Aortic aneurysm: sizing, growth and repair thresholds

• This page covers how the aorta is measured, when a dilated aorta becomes an aneurysm, how often each segment is re-imaged, which medicines help, and the diameters at which repair is offered.^[1]

It covers the thoracic and abdominal aorta, with the heritable and bicuspid-valve exceptions, pregnancy and surveillance after repair.^[1][9]

• Acute aortic syndromes are covered in Acute aortic dissection: type A and type B; the valve itself is covered in Aortic regurgitation: quantitation and surgery timing and Severe aortic stenosis: TAVI versus surgical valve replacement.

Dilatation, aneurysm and what the numbers mean

• ESC 2024 defines aortic dilatation as an aortic diameter >2 standard deviations of the predicted mean diameter for age, sex and body size (z-score >2).^[1]
• It adds that in clinical practice aortic root dilatation can be suspected in adult men when the diameter is >40 mm and in women at >36 mm, or with an aortic size index (diameter/BSA) >22 mm/m².^[1]

An arterial aneurysm is a diameter >1.5 times (>50%) larger than predicted.^[1] An AAA is a focal dilation at least 1.5 times its normal diameter, generally ≥30 mm.^[1]

• Because the surgical indication is often reached before a thoracic aorta is aneurysmal by that definition, ESC 2024 strongly recommends the term significant aortic dilation, with the diameter or indexed diameter stated, in place of the term aneurysm.^[1]
• Normal ageing is slow: adult aortic growth is about 0.9 mm per 10 years in men and 0.7 mm per 10 years in women, and may be influenced by BP, physical activity and genetic factors.^[1]

Natural history: growth and rupture by segment

Thoracic aorta

• ESC 2024 gives an incidence of thoracic aortic aneurysm of 5–10 per 100 000 person-years, with about 60% in the root and/or ascending aorta, about 10% in the arch and about 30% in the descending aorta.^[1]

Hypertension is the main risk factor (80%), and genetics may be involved in 20%.^[1] Patients are usually asymptomatic and are diagnosed incidentally on imaging done for something else or on screening.^[1] Growth is variable and depends on aetiology, location and baseline diameter.^[1]

• Thoracic aneurysms are four times more common in men, but the growth rate is greater in women (0.96 ± 1.00 mm per year versus 0.45 ± 0.58 mm per year), and so is the risk of aortic adverse events.^[1]

Degenerative thoracic aneurysms grow faster in women and carry a three-fold higher risk of aortic adverse events.^[1] At 57.5 mm, ESC 2024 reports yearly rates of rupture, dissection and death of 3.6%, 3.7% and 10.8%.^[1]

• Saccular aneurysms, linked to infection, penetrating atherosclerotic ulcer, trauma or inflammatory disease, are considered more malignant than fusiform ones, although evidence on their natural course is limited.^[1]

• ESC 2024 says that although many risk factors for aortic adverse events have been described, such as elongation, angulation and unfavourable biomechanics, aortic diameter is still the main determinant of aortic complications and death.^[1]

• Most acute type A dissections occur at diameters below 55 mm; the risk exceeds 1% between 50 and 54 mm, with a critical point at 52–53 mm.^[1]

Over 60% of non-Marfan, non-BAV patients with acute type A dissection had a non-dilated ascending aorta before dissection.^[1] The root phenotype has been reported to be more malignant than the ascending phenotype, with faster progression and higher risk of aortic adverse events.^[1]

• An ascending aortic length ≥13 cm is linked to nearly five-fold higher yearly event rates than a length <9 cm, and >11 cm is used as a risk indicator.^[1]

Most descending and thoracoabdominal aneurysms are degenerative with calcification; trauma, infection, inflammation and genetic factors are other causes.^[1] They grow by 1.9–3.4 mm per year, and growth tends to increase markedly above 50 mm or after proximal aortic surgery in Marfan syndrome.^[1] For untreated descending thoracic aneurysms, 5-year survival is about 54%, and rupture is the leading cause of death.^[1]

• Rupture risk factors include HTAD, a diameter over 50 mm, hypertension, smoking, COPD, symptoms, chronic aortic dissection and age, and the risk of aortic adverse events rises significantly at 60 mm.^[1]

Abdominal aorta

AAA prevalence rises with age, with a 4:1 male to female ratio.^[1]

• Smoking, age, male sex and family history of aneurysmal disease are the major risk factors; diabetes is associated with a lower risk and slower growth.^[1]

The aneurysm reaches the common iliac arteries in 25%, and up to 20% of patients also have a femoral and/or popliteal aneurysm.^[1] Mean growth is around 3 mm per year (range 1–6 mm), depending on sac diameter, genetic disorders, continued smoking, inflammation and wall calcification.^[1]

