What is the sensitivity and specificity of transesophageal echocardiography (TEE) for diagnosing endocarditis in native, prosthetic, and mechanical valves?

Sensitivity and Specificity of Transesophageal Echocardiography for Diagnosing Endocarditis

Transesophageal echocardiography (TEE) has superior sensitivity (>90%) and high specificity (91-100%) for diagnosing endocarditis across native, prosthetic, and mechanical valves, making it the gold standard imaging modality for definitive diagnosis, particularly in high-risk cases. 1

Diagnostic Accuracy by Valve Type

Native Valves

• TEE demonstrates approximately 99% sensitivity for native valve endocarditis, significantly outperforming transthoracic echocardiography (TTE) 1
• Specificity ranges from 91-100% for detecting vegetations on native valves 1
• For native valve endocarditis, TEE has sensitivity and specificity of >90% for detecting intracardiac lesions 1

Prosthetic Valves

• TEE has approximately 90% sensitivity for detecting prosthetic valve vegetations, compared to only about 50% sensitivity with TTE 1
• Specificity remains high at 91-100% for prosthetic valve endocarditis 1
• TEE is significantly more accurate than TTE for prosthetic valve endocarditis and is mandatory when clinical suspicion exists 1, 2
• In prosthetic valve endocarditis, combining TTE and CT showed a trend toward higher sensitivity than TEE alone (100% vs 86%) for periannular complications, with similar specificity (94% and 98%) 1

Mechanical Valves

• TEE has similar high sensitivity (approximately 90%) for mechanical valve endocarditis 1
• TEE allows better visualization of mechanical valve leaflet excursions and can detect valve dehiscence 1
• Specificity remains in the 91-100% range for mechanical valves 1

Comparative Performance with TTE

• TEE has significantly higher sensitivity than TTE for identifying vegetations, while specificities are similar (91-100% for TEE vs 91-98% for TTE) 1
• For detecting paravalvular abscesses, TEE demonstrates superior sensitivity and accuracy compared to TTE 1
• In left-sided endocarditis, TEE is significantly more sensitive than TTE 1
• In right-sided endocarditis, TTE and TEE perform comparably, demonstrating similar detection of tricuspid vegetations and regurgitation 1

Clinical Decision Algorithm

1. Initial Assessment:

   • For low-risk patients with native valves: Begin with TTE (sensitivity ~61%, specificity ~94%) 3
   • For intermediate/high-risk patients: Proceed directly to TEE 1
   • For any prosthetic/mechanical valve suspicion: TEE is mandatory (sensitivity ~90%, specificity >90%) 1

2. When TTE is negative:

   • In low-risk native valve cases with conclusively negative TTE: May consider observation (negative likelihood ratio 0.14) 3
   • In intermediate/high-risk cases: Proceed to TEE regardless of TTE findings 1, 4
   • With prosthetic/mechanical valves: Always proceed to TEE (TTE sensitivity only ~50%) 1

3. Special Considerations:

   • For cardiac implantable electronic devices (CIEDs): TEE sensitivity ~90% (vs 25-40% for TTE) 1
   • For left ventricular assist devices (LVADs): TEE is recommended for evaluation of all components 1

Important Caveats and Pitfalls

• TEE has up to 98.6% negative predictive value in suspected infective endocarditis, but false negatives can still occur 1
• Acoustic shadowing from prosthetic materials can limit visualization, requiring complementary imaging approaches 1
• Anterior prosthetic ring abscesses or distal right ventricular lead infections may be missed by TEE alone 1
• Normal struts seen on TEE following surgery should not be confused with vegetations 2
• Normal prosthetic regurgitation should not be confused with paravalvar leakage 2
• In cases where TEE is inconclusive for prosthetic valve endocarditis, cardiac CT may provide complementary information 1

By using TEE as the primary diagnostic tool for suspected endocarditis, particularly in prosthetic and mechanical valves, clinicians can achieve the highest diagnostic accuracy and make appropriate management decisions to reduce morbidity and mortality.