Bicuspid aortic valve with severe aortic regurgitation and a dilated ascending aorta — case discussion

Presentation

Practice case (not a real patient). A 44-year-old man in a regional town is referred after his GP hears a murmur at a routine check. He plays social tennis and says he has no symptoms. His blood pressure is 128/58 mm Hg.^[3] Transthoracic echocardiography shows a bicuspid aortic valve and a dilated LV.^[2] The vena contracta is 0.8 cm, regurgitant volume 70 mL/beat, regurgitant fraction 55% and ERO 0.4 cm², with holodiastolic flow reversal in the proximal abdominal aorta.^[2] LVEF is 59%, LVESD 52 mm (LVESDi 26 mm/m²) and the maximal diameter of the ascending aorta is 47 mm, with a sinus diameter of 40 mm.^[1]

Step 1 — How severe, and which stage?

The severe AR criteria of ACC/AHA 2020 Table 15 include vena contracta >0.6 cm, holodiastolic flow reversal in the proximal abdominal aorta, regurgitant volume ≥60 mL/beat, regurgitant fraction ≥50% and ERO ≥0.3 cm².^[2] It also requires evidence of LV dilation for chronic severe AR. He has all of these.^[2] Table 15 defines Stage C2 as depressed LVEF (≤55%) or severe LV dilation (LVESD >50 mm or indexed LVESD >25 mm/m²).^[2] With no symptoms and an LVESD above 50 mm, he is in Stage C2 despite an LVEF above 55%.^[2] ACC/AHA 2020 says that in patients with a BAV or with known dilation of the aortic sinuses or ascending aorta, TTE is indicated to evaluate the presence and severity of AR (COR 1, LOE B-NR).^[3] ESC 2024 recommends initial TTE to assess diameters of the aorta at several levels when a BAV is first diagnosed (Class I, Level B); his TTE measured the sinus and the ascending aorta.^[4]

Step 2 — Is he really asymptomatic?

ACC/AHA 2020 says that in chronic severe AR the most important aspect of the clinical evaluation is a careful, detailed history to elicit symptoms or diminution of exercise capacity.^[3] ESC/EACTS 2025 advises exercise testing, when feasible, for patients with severe AR who do not report symptoms and do not meet criteria for surgery; he already meets criteria on LV size (Step 3).^[1]

Step 3 — Does he need surgery?

ESC/EACTS 2025 recommends AV surgery in asymptomatic patients with severe AR and LVESD >50 mm or LVESDi >25 mm/m² [especially in patients with small body size (BSA <1.68 m²)] or resting LVEF ≤50% (Class I, Level B).^[1] His LVESD of 52 mm meets it, and so does his LVESDi of 26 mm/m².^[1] His LVESDi also exceeds the 22 mm/m² cut-off of the ESC/EACTS 2025 Class IIb, Level B row (AV surgery may be considered if the surgical risk is low).^[1] The Class I, Level B row is the stronger of the two.^[1] ACC/AHA 2020 says that in asymptomatic severe AR with normal LV systolic function (LVEF >55%), aortic valve surgery is reasonable when the LV is severely enlarged.^[3] Its threshold for that row is LVESD >50 mm or indexed LVESD >25 mm/m² (Stage C2) (COR 2a, LOE B-NR).^[3] His LVEF of 59% is above the 55% cut-off of the ACC/AHA 2020 COR 1 row, so it is the COR 2a row that his LV numbers meet.^[3] Its supportive text for that row says that if LVEF is normal, an increased LVESD indicates a significant degree of LV remodelling and is associated with subsequent development of symptoms and/or LV systolic dysfunction and an increased mortality rate after AVR.^[3]

Step 4 — What operation?