Rupture risk rises exponentially with diameter and is higher in women.^[1] Women have similar growth rates but a four-fold higher rupture risk.^[1] Two-thirds of AAAs are asymptomatic, and when one becomes symptomatic, rupture is the main presentation.^[1] Five-year mortality is higher even after repair (×4 in women, ×2 in men), likely because of cardiovascular disease elsewhere.^[1]

Measuring the aorta

Serial decisions depend on comparing like with like.^[1]

• ESC 2024 recommends measuring diameters at pre-specified anatomical landmarks, with the largest diameter of the section perpendicular to the longitudinal axis, and using the same modality and measurement method for serial imaging (both Class I, Level C).^[1]
• ACC/AHA 2022 says diameters should be measured at reproducible anatomic landmarks perpendicular to the axis of blood flow and, for an asymmetric or oval contour, the longest diameter and its perpendicular diameter should be reported (COR 1, LOE B-NR).^[2]

How each modality measures the aorta

^{[1] [2]}

ESC 2024 text explains why the root is measured in the parasternal long axis: the short axis underestimates the diameter because of plane obliquity.^[1] A root diameter difference >5 mm within one modality indicates asymmetry, which is frequent in BAV and genetic aortopathies and causes underestimation.^[1]

• Echocardiography can show arch or descending aortic enlargement but lacks diagnostic certainty for precise measurement of those diameters, and the distal ascending aorta and proximal arch form a blind spot behind the left main bronchus.^[1]

Growth must be confirmed

ESC 2024 text says a change in diameter needs a ≥3 mm increase on echocardiography, confirmed with CCT or CMR and compared with baseline.^[1]

• Its row says that if TTE shows an increase of ≥3 mm per year, confirmation by CCT or CMR should be considered (Class IIa, Level C).^[1]

The same text asks for the same technique, centre and method, with side-by-side comparison.^[1]

Indexing to body size

• ESC 2024 says indexing to BSA, with nomograms, z-scores or other indexing methods, should be considered for more accurate assessment of aortic size, especially at the lower end of the body-size range (Class IIa, Level B).^[1]
• ACC/AHA 2022 says it is reasonable to index a dilated root or ascending aorta to height or BSA in the report to aid clinical risk assessment (COR 2a, LOE C-LD).^[2]

BSA is the most used method, so an ascending aorta >22 mm/m² or a descending aorta >16 mm/m² counts as dilatation.^[1]

• At extremes of body weight, ESC 2024 says surgical thresholds may involve indexing aortic diameter by height (an aortic height index >32.1 mm/m is associated with a 12% yearly risk of aortic adverse events), aortic cross-sectional area to height (a ratio ≥10 cm²/m implies reduced long-term survival) or aortic length from the annulus to the innominate artery (a length >11 cm considered a threshold for surgery).^[1]

Nomograms or z-scores are advised especially in HTAD.^[1]

^[1]

When an aneurysm is found

Recommendation Table 34 (ESC 2024)

^[1]

• ACC/AHA 2022 recommends TTE at diagnosis of a dilated thoracic aorta to assess aortic valve anatomy and function and thoracic aortic diameters (COR 1, LOE C-LD), and says CT or MRI at diagnosis is reasonable to assess anatomy and diameters (COR 2a, LOE C-LD).^[2]
• For root or ascending aneurysms or thoracic aortic dissection, ESC 2024 recommends a family history covering at least three generations (Class I, Level B), and for root or ascending aneurysms or aortic dissection ACC/AHA 2022 recommends a multigenerational family history (COR 1, LOE B-NR), each covering thoracic aortic disease, unexplained sudden deaths and peripheral and intracranial aneurysms.^[1][2]

Surveillance of thoracic aneurysms

Recommendation Table 35 (ESC 2024)

^[1]

• The ESC 2024 text says imaging is required at 6–12 months after diagnosis, depending on aetiology and baseline diameter; after that it can be performed annually if there is no expansion or extension, or customized to the underlying condition.^[1]

Rapid expansion (≥3 mm per year) or an aorta approaching the repair threshold calls for closer evaluation every 6 months.^[1] For arch or descending thoracic aneurysms of 50–55 mm, the aorta should be re-imaged every 6 months until the intervention threshold is reached.^[1] Stable diameters over years could lengthen intervals, especially in non-genetic aneurysms and those <45 mm.^[1]

• For root or proximal ascending dilatation, TTE can be used for follow-up if it agrees with CCT or CMR; a difference of ≥3 mm means surveillance must be by CMR or CCT.^[1]

