Aortic Stenosis — Med2Date

📋 Key Information Summary

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Aortic stenosis (AS) is the most common valvular heart disease in Australia, with prevalence increasing sharply after age 65, driven by degenerative calcific disease.
Severity grading relies on echocardiography: mild (AVA >1.5 cm², mean gradient <20 mmHg, Vmax <3.0 m/s), moderate (AVA 1.0–1.5 cm², mean gradient 20–40 mmHg, Vmax 3.0–4.0 m/s), and severe (AVA ≤1.0 cm², mean gradient ≥40 mmHg, Vmax ≥4.0 m/s).
Low-flow low-gradient severe AS (AVA ≤1.0 cm², mean gradient <40 mmHg, LVEF <50%) requires dobutamine stress echocardiography to distinguish true severe AS from pseudo-severe AS.
Symptomatic severe AS carries a dismal prognosis without intervention (2-year mortality ~50%); classic triad includes angina, syncope, and heart failure (dyspnoea).
Exercise testing is contraindicated in symptomatic AS but is recommended in asymptomatic severe AS to unmask latent symptoms or abnormal blood pressure response.
TAVR (transcatheter aortic valve replacement) is now the standard of care for patients aged ≥75 years or those at high/intermediate surgical risk (STS-PROM ≥4%), and is increasingly used in low-risk patients based on trial data.
Surgical AVR (SAVR) remains the gold standard for younger, low-risk patients and those with concomitant cardiac pathology requiring surgery (e.g., severe CAD, mitral disease).
Asymptomatic severe AS with very low AVA (≤0.6 cm²), rapid progression (Vmax increase ≥0.3 m/s/year), elevated BNP, or abnormal exercise response should be considered for early intervention.
Post-TAVR management includes dual antiplatelet therapy (aspirin + clopidogrel) for 3–6 months; post-SAVR management includes warfarin for 3 months if a mechanical valve is used; bioprosthetic valves require only aspirin long-term.
Paravalvular leak (PVL) post-TAVR is common (10–25% mild); moderate-to-severe PVL warrants consideration of percutaneous closure. Structural valve deterioration (SVD) mandates regular echocardiographic surveillance.
Aboriginal and Torres Strait Islander peoples experience higher rates of rheumatic heart disease–related valvular pathology, later presentation, and barriers to specialist access, requiring culturally safe pathways and outreach echocardiography programmes.
Multidisciplinary Heart Team discussion is mandatory for all patients being considered for valve intervention to ensure evidence-based, patient-centred decision-making.

Introduction & Australian Epidemiology

Aortic stenosis (AS) is the most prevalent valvular heart disease in high-income countries, including Australia. Degenerative calcific AS accounts for the vast majority of cases in adults aged >65 years, with prevalence estimated at 2–4% of Australians over 65 and rising sharply with age. Bicuspid aortic valve (BAV), affecting approximately 1–2% of the population, accelerates calcification and typically presents 10–15 years earlier than trileaflet degenerative AS. Rheumatic AS remains an important cause in Aboriginal and Torres Strait Islander communities and in migrants from endemic regions.

The Australian Institute of Health and Welfare (AIHW) reports that valvular heart disease accounts for a significant proportion of cardiac surgical admissions nationally. With Australia's ageing population, the burden of AS is projected to increase substantially over the coming decades, placing greater demands on echocardiography services, Heart Team capacity, and access to both surgical AVR (SAVR) and transcatheter aortic valve replacement (TAVR).

AS progresses from a prolonged asymptomatic phase to a symptomatic phase characterised by angina, syncope, and heart failure. Once symptoms develop, prognosis without intervention is poor — median survival is approximately 2–5 years depending on symptom severity. Timely detection through clinical examination (ejection systolic murmur, narrow pulse pressure, slow-rising carotid pulse) and confirmation with transthoracic echocardiography (TTE) are the cornerstones of early management.

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Australian context: The Heart Foundation of Australia and Cardiac Society of Australia and New Zealand (CSANZ) recommend opportunistic screening with cardiac auscultation in adults >65 years presenting for routine health assessments. An ejection systolic murmur at the right upper sternal border radiating to the carotids warrants TTE.

Grading Severity

Accurate grading of AS severity is essential for clinical decision-making. Transthoracic echocardiography (TTE) is the primary diagnostic modality. The 2020 ACC/AHA and 2021 ESC/EACTS guidelines endorse a multiparametric approach integrating valve area, transvalvular gradients, and flow velocities.

