Prosthetic Heart Valve

Aka: Prosthetic Heart Valve, Prosthetic Cardiac Valve, Mechanical Heart Valve, Artificial Cardiac Valve Prosthesis, Bioprosthetic Heart Valve, Biologic Cardiac Valve Prosthesis, Heart Valve Replacement, Valve Replacement, Prosthetic Cardiac Valve Disorder, Prosthetic Cardiac Paravalvular Leak, Prosthetic Valve Thrombosis, Prosthetic Cardiac Valve Obstruction, Transcatheter Aortic Valve Implantation, TAVI, Transcatheter Aortic Valve Replacement, TAVR

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II. Epidemiology

  1. Heart Valve Replacement Incidence
    1. Worldwide: 290,000 per year
    2. U.S.: Up to 95,000 per year

III. Types

  1. Mechanical Heart Valves (Artificial Heart Valves)
    1. Composed of metal or carbon alloys
    2. Subtypes include caged ball, single tilting disk or bileaflet tilting disk
  2. Transcatheter Aortic Valve Implantation (TAVI)
    1. Previously known as Transcatheter Aortic Valve Replacement (TAVR)
    2. Mechanical Heart Valve deployed within native valve via catheter (similar to a cardiac stent placement)
  3. Bioprosthetic Heart Valves (biologic Heart Valves)
    1. Heterografts
      1. Porcine or bovine tissue mounted on metal support
    2. Homografts
      1. Preserved human valve tissue

IV. Management: Valve Type Selection

  1. Historically, Valve Replacement type is chosen based on age
    1. Mechanical Heart Valves (Artificial Heart Valves) for younger patients (age <60 years)
      1. More short-term complications in first 1-2 decades (bleeding and Thromboembolism risk)
      2. Requires Anticoagulation
        1. See Anticoagulation after Heart Valve Replacement
    2. Bioprosthetic Heart Valves (biologic Heart Valves) for older patients (age >70 years)
      1. Structural integrity decreases overtime and requires earlier repeat replacement
  2. Transcatheter Aortic Valve Implantation or Replacement (TAVI, TAVR)
    1. Higher surgical risk patients with severe Aortic Stenosis
    2. Failed prior bioprosthetic valves
  3. Some experts argue that bioprosthetic valves should be considered for all patients
    1. Require Anticoagulation and greater complications in the first 2 decades
    2. Equivalent morbidity and mortality for the first 15 years after Valve Replacement with either technique
    3. Repeat Valve Replacements for bioprosthetic valves are safe (and required less frequently then prior studies)
    4. http://www.acc.org/latest-in-cardiology/articles/2015/03/03/09/28/surgical-aortic-valve-replacement-biologic-valves-are-better-even-in-the-young-patient

V. Management: Anticoagulation

  1. See Anticoagulation after Heart Valve Replacement
  2. Mechanical Heart Valves (Artificial Heart Valves)
    1. Warfarin with target INR 2 to 3 for most patients
    2. Warfarin with target INR 2.5 to 3.5 for mitral Valve Replacement, Atrial Fibrillation and aortic Valve Replacement
    3. Do NOT Use DOACs (e.g. Apixaban) or Pradaxa for mechanical valve Anticoagulation
      1. Higher risk of thrombosis when compared with Warfarin
      2. Eikelboom (2013) N Engl J Med 369(13):1206-14 +PMID: 23991661 [PubMed]
  3. Transcatheter Aortic Valve Implantation or Replacement (TAVI, TAVR)
    1. Single Antiplatelet Therapy with Aspirin 75 to 100 mg orally daily
    2. Single agent replaces Dual Antiplatelet Therapy since 2020
    3. Granger (2022) J Clin Med11(8):2190 +PMID: 35456283 [PubMed]
  4. Bioprosthetic Heart Valves (biologic Heart Valves from human, pig or cow)
    1. Aspirin 75 to 100 mg orally daily for most patients
    2. If Anticoagulation is indicated for other reason (e.g. Atrial Fibrillation), DOACs, Warfarin or Pradaxa may be used

VI. Complications

  1. General
    1. Overall complication rate: 6%
    2. Echocardiogram (TTE or TEE) is the first-line tool for Prosthetic Heart Valve complication evaluation
      1. Acoustic shadowing with Mechanical Heart Valves may limit diagnostic efficacy
  2. Mechanical valves
    1. Thromboembolism (often non-obstructive thrombi)
      1. Always consider as source in thromboembolic disease
    2. Valvular obstruction (due to valve thrombus from under-anticoagulated)
      1. Fibrinolytics: Small valve thrombus with mild symptoms (NYHA Class 1-2)
      2. Emergent Surgery: Large thrombus is critically ill patients
    3. Hemorrhage (typically associated with Anticoagulation)
    4. Valve regurgitation (due to paravalvular leak)
    5. Hemolytic Anemia (less common with modern mechanical valves)
  3. Bioprosthetic valves
    1. Structural dysfunction (e.g. valve degeneration, calcification or Fracture)
      1. Results ultimately in repeat Valve Replacement
    2. Valve regurgitation (due to paravalvular leak or structural degeneration)

VII. References

  1. (2023) Presc Lett 30(8): 44
  2. Schauer et al. (2016) Crit Dec Emerg Med 30(9):13-9
  3. Otto (2021) Circulation 143(5):e35-e71 +PMID: 33332149 [PubMed]
  4. Vahanian (2022) Eur Heart J 43(7):561-632 +PMID: 34453165 [PubMed]

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