For an aneurysm of moderate size that stays stable, CMR is reasonable in place of CCT to limit radiation.^[1]

• ACC/AHA 2022 says follow-up imaging with TTE, CT or MRI in 6 to 12 months is reasonable to determine the rate of enlargement and, if stable, surveillance every 6 to 24 months depending on aortic diameter is reasonable (COR 2a, LOE C-LD).^[2]

Screening for AAA

Who to screen for AAA

^{[1] [2]}

ESC 2024 defines smoking for its AAA screening recommendations (Recommendation Table 6) as lifetime smoking of >100 cigarettes or equivalent.^[1] Its text says duplex screening is effective in reducing rupture-related mortality in populations with high AAA prevalence, especially male smokers aged ≥65 years.^[1] ESC 2024 reports that opportunistic screening during TTE identified AAA in about 2% of subjects.^[1]

• It also reports a Danish trial in which screening men aged 65–74 years by non-contrast CT was not found to be effective over 5 years.^[1]

^[5]

Surveillance of AAA

AAA surveillance intervals by diameter

^{[1] [2]}

ESC 2024 recommends duplex ultrasound for AAA surveillance (Class I, Level C).^[1]

• Its text says CCT gives better views of the abdominal aorta and branches, especially for planning, and CMR is reasonable in selected young and female patients facing long follow-up.^[1]

A diameter <25 mm carries a low risk of a large AAA in 10 years, while 25–29 mm deserves reassessment after 4 years.^[1]

• With rapid growth (≥10 mm per year or ≥5 mm per 6 months), ESC 2024 says to consider shorter intervals, and repair may be considered.^[1]

ACC/AHA 2022 recommends CT for preoperative planning once an AAA meets repair criteria (COR 1, LOE C-EO).^[2]

^[6]

• ESC 2024 summarises a meta-analysis that advises intervals of 3 years for 30–39 mm, 1 year for 40–44 mm and 6 months for 45–54 mm in men, with <1% rupture risk.^[1]

^[1]

Medical therapy and risk factors

ESC 2024 says medical treatment aims to lower cardiovascular morbidity, slow growth, delay surgery, reduce peri-operative risk and prevent aortic adverse events.^[1]

• Aneurysm patients face raised cardiovascular risk from shared risk factors, and their 10-year cardiovascular event mortality risk (heart attacks or strokes) is 15 times higher than their risk of aortic adverse events, even after repair.^[1]

Medical therapy rows

^{[1] [2]}

The ESC 2024 text says to follow general hypertension guidance, aiming for BP below 140/90 mmHg with a target of 120/80 mmHg if tolerated.^[1]

• Data on beta-blockers and ARBs in TAA and AAA are limited and mostly from Marfan cohorts, but ESC 2024 calls them reasonable first-line antihypertensive drugs in TAA and AAA.^[1]
• ESC 2024 reports one meta-analysis that suggested a possible effect of ACE inhibitors, but not ARBs, on rupture risk, and another that did not indicate an effect of ACE inhibitors on AAA growth.^[1]

It reports that a recent meta-analysis indicates a reduction of AAA growth by statins.^[1] It reports an RCT in patients with AAA of 35–44 mm in which ticagrelor did not reduce growth rate.^[1] Some evidence suggests fluoroquinolones could be associated with aneurysm progression and dissection, but ESC 2024 adds that conflicting analyses do not support this association.^[1]

• On exercise, ESC 2024 says physical exercise and sport should be considered in aortic disease after risk stratification based on aneurysm extent, dissection risk and BP control (Class IIa, Level C).^[1]
• ACC/AHA 2022 says patients with significant aortic disease should be educated about avoiding intense isometric exercise such as heavy weightlifting or Valsalva-type activity, burst exertion and collision sports (COR 1, LOE C-EO).^[2]

Repair thresholds by segment

• ESC 2024 notes that surgical risk for ascending aortic and aortic root surgery has dropped, and experienced cardiac surgery centres now report <1% mortality with elective surgery.^[1]
• ACC/AHA 2022 recommends shared decision-making when setting intervention thresholds, choosing the repair, choosing open versus endovascular approaches and planning medical management and surveillance (COR 1, LOE C-LD).^[2]
• It says referral to a high-volume centre (performing at least 30–40 aortic procedures a year) with experienced surgeons in a Multidisciplinary Aortic Team is reasonable to optimise treatment outcomes for patients who are asymptomatic with extensive aortic disease, who may benefit from complex open and endovascular aortic repairs, or who have multiple comorbidities and are being considered for intervention (COR 2a, LOE C-LD).^[2]