Standard Echocardiographic Parameters

Parameter	Mild	Moderate	Severe
Aortic valve area (AVA)	>1.5 cm²	1.0–1.5 cm²	≤1.0 cm²
Indexed AVA (AVAi)	>0.85 cm²/m²	0.60–0.85 cm²/m²	≤0.6 cm²/m²
Mean transvalvular gradient	<20 mmHg	20–40 mmHg	≥40 mmHg
Peak aortic jet velocity (Vmax)	<3.0 m/s	3.0–4.0 m/s	≥4.0 m/s
Dimensionless velocity index (DVi)	>0.50	0.25–0.50	<0.25

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Discordance is common: Up to 30% of patients with severe AS by AVA criteria have a mean gradient <40 mmHg. Always consider flow status, LV function, and blood pressure when parameters are discordant. Do not rely on a single parameter to determine severity.

Low-Flow Low-Gradient AS

Low-flow low-gradient (LF-LG) AS is defined as AVA ≤1.0 cm² with mean gradient <40 mmHg and stroke volume index (SVi) ≤35 mL/m². It accounts for 5–10% of severe AS presentations and may occur with reduced LVEF (<50%) or with preserved LVEF (normal-flow LG or paradoxical LF-LG).

Reduced LVEF LF-LG AS (classical LF-LG): Distinguishing true severe AS from pseudo-severe AS (where low flow causes incomplete valve opening of a moderately diseased valve) is critical. Dobutamine stress echocardiography (DSE) is the recommended investigation.

Dobutamine Stress Echocardiography Protocol

1

Indication

LF-LG AS with LVEF <50% where true severe vs pseudo-severe AS must be differentiated before intervention.

2

Protocol

Dobutamine infusion starting at 5 mcg/kg/min, increasing by 5 mcg/kg/min every 5–8 minutes to a maximum of 20 mcg/kg/min. Target heart rate increase of ≥20% from baseline or achievement of contractile reserve.

3

True Severe AS

With increased flow, AVA remains ≤1.0 cm² and mean gradient rises to ≥40 mmHg. Contractile reserve is present (stroke volume increase ≥20%).

4

Pseudo-Severe AS

With increased flow, AVA increases to >1.0 cm² and gradient remains <40 mmHg. The valve is moderately diseased; intervention is not indicated.

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No contractile reserve: If stroke volume does not increase by ≥20% during DSE (absence of contractile reserve), operative mortality for SAVR is very high (~30%). Prognosis is poor regardless of treatment. Consider futility of intervention and patient goals of care.

Paradoxical low-flow low-gradient AS (preserved LVEF): Occurs when LVEF is ≥50% but SVi is ≤35 mL/m² due to pronounced LV concentric remodelling, small LV cavity, diastolic dysfunction, atrial fibrillation, or significant mitral regurgitation. AVA is ≤1.0 cm² with mean gradient <40 mmHg. CT calcium scoring of the aortic valve (Agatston score >2000 AU in men, >1200 AU in women) can help confirm true severe AS in equivocal cases. Cardiac MRI may also be useful for quantifying flow and LV geometry.

CT Aortic Valve Calcium Scoring

CT calcium scoring of the aortic valve is increasingly used in Australian centres (available at major tertiary hospitals; MBS item numbers for CT coronary angiography may apply in selected cases, though dedicated valve calcium scoring is not separately listed on the MBS). Thresholds for severe AS:

Men: >2000 Agatston units (AU)
Women: >1200 AU

This is particularly useful when echo parameters are discordant and DSE is not feasible or inconclusive.

Symptomatic Severe AS

The development of symptoms in severe AS marks a critical inflection point. Once the classic triad emerges, the natural history becomes devastating without intervention, with 2-year mortality approaching 50% in patients with heart failure symptoms.

Classic Triad

Angina

Exertional Chest Pain

Occurs in 35% of symptomatic AS. Due to supply–demand mismatch (increased LV mass, prolonged systole, subendocardial ischaemia) even without coronary artery disease. 50% of patients with AS angina have concomitant CAD.

Mean survival: ~5 years without intervention

Syncope

Exertional Syncope or Pre-Syncope

Occurs in 15% of symptomatic AS. Mechanisms include fixed cardiac output unable to meet peripheral vasodilation during exercise, vasodepressor response, or transient arrhythmia. Associated with sudden cardiac death risk.

