australia and New Zealand: Australian Clinical Guideline for Diagnosing and Managing Acute Coronary Syndromes 2025. Med J Aust, 2026.PMID 41693087
7. [7]Halvorsen S, et al. 2022 ESC Guidelines on cardiovascular assessment and management of patients undergoing non-cardiac surgery. Eur Heart J, 2022.PMID 36017553
8. [8]Heidenreich PA, et al. 2022 AHA/ACC/HFSA Guideline for the Management of Heart Failure: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines. J Am Coll Cardiol, 2022.PMID 35379503
9. [9]Køber L, et al. 2026 ESC Guidelines for the management of heart failure. Eur Heart J, 2026.PMID 42661420
10. [10]De Backer J, et al. 2025 ESC Guidelines for the management of cardiovascular disease and pregnancy. Eur Heart J, 2025.PMID 40878294
11. [11]Praz F, et al. 2025 ESC/EACTS Guidelines for the management of valvular heart disease. Eur Heart J, 2025.PMID 40878295
12. [12]Bäck M, et al. 2026 ESC Guidelines on cardiac rehabilitation. Eur Heart J, 2026.PMID 42661418
13. [13]Otto CM, et al. 2020 ACC/AHA Guideline for the Management of Patients With Valvular Heart Disease: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines. J Am Coll Cardiol, 2021.PMID 33342586
14. [14]Joglar JA, et al. 2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines. Circulation, 2024.PMID 38033089
15. [15]Atherton JJ, et al. National Heart Foundation of Australia and Cardiac Society of Australia and New Zealand: Guidelines for the Prevention, Detection, and Management of Heart Failure in Australia 2018. Heart Lung Circ, 2018.PMID 30077227
16. [16]Picano E, et al. The clinical use of stress echocardiography in chronic coronary syndromes and beyond coronary artery disease: a clinical consensus statement from the European Association of Cardiovascular Imaging of the ESC. Eur Heart J Cardiovasc Imaging, 2024.PMID 37798126
17. [17]Duvall WL, et al. 2026 ASNC guideline for stress testing in single-photon emission computed tomography (SPECT) and positron emission tomography (PET) myocardial perfusion imaging. J Nucl Cardiol, 2026.PMID 42710612
18. [18]Douglas PS, et al. Outcomes of anatomical versus functional testing for coronary artery disease. N Engl J Med, 2015.PMID 25773919
19. [19]Maron DJ, et al. Initial Invasive or Conservative Strategy for Stable Coronary Disease. N Engl J Med, 2020.PMID 32227755