Makindo Medical Notes

Related Subjects: Chronic Heart Failure |Heart Failure and Pulmonary Oedema |Loop Diuretics |Prosthetic Metal and Tissue Valves | Ivabradine | Furosemide | Angiotensin Converting Enzyme Inhibitors | Cardiac Resynchronisation Therapy (CRT) Pacemaker |

Problems with prosthetic valve issues should be referred urgently to a Cardiologist. Elective Operative mortality is approximately 2%, but this is increased in patients with IHD (when it is usually combined with CABG), lung disease and the elderly.

Feature	Biological (Bioprosthetic) Valves	Mechanical (Metal) Valves
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Material	Made from animal tissues (porcine or bovine) or human donor valves (homografts). Medtronic tissue valve	Made from durable materials such as titanium or carbon-based compounds. Above is a Medtronic bileaflet valve.
Longevity	Lasts approximately 10-15 years.	Can last a lifetime, often over 20-30 years.
Anticoagulation Requirements	Requires anticoagulation for the initial 3 months (e.g., Warfarin) to prevent clotting. After 3 months, anticoagulation can usually be stopped if the patient is in sinus rhythm (SR).	Requires lifelong anticoagulation therapy (e.g., Warfarin) to prevent thrombosis. Target INR is typically 2.5-3.5.
Risk of Thrombosis	Lower risk of thrombosis compared to mechanical valves, similar to native valves.	Higher risk of thrombosis, necessitating lifelong anticoagulation.
Haemodynamics	Offers better hemodynamics, with a more natural flow similar to native valves.	Slightly less natural flow compared to bioprosthetic valves due to mechanical nature.
Infection Risk (Endocarditis)	Risk of infection, but similar to mechanical valves. Requires antibiotic prophylaxis for certain procedures.	At risk for prosthetic valve endocarditis. Requires antibiotic prophylaxis for certain procedures.
Sound	Bioprosthetic valves are usually silent.	Mechanical valves often produce an audible "click" when opening and closing.
Complications	Structural valve deterioration over time, requiring possible re-replacement. Risk of valve infection (endocarditis).	Thrombosis and embolism (without proper anticoagulation). Anticoagulant-related haemorrhage. Prosthetic valve endocarditis.
Clinical Indications	Preferred in older patients (>65 years) who may not require re-replacement. Used in patients with contraindications to lifelong anticoagulation (e.g., history of bleeding).	Preferred in younger patients (<65 years) due to durability. Recommended for patients already on long-term anticoagulation therapy (e.g., atrial fibrillation).
Examples	Carpentier-Edwards (porcine). Homografts (cadaveric).	Starr-Edwards (ball/cage type). Bjork-Shiley (tilting disc). St Jude (double tilting disc).

References

• Prosthetic Valves at Medscape