Mean survival: ~3 years without intervention

Heart Failure

Dyspnoea / Exercise Intolerance / Pulmonary Oedema

The most ominous symptom. Reflects LV decompensation — diastolic then systolic dysfunction, elevated filling pressures, pulmonary congestion. Includes exertional dyspnoea, orthopnoea, PND, and reduced exercise tolerance.

Mean survival: ~2 years without intervention

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Critical: Many elderly patients unconsciously reduce their activity to avoid symptoms, masking the true severity. A thorough symptom history from both the patient and carers, supplemented by objective functional assessment, is essential. Do not attribute dyspnoea solely to deconditioning or ageing.

Role of Exercise Testing

Exercise testing is contraindicated in symptomatic severe AS. It plays a vital role only in asymptomatic severe AS (discussed below).

In symptomatic patients, the diagnosis and severity assessment are established by resting TTE. Exercise testing in this context is unsafe and unnecessary — the presence of symptoms with confirmed severe AS on echo is sufficient to recommend intervention.

Timing of Intervention

Intervention (SAVR or TAVR) is a Class I recommendation for symptomatic severe AS, regardless of LVEF. Key timing considerations:

Urgent/emergent intervention: Patients presenting with acute decompensated heart failure, cardiogenic shock, or haemodynamic instability secondary to AS require stabilisation (inotropes, cautious diuresis, avoidance of vasodilators) followed by expedited intervention.
Early intervention: Once symptoms are confirmed and severe AS is documented, intervention should not be delayed. Prolonged waiting increases the risk of irreversible LV dysfunction, sudden death, and operative mortality.
Pre-operative optimisation: Address reversible comorbidities (anaemia, renal impairment, infection) but do not delay intervention indefinitely. Coronary angiography should be performed pre-SAVR; for TAVR, CT coronary angiography may suffice.

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Medical therapy: There is no medical therapy that slows AS progression or improves survival. Statins have NOT been shown to alter calcific AS progression (SEAS, ASTRONOMER trials). Medical therapy for symptoms (diuretics for congestion, cautious ACE inhibitors for LV dysfunction) is bridging only — not a substitute for intervention.

TAVR vs Surgical AVR

The choice between transcatheter aortic valve replacement (TAVR) and surgical aortic valve replacement (SAVR) is one of the most significant decisions in valvular heart disease management. All patients should be evaluated by a multidisciplinary Heart Team (interventional cardiologist, cardiac surgeon, imaging specialist, anaesthetist, geriatrician where appropriate) and undergo shared decision-making with the patient.

Risk Assessment

Surgical risk stratification guides the choice between SAVR and TAVR. Multiple scoring systems are used in Australian practice:

Scoring System	Low Risk	Intermediate Risk	High Risk	Prohibitive Risk
STS-PROM	<4%	4–8%	>8%	Predicted mortality >15% or ≥50% risk of irreversible morbidity
EuroSCORE II	<4%	4–10%	>10%	Not directly applicable

In addition to formal scores, the Heart Team integrates frailty indices, porcelain aorta, hostile chest (prior radiation, chest wall deformity), liver disease, prior cardiac surgery, and patient cognitive/psychosocial status.

Anatomical Suitability for TAVR

Pre-procedural CT angiography (aorto-femoral or CT aorta with 3D reconstruction) is mandatory for TAVR planning. Key measurements include:

Aortic annulus: Perimeter, area, and mean diameter — determines prosthesis sizing
Sinus of Valsalva: Height and width — coronary obstruction risk
Sinotubular junction: Diameter — sealing and anchoring
Ascending aorta: Diameter and tortuosity
Iliofemoral access: Minimum lumen diameter (≥5.0–5.5 mm for most current systems), calcification, tortuosity
Distance from annulus to coronary ostia: ≥10 mm reduces coronary obstruction risk
Aortic valve morphology: Bicuspid vs trileaflet (bicuspid valves are associated with higher paravalvular leak and conduction disturbance rates, though expanding evidence supports TAVR in bicuspid anatomy)