^[1]

Aortic root and ascending aorta (tricuspid valve)

Recommendation Table 38 (ESC 2024)

^[1]

• For surgery before pregnancy, the last row is partly replaced by the newer ESC 2025 pregnancy rows: in women without an identifiable pathogenic or likely pathogenic variant, surgery before pregnancy is recommended at a root or ascending diameter ≥50 mm (Class I, Level C) and should be considered at ≥45 mm with a family history of aortic aneurysm or dissection, uncontrolled hypertension or on patient preference (Class IIa, Level C).^[9]

• In that table, resistant hypertension means BP that cannot be adequately controlled despite three or more agents recommended by a physician with expertise in hypertension, and aortic length is the curvilinear centreline distance from the ventriculo-aortic junction to the innominate artery origin.^[1]

Root and ascending aorta rows (ACC/AHA 2022)

^[2]

• For valve surgery, the ESC/EACTS 2025 valvular guideline recommends valve-sparing aortic root replacement in young patients with root dilatation at experienced centres when durable results are expected (Class I, Level B).^[10]
• It says that when aortic valve surgery is indicated and predicted surgical risk is low, replacement of the root or ascending aorta should be considered at a maximal diameter ≥45 mm (Class IIa, Level C), considering age, BSA, aetiology, a bicuspid valve and the shape and thickness of the aorta at operation.^[10]
• ACC/AHA 2022 says valve-sparing root replacement is reasonable if the valve is suitable for sparing or repair and the operation is done by experienced surgeons in a Multidisciplinary Aortic Team (COR 2a, LOE B-NR).^[2]

Aortic arch

Arch rows

^{[1] [2]}

Descending thoracic aorta

Descending thoracic aorta rows

^{[1] [2]}

ESC 2024 text explains the threshold: at 60 mm a descending aneurysm has a 10% annual rupture risk, which justifies intervention at ≥55 mm.^[1]

• Below 55 mm, intervention may bring no further survival benefit except in women, connective tissue disorders or rapid growth (≥10 mm per year or ≥5 mm every 6 months).^[1]

The threshold may be raised in patients at high surgical risk.^[1]

Thoracoabdominal aorta

Thoracoabdominal aorta rows

^{[1] [2]}

• ESC 2024 text explains the higher bar: aortic adverse events increase above 60 mm, and thoracoabdominal repair is technically harder than repair of a descending aneurysm or AAA, so repair in low-to-moderate-risk patients is proposed at ≥60 mm.^[1]

Mortality after open repair is 6–8% in high-volume centres and 30% in less experienced centres.^[1] Post-operative spinal cord injury occurs in about 5%, similar with endovascular and open repair.^[1]

Abdominal aorta

Abdominal aorta rows

^{[1] [2]}

• ESC 2024 reports that different studies, including UKSAT and ADAM, found no benefit from open or endovascular repair (despite lower peri-operative complication rates) in asymptomatic AAA with a maximal diameter <55 mm in men and <50 mm in women.^[1]

Evidence that women rupture more often under surveillance, and at smaller diameters, justified the lower 50 mm threshold.^[1] Open repair through a midline laparotomy carries a 2–5% mortality, while EVAR lowers peri-operative mortality to <1% at the cost of more late re-interventions.^[1] ESC 2024 adds that elective repair is not recommended in frail patients or those with life expectancy <2 years.^[1]

^{[3] [4] [7] [8]}

• ESC 2024 reports that studies showed a significant short-term survival benefit for EVAR with long-term outcomes similar to open repair (up to 15 years), and that loss of the early benefit is associated with more late complications after 8 years, especially late ruptures.^[1]

Cardiac work-up before aneurysm repair

• ESC 2024 says coronary artery disease is the leading cause of early death after AAA repair and is linked to a 5–10% rate of peri-operative cardiovascular complications.^[1]
• It says coronary revascularization before elective aortic surgery in stable patients cannot be recommended, as it does not improve outcomes or the 30-day MI rate.^[1]

Its row says routine coronary angiography and systematic revascularization before AAA repair in chronic coronary syndromes is not recommended (Class III, Level C).^[1] ESC 2024 also calls a complete evaluation of the whole aorta mandatory before AAA management, with CCT by consensus the optimal pre-operative imaging.^[1]

Recommendation Table 28 (ESC 2022)

^[12]

• The same guideline says patients with a large AAA (>5 cm in women and >5.5 cm in men) should be evaluated for repair, preferably EVAR, before non-vascular non-cardiac surgery is planned, particularly with malignant tumours depending on the cancer stage.^[12]