The Heart Team judges his predicted surgical risk low. ESC/EACTS 2025 says AV replacement is still the standard surgical approach in most AR cases.^[1] It says valve preservation or valve repair should also be considered for patients with BAV based on age, anatomical presentation and centre experience.^[1] AV repair should be considered in selected patients with severe AR at experienced centres, when durable results are expected (ESC/EACTS 2025, Class IIa, Level B).^[1] When performed by experienced surgeons in well-selected young individuals, the ESC/EACTS 2025 text says the Ross operation may also be a good alternative to prosthetic valve replacement.^[1]

His ascending aorta was measured on TTE. ESC/EACTS 2025 says that when a dilated ascending aorta is initially diagnosed by TTE, a multislice ECG-triggered CCT/CMR scan is recommended to confirm the maximal diameter, rule out isolated single sinus dilatation and provide a baseline reference.^[1] ESC 2024 recommends CCT or CMR of the entire thoracic aorta at first diagnosis, when important discrepancies in measurements are found between subsequent TTE controls during surveillance, or when the diameter of the aorta exceeds 45 mm (Class I, Level C).^[4] His BAV and aortic dilatation are first diagnosed on this TTE and his ascending aorta measures 47 mm, so both the first-diagnosis and the >45 mm conditions apply.^[4]

For his aorta, ESC/EACTS 2025 says that when AV surgery is indicated and the predicted surgical risk is low, replacement of the aortic root or ascending aorta should be considered if the maximal diameter is ≥45 mm (Class IIa, Level C).^[1] Its footnote asks the team to consider age, BSA, the aetiology of the valvular disease, the presence of a bicuspid AV, and the intraoperative shape and thickness of the ascending aorta.^[1] Both conditions apply to him: his valve surgery is indicated and the Heart Team judges his predicted surgical risk low.^[1] ESC 2024 says surgery for bicuspid aortopathy in patients undergoing aortic valve surgery should be considered at a root or ascending diameter ≥45 mm (Class IIa, Level C).^[4] TAVI is not an option for him. ACC/AHA 2020 says that in isolated severe AR with indications for SAVR in a surgical candidate, TAVI should not be performed (COR 3: Harm, LOE B-NR).^[3] The ESC/EACTS 2025 TAVI row is for symptomatic patients ineligible for surgery according to the Heart Team, if the anatomy is suitable (Class IIb, Level B); he is asymptomatic and a surgical candidate.^[1]

Step 5 — His family

ESC 2024 says screening by TTE in first-degree relatives of all BAV patients should be considered (Class IIa, Level B).^[4] Its Class I, Level C screening row is narrower: first-degree relatives of BAV patients with root phenotype aortopathy (aortic dilatation with sinus diameter > tubular diameter) and/or isolated aortic regurgitation.^[4] His dilatation is of the ascending phenotype (aortic dilatation with tubular diameter > sinus diameter: 47 mm against 40 mm), so the root phenotype limb does not cover his relatives.^[4] The held ESC 2024 text does not define “isolated aortic regurgitation”, so it does not settle whether he, with severe AR and a dilated ascending aorta, falls within that limb; the Class IIa, Level B row covers his relatives either way.^[4] ESC/EACTS 2025 adds that aortic dilation is present in about 10% of first-degree relatives of patients with a BAV, so encouraging echocardiographic screening is considered appropriate.^[1]

Learning points

• Chronic severe AR on ACC/AHA 2020 Table 15 needs the haemodynamic criteria and evidence of LV dilation.^[2]
• ESC/EACTS 2025 recommends AV surgery in asymptomatic severe AR with LVESD >50 mm, LVESDi >25 mm/m² (especially with small body size, BSA <1.68 m²) or resting LVEF ≤50% (Class I, Level B); for the same LV size with LVEF >55%, ACC/AHA 2020 calls surgery reasonable (COR 2a, LOE B-NR). State each by body and year.^[1][3]
• When AV surgery is indicated and the predicted surgical risk is low, ESC/EACTS 2025 says replacement of the aortic root or ascending aorta should be considered at a maximal diameter ≥45 mm (Class IIa, Level C), considering age, BSA, the aetiology of the valvular disease, the presence of a bicuspid AV, and the intraoperative shape and thickness of the ascending aorta.^[1]
• In a surgical candidate with isolated severe AR and indications for SAVR, ACC/AHA 2020 says TAVI should not be performed (COR 3: Harm, LOE B-NR).^[3]