The Ongoing Debate: Longevity of Biological Valves in Pulmonary Position.

Background:  In patients with tetralogy of Fallot (ToF) or ToF-like anatomy, factors possibly impacting the longevity of biological valves in the pulmonary position were investigated.

Method:  Between 1997 and 2017, 79 consecutive hospital survivors with a median age of 8.7 years (range: 0.2-56.1 years; interquartile range [IQR]: 14.8 years) with ToF or ToF-like anatomy underwent surgical implantation of Contegra ( = 34), Hancock ( = 23), Perimount ( = 9), pulmonary homograft ( = 9), and miscellaneous ( = 4) conduits. The median internal graft diameter was 19 mm (range: 11-29 mm; IQR: 8 mm) which refers to a median z-score of 0.6 standard deviation (SD) (range: -1.8 to 4.0 SD; IQR: 2.1 SD).

Results:  The median time of follow-up was 9.4 years (range: 1.1-18.8 years; IQR: 6.0 years). Thirty-nine patients (49%) underwent surgical ( = 32) or interventional ( = 7) pulmonary valve re-replacement. Univariate Cox regression revealed patient age ( = 0.018), body surface area ( = 0.004), internal valve diameter ( = 0.005), and prosthesis z-score ( = 0.018) to impact valve longevity. Multivariate Cox regression analysis, however, did not show any significant effect (likely related to multicollinearity). Subgroup analysis showed that valve-revised patients have a higher average z-score ( = 0.003) and younger average age ( = 0.007).

Conclusion:  A decreased longevity of biological valves in the pulmonary position is related to younger age, lower valve diameter, and higher z-score. Because valve size (diameter and z-score) can be predicted by age, patient age is the crucial parameter influencing graft longevity.