Heritable thoracic aortic disease and bicuspid valves

• ESC 2024 recommends genetic counselling at an expert centre, then testing if indicated, for root or ascending aneurysm or thoracic dissection with risk factors for HTAD (Class I, Level B).^[1]
• In thoracic aortic disease with risk factors for HTAD, a negative family history of thoracic aortic disease and no pathogenic or likely pathogenic variant identified, TTE screening of first-degree relatives is recommended (Class I, Level B).^[1]
• When thoracic aortic disease with risk factors for HTAD has no pathogenic or likely pathogenic variant identified, imaging screening of family members starting at age 25, or 10 years below the youngest case, whichever is younger, then every 5 years to age 60 if the initial screening is normal, should be considered (Class IIa, Level C).^[1]
• ACC/AHA 2022 recommends genetic testing to identify pathogenic or likely pathogenic variants in root or ascending aneurysm or aortic dissection with risk factors for HTAD (COR 1, LOE B-NR).^[2]
• Separately, in any patient with a root or ascending aneurysm or aortic dissection, it recommends screening aortic imaging of first-degree relatives when there is neither a known family history of thoracic aortic disease nor a pathogenic or likely pathogenic variant (COR 1, LOE C-LD).^[2]

Repair thresholds in heritable aortic disease

^{[1] [9] [2]}

The ESC 2024 Marfan risk factors are a family history of dissection at <50 mm, resistant hypertension and annualized growth ≥3 mm in adults.^[1] The ESC 2024 Turner risk factors are a bicuspid valve, an elongated transverse aorta, coarctation and/or uncontrolled hypertension despite more than three drug classes.^[1]

• Both guidelines use indexed size in Turner syndrome: ESC 2024 recommends ASI, AHI or z-score in women ≥15 years (Class I, Level C), and ACC/AHA 2022 recommends ASI from age 15 (COR 1, LOE B-NR).^[1][2]

ESC 2024 says there are no clear recommendations on the diameters at which to intervene in vascular Ehlers–Danlos syndrome.^[1]

• In ACTA2 disease, type A dissection may occur below 45 mm, so surgery below 45 mm is guided by other clinical and genetic risk factors.^[1]

• In Marfan syndrome, ESC 2024 recommends either a beta-blocker or an ARB at maximally tolerated doses (unless contraindicated) to reduce the rate of aortic dilatation (Class I, Level A); ACC/AHA 2022 gives the same choice, also unless contraindicated (COR 1, LOE A).^[1][2]

• In Marfan syndrome, ESC 2024 recommends TTE at least annually if the aortic root is <45 mm without additional risk factors, at least every 6 months if <45 mm with additional risk factors, and at least every 6–12 months if ≥45 mm without additional risk factors (Class I, Level C).^[1]

• The ESC 2024 risk factors for this row are a root of >40 to ≤45 mm with a family history of dissection at <50 mm, resistant hypertension and annualized growth ≥3 mm in adults.^[1]

• In Marfan syndrome, ACC/AHA 2022 recommends TTE at diagnosis and 6 months later to determine the growth rate, then yearly if the diameters are stable, with CT or MRI of the thoracic aorta when the root or ascending aorta is not adequately seen on TTE (COR 1, LOE C-EO).^[2]

Bicuspid aortopathy

Bicuspid aortopathy rows

^{[1] [9] [2] [11]}

• The 2025 congenital guideline lists the dissection risk factors for its surveillance row as a family history of dissection, growth ≥0.3 cm per year, coarctation and root-phenotype aortopathy, and marks the row as modified from the 2022 ACC/AHA aortic guideline.^[11]
• ACC/AHA 2022 recommends TTE in every patient with a BAV to evaluate valve morphology and function, the root and ascending diameters, and coarctation and other associated cardiovascular defects (COR 1, LOE B-NR).^[2]
• It recommends CT or MRI of the thoracic aorta when the diameter and morphology of the aortic root, ascending aorta or both cannot be assessed accurately or completely by TTE (COR 1, LOE C-LD).^[2]
• ESC 2024 reports that in both large mixed and purely BAV series an ascending diameter of about 52 mm already marked a rise in aortic adverse event risk from about 1% to 4–5%.^[1]

For aortic root dilatation in BAV patients, it gives the hinge point as 50 mm.^[1]

^[1]

Aortic disease and pregnancy

Recommendation Table 8 (ESC 2025 pregnancy)

^[9]

Before pregnancy (ACC/AHA 2022)

^[2]

