Don't forget about mechanical valves!!!

Mechanical prosthetic heart valves have been implanted for decades, but have seen declining utilization in modern cardiac surgery. We aim to explore recent literature on the risks and benefits of mechanical prostheses.

The desire of patients to avoid anticoagulation and good performance of bioprosthetic valves appears to have driven a decline in the percentage of mechanical valve use, with mechanical valves now accounting for <20% of aortic and mitral prosthetic implants. However, modern mechanical valves exhibit excellent hemodynamics and durability. Modern bioprosthetic surgical valves are durable, but still experience structural valve deterioration (SVD), especially in younger patients. Transcatheter aortic valve replacement (TAVR) valves are a special case of bioprostheses in which long-term valve durability remains unclear, but presumably will have similar SVD rates to surgical bioprostheses. The true durability of TAVR-in-surgical aortic valve replacement (SAVR) remains unproven and the promise of this for younger patients is without significant data. Moreover, though bleeding risks due to anticoagulation are real and warfarin alternatives elusive, lower INR targets for mechanical valves may be a safe and promising approach. In keeping with the data on the tradeoffs of SVD and anticoagulation, multiple well conducted retrospective studies have confirmed age cutoffs below which patients have a mortality benefit from mechanical valves.

Mechanical valves are associated with improved survival in younger patients with excellent hemodynamics and may be underutilized.