Valvular heart disease: murmur evaluation, aortic stenosis, and GP role

Valvular heart disease (VHD) covers a spectrum of structural abnormalities affecting the aortic, mitral, tricuspid, and pulmonary valves — from benign flow murmurs in young adults to severe aortic stenosis carrying two-year mortality without intervention. The GP role is murmur evaluation, risk stratification, echocardiographic referral, ongoing surveillance, and timely cardiology referral before the window for intervention closes.

Two conditions dominate the general practice caseload in Australia. Aortic stenosis (AS) — calcific and degenerative in older adults, bicuspid in younger — is the commonest VHD requiring intervention, with prevalence rising steeply after age 65. Mitral regurgitation (MR) — primary degenerative or secondary from left ventricular remodelling — is the second most common. Rheumatic heart disease, historically driven by untreated Group A streptococcal throat infection, now occurs predominantly in Aboriginal and Torres Strait Islander communities and recent migrants from endemic regions.

The Therapeutic Guidelines (eTG), ESC/EACTS 2021 VHD guideline, ACC/AHA 2020, and CSANZ all converge on the same core principle: echocardiography for any audible adult murmur, and surgical or transcatheter intervention before irreversible ventricular dysfunction develops.

A. Core clinical — the AU general practice framework

Murmur evaluation framework

The auscultatory assessment of a murmur aims to characterise:

• Timing — systolic (ejection versus holosystolic), diastolic (early decrescendo versus mid-late rumble), or continuous.
• Location and radiation — aortic area (right upper sternal edge) radiating to carotids (AS); mitral area (apex) radiating to axilla (MR); left sternal edge in aortic regurgitation (AR); lower sternal edge increasing with inspiration (tricuspid regurgitation).
• Quality — harsh ejection (AS), blowing holosystolic (MR, VSD), decrescendo diastolic (AR), low rumbling diastolic (mitral stenosis).
• Intensity — Levine grade 1–6; thrill palpable at ≥4/6.
• Dynamic manoeuvres — Valsalva decreases most murmurs but increases hypertrophic cardiomyopathy and mitral valve prolapse; inspiration increases right-sided murmurs; handgrip increases MR and AR, decreases AS.

Innocent / functional murmurs — soft (≤2/6), systolic, ejection quality, no radiation, no symptoms, no thrill, normal rest of cardiovascular exam — are common in children, young adults, and pregnancy. No investigation is required in a clearly innocent murmur in a child or young adult; clinical vigilance and review are appropriate.

Pathological features — diastolic murmur (always pathological), grade ≥3/6, thrill, holosystolic quality, radiation, accompanying S3 or S4, cyanosis, oedema, or symptoms — require echocardiographic evaluation.

Specific valvular conditions

Aortic stenosis (AS): Calcific degenerative AS affects ~3% of adults over 65 and increases with age. Bicuspid aortic valve (1–2% of the population) develops AS earlier, in the 40s–60s, and carries aortopathy risk requiring aortic root surveillance. Symptoms — angina, exertional syncope, dyspnoea — carry 2–3 year median survival without intervention. Examination reveals an ejection systolic murmur at the right upper sternal edge radiating to the carotids, a slow-rising “parvus et tardus” pulse, narrow pulse pressure, and soft or absent aortic component of the second heart sound. Echocardiography grades severity by peak jet velocity, mean gradient, and aortic valve area (AVA): severe AS is defined as peak velocity ≥4 m/s, mean gradient ≥40 mmHg, or AVA ≤1.0 cm².

Mitral regurgitation (MR): Primary (degenerative) MR includes mitral valve prolapse/Barlow’s, myxomatous degeneration, rheumatic, and endocarditis. Secondary (functional) MR results from left ventricular dilation or ischaemia remodelling the subvalvular apparatus. Symptoms — exertional dyspnoea, orthopnoea, palpitations (AF is common) — appear once ventricular compensation fails. Examination reveals a holosystolic apical murmur radiating to the axilla, displaced hyperdynamic apex beat, and S3 in significant volume overload.

Aortic regurgitation (AR): Causes include bicuspid aortic valve, rheumatic, endocarditis, Marfan syndrome, and aortic root disease. The characteristic signs are a diastolic decrescendo murmur at the left sternal edge (sit forward, held expiration), wide pulse pressure, Corrigan’s water-hammer pulse, and displaced apex.