Valve Choice: TAVR vs SAVR by Risk Category

Risk Category	Preferred Intervention	Key Evidence	Considerations
Prohibitive / extreme risk	TAVR (if anatomically suitable)	PARTNER 1B, CoreValve Extreme Risk	Palliative TAVR superior to medical therapy. Not all patients are suitable — assess futility.
High risk (STS ≥8%)	TAVR or SAVR (Heart Team decision)	PARTNER 1A, CoreValve High Risk, SURTAVI (expanded criteria)	TAVR non-inferior or superior to SAVR for 1–5 year outcomes. Transfemoral TAVR preferred access.
Intermediate risk (STS 4–8%)	TAVR or SAVR (Heart Team decision)	SURTAVI, PARTNER 2A	TAVR non-inferior. Patient age, anatomy, and preference guide choice. TAVR increasingly favoured in elderly.
Low risk (STS <4%)	SAVR or TAVR (individualised)	PARTNER 3, Evolut Low Risk	TAVR non-inferior/superior at 2 years. Long-term (>10 year) durability data for TAVR bioprostheses limited. SAVR preferred in younger patients (<65–70 years) for durability and potential future redo access.

Bioprosthetic vs Mechanical Valve (SAVR)

For patients undergoing SAVR:

Age ≥65 years: Bioprosthetic valve (bovine pericardial or porcine) is preferred. Avoids lifelong anticoagulation. SVD expected at 10–20 years.
Age <65 years: Mechanical valve may be preferred if the patient accepts lifelong warfarin therapy. Superior durability. Shared decision-making is critical.
Age <50 years: Consider the Ross procedure (pulmonary autograft) in selected patients at experienced centres.

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Australian TAVR access: TAVR is available at most major metropolitan tertiary centres across Australia (public and private). Medicare Benefits Schedule (MBS) item numbers cover TAVR procedures. Patients in regional and remote areas may require interstate transfer. Royal Flying Doctor Service and aeromedical retrieval facilitate access.

Shared Decision-Making

The Heart Team discussion should incorporate:

Life expectancy and quality of life goals
Patient values regarding anticoagulation, reoperation risk, recovery time
Anatomical suitability and procedural risks specific to the patient
Cognitive status, frailty, and social support for post-procedural rehabilitation
Patient preference after clear explanation of risks, benefits, and alternatives of both SAVR and TAVR

Asymptomatic Severe AS

Many patients with severe AS are initially asymptomatic. Current guidelines recommend watchful waiting with serial echocardiographic surveillance in most cases. However, certain high-risk features may warrant earlier intervention.

Surveillance Protocol

AS Severity	Echo Frequency	Clinical Review
Severe (AVA ≤1.0 cm²)	Every 6–12 months	Every 6 months
Moderate (AVA 1.0–1.5 cm²)	Every 1–2 years	Every 12 months
Mild (AVA >1.5 cm²)	Every 3–5 years	As per routine

Exercise Testing in Asymptomatic Severe AS

Exercise testing (symptom-limited treadmill or semi-supine bicycle echo) is recommended (Class IIa) in asymptomatic severe AS to unmask:

Exertional symptoms (angina, dyspnoea, pre-syncope) — present in up to 30–40% of patients who report being asymptomatic
Abnormal blood pressure response (failure of SBP to rise ≥20 mmHg or fall ≥20 mmHg from baseline)
Exercise-induced ST changes or arrhythmias

A positive exercise test in asymptomatic severe AS confers significantly worse prognosis and supports early intervention.

Very Severe AS

Very severe AS is defined as AVA ≤0.6 cm² (or Vmax ≥5.0 m/s). These patients have a markedly worse natural history even when asymptomatic, with event rates of 20–40% per year. Current guidelines (ESC 2021, ACC/AHA 2020) support consideration of early intervention in very severe AS when performed at a centre with low operative mortality (<1–2% for SAVR, <3% for TAVR).

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Important: Early intervention for asymptomatic severe AS should only be considered at experienced Heart Valve Centres with documented low procedural mortality rates. The risk of intervention must be weighed against the risk of watchful waiting. Most Australian tertiary centres have mortality rates within these thresholds for SAVR; TAVR mortality should be confirmed locally.

Rapid Progression

AS progression is variable. Rapid progression is defined as:

Increase in Vmax ≥0.3 m/s per year
Decrease in AVA ≥0.1 cm² per year
Increase in mean gradient ≥7–10 mmHg per year

Rapid progression is associated with earlier symptom onset and worse outcomes. More frequent surveillance (every 6 months) is warranted, and earlier intervention may be justified.

