II. Epidemiology
- Heart Valve Replacement Incidence
- Worldwide: 290,000 per year
- U.S.: Up to 95,000 per year
III. Types
- Mechanical Heart Valves (Artificial Heart Valves)
- Composed of metal or carbon alloys
- Subtypes include caged ball, single tilting disk or bileaflet tilting disk
- Bioprosthetic Heart Valves (biologic Heart Valves)
- Heterografts
- Porcine or bovine tissue mounted on metal support
- Homografts
- Preserved human valve tissue
- Heterografts
IV. Management: Valve type selection
- Historically, Valve Replacement type is chosen based on age
- Mechanical Heart Valves (Artificial Heart Valves) for younger patients (age <60 years)
- More short-term complications in first 1-2 decades (bleeding and Thromboembolism risk)
- Requires Anticoagulation
- Bioprosthetic Heart Valves (biologic Heart Valves) for older patients (age >70 years)
- Structural integrity decreases overtime and requires earlier repeat replacement
- Mechanical Heart Valves (Artificial Heart Valves) for younger patients (age <60 years)
- Some experts argue that bioprosthetic valves should be considered for all patients
- Require Anticoagulation and greater complications in the first 2 decades
- Equivalent morbidity and mortality for the first 15 years after Valve Replacement with either technique
- Repeat Valve Replacements for bioprosthetic valves are safe (and required less frequently then prior studies)
- 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. Complications
-
General
- Overall complication rate: 6%
- Echocardiogram (TTE or TEE) is the first-line tool for Prosthetic Heart Valve complication evaluation
- Acoustic shadowing with Mechanical Heart Valves may limit diagnostic efficacy
- Mechanical valves
- Thromboembolism (often non-obstructive thrombi)
- Always consider as source in thromboembolic disease
- Valvular obstruction (due to valve thrombus from under-anticoagulated)
- Fibrinolytics: Small valve thrombus with mild symptoms (NYHA Class 1-2)
- Emergent Surgery: Large thrombus is critically ill patients
- Hemorrhage (typically associated with Anticoagulation)
- Valve regurgitation (due to paravalvular leak)
- Hemolytic Anemia (less common with modern mechanical valves)
- Thromboembolism (often non-obstructive thrombi)
- Bioprosthetic valves
- Structural dysfunction (e.g. valve degeneration, calcification or Fracture)
- Results ultimately in repeat Valve Replacement
- Valve regurgitation (due to paravalvular leak or structural degeneration)
- Structural dysfunction (e.g. valve degeneration, calcification or Fracture)
VI. References
- Schauer et al. (2016) Crit Dec Emerg Med 30(9):13-9