Mitral stenosis (MS): Almost always rheumatic in origin. Diastolic rumble at the apex (best heard in left lateral position with the bell), opening snap after S2, loud S1. AF and pulmonary symptoms are common. Prevalence is declining in Australia outside Aboriginal and Torres Strait Islander communities and migrant populations.

Rheumatic heart disease (RHD) in Aboriginal and Torres Strait Islander peoples: RHD Australia coordinates a national control programme. Secondary penicillin prophylaxis (monthly benzathine penicillin injections) prevents further Group A streptococcal infection and halts RHD progression. Echocardiographic screening in endemic communities detects subclinical disease. Endocarditis prophylaxis is recommended for ATSI people with RHD per eTG.

Investigations

• TTE (transthoracic echocardiogram) — first-line; item 55113; gold standard for severity grading.
• TOE (transoesophageal) — refined assessment; endocarditis evaluation; prosthetic valve; pre-surgical planning; item 55118.
• ECG — LVH (AS, AR), LAH (MR), AF, P pulmonale (MS).
• CXR — cardiomegaly, pulmonary congestion, valve calcification, aortic root dilation.
• Stress echocardiogram — risk-stratifies asymptomatic severe AS or MR; Medicare-rebatable.
• Cardiac MRI — quantifies regurgitant volume and LV/RV function with precision.
• Gated cardiac CT — pre-TAVR aortic root anatomy; coronary assessment.
• BNP / NT-proBNP — marker of haemodynamic burden; raised in significant VHD.
• Bloods — FBE (anaemia), electrolytes, creatinine, TSH, lipids, HbA1c.

B. Evidence appraisal — TAVR, mitral repair, and the evidence that shifted practice

TAVR across surgical risk strata

Transcatheter aortic valve replacement (TAVR, or TAVI) expanded from high-risk to all-risk patients after two landmark trials. The PARTNER 3 trial (Mack et al., NEJM 2019) randomised 1,000 low-surgical-risk patients with severe AS: TAVR was non-inferior and by the 2-year composite outcome (death, stroke, rehospitalisation) was superior to surgical aortic valve replacement (SAVR) — 8.5% versus 15.1%. The Evolut Low Risk trial (Popma et al., NEJM 2019) confirmed non-inferiority of a self-expanding valve. TAVR is now the preferred approach in elderly patients with suitable anatomy; younger patients with longer expected valve durability horizons and anatomical complexity are still assessed by the heart team with SAVR remaining appropriate.

Mitral valve repair over replacement

For primary (degenerative) severe MR, mitral valve repair is preferred over replacement. Repair confers better long-term survival, preserves ventricular function, avoids anticoagulation requirements in sinus rhythm, and has greater durability in experienced hands. Surgeon expertise is a critical variable — centres with high repair rates achieve better outcomes.

Transcatheter edge-to-edge repair (TEER) for MR

The COAPT trial (Stone et al., NEJM 2018) enrolled 614 patients with secondary MR on optimal heart failure therapy: MitraClip (TEER) reduced heart failure hospitalisation by 47% and all-cause mortality at 2 years by 38% in selected patients. The contrast finding — the MITRA-FR trial showed no benefit — reflects patient selection: COAPT enrolled patients with proportionate MR on maximised medical therapy; MITRA-FR enrolled patients with more advanced LV dysfunction and disproportionate MR. Patient selection for TEER is anatomy- and heart-failure-stage-dependent.

DOACs contraindicated in mechanical valves

The RE-ALIGN trial (Eikelboom et al., NEJM 2013) was stopped early due to significantly higher rates of valve thrombosis, stroke, and bleeding with dabigatran versus warfarin in mechanical valve patients. DOACs are contraindicated in mechanical valves; warfarin with INR monitoring remains mandatory.

C. Management — surveillance, medical therapy, and intervention thresholds

Surveillance cadence

Asymptomatic VHD requires structured follow-up:

• Mild VHD — clinical review and echocardiogram every 3–5 years.
• Moderate VHD — echocardiogram every 1–2 years.
• Severe asymptomatic VHD — echocardiogram every 6–12 months; consider stress echocardiogram for risk stratification.