Elevated Biomarkers

Elevated B-type natriuretic peptide (BNP) or NT-proBNP (>3× age- and sex-adjusted normal range) in asymptomatic severe AS is an independent predictor of symptom onset and adverse outcomes. Serial BNP monitoring can help identify subclinical LV decompensation. An increase in BNP >75 pg/mL (or NT-proBNP >300 pg/mL) from baseline supports consideration of earlier intervention, particularly when combined with other high-risk features.

High-sensitivity cardiac troponin (hs-cTn) elevation is also emerging as a prognostic marker in asymptomatic AS, reflecting ongoing myocardial injury from pressure overload. It is not yet standard of care for decision-making but adds to risk stratification.

Summary: When to Intervene in Asymptomatic Severe AS

Feature	Recommendation	Class/Level
LVEF <50% (confirmed severe AS)	Intervention indicated	Class I / LOE B
Abnormal exercise test (symptoms or BP drop)	Intervention reasonable	Class IIa / LOE B
Very severe AS (AVA ≤0.6 cm²) at low surgical risk centre	Intervention reasonable	Class IIa / LOE C
Rapid progression (Vmax increase ≥0.3 m/s/year)	Intervention may be considered	Class IIb / LOE C
Elevated BNP (>3× normal)	Intervention may be considered	Class IIb / LOE C

Post-Intervention Management

Lifelong follow-up is essential after valve intervention. Post-procedural management includes antithrombotic therapy, surveillance for complications, endocarditis prophylaxis counselling, and management of comorbidities.

Antithrombotic Therapy

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Aspirin

Cartia® · Aspen · Antiplatelet

Adult dose 75–100 mg PO once daily

Duration Lifelong post-bioprosthetic valve (SAVR or TAVR)

Renal adjustment No adjustment required

PBS status ✔ PBS General Benefit

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Clopidogrel

Plavix® · Sanofi · P2Y12 inhibitor

Adult dose 75 mg PO once daily

Post-TAVR duration 3–6 months in combination with aspirin (DAPT), then aspirin alone lifelong

Renal adjustment No adjustment required (use with caution in severe renal impairment)

PBS status ✔ PBS General Benefit

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Warfarin

Marevan® · Generic · Vitamin K antagonist

Adult dose Individualised to target INR 2.5–3.5 (mechanical valve) or 2.0–3.0 (bioprosthetic with AF)

Post-SAVR (mechanical valve) Lifelong with INR target 2.5 (bileaflet, aortic position, no risk factors) or 3.0 (higher risk)

Post-SAVR (bioprosthetic, no AF) Aspirin alone lifelong; consider warfarin for first 3 months if high thrombotic risk

Renal adjustment No dose adjustment; monitor INR more frequently

PBS status ✔ PBS General Benefit

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Post-TAVR antithrombotic summary: Single antiplatelet therapy (aspirin 75–100 mg daily) is recommended lifelong. Dual antiplatelet therapy (aspirin + clopidogrel) is recommended for 3–6 months post-TAVR, particularly if no indication for anticoagulation. If the patient has concomitant AF, anticoagulation alone (warfarin or DOAC) is recommended — the role of DOACs post-TAVR is supported by the ATLANTIS and ENVISAGE-TAVI trials, with edoxaban and apixaban showing favourable profiles.

Paravalvular Leak (PVL)

Paravalvular leak is more common after TAVR (10–25% mild, 2–5% moderate-to-severe) than SAVR (<5%).

Mild PVL: Generally well-tolerated. Surveillance only. No specific treatment.
Moderate PVL: Associated with increased mortality, heart failure, and haemolytic anaemia. Echocardiographic surveillance at 1, 6, and 12 months, then annually. Consider percutaneous closure if symptomatic or progressive.
Severe PVL: Requires intervention. Percutaneous PVL closure (with Amplatzer Vascular Plug or dedicated PVL devices) is the first-line approach. Redo surgery carries high mortality risk and is reserved for cases not amenable to percutaneous closure.

Haemolytic anaemia secondary to PVL should be investigated with FBC, reticulocyte count, LDH, haptoglobin, and peripheral blood film. Erythropoietin-stimulating agents and iron supplementation may be required; definitive treatment is PVL closure.

Structural Valve Deterioration (SVD)

All bioprosthetic valves (surgical and transcatheter) are subject to SVD over time.

