Infective Endocarditis — Diagnostic Pathway

Step-by-step decision

Choose step by step as prompted; reaching an endpoint gives the management recommendation. You can go back a step or restart anytime.

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Full pathway

1. [Decision] Modified Duke determination
   Modified Duke (2023 ISCVID) diagnostic category? (Major criteria: 1) microbiology — typical organisms in ≥2 positive blood culture sets (Staph aureus, viridans strep, Strep bovis, HACEK, community-acquired enterococci, etc.) or persistently positive / Coxiella; 2) imaging — echo (TTE → TEE more sensitive) or cardiac CT showing vegetation/abscess/perivalvular pseudoaneurysm/fistula/valve perforation/prosthetic dehiscence, or new valvular regurgitation, or abnormal PET/CT uptake; 3) (new) direct intraoperative evidence. Minor criteria: predisposing factor (heart disease/IV drug use/prosthetic valve/CIED/prior IE), fever ≥38°C, vascular signs, immunologic signs, microbiologic evidence not meeting major.)
   • Definite (2 major / 1 major+3 minor / 5 minor) → Definite IE
   • Possible (1 major+1 minor / 3 minor) → Possible IE
   • Rejected → Rejected
2. [End] Rejected
   Look for another cause of bacteremia/fever; if clinical suspicion persists, complete blood cultures and TEE then re-evaluate.
3. [End] Possible IE
   1 major+1 minor, or 3 minor: obtain ≥3 blood culture sets before antibiotics, perform echo (TTE → TEE), add cardiac CT/PET-CT if needed; multidisciplinary (infectious disease/cardiology/cardiac surgery) assessment, close follow-up and re-grading.
4. [End] Definite IE
   2 major, or 1 major+3 minor, or 5 minor: ≥3 blood culture sets before antibiotics → targeted (empiric) antibiotics for a full course; echo to assess vegetations/complications; multidisciplinary (infectious disease/cardiology/cardiac surgery) management. Surgical indications: heart failure, uncontrolled infection (abscess/persistent bacteremia), embolism prevention (large vegetations).

Source guidelines & references

• 2023 Duke-ISCVID criteria for infective endocarditis. Clin Infect Dis 2023

This pathway is our own synthesis of the decision logic in the guidelines above (not the guideline verbatim); thresholds and workflows change as guidelines update — in practice follow the latest guideline, your institution's protocol and the individual patient.

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