Medical therapy

There is no pharmacological therapy proven to slow AS progression or delay intervention. Managing hypertension cautiously (avoiding excessive afterload reduction in severe AS) and optimising comorbidities are the medical priorities. For MR, guideline-directed heart failure therapy (beta-blocker, ACE inhibitor/ARNI, MRA, SGLT2 inhibitor) reduces LV remodelling and symptom burden while awaiting intervention. For AR, vasodilators (ACE inhibitors, dihydropyridine CCBs) may provide haemodynamic benefit in severe chronic AR pending surgery.

Intervention thresholds (ESC/EACTS 2021; ACC/AHA 2020)

Aortic stenosis:

• Severe symptomatic AS → intervention (Class I).
• Severe asymptomatic AS with LVEF below 50%, abnormal exercise test, or rapidly progressive disease → consider intervention (Class IIa).
• Options: TAVR (preferred in elderly and increasing proportion of younger patients), SAVR (mechanical or bioprosthetic); heart team decision.

Mitral regurgitation (primary):

• Severe symptomatic primary MR → surgical intervention (Class I).
• Severe asymptomatic primary MR with LVEF ≤60%, LVESD ≥40 mm, new AF, or pulmonary hypertension → Class IIa.
• Options: surgical repair preferred over replacement; TEER (MitraClip) for high surgical risk with suitable anatomy.

Mitral regurgitation (secondary):

• Optimise guideline-directed heart failure therapy first.
• TEER for severe symptomatic secondary MR on optimal therapy with suitable anatomy (COAPT criteria).

Endocarditis prophylaxis

Current eTG indications — narrowed significantly since 2007:

High-risk cardiac conditions warranting prophylaxis:

• Prosthetic valves (mechanical, bioprosthetic, TAVR).
• Prior infective endocarditis.
• Specific congenital heart disease (unrepaired cyanotic CHD; repaired with prosthetic material in first 6 months; residual defect adjacent to prosthetic).
• Cardiac transplant recipients with valvulopathy.
• Valve repair with prosthetic material (first 6 months).
• ATSI peoples with rheumatic heart disease.

NOT indicated for: mitral valve prolapse, mitral regurgitation, bicuspid aortic valve, aortic regurgitation, or healed congenital lesions without prosthesis.

Regimen (single dose 30–60 minutes pre-procedure): amoxicillin 2 g PO (50 mg/kg paediatric); clindamycin 600 mg PO if penicillin-allergic; cephalexin 2 g PO for non-anaphylactic penicillin allergy.

Triggering procedures: dental procedures involving gingival tissue manipulation, periapical region, or oral mucosa perforation (extractions, scaling with bleeding, implants). Not required for routine dental cleaning without bleeding or most GI/GU procedures without active infection.

D. Australian operations

MBS items

MBS Online items for GP management: 23, 36, 44 (standard consultations); Heart Health Check (item 699) for cardiovascular risk assessment (≥30 years, ≥18 years for ATSI); GPCCMP (items 965/967) for chronic VHD management; 75+ Health Assessment (item 707); ATSI Health Assessment (item 715) with particular relevance for RHD.

Echocardiography: TTE (item 55113), TOE (item 55118), stress echo (item range); cardiac MRI and CT (items available through specialist referral).

PBS medications

• Warfarin — PBS general; INR monitoring required for mechanical valves.
• DOACs (apixaban, rivaroxaban, dabigatran) — PBS Authority for non-valvular AF; contraindicated in mechanical valves.
• Antibiotic prophylaxis (amoxicillin, clindamycin, cephalexin) — PBS general for single-dose indication.
• Heart failure medications — beta-blockers, ACE inhibitors/ARNI, MRA, SGLT2 inhibitors — PBS-listed; see GPCCMP for access.

Specialist services

• General cardiology — initial referral for murmur evaluation and echo interpretation.
• Heart Team (cardiology + cardiac surgery + interventional cardiology + anaesthetics) — for intervention decisions; major tertiary centres.
• Cardiothoracic surgery — SAVR, mitral repair/replacement.
• Interventional cardiology — TAVR, TEER, balloon valvuloplasty.
• Telehealth cardiology — accessible regional and rural.

Driving — Austroads 2022

Symptomatic VHD, post-cardiac surgery, and post-TAVR/TEER carry specific Austroads 2022 driving restrictions. Cardiac event or procedure dates, functional status, and LVEF all factor into the period of driving restriction. Document advice given.