Valve Type	Expected SVD Timeline	Key Features
SAVR bioprosthetic	10–20 years (age-dependent; younger patients → faster SVD)	Stenosis predominant in younger patients; regurgitation predominant in older patients
TAVR bioprosthetic	Data emerging; 5-year durability appears comparable to SAVR; 10+ year data limited	May be less prone to SVD due to supra-annular positioning and newer designs
Mechanical valve	Virtually unlimited durability	Requires lifelong anticoagulation. Thrombotic obstruction is the primary long-term failure mode.

SVD is defined using the Valve Academic Research Consortium (VARC-3) criteria as haemodynamic deterioration (increase in mean gradient ≥10 mmHg from post-implant baseline and/or new or worsening regurgitation ≥ moderate) with or without clinical consequences. Management options include redo SAVR, TAVR-in-TAVR (valve-in-valve), or TAVR-in-SAVR.

Follow-Up Protocol

1 month

Clinical review, transthoracic echocardiography (TTE). Assess for PVL, valve gradients, LVEF recovery. Wound check (SAVR). Vascular access site assessment (TAVR). Bloods: FBC, renal function, LDH (haemolysis screen).

6 months

Clinical review, TTE. Assess valve function stability, PVL severity, LVEF. INR review if on warfarin. Transition from DAPT to single antiplatelet (TAVR) per protocol.

12 months

Clinical review, TTE. Establish baseline valve gradients for future SVD surveillance. BNP/NT-proBNP if indicated. Cardiac rehabilitation review.

Annually thereafter

Clinical review with TTE. Compare valve gradients to baseline. Screen for SVD, PVL progression, new arrhythmias (AF common post-intervention). Dental review. Endocarditis prophylaxis counselling reinforcement.

5 years

Comprehensive review. TTE. Consider CT if TAVR valve and suspicion of SVD. Discussion of valve longevity and future planning, especially in younger patients with bioprostheses.

Endocarditis Prophylaxis

The Australian Therapeutic Guidelines and the 2020 AHA/ACC guidelines recommend antibiotic prophylaxis for infective endocarditis in patients with prosthetic heart valves (including TAVR prostheses) undergoing high-risk dental procedures (dental extractions, periodontal procedures, dental implant placement). Recommend good oral hygiene and regular dental review for all prosthetic valve recipients.

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Amoxicillin

Amoxil® · Generic · Penicillin antibiotic

Adult dose 2 g PO, 30–60 minutes before procedure

Paediatric dose 50 mg/kg PO (max 2 g), 30–60 minutes before procedure

Penicillin allergy Clindamycin 600 mg PO (adults) or 20 mg/kg PO (paeds, max 600 mg)

PBS status ✔ PBS General Benefit

Investigations

Essential and Supplementary Investigations

Essential Transthoracic Echocardiography (TTE) First-line investigation. Assess AVA, mean gradient, Vmax, LVEF, LV wall thickness, diastolic function, coexistent valvular disease, aortic root dimensions. Available at all major hospitals and many private practices. MBS Item 55122 (transthoracic echocardiography).

Available Transoesophageal Echocardiography (TOE) When TTE quality is suboptimal or to better characterise PVL post-intervention. Intraprocedural TOE is routine during SAVR. MBS Item 55124.

Available Dobutamine Stress Echocardiography (DSE) For LF-LG AS with reduced LVEF to differentiate true severe from pseudo-severe AS. Performed in specialised echo labs. MBS Item 55132 (stress echocardiography).

Available CT Aortic Valve Calcium Scoring For discordant echo parameters, especially paradoxical LF-LG AS. Non-contrast ECG-gated CT. Available at tertiary centres. MBS may apply under general CT item numbers; dedicated valve calcium scoring not separately listed.

Available CT Aorto-Iliac / Femoral CT Angiography Mandatory pre-TAVR planning. Assesses annular dimensions, access vessel calibre/calcification, coronary ostia height. MBS Item 57358 or related CT angiography items.

Available Coronary Angiography (Invasive or CT) Pre-SAVR: invasive coronary angiography is standard. Pre-TAVR: CT coronary angiography (CTCA) may suffice to exclude significant CAD. MBS Item 38218 (CTCA) or 38200 (invasive catheter).

Available BNP / NT-proBNP Baseline and serial measurement in asymptomatic severe AS to risk-stratify. Elevated levels predict symptom onset and worse prognosis. MBS Item 66836.

