133 Ch 133. Infective Endocarditis

感染性心內膜炎 (Infective Endocarditis, IE) 是心內膜 (含 native valve、prosthetic valve、mural endocardium、indwelling cardiac device) 被病原入侵後形成 vegetation (贅生物) 的疾病；未治療死亡率 ~ 30%，治療後仍 15-25%，是內科最不能漏診的感染之一。診斷依 Modified Duke Criteria：Definite IE = 2 major OR 1 major + 3 minor OR 5 minor，Possible IE = 1 major + 1 minor OR 3 minor。Major (2 個 — 血培養 + 心超)：(1) Positive blood culture with typical organism (S. viridans、S. gallolyticus、HACEK、S. aureus、community Enterococcus without primary focus) × 2 套 separate cultures，或 persistent positive (≥ 2 cultures > 12 hr apart, 或 3/3, 或 4/4)，或 single positive Coxiella burnetii (Q fever) 或 anti-phase I IgG > 1:800；(2) Echocardiographic evidence：vegetation、abscess、valvular perforation、new prosthetic dehiscence，或 new valvular regurgitation (worsening murmur)。Minor (5 個 — 助記 PFEVE / FEVI-M)：(1) Predisposition (pre-existing cardiac、IVDU)、(2) Fever ≥ 38.0°C、(3) Vascular phenomena (arterial emboli、septic pulmonary infarct、mycotic aneurysm、ICH、conjunctival hemorrhage、Janeway lesions 無痛掌心/腳底紅斑)、(4) Immunologic phenomena (glomerulonephritis、Osler nodes 痛性指端結節、Roth spots 視網膜白心出血、RF +)、(5) Microbiology not meeting major (single + or atypical organism、serology consistent)。經典記憶 — 三大皮膚表徵：Janeway lesions = 無痛 (vascular embolic)、Osler nodes = 有痛 (immunologic)、Roth spots = 視網膜白心出血 (immunologic)，加上 splinter hemorrhages 指甲下線狀出血。病原分情境：Native valve community subacute = S. viridans (口腔來源、牙科操作)；Native valve acute fulminant = S. aureus (近年即使 native 也常見)；IVDU = S. aureus 主導，多 right-sided tricuspid，可能 MRSA、Pseudomonas、Candida；Prosthetic valve early (< 60 d) = CoNS (S. epidermidis)、S. aureus、Enterobacteriaceae、Pseudomonas、fungi (來自手術污染)；Prosthetic valve late (> 60 d) = 同 native (S. viridans、Enterococcus、CoNS)；HACEK 群 (Haemophilus、Aggregatibacter、Cardiobacterium、Eikenella、Kingella) 是 slow-growing GN，口腔常在菌；Culture-negative IE (~10%) = Coxiella (Q fever、牧區/屠宰場)、Bartonella (B. henselae 貓接觸、B. quintana 街友)、Brucella (未殺菌乳)、Tropheryma whipplei (Whipple disease)、fungi、prior antibiotic exposure (最常見原因)。Empirical 抗生素：Native subacute → Vancomycin + Ceftriaxone (cover MRSA + S. viridans + HACEK + Enterococcus)；Native acute → Vancomycin + Cefepime 或 Pip-tazo (wider gram-negative)；IVDU → Vancomycin + Pip-tazo (cover MRSA + Pseudomonas)；Prosthetic early → Vancomycin + Gentamicin + Cefepime (cover CoNS + S. aureus + Enterobacteriaceae)；Prosthetic late → Vancomycin + Gentamicin + Ceftriaxone。Culture-targeted 治療：S. viridans (PSSV, MIC ≤ 0.12) → Penicillin G 或 Ceftriaxone × 4 wk (+ Gentamicin × 2 wk synergy)；MSSA → Cefazolin 或 Nafcillin × 6 wk；MRSA → Vancomycin × 6 wk (或 daptomycin alternative)；Enterococcus → Ampicillin + Ceftriaxone × 6 wk (or Amp + Gent if synergy)；HACEK → Ceftriaxone × 4 wk；Prosthetic + Staph → Vanco + Gent × 2 wk + Rifampin × 6 wk (biofilm penetration)。Duration 整理：native S. viridans 4 週、native S. aureus 6 週、prosthetic 6 週 + Gent 2 週 + (Staph) Rif 6 週。手術 indications (Class I-IIa, 2023 ESC + 2024 AHA)：(1) Heart failure 因 severe valvular dysfunction (acute regurgitation 是最常見手術原因)、(2) Uncontrolled infection (持續發燒 > 7-10 天、abscess、perforation、fistula、large mobile vegetation)、(3) Prevent embolism (vegetation > 10 mm + 已有 embolic event, 或 > 15 mm 即使無 embolic event)、(4) Prosthetic valve dehiscence、(5) Fungal endocarditis (definite surgery, 抗生素穿透 vegetation 困難)。Timing：多在發作 1-2 週內，不必等抗生素完成。併發症：HF (acute regurgitation)、stroke (mycotic aneurysm + septic embolism)、splenic/kidney infarct、pulmonary embolism (右側 IE)、aortic root abscess → high-grade conduction block (emergent surgery sign!)、mycotic aneurysm 破裂、immune complex glomerulonephritis、septic shock。Endocarditis prophylaxis (2007 AHA + 2023 update)：只給 high-risk 族群 (prosthetic valve/repaired、previous IE、特定 congenital heart disease、heart transplant with valvulopathy)；procedures requiring = dental gingival manipulation 或 oral mucosa perforation、respiratory incision/biopsy；NOT routine for GI / GU procedures (除非感染組織)；首選 Amoxicillin 2 g PO 30-60 min before procedure (不能 PO 用 ampicillin/cefazolin/ceftriaxone IV)；penicillin 過敏改 cephalexin 2 g、azithromycin 500 mg、doxycycline 100 mg。S. gallolyticus (S. bovis) 必考點：與大腸癌高度關聯，診斷 IE 後必做 colonoscopy screening。22e 重點：POET trial 2019 NEJM 證明穩定 IE 病人 IV 7-10 天後改 PO 抗生素 non-inferior，改變治療 paradigm；OPAT (Outpatient Parenteral Antibiotic Therapy) 讓穩定病人可在門診完成 IV course；PET-CT FDG 用於 prosthetic valve IE 增加 Duke major criteria sensitivity；Daptomycin high-dose 8-10 mg/kg 用於 MRSA IE，Ceftaroline 為 refractory MRSA alternative；Cefiderocol 用於 MDR Pseudomonas IE。台灣 context：CAIE 仍以 S. viridans + S. aureus 為主；HCAIE 增加 (catheter-related、hemodialysis、cardiac devices)；Q fever 牧區/屠宰場接觸；Brucella 未殺菌乳製品；TB endocarditis 罕見但 TB endemic 區仍要想到 (多 prosthetic + 免疫低下)。