Chest pain evaluation — structured written assessment

SAQ 1 (10 marks)

Practice scenario. A 54-year-old man presents to the emergency department with central chest pressure that began 2 hours before arrival and has now settled. His 0 h high-sensitivity troponin sample is drawn on arrival. He is haemodynamically stable. NSTEMI is suspected and there is no indication for immediate invasive angiography.^[2]

1. State the ECG recommendation for patients with acute chest pain in the 2021 AHA/ACC chest pain guideline and for patients with suspected ACS in the 2023 ESC ACS guideline, with class and level. (2)^[1][2]
2. Describe the three pathways of the ESC 2023 0 h/1 h or 0 h/2 h hs-cTn algorithm and the next step in each. (4)^[2]
3. Give two caveats in the ESC 2023 Figure 6 legend or text that limit rule-out on a very low initial hs-cTn value or what assignment to the rule-out pathway implies. (2)^[2]
4. How do the 2021 AHA/ACC chest pain guideline and the 2025 ACC/AHA ACS guideline differ on the timing of a repeat high-sensitivity troponin? (2)^[1][4]

Model answers — SAQ 1

1. AHA/ACC 2021: in all patients who present with acute chest pain regardless of the setting, an ECG should be acquired and reviewed for STEMI within 10 minutes of arrival (COR 1, LOE C-LD).^[1] ESC 2023, in patients with suspected ACS: twelve-lead ECG recording and interpretation is recommended as soon as possible at the point of first medical contact, with a target of under 10 min (Class I, Level B).^[2] Also creditable: ACC/AHA 2025 recommends acquisition and interpretation of an ECG within 10 minutes in suspected ACS to help guide patient management (COR 1, LOE B-NR); the row is marked as adapted from the 2021 chest pain guideline.^[4]
2. Rule-out: a very low initial hs-cTn value (only applicable if chest pain onset was more than 3 h before the 0 h measurement; not met here, see answer 3), or a low initial value with no 1 h/2 h change. The NPV for MI has exceeded 99% in several large validation cohorts, but assignment to rule-out does not always equal outpatient management; even after ruling out MI, elective imaging may be appropriate according to clinical and risk assessment, and an alternative diagnosis should be identified.^[2] Rule-in: a high initial hs-cTn value or a 1 h/2 h change. The PPV for MI in patients meeting the rule-in criteria has been about 70–75% in several studies, and the vast majority will require hospital admission and invasive coronary angiography.^[2] Observe: patients meeting neither set of criteria. Their mortality is comparable to rule-in patients; individual assessment based on the risk profile (i.e. risk scores) is of paramount importance, and a third cTn measurement at 3 h (± echocardiography) is recommended as the next step.^[2]
3. The very low initial hs-cTn criterion is only applicable if chest pain onset was more than 3 h before the 0 h measurement; his 0 h sample was drawn about 2 hours after onset.^[2] Assignment to the rule-out pathway does not always equal outpatient management; used with clinical and ECG findings, the algorithms identify appropriate candidates for early discharge and outpatient management.^[2] Also creditable: repeat blood sampling is mandatory in cases with ongoing or recurrent chest pain, and the algorithms should always be integrated with a detailed clinical assessment and a 12-lead ECG.^[2]
4. AHA/ACC 2021: in patients presenting with acute chest pain and suspected ACS for whom serial troponins are indicated to exclude myocardial injury, the recommended repeat intervals after the initial sample (time zero) are 1 to 3 hours for high-sensitivity troponin and 3 to 6 hours for conventional assays (COR 1, LOE B-NR).^[1] ACC/AHA 2025: in patients with suspected ACS with an initial hs-cTn or cTn that is nondiagnostic, the recommended repeat intervals after the initial sample (time zero) are 1 to 2 hours for hs-cTn and 3 to 6 hours for conventional cTn assays (COR 1, LOE B-NR); the row is marked as adapted from the 2021 chest pain guideline.^[4]

SAQ 2 (10 marks)

Practice scenario. A 65-year-old woman is referred to the cardiology clinic with 3 months of constricting retrosternal chest discomfort that is brought on by exertion and relieved by rest within 5 minutes, unchanged over that time. She has hypertension, dyslipidaemia and diabetes and is a current smoker. Chronic coronary syndrome is suspected; acute coronary syndrome is not suspected. Her resting ECG is normal. She can exercise.^[1][3]

1. Name the model ESC 2024 recommends for estimating her pre-test likelihood of obstructive CAD, give its components and class, and give one ESC 2024 recommendation on adjusting the estimate. (3)^[3]
2. Her RF-CL estimate is 19% (women aged 60–69, symptom score 3, 4–5 risk factors), and the clinical data give no reason to adjust it. State the ESC 2024 recommendations on the initial test and on the preferred modality to rule out obstructive CAD, with class and level. (3)^[3]
3. List four conditions in which ESC 2024 does not recommend CCTA. (2)^[3]
4. Summarise the design and primary result of SCOT-HEART. (2)^[7]

Model answers — SAQ 2

1. ESC 2024 recommends estimating the pre-test likelihood of obstructive epicardial CAD using the Risk Factor-weighted Clinical Likelihood (RF-CL) model (Class I, Level B).^[3] The RF-CL model includes sex, age, angina symptoms and number of risk factors.^[3] Adjustment: it is recommended to use additional clinical data (e.g. examination of peripheral arteries, resting ECG, resting echocardiography, presence of vascular calcifications on previously performed imaging tests) to adjust the RF-CL estimate (Class I, Level C).^[3] Also creditable: individual adjustment may be necessary for severe single risk factors or comorbidities associated with an increased prevalence of obstructive CAD that are not reflected in RF-CL, e.g. familial hypercholesterolaemia, severe kidney dysfunction, rheumatic/inflammatory diseases and peripheral artery disease.^[3]
2. 19% lies in the ESC 2024 moderate band (more than 15% to 50%). In symptomatic patients whose pre-test likelihood of obstructive CAD by clinical assessment is above 5%, CCTA or non-invasive functional imaging for myocardial ischaemia is recommended as the initial diagnostic test (Class I, Level B).^[3] To rule out obstructive CAD in individuals with low or moderate (more than 5% to 50%) pre-test likelihood, CCTA is recommended as the preferred diagnostic modality (Class I, Level B).^[3] Also creditable: in suspected CCS with low or moderate (more than 5% to 50%) likelihood, CCTA (if available and supported by local expertise) is recommended to diagnose obstructive CAD and to estimate the risk of MACE (Class I, Level A).^[3] Also creditable: in individuals with a low or moderate (more than 5% to 50%) pre-test likelihood, an exercise ECG is not recommended to rule out CAD if CCTA or functional imaging tests are available (Class III, Level C).^[3]
3. ESC 2024 does not recommend CCTA in patients with severe renal failure (eGFR below 30 mL/min/1.73 m²), decompensated heart failure, extensive coronary calcification, fast irregular heart rate, severe obesity, inability to cooperate with breath-hold commands, or any other conditions that can make obtaining good imaging quality unlikely (Class III, Level C); any four earn the marks.^[3]
4. SCOT-HEART was an open-label, multicentre, parallel-group trial that randomly assigned 4146 patients with stable chest pain referred to a cardiology clinic to standard care plus CTA (2073) or standard care alone (2073).^[7] The primary end point, death from coronary heart disease or nonfatal MI at 5 years, occurred in 2.3% (48 patients) with CTA versus 3.9% (81 patients) with standard care (HR 0.59, 95% CI 0.41 to 0.84, P=0.004), over a median follow-up of 4.8 years.^[7]