Surveillance after repair

ESC 2024 defines an endoleak as persistent flow outside the graft but inside the sac, which prevents complete thrombosis.^[1] Type I and type III endoleaks need correction with a new, usually endovascular, procedure.^[1] Type II is present in about 25% of patients but may seal spontaneously in approximately 50% of cases.^[1] ESC 2024 says late complications after TEVAR for a descending aneurysm are higher than with surgery (up to 38%), leading to re-operation in 24%.^[1] After AAA repair, anastomotic or para-anastomotic complications of surgery are rare (2–4%), whereas EVAR has higher complication rates (16–30%), necessitating lifelong surveillance.^[1]

Recommendation Table 42 (ESC 2024)

^[1]

Follow-up imaging after repair

^{[1] [2]}

In the ESC 2024 table, an abnormality includes any endoleak, enlargement of the excluded aneurysm, and stent-graft migration, separation or fracture.^[1] Low risk after EVAR means early sac shrinkage >10 mm, relatively younger age (<70 years), proximal and distal sealing >10 mm and no endoleak.^[1] For higher-risk patients the table gives the example of imaging every 6 months in the first year, then every 2–3 years.^[1]

• For Marfan syndrome after root replacement, ESC 2024 recommends thoracic CMR (or CCT) at least every 3 years (Class I, Level C); ACC/AHA 2022 recommends MRI (or CT) yearly at first, then every other year if normal and unchanged after 2 years (COR 1, LOE C-LD).^[1][2]

ESC 2024 notes that surveillance intervals after repair rest mostly on consensus or single-centre observational studies.^[1]

^[1]

Pitfalls

• Mixing conventions: echocardiography uses leading-to-leading edge in end-diastole, CT and CMR use inner-to-inner edge on double-oblique images (ESC 2024, Class I, Level C).^[1]
• Calling growth on TTE alone: with an increase of ≥3 mm per year on TTE, confirmation by CCT or CMR should be considered (ESC 2024, Class IIa, Level C).^[1]
• Following a distal ascending, arch or descending aneurysm with TTE: ESC 2024 says this is not recommended (Class III, Level C).^[1]
• Applying the AAA threshold for men to women: elective repair is recommended at ≥55 mm in men but at ≥50 mm in women (ESC 2024, Class I, Level A).^[1]
• Repairing a small AAA early: in randomised trials of open repair against surveillance, UKSAT (1090 patients aged 60–76 years with symptomless AAA of 4.0–5.5 cm, early elective open surgery versus ultrasound surveillance, mean follow-up 4.6 years) and ADAM (patients aged 50–79 years with AAA of 4.0–5.4 cm who did not have high surgical risk, immediate open repair versus ultrasound or CT surveillance every 6 months, mean follow-up 4.9 years) found no survival benefit from early repair.^[3][4]
• Stopping imaging after EVAR: ESC 2024 states that lifelong surveillance is currently mandatory after EVAR, as these patients are more prone to late complications and re-interventions.^[1]
• Ordering routine coronary angiography with systematic revascularization before AAA repair in chronic coronary syndromes: not recommended (ESC 2024, Class III, Level C).^[1]

Evidence, guidelines and regional differences

^{[1] [2]}

The repair thresholds agree closely; the differences are in units, in the growth trigger and in screening.^[1][2]

• For screening, ESC 2024 recommends duplex in men aged ≥65 years with a history of smoking (Class I, Level A), while ACC/AHA 2022 also calls screening reasonable in women aged ≥65 years who have ever smoked (COR 2a, LOE C-EO).^[1][2]

In Australia and New Zealand

• No Australian or New Zealand aortic guideline is quoted on this page, so the thresholds shown are rows from the ESC and ACC/AHA guidelines listed below, such as elective AAA repair at ≥55 mm in men or ≥50 mm in women (ESC 2024, Class I, Level A) or repair of an unruptured AAA at ≥5.5 cm in men or ≥5.0 cm in women (ACC/AHA 2022, COR 1, LOE A).^[1][2]
• The documents below are those with a held-status entry in the census 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 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.
• 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.
• 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.
• 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.

Guidelines checked for this topic

• Rows on this page come from the ESC 2024 peripheral arterial and aortic diseases, ESC/EACTS 2025 valvular heart disease, ESC 2025 pregnancy and ESC 2022 non-cardiac surgery guidelines.^{[1][10][9][12]}

• AHA/ACC rows come from the 2022 aortic disease guideline and the 2025 adult congenital heart disease guideline (ACC/AHA/HRS/ISACHD/SCAI).^[2][11]

• Study results are quoted from the PubMed abstracts of the UKSAT, ADAM, MASS, EVAR trial 1 and OVER trials and the RESCAN individual-patient-data meta-analysis.^{[3][4][5][6][7][8]}

• For the rows on this page, the same-month and newer guidelines of the same body in the census below were checked and give no revising row, except where a newer row is shown in its place (census 2026-10-22).

