285.3 🏥 內科專科考前版

285.3.1 Mechanistic Deep Dive

285.3.1.1 Calcific AS Pathobiology

  • Active lipid + inflammatory infiltration
  • Osteogenic differentiation of valve interstitial cells
  • BMP, OPG pathway dysregulation
  • Lp(a) ↑ associated with calcific AS — pelacarsen trials may help
  • ApoB, apoB-100, oxidized phospholipids
  • Lipid-lowering trials negative (SEAS, ASTRONOMER, SALTIRE)
  • Newer trials with PCSK9i and Lp(a) lowering — ongoing

285.3.1.2 Subclinical LV Damage in AS

  • Myocardial fibrosis (CMR LGE)
  • Diastolic dysfunction precedes systolic
  • BNP elevation precedes symptoms
  • Strain imaging detects early LV dysfunction
  • Predicts post-intervention outcomes

285.3.2 Recent Trials & Updates

285.3.2.1 EARLY-TAVR (2024)

  • N = 901 asymptomatic severe AS (peak ≥ 4 m/s)
  • Early TAVR vs surveillance
  • ↓ unplanned hospitalization, AVR
  • 2024 ACC/AHA Focused Update: Class IIa early intervention
  • 2024 ESC update similarly evolved

285.3.2.2 EVOLVED (2024)

  • Asymptomatic severe AS with myocardial fibrosis (CMR LGE)
  • Early TAVR may benefit
  • Imaging biomarker-guided approach

285.3.2.3 PARTNER 3 + Evolut Low Risk (2019 → 2024)

  • TAVR non-inferior to SAVR in low-risk patients
  • 5-year data confirms durability
  • TAVR now standard for ≥ 65 yo across risk levels

285.3.2.4 Long-Term Durability

  • 10-year SAPIEN and CoreValve data emerging
  • Bioprosthetic valve dysfunction rates similar to SAVR bioprostheses
  • Valve-in-valve TAVR feasible (TVT registry)

285.3.2.5 Bicuspid AV TAVR

  • Initial caution due to elliptical annulus, complex anatomy
  • 2024 data improving — comparable to SAVR in select
  • BAV outcomes generally good with newer devices

285.3.2.6 Anticoagulation Post-TAVR

  • Class I: ASA monotherapy 3 mo (CMA-3 trial)
  • DOAC + ASA: increased mortality (GALILEO trial) — AVOID
  • For AF: DOAC alone (ATLANTIS, ENVISAGE-TAVI AF)
  • POPular TAVI: ASA mono > ASA + clopidogrel

285.3.3 High-Yield Specialist Points

285.3.3.1 Patient Selection for TAVR

  • Heart team review
  • Frailty assessment (Edmonton Frail Scale, Katz ADL)
  • Life expectancy > 1 year
  • CT for annulus, calcium, vascular access
  • Coronary CT for CAD assessment
  • Pulmonary function, cognition

285.3.3.2 TAVR Complications + Management

  • Stroke: 3-5% — cerebral embolic protection (SENTINEL device, PROTECTED TAVR 2022 — mixed)
  • PVL (paravalvular leak): percutaneous closure if severe
  • Permanent pacemaker: 5-15% — Evolut > SAPIEN; LBBB risk factor
  • Coronary obstruction: pre-procedural CT, BASILICA technique (laceration)
  • Annular rupture: rare, surgical emergency
  • Acute kidney injury: hydration, contrast minimization
  • Subclinical leaflet thrombosis (HALT): incidence higher with TAVR; clinical significance debated

285.3.3.3 Valve-in-Valve TAVR

  • For failed surgical bioprosthesis
  • Patient prosthesis mismatch risk
  • BASILICA may be needed for coronary obstruction risk

285.3.3.4 Ross Procedure

  • Pulmonic autograft to aortic position + pulmonic homograft
  • Living valve, growing in children
  • Good in young, complex with surgery requirements
  • Reintervention for both positions over decades

285.3.3.5 Aortopathy + AVR

  • BAV + dilated aorta: combine AVR + root replacement if root > 5.0
  • Marfan: root replacement ≥ 5.0 (sometimes 4.5)
  • Loeys-Dietz: 4.0
  • Valve-sparing root replacement (David, Yacoub) preserves native valve

285.3.3.6 Acute AR Specifics

  • Aortic dissection Type A: emergency
  • Endocarditis: 6-week IV antibiotics + surgery if HF/persistent infection
  • AVR + repair of root in most cases

285.3.3.7 AR + Aortic Root Disease

  • Combined AVR + ascending aorta replacement
  • Bentall, David, Yacoub procedures

285.3.3.8 Aortic Valve Repair (vs Replacement)

  • For type I AR (root dilation): repair with root replacement
  • Selected patients with good cusps
  • Long-term outcomes comparable in expert centers

285.3.3.9 Special Forms

  • Subvalvular AS: HOCM (treat HOCM), subaortic membrane (surgical resection)
  • Supravalvular AS: Williams syndrome, William-Beuren; surgical patching

285.3.3.10 Echocardiographic Pitfalls

  • Aortic regurgitation severity is operator-dependent
  • Multi-modality assessment recommended (echo + CMR + cath if needed)
  • Hemodynamic pressure-flow relationship

285.3.4 Pearls

  • AS severe: peak vel ≥ 4 m/s + mean gradient ≥ 40 + AVA ≀ 1.0
  • AS symptoms = SAD (syncope, angina, dyspnea); urgent AVR
  • TAVR ≥ 65 yo, all risk levels (2024 update)
  • EARLY-TAVR 2024: asymptomatic severe AS may benefit from early TAVR
  • Low-flow, low-gradient AS requires dobutamine stress echo
  • AR surgical timing: symptoms / EF < 55% / LVESD > 50 mm
  • Acute AR is emergency: avoid β-blocker (tachycardia compensatory) and IABP
  • Lp(a) ↑ associated with calcific AS — potential future target
  • Anticoag post-TAVR: ASA alone (POPular TAVI); avoid DOAC + ASA (GALILEO)