Aortic aneurysm: sizing, growth and repair thresholds — structured written assessment

SAQ 1 (10 marks)

Practice scenario. A 69-year-old man who still smokes cigarettes, as he has all his adult life, has an AAA of 42 mm found on screening ultrasound. He has no symptoms, his BP averages 142/86 mm Hg, and CT shows aortic atherosclerosis.^[1][2]

1. Give the ESC 2024 screening row that applies to him and its class and level, and the matching ACC/AHA 2022 row with its COR and LOE. (2)^[1][2]
2. How often should his aneurysm be imaged, and with what, under ESC 2024 and ACC/AHA 2022? Give class or COR. (2)^[1][2]
3. Give two ACC/AHA 2022 medical therapy rows that apply to him, with COR and LOE. (2)^[2]
4. At what diameter is elective repair recommended for him under ESC 2024 and ACC/AHA 2022, and what growth rate would lead ESC 2024 to consider repair earlier? (2)^[1][2]
5. Name one randomised trial supporting surveillance rather than early repair of small AAA, and give its population, design and main result. (2)^[3][4]

Model answers — SAQ 1

1. ESC 2024: duplex screening for AAA is recommended in men aged ≥65 years with a history of smoking to reduce the risk of death from ruptured AAA (Class I, Level A) (1 mark).^[1] ACC/AHA 2022: in men ≥65 years who have ever smoked, ultrasound screening for AAA is recommended (COR 1, LOE B-R) (1 mark).^[2]
2. ESC 2024: duplex ultrasound is recommended for AAA surveillance (Class I, Level C), and duplex surveillance should be considered annually in men with AAA of 40 to <50 mm (in women, 40 to <45 mm) (Class IIa, Level B) (1 mark).^[1] ACC/AHA 2022: in men with an AAA of 4.0–4.9 cm (in women, 4.0–4.4 cm), surveillance ultrasound is recommended annually (COR 1, LOE B-NR) (1 mark).^[2]
3. With an average SBP ≥130 mm Hg or DBP ≥80 mm Hg, antihypertensive medication is recommended to reduce risk of cardiovascular events (COR 1, LOE B-NR) (1 mark).^[2] With evidence of aortic atherosclerosis, moderate- or high-intensity statin therapy is recommended (COR 1, LOE B-NR); smoking cessation efforts are also recommended in people with AAA who smoke cigarettes (COR 1, LOE C-LD) (1 mark for either).^[2]
4. ESC 2024 recommends elective repair at ≥55 mm in men (≥50 mm in women) (Class I, Level A); ACC/AHA 2022 recommends repair of an unruptured AAA at ≥5.5 cm in men (≥5.0 cm in women) (COR 1, LOE A) (1 mark).^[1][2] ESC 2024 says repair of an unruptured AAA may be considered with aneurysm growth ≥5 mm in 6 months or ≥10 mm per year (Class IIb, Level C) (1 mark).^[1]
5. UK Small Aneurysm Trial: 1090 patients aged 60–76 years with symptomless AAA of 4.0–5.5 cm randomised to early elective open surgery or ultrasound surveillance, mean follow-up 4.6 years (1 mark); all-cause mortality hazard ratio with early surgery 0.94 (95% CI 0.75–1.17) (1 mark).^[3] Or ADAM: patients aged 50–79 years with AAA of 4.0–5.4 cm who did not have high surgical risk, randomised to immediate open repair or to ultrasound or CT surveillance every 6 months with repair reserved for aneurysms that became symptomatic or enlarged to 5.5 cm, mean follow-up 4.9 years; all-cause death was not significantly different (relative risk with immediate repair vs surveillance 1.21; 95% CI 0.95–1.54) (2 marks).^[4]

SAQ 2 (10 marks)

Practice scenario. A 45-year-old man has a bicuspid aortic valve with mild aortic regurgitation. TTE suggests a dilated ascending aorta of the ascending phenotype, with the tubular diameter larger than the sinus diameter. He has no symptoms, no coarctation, no family history of aortic disease and low surgical risk.^[1]

1. What imaging does ESC 2024 recommend to confirm the TTE finding, and when? Give class and level. (2)^[1]
2. How does ESC 2024 recommend measuring the ascending aorta on CT or CMR? Give two conventions with class and level. (2)^[1]
3. CT confirms a maximum ascending diameter of 51 mm. Under ESC 2024, which age-based feature makes surgery a consideration at this diameter? Give the row and its class and level. (2)^[1]
4. A repeat CT a year later still measures 5.1 cm. Give the ACC/AHA 2022 BAV row that applies to him, with COR and LOE. (2)^[2]
5. What family screening is advised under ESC 2024 and the 2025 ACC/AHA/HRS/ISACHD/SCAI adult congenital heart disease guideline? Give class or COR. (2)^[1][11]

Model answers — SAQ 2

1. ESC 2024: CCT or CMR of the entire thoracic aorta is recommended at first diagnosis, when important discrepancies are found between TTE controls during surveillance, or when the diameter exceeds 45 mm (Class I, Level C) (1 mark).^[1] In thoracic aortic dilatation, CCT or CMR is recommended to confirm TTE measurements, rule out asymmetry and determine baseline diameters for follow-up (Class I, Level C) (1 mark).^[1]
2. Report diameters with the inner-to-inner edge convention in end-diastole by CCT or CMR (Class I, Level C) (1 mark).^[1] Report diameters from double-oblique images, not axial images, by CCT or CMR (Class I, Level C) (1 mark).^[1]
3. Age <50 years (1 mark).^[1] ESC 2024: in low-surgical-risk ascending-phenotype bicuspid aortopathy, surgery should be considered at a maximum diameter ≥50 mm if any listed feature is present, which includes age <50 years (Class IIa, Level C) (1 mark).^[1]
4. ACC/AHA 2022 lists family history of dissection, growth ≥0.3 cm/y, coarctation and root-phenotype aortopathy as risk factors for dissection, and he has none; in patients with a BAV, a root or ascending diameter of 5.0–5.4 cm, no other risk factors for dissection and low surgical risk, surgery may be reasonable when performed by experienced surgeons in a Multidisciplinary Aortic Team (1 mark).^[2] COR 2b, LOE B-NR (1 mark).^[2]
5. ESC 2024: TTE screening of first-degree relatives of all BAV patients should be considered (Class IIa, Level B) (1 mark).^[1] ACC/AHA/HRS/ISACHD/SCAI 2025: in first-degree relatives of adults with a BAV, 1-time echocardiographic screening for a congenitally abnormal aortic valve or aortic aneurysm is reasonable (COR 2a, LOE B-NR) (1 mark).^[11]