• 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 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 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 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 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 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 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 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.

• 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.

• 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.

• 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 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 Management of Peripheral Artery Disease in Adults With Diabetes: 2025 ACC Scientific Statement (PMID 41405527) is not held as text in the evidence caches, so it 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.

• ACC/AHA 2020 valvular heart disease (PMID 33332150): its bicuspid aortopathy rows are older than the 2022 aortic disease and 2025 adult congenital heart disease rows used here.

• ESC 2020 adult congenital heart disease (PMID 32860028): its aortopathy rows are older than the ESC 2024 aortic rows used here; coarctation and conotruncal neo-aortic dilatation are outside this topic.

• ACC/AHA 2022 aortic disease (PMID 36322642) rows on bicuspid surveillance and family screening are not used, because the 2025 adult congenital heart disease rows from the same bodies are given in their place.^[11]

• ESC 2020 sports cardiology (PMID 32860412): its aortic recommendation table is held only as an image; AHA/ACC 2025 competitive sports scientific statement (PMID 39973614): sports participation for athletes, a population outside this topic.

• ESC 2023 diabetes (PMID 37622663): its aortic aneurysm row asks for the same work-up and treatment as without diabetes and sets no threshold; the held OUP HTML holds that table only as an image, and the held PDF text carries the row.

• ADA Standards of Care in Diabetes 2026, section 10 (PMID 41358899): aortic aneurysm is named only within ASCVD and in a narrative on a combined vascular screening trial, with no aneurysm row.

• ESC 2024 hypertension (PMID 39210715) and AHA/ACC 2025 high blood pressure (PMID 40811497): aortic disease appears only as narrative without a row; ESC 2021 prevention (PMID 34458905): aortic aneurysm is named as documented ASCVD, in a narrative on an ultrasound screening trial and as associated with COPD, with no aneurysm row.

• AHA/ACC 2024 perioperative (PMID 39316661): no aortic aneurysm recommendation row in the held text, and it is replaced by the 2026 edition listed above; AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR 2021 chest pain (PMID 34709879): acute aortic syndromes, outside this topic.

• Heart failure guidelines (AHA/ACC/HFSA 2022, PMID 35363499; ESC 2026, PMID 42661420; NHFA/CSANZ 2018, Heart Lung Circ PMID 30077227 and its Med J Aust summary PMID 30067937): heart failure care, outside this topic.

• Coronary guidelines (ESC 2024 chronic coronary syndromes, PMID 39210710; AHA/ACC 2023 chronic coronary disease, PMID 37471501; ESC 2023, PMID 37622654, and ACC/AHA 2025, PMID 40014670, acute coronary syndromes; the NHFA/CSANZ 2025 ACS summary, PMID 41693087) and the Fourth (PMID 30571511) and Fifth (PMID 42661425) universal definitions of MI: coronary disease, outside this topic.

• Rhythm guidelines (ACC/AHA/HRS 2018 bradycardia, PMID 30412709; ESC 2019 SVT, PMID 31504425; ESC 2021 pacing, PMID 34455430; ESC 2022 ventricular arrhythmias, PMID 36017572; ESC 2024 AF, PMID 39210723; ACC/AHA/ACCP/HRS 2023 AF, PMID 38033089, whose aneurysm mention concerns preventing postoperative AF at ascending aortic aneurysm operations): outside this topic.

• Lipid guidelines (ESC/EAS 2019, PMID 31504418, with its 2025 focused update, PMID 40878289; ACC/AHA 2026, PMID 41824552): ESC/EAS 2019 discusses secondary prevention in abdominal aortic aneurysm only in narrative, and ACC/AHA 2026 names aortic aneurysm within clinical ASCVD; none of the three gives an aneurysm row, and the statin and risk-management rows of the aortic guidelines are used here instead.

• ESC 2023 cardiomyopathies (PMID 37622657), AHA/ACC 2024 hypertrophic cardiomyopathy (PMID 38718139), ESC 2023 endocarditis (PMID 37622656), ESC 2025 myocarditis and pericarditis (PMID 40878297), ESC 2019 (PMID 31504429) and AHA/ACC 2026 (PMID 41712677) pulmonary embolism, ESC/ERS 2022 pulmonary hypertension (PMID 36017548), the 2024 pulmonary hypertension documents (PMIDs 39209475, 39209476), AHA/ACC/ADA/ASN 2026 cardiovascular-kidney-metabolic (PMID 42263157) and ESC 2026 cardiac rehabilitation (PMID 42661418): outside this topic.