Available Exercise Stress Testing (Treadmill / Bicycle) For asymptomatic severe AS only (contraindicated if symptomatic). Semi-supine bicycle with echo monitoring is ideal. MBS Item 11012.

Available Cardiac MRI For assessment of LV fibrosis (LGE), quantification of regurgitation, and flow assessment in discordant cases. Limited availability. MBS Item 63541.

Available FBC, Iron Studies, LDH, Haptoglobin Post-intervention haemolysis screen, especially if PVL suspected. Baseline renal function for contrast planning.

Special Populations

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Pregnancy

Severe AS in pregnancy

Haemodynamic changes of pregnancy (increased blood volume, heart rate, cardiac output) may precipitate decompensation in severe AS. Pre-pregnancy counselling is essential. Moderate-to-severe AS requires close monitoring by a combined obstetric–cardiology team at a tertiary centre. TTE at each trimester and before delivery.

Timing of delivery

Vaginal delivery is preferred with epidural anaesthesia and avoidance of prolonged Valsalva. Caesarean section reserved for obstetric indications or haemodynamic instability. Avoidance of systemic vasodilators (e.g., GTN) and aggressive fluid loading.

Intervention timing

If intervention is required during pregnancy, balloon aortic valvuloplasty (BAV) may be performed as a bridge (in rheumatic/congenital AS). SAVR and TAVR carry significant fetal risk (radiation, cardiopulmonary bypass) and are reserved for refractory cases. Ideally, intervention is performed before pregnancy if severe AS is identified.

Anticoagulation

Mechanical valves require warfarin throughout pregnancy (despite teratogenic risk in 1st trimester) or LMWH with anti-Xa monitoring. Shared decision-making is critical. Do NOT discontinue anticoagulation in pregnant women with mechanical valves without specialist input.

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Paediatrics

Bicuspid aortic valve

BAV is the most common congenital heart defect (~1–2% of births). May cause AS, AR, or both. Paediatric AS is typically due to BAV or rheumatic heart disease (in ATSI communities). Echocardiographic surveillance from childhood.

Intervention thresholds

Peak instantaneous gradient >60 mmHg (or mean >40 mmHg) with symptoms, LV hypertrophy, or ECG changes. Balloon aortic valvuloplasty (BAV) is first-line in children and adolescents. SAVR or Ross procedure for BAV failure or severe calcification (rare in paediatrics).

TAVR in paediatrics

Not currently approved for primary implantation in children. Valve-in-valve TAVR may be considered in adolescents/young adults with failed bioprostheses in appropriately sized annuli.

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Elderly (>80 years)

TAVR preference

In patients aged ≥80 years, TAVR is generally preferred over SAVR due to lower perioperative morbidity, shorter recovery, and comparable or superior survival. Comprehensive geriatric assessment (frailty, cognition, sarcopenia, polypharmacy) should be integrated into the Heart Team evaluation.

Frailty assessment

Clinical Frailty Scale (CFS), grip strength, gait speed, and Katz ADL score help predict post-procedural recovery. Severe frailty (CFS ≥7) is associated with poor outcomes regardless of intervention type.

Non-cardiac comorbidity

Chronic kidney disease, COPD, cognitive impairment, and multimorbidity are common. Shared decision-making should incorporate life expectancy and quality-of-life goals. Palliative care input may be appropriate for patients where intervention is of uncertain benefit.

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Renal Impairment

Contrast nephropathy risk

Pre-TAVR CT and the TAVR procedure itself involve iodinated contrast. Pre-hydration (NaCl 0.9%, 1 mL/kg/hr for 6–12 hours pre-procedure) and minimisation of contrast volume are essential in CKD stages 3–5.

Dialysis patients

TAVR can be performed safely in haemodialysis patients. Coordinate dialysis timing around the procedure. Higher bleeding risk and vascular complications. Bioprosthetic valve preferred (mechanical valve anticoagulation is challenging in dialysis).

Warfarin monitoring

If warfarin is indicated (mechanical valve), INR variability is greater in CKD/dialysis patients. More frequent INR monitoring and individualised target INR.

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Hepatic Impairment

Bleeding risk

Significant liver disease (Child-Pugh B/C) increases bleeding risk during and after valve intervention. Coagulopathy should be corrected pre-procedure. TAVR may be preferred over SAVR to avoid cardiopulmonary bypass and sternotomy.

