Cardiac CT — structured written assessment

SAQ 1 (10 marks)

Practice scenario. A 57-year-old man with suspected chronic coronary syndrome has a pre-test likelihood of obstructive CAD of 25% by the Risk Factor-weighted Clinical Likelihood model. CCTA is available locally and supported by local expertise. His eGFR is 75 mL/min/1.73 m², his heart rhythm is regular and he can hold his breath on command.^[1]

1. Give the ESC 2024 Recommendation Table 8 row that supports CCTA for him, with its class and level, and the ESC 2024 Recommendation Table 13 row on CCTA as the preferred test to rule out obstructive CAD. (2)^[1]
2. List four conditions in which ESC 2024 says CCTA is not recommended, and give the class and level of that row. (2)^[1]
3. His CCTA shows a single 70% stenosis by visual estimate in the mid circumflex artery, with no left main or proximal LAD disease. Give the ESC 2024 row on a further CT-based test, with its class and level and its footnote definition of an intermediate stenosis. (2)^[1]
4. Give the ESC 2024 CCTA results that identify high risk of adverse events, and the row on what to do for a person at high risk, each with its class and level. (2)^[1]
5. Give two ESC 2024 statements on why CCTA is less suitable in some patients, naming the groups. (2)^[1]

Model answers — SAQ 1

1. ESC 2024 Recommendation Table 8 (CCTA, if available, and supported by local expertise): in individuals with suspected CCS and low or moderate (>5%–50%) pre-test likelihood of obstructive CAD, CCTA is recommended to diagnose obstructive CAD and to estimate the risk of MACE (Class I, Level A) (1 mark).^[1] ESC 2024 Recommendation Table 13: to rule out obstructive CAD in individuals with low or moderate (>5%–50%) pre-test likelihood, CCTA is recommended as the preferred diagnostic modality (Class I, Level B) (1 mark).^[1] Not marked, but also applicable at 25%: in individuals with suspected CCS and moderate or high (>15%–85%) pre-test likelihood of obstructive CAD, ESC 2024 recommends stress echocardiography to diagnose myocardial ischaemia and to estimate the risk of MACE; stress SPECT or, preferably, PET myocardial perfusion imaging to diagnose and quantify myocardial ischaemia and/or scar, estimate the risk of MACE and quantify myocardial blood flow (PET); 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, if available and supported by local expertise).^[1]
2. Any four of: severe renal failure (eGFR <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 (1 mark).^[1] Class III, Level C (1 mark).^[1]
3. ESC 2024 Recommendation Table 13: in patients with a known intermediate coronary artery stenosis in a proximal or mid coronary segment on CCTA, CT-based FFR may be considered (Class IIb, Level B) (1 mark).^[1] Footnote d: an intermediate stenosis is typically around 40%–90% by visual estimate (1 mark).^[1]
4. ESC 2024 Recommendation Table 14 (Class I, Level B) lists these CCTA results among those that identify individuals at high risk of adverse events: left main disease with ≥50% stenosis, three-vessel disease with ≥70 stenosis, or two-vessel disease with ≥70% stenosis, including the proximal LAD, or one-vessel disease of the proximal LAD with ≥70% stenosis and FFR-CT ≤0.8 (1 mark).^[1] In individuals at high risk of adverse events (regardless of symptoms), ICA, complemented by invasive coronary pressure (FFR/iFR) when appropriate, is recommended, with the aim of refining risk stratification and improving symptoms and cardiovascular outcomes by revascularization (Class I, Level A) (1 mark).^[1]
5. ESC 2024: temporal and spatial resolution remain technical limitations and can hinder precision in adjudicating coronary stenosis severity, which is most problematic in older patients with heavily calcified coronary arteries, in whom functional testing may be more appropriate than CCTA (1 mark).^[1] ESC 2024: functional imaging tests overcome the limitations of CCTA in older patients with more extensive coronary calcifications, AF and other irregular or fast heart rates, renal insufficiency or iodinated contrast allergy, and avoid ionizing radiation in young individuals and in those suspected of ANOCA/INOCA (1 mark).^[1]

SAQ 2 (10 marks)

Practice scenario. An 81-year-old woman has symptomatic severe aortic stenosis with low-flow, low-gradient haemodynamics and reduced LVEF, and is being assessed by the Heart Team for TAVI. Her pre-test likelihood of obstructive CAD is moderate or lower (≤50%).^[6]

1. Name four things that ESC/EACTS 2025 says cardiac CT assesses when planning TAVI. (2)^[6]
2. Give the ESC/EACTS 2025 Recommendation Table 1 row on coronary CT before valve intervention for her, and the row on omitting invasive coronary angiography in TAVI candidates, each with its class and level. (2)^[6]
3. Give the sensitivity and specificity of CCT angiography for obstructive CAD in elderly TAVI candidates that ESC/EACTS 2025 reports, and the reason it gives for the modest specificity. (2)^[6]
4. Give the ESC/EACTS 2025 aortic valve calcium thresholds that indicate severe AS in men and women, and the ACC/AHA 2020 threshold for women. (2)^[6][7]
5. After TAVI, a colleague proposes routine CT to look for leaflet thickening. Give the ESC/EACTS 2025 statement on routine CCT for HALT and the ESC/EACTS 2025 row for suspected valve thrombosis, with its class and level. (2)^[6]

Model answers — SAQ 2

1. Any four of: annulus size; dimensions of the aortic root and ascending aorta; the extent and distribution of valve and LVOT calcification; the distance of coronary ostia from the annular plane; optimal fluoroscopic projections for transcatheter valve deployment; the feasibility of vascular access (½ mark each, 2 marks).^[6]
2. CCTA is recommended before valve intervention in patients with moderate or lower (≤50%) pre-test likelihood of obstructive CAD (Class I, Level B) (1 mark).^[6] Omission of invasive coronary angiography should be considered in TAVI candidates, if procedural planning CT angiography is of sufficient quality to rule out significant CAD (Class IIa, Level B) (1 mark).^[6]
3. ESC/EACTS 2025 reports that several studies of CCT angiography for CAD screening in elderly TAVI candidates found sensitivity for the detection of obstructive CAD is high (95%–97%) while specificity (68%–73%) is modest (1 mark).^[6] Mainly explained by the high prevalence of coronary artery calcification and AF in patients with severe AS, which limit imaging resolution and interpretability (1 mark).^[6]
4. ESC/EACTS 2025, on calcium AV scoring in low-flow, low-gradient AS: >2000 AU in men and >1200 AU in women indicate severe AS with high sensitivity and specificity (∼85%) (1 mark).^[6] ACC/AHA 2020: the sex-specific Agatston threshold for severe AS in women is 1300 (1 mark).^[7]
5. ESC/EACTS 2025: routine use of CCT to detect HALT is not indicated, because the significance and clinical implications for thromboembolic risk and valve durability remain uncertain (1 mark).^[6] ESC/EACTS 2025 Recommendation Table 17: TOE and/or 4D-CT are recommended in patients with suspected valve thrombosis to confirm the diagnosis (Class I, Level C) (1 mark).^[6]