• Society guidelines from vascular and cardiothoracic surgery were checked through PubMed: the ESVS 2024 abdominal aorto-iliac (PMID 38307694), ESVS 2026 descending thoracic and thoraco-abdominal (PMID 41448425) and SVS 2018 AAA (PMID 29268916) guidelines are held only as PubMed abstracts, and the EACTS/STS 2024 aortic guideline (PMID 38416090) has no PubMed abstract and is not held as text; none is used.

Exam pearls

• ESC 2024 intervention diameters: surgery at ≥55 mm for the root or ascending aorta with a tricuspid valve (Class I); open surgical replacement should be considered at ≥55 mm for an isolated asymptomatic arch aneurysm at low operative risk (Class IIa); elective repair at ≥55 mm for an unruptured descending aneurysm without HTAD (Class I), at ≥60 mm for an unruptured degenerative TAAA (Class I), and for AAA at ≥55 mm in men or ≥50 mm in women (Class I).^[1]
• Surgery for a bicuspid root phenotype at a maximum aortic diameter ≥50 mm and for Marfan root disease at a maximal sinus diameter ≥50 mm: Class I, Level B (ESC 2024).^[1]
• Growth trigger for the root or ascending aorta <5.5 cm (ACC/AHA 2022): ≥0.3 cm/y in 2 consecutive years or ≥0.5 cm in 1 year on tomographic imaging.^[2]
• AAA duplex (ESC 2024): every 3 years at 30 to <40 mm should be considered (Class IIa, Level B); yearly at 40 to <45 mm in women and 40 to <50 mm in men should be considered (Class IIa, Level B); every 6 months at 50–55 mm in men or 45–50 mm in women is recommended (Class I, Level B).^[1]
• After EVAR (ESC 2024): imaging at 1 and 12 months, then yearly ultrasound with CCT or CMR every 5 years if no abnormalities (Class I, Level A).^[1]
• Re-intervention to seal type I and type III endoleaks is recommended (ESC 2024, Class I, Level B); for type II or V endoleak it should be considered with significant sac expansion ≥10 mm or a significantly decreasing proximal or distal seal (Class IIa, Level C).^[1]

References12ShowHide

1. [1]Mazzolai L, et al. 2024 ESC Guidelines for the management of peripheral arterial and aortic diseases. Eur Heart J, 2024.PMID 39210722
2. [2]Isselbacher EM, et al. 2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease: A Report of the American Heart Association/American College of Cardiology Joint Committee on Clinical Practice Guidelines. Circulation, 2022.PMID 36322642
3. [3]The UK Small Aneurysm Trial Participants Mortality results for randomised controlled trial of early elective surgery or ultrasonographic surveillance for small abdominal aortic aneurysms. The UK Small Aneurysm Trial Participants. Lancet, 1998.PMID 9853436
4. [4]Lederle FA, et al. Immediate repair compared with surveillance of small abdominal aortic aneurysms. N Engl J Med, 2002.PMID 12000813
5. [5]Ashton HA, et al. The Multicentre Aneurysm Screening Study (MASS) into the effect of abdominal aortic aneurysm screening on mortality in men: a randomised controlled trial. Lancet, 2002.PMID 12443589
6. [6]Bown MJ, et al. Surveillance intervals for small abdominal aortic aneurysms: a meta-analysis. JAMA, 2013.PMID 23443444
7. [7]Patel R, et al. Endovascular versus open repair of abdominal aortic aneurysm in 15-years' follow-up of the UK endovascular aneurysm repair trial 1 (EVAR trial 1): a randomised controlled trial. Lancet, 2016.PMID 27743617
8. [8]Lederle FA, et al. Open versus Endovascular Repair of Abdominal Aortic Aneurysm. N Engl J Med, 2019.PMID 31141634
9. [9]De Backer J, et al. 2025 ESC Guidelines for the management of cardiovascular disease and pregnancy. Eur Heart J, 2025.PMID 40878294
10. [10]Praz F, et al. 2025 ESC/EACTS Guidelines for the management of valvular heart disease. Eur Heart J, 2025.PMID 40878295
11. [11]Gurvitz M, et al. 2025 ACC/AHA/HRS/ISACHD/SCAI Guideline for the Management of Adults With Congenital Heart Disease: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines. Circulation, 2026.PMID 41411375
12. [12]Halvorsen S, et al. 2022 ESC Guidelines on cardiovascular assessment and management of patients undergoing non-cardiac surgery. Eur Heart J, 2022.PMID 36017553