E. Special populations

Older adults (≥75 years). Calcific AS is predominantly a disease of ageing; surgical risk is highest in this group, making TAVR the preferred modality in most. Polypharmacy review is important — medications that lower afterload (excessive antihypertensive, nitrates) can precipitate haemodynamic compromise in severe AS. Frailty assessment and geriatric input improve outcomes in the heart team decision.

Bicuspid aortic valve. Affects 1–2% of the population; develops AS 10–20 years earlier than tricuspid aortic valve. Associated with aortopathy (aortic root and ascending aortic dilation) requiring separate surveillance with echocardiography or CT. First-degree relatives have 9% prevalence of bicuspid valve — screen with echocardiography. Surgical threshold for aortic root dilation is typically ≥5.0 cm (or lower with rapid expansion or family history of dissection).

Rheumatic heart disease and Aboriginal and Torres Strait Islander populations. RHD disproportionately affects ATSI communities. The RHD Australia national control programme coordinates echocardiographic screening, secondary prophylaxis registers, and community-based care. GPs working with ATSI populations play a critical role in secondary prophylaxis delivery and endocarditis prophylaxis counselling. Mitral stenosis from rheumatic origin may be amenable to percutaneous balloon mitral valvuloplasty (Wilkins score ≤8).

Pregnancy and VHD. Pre-conception cardiology review is essential for any patient with significant VHD using the modified WHO (mWHO) pregnancy risk classification. Severe AS, severe MS, and mechanical valves carry high maternal risk. Anticoagulation in pregnancy with a mechanical valve is particularly complex: warfarin is teratogenic in the first trimester but most effective for valve protection; LMWH is used in the first trimester with transition back to warfarin in the second. Specialist obstetric–cardiology co-management is required.

Infective endocarditis. Fever plus a new or changed murmur in a patient with risk factors (prosthetic valve, previous IE, IVDU, indwelling catheter, recent dental/surgical procedure) requires blood cultures × 3 sets before antibiotics, urgent TTE, and inpatient admission. Modified Duke criteria guide diagnosis; cardiothoracic surgical involvement is required for complex cases.

When to escalate

• Any diastolic murmur — echocardiography urgently; always pathological.
• Symptomatic severe AS (angina, syncope, dyspnoea) — urgent cardiology referral; poor prognosis without intervention.
• Acute severe MR or AR (flash pulmonary oedema, haemodynamic compromise) — emergency; 000.
• Fever plus new murmur (suspected endocarditis) — blood cultures, urgent TTE, hospital admission.
• Severe asymptomatic AS with LVEF falling below 50% — cardiology for intervention timing.
• Moderate or severe asymptomatic MR/AR — cardiology for surveillance echocardiogram schedule.
• Bicuspid aortic valve — aortic root surveillance; first-degree relative screening.
• Pre-conception with significant VHD — cardiology before pregnancy.

What this article is and is not

This is general health information drawn from current Australian and international guidelines — Therapeutic Guidelines, ESC/EACTS 2021, ACC/AHA 2020, CSANZ, Heart Foundation Australia, and RHD Australia — alongside key clinical trials including PARTNER 3, Evolut Low Risk, COAPT, and RE-ALIGN. It is not personal medical advice and does not create a doctor–patient relationship. Decisions about echocardiographic monitoring intervals, timing of valve intervention, anticoagulation management, and endocarditis prophylaxis are made by your own GP and treating cardiologist based on your complete clinical picture.

For Australian consumer resources: HealthDirect — Heart valve disease, Heart Foundation Australia, Better Health Channel — Heart valve problems.

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Sources cited

1. Therapeutic Guidelines (eTG) — Cardiovascular / Valvular heart disease
2. ESC/EACTS 2021 Guidelines for valvular heart disease
3. ACC/AHA 2020 Guideline for VHD
4. CSANZ — Cardiac Society of Australia and New Zealand
5. Heart Foundation Australia
6. Australian Medicines Handbook (AMH)
7. RACGP
8. RHD Australia
9. PBS
10. MBS Online
11. Mack MJ et al. — PARTNER 3 trial (NEJM 2019)
12. Popma JJ et al. — Evolut Low Risk trial (NEJM 2019)
13. Stone GW et al. — COAPT trial (NEJM 2018)
14. Eikelboom JW et al. — RE-ALIGN trial (NEJM 2013)
15. HealthDirect — Heart valve disease
16. Better Health Channel — Heart valve problems