Valvular heart disease

Quick Overview

Valvular heart disease encompasses stenotic and regurgitant lesions requiring precise severity grading and intervention thresholds. Key decisions hinge on symptom status and echocardiographic parameters. NICE NG208 emphasizes surveillance intervals for moderate disease and clarifies endocarditis prophylaxis indications (now restricted to high-risk groups undergoing specific procedures).

Core Facts & Concepts

Aortic Stenosis (AS) Severity Grading:


Aortic Regurgitation (AR) Severity:

• Severe: Vena contracta ≥6 mm, regurgitant volume ≥60 mL/beat, regurgitant fraction ≥50%
• Key measurement: LV end-systolic dimension (intervene if >50 mm or LVEF <50%)

Mitral Regurgitation (MR) Severity:

• Severe primary MR: Effective regurgitant orifice area (EROA) ≥40 mm², regurgitant volume ≥60 mL/beat
• Severe secondary MR: EROA ≥20 mm² (lower threshold)

Surveillance Intervals (Asymptomatic Moderate Disease):

• Moderate AS/AR/MR: Echo every 12 months
• Severe AS: Echo every 6 months
• Severe AR with normal LV: Echo every 6-12 months

Endocarditis Prophylaxis (NICE NG208):

• Indicated ONLY for: Prosthetic valves, previous endocarditis, structural congenital heart disease (including surgically corrected/palliated but excluding isolated ASD/fully repaired VSD/PDA)
• Procedures requiring prophylaxis: Upper GI/GU procedures in high-risk patients (case-by-case basis)
• NOT routinely recommended for dental procedures (major guideline shift)

Problem-Solving Approach

Intervention Thresholds for AS:

1. Symptomatic severe AS → Valve replacement (AVR/TAVR) regardless of LVEF
2. Asymptomatic severe AS → Intervene if:
   • LVEF <50%
   • Abnormal exercise test (symptoms/hypotension)
   • Undergoing other cardiac surgery
   • Very severe AS (peak velocity >5.0 m/s, mean gradient >60 mmHg)

Intervention Thresholds for AR:

🚩 Red flags for surgery:

• Symptoms (NYHA II-IV) + severe AR
• Asymptomatic: LVEF <50% OR LV end-systolic diameter >50 mm OR LV end-diastolic diameter >70 mm

Intervention Thresholds for MR:

• Primary MR: Symptoms + severe MR, OR asymptomatic with LVEF 30-60% or LV end-systolic diameter ≥40 mm
• Secondary MR: Optimize medical therapy first; surgery if revascularization planned or persistent symptoms despite optimal therapy

⚠️ Warning: "Asymptomatic" patients may self-limit activity-exercise testing unmasks true functional capacity

Analysis Framework

Differentiating Primary vs Secondary MR:

Deciding AVR vs TAVR:

• TAVR preferred: Age >75, surgical risk score high, frailty, porcelain aorta
• AVR preferred: Age <65, bicuspid valve, need for concomitant surgery, patient preference for durability

Visual Aid

Key Points Summary

✓ Severe AS: Valve area <1.0 cm², mean gradient >40 mmHg, peak velocity >4.0 m/s-intervene if symptomatic or LVEF <50%

✓ Severe AR/MR: Intervene when symptomatic OR LV dysfunction (LVEF <50%) OR LV dilatation (LVESD ≥40-50 mm)

✓ Surveillance: Moderate disease = 12-month echo; severe asymptomatic AS = 6-month echo

✓ Endocarditis prophylaxis: Only for prosthetic valves, previous IE, or structural congenital heart disease-NOT routine for dental procedures (NICE NG208)

✓ Exercise testing: Essential in "asymptomatic" patients to unmask symptoms and guide intervention

✓ Secondary MR threshold: EROA ≥20 mm² (lower than primary MR's 40 mm²)-optimize HF therapy before considering surgery

✓ Common pitfall: Delaying intervention in asymptomatic patients with objective LV dysfunction-irreversible damage may occur