When Survival Is Not Enough: Rethinking Mechanical Mitral Valve Replacement in Young Children

To the Editor,

We read with great interest the article by Park et al. [1] entitled “Long-term results after mitral valve replacement with mechanical prostheses in children under 3 years of age.” The authors should be commended for reporting long-term outcomes in this particularly vulnerable population, an area in which robust data remain limited.

Despite these valuable contributions, the reported experience reinforces a longstanding concern: mechanical mitral valve replacement in very young children remains a suboptimal solution, both in the early postoperative period and over the long term. While survival can be achieved, morbidity continues to be substantial, and the overall burden imposed on patients and their families remains considerable [2].

Mechanical prostheses require strict and uninterrupted anticoagulation with warfarin, a drug characterized by a narrow therapeutic window and frequent interactions with medications commonly prescribed in children, particularly antibiotics. Maintaining stable anticoagulation in infants and toddlers is notoriously difficult and necessitates frequent blood testing and close clinical monitoring. Moreover, the active nature of young children, with frequent falls and minor trauma, exposes them to a persistent risk of bleeding, thereby placing a profound psychological and logistical burden on families.

Bioprosthetic valves, while avoiding the need for anticoagulation, also represent an imperfect alternative in this age group because of rapid structural degeneration and limited durability. Therefore, mitral valve repair—whenever technically feasible—remains the most appropriate option for infants and young children. Repair preserves native tissue, avoids prosthesis-related complications, and better accommodates somatic growth. Valve replacement should therefore remain a last resort [3].

Looking forward, continued research and innovation in pediatric valve therapy are urgently needed. Advances in biomedical engineering and tissue engineering may ultimately provide growth-accommodating valve substitutes that are better suited to the unique physiological demands of children [4,5].

In summary, while mechanical mitral valve replacement may offer survival in selected cases, it does not yet represent an optimal long-term solution for young children. Mitral valve repair should therefore remain the preferred therapeutic strategy until improved valve technologies become available.