A Comprehensive Guide to Choosing an Artificial Heart Valve

When a patient requires heart valve replacement, it entails replacing valvular heart disease with a different condition known as artificial heart valve disease. Selecting the most suitable artificial heart valve is crucial to ensure optimal functionality and minimize potential complications. 

The ideal valve should closely mimic a natural heart valve, exhibit excellent hemodynamics, demonstrate durability, reduce the risk of thrombosis, and facilitate convenient cardiac placement. This article will delve into the types of artificial heart valves, considerations for valve selection, and factors influencing the choice of valve type and size.

Types of Artificial Heart Valves:

Mechanical Valves:

• Made from artificial materials such as titanium and silicon.

• Longevity of 20-30 years or more.

• High thrombogenicity, necessitating permanent anticoagulation therapy with vitamin K antagonists.

• Three types: ball valves, single-blade valves, and double-bladed valves.
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Biological Valves:

• Derived from animal tissues (e.g., cows, pigs, horses) or human organ donors.

• Lifespan of 10-15 years or less.

• Lower risk of thrombosis compared to mechanical valves, typically requiring vitamin K antagonist anticoagulation for only three months.

• Various types: biological valves with holders, bracketless biovalves, and percutaneous biovalves.
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Valve Selection: The choice of an artificial heart valve depends on individual patient factors and preferences. The selection process involves considering whether a mechanical or biological valve is most appropriate and then determining the specific valve type.

Factors favoring Mechanical Valves:

• Patient preference and no contraindications to long-term vitamin K antagonist anticoagulation.

• Indication for long-term anticoagulation therapy with vitamin K antagonists (e.g., concomitant atrial fibrillation).

• Increased risk of biological valve degeneration due to factors such as young age, hyperparathyroidism, or renal failure.

• Patients under 65 years of age and in good overall health.

Factors favoring Biological Valves:

• Patient preference following comprehensive explanation of both valve types.

• Poor ability to monitor anticoagulant effects (e.g., due to geographical constraints) or reluctance to use anticoagulants (e.g., athletes, certain occupations).

• Patients over 65 years old or with significant comorbidities.

• Young women planning to have children, considering that biological valves degrade more rapidly in young adults and during pregnancy.

Selection of Valve Type and Size: This critical decision-making process lies with the heart surgeon, who relies on long-term, reliable studies to determine the most suitable valve for each patient.

• For biological valves, prioritizing valve longevity is crucial.

• For mechanical valves, minimizing thrombus formation is paramount.

• The surgeon will also consider hemodynamic factors to minimize the discrepancy between the valve orifice size and the patient's anatomy.

• Factors influencing hemodynamics include valve manufacturer, valve placement (above the annulus vs. within the ring), and valve design (unsupported vs. bracketed for biological valves).

• Surgeons will also consider surgical techniques that can preserve natural leaflets and ligaments to avoid complications and improve cardiac function post-surgery.

Conclusion: Choosing the right artificial heart valve requires careful evaluation of patient factors, weighing the advantages and limitations of mechanical and biological valves, and considering individual preferences. The decision-making process involves selecting the appropriate valve type based on longevity, thrombogenicity, and hemodynamics. The expertise of the heart surgeon is vital in ensuring the best possible outcome, taking into account surgical techniques and patient-specific considerations. 

By understanding the nuances of artificial heart valve selection, healthcare professionals can optimize patient care and improve long-term outcomes for individuals undergoing heart valve replacement. Close collaboration between patients, healthcare providers, and surgeons is crucial in making informed decisions regarding artificial heart valve selection.

Future Developments: The field of artificial heart valves continues to evolve, with ongoing research and technological advancements aiming to improve the durability, functionality, and biocompatibility of these devices. Emerging developments include tissue-engineered heart valves, which have the potential to overcome limitations associated with current valve options. These innovative approaches hold promise for enhancing patient outcomes and reducing the need for long-term anticoagulation therapy.