Anticoagulation

Warfarin is difficult to manage in advanced liver disease. DOACs are contraindicated in severe hepatic impairment (Child-Pugh C). Individualised antithrombotic strategy with haematology input.

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Immunocompromised

Infective endocarditis risk

Immunocompromised patients (transplant recipients, HIV, chemotherapy, biologics) with prosthetic valves have a heightened risk of prosthetic valve endocarditis. Vigilant dental care, strict endocarditis prophylaxis, and prompt investigation of febrile episodes.

Procedural considerations

Wound healing may be impaired post-SAVR. TAVR may be preferred to avoid sternotomy. Immunosuppressive medication adjustments should be discussed with the treating specialist pre-procedure.

Aboriginal and Torres Strait Islander Health Considerations

Aboriginal and Torres Strait Islander Health

Rheumatic heart disease

Acute rheumatic fever (ARF) and rheumatic heart disease (RHD) remain significantly more prevalent in Aboriginal and Torres Strait Islander peoples, particularly in remote Northern Territory, Queensland, and Western Australian communities. RHD-related aortic stenosis presents at a younger age than degenerative AS and may be accompanied by multivalvular disease. The RHDAustralia Clinical Guidelines (2020) recommend echocardiographic screening for RHD in high-prevalence communities.

Later presentation

Aboriginal and Torres Strait Islander patients are more likely to present with advanced symptomatic AS and reduced LVEF, reflecting delayed diagnosis and barriers to accessing echocardiography. Culturally safe cardiac outreach programmes (e.g., CRANAplus, RHDAustralia echocardiography screening) are essential to enable earlier detection.

Geographic barriers

Access to specialist cardiology services and valve intervention centres is limited for patients in regional and remote communities. Transfer to metropolitan tertiary centres (Darwin, Adelaide, Brisbane, Perth) is often required. Royal Flying Doctor Service (RFDS) aeromedical retrieval is critical. Post-procedural follow-up requires locally supported models of care with telehealth and visiting specialist services.

Social determinants

Overcrowded housing, food insecurity, limited health literacy, and systemic racism in healthcare impact engagement with surveillance programmes, medication adherence (e.g., warfarin monitoring), and rehabilitation. Aboriginal Health Workers and Practitioners (AHWPs) are vital for culturally safe education, navigation, and continuity of care.

Secondary prophylaxis

For RHD-related AS, secondary prophylaxis with benzathine penicillin G (BPG) 4-weekly IM injections is essential to prevent ARF recurrence and further valve damage. Adherence support through school-based and community-based programmes, patient-held records, and reminder systems. Where BPG is declined or not tolerated, oral phenoxymethylpenicillin (penicillin V) 250 mg BD may be considered, though intramuscular BPG is strongly preferred.

Culturally safe care

Engage Aboriginal Community Controlled Health Organisations (ACCHOs) in care planning. Use plain language, visual aids, and interpreter services where needed (including for patients for whom English is a second or third language). Recognise the importance of family and community in decision-making. Respect Sorry Business and cultural obligations that may affect appointment attendance.

Endocarditis awareness

Injection-related infections (including from non-sterile practices) and skin infections in remote communities may increase endocarditis risk. Skin sores and scabies management programmes (e.g., Healthy Skin Programme in the NT) reduce this risk. Prosthetic valve recipients in remote settings need accessible pathways for febrile illness assessment and early echocardiography.

Quick Reference: Antithrombotic Therapy Post-Valve Intervention

TAVR (no AF, no other indication)

Aspirin 75–100 mg + Clopidogrel 75 mg (DAPT) → Aspirin alone

DAPT 3–6 months, then aspirin lifelong

Consider single antiplatelet (aspirin alone) from day 0 in high-bleeding-risk patients

SAVR — bioprosthetic (no AF)

Aspirin 75–100 mg daily

Lifelong

Consider warfarin for 3 months post-op if high thrombotic risk (e.g., LAA thrombus, AF)

SAVR — mechanical valve (aortic position)

Warfarin (target INR 2.5)

Lifelong

Add aspirin 75 mg if additional risk factors (AF, LV thrombus, hypercoagulable state). INR 3.0 if caged-ball or tilting disc valve.

Any valve + atrial fibrillation

Anticoagulation (warfarin or DOAC per indication)

Lifelong

DOACs acceptable post-TAVR and post-bioprosthetic SAVR. Warfarin mandatory for mechanical valves.

📚 References

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