Homografts in aortic position: does blood group incompatibility have an impact on patient outcomes?

Aortic homografts are an alternative to mechanical or biological valve prostheses. Homografts are generally not transplanted ABO-compatible while this policy is still under debate. The purpose of this study was to investigate whether ABO compatibility impacts on long-term outcomes or not.

Between 1992 and 2009, 363 adult patients with a mean age of 52 years received homografts in aortic position. Donor and acceptor blood groups could be obtained for 335 patients. Sixty-three percent received blood group-compatible (n = 212) (Group iso) and 37% non-blood group-compatible allografts (n = 123) (Group non-iso).

The overall event-free survival (freedom from death or reoperation) was 55.5% (n = 186). In the iso group, the event-free survival was 84.1% at 5 years and 63.3% at 10 years. In the non-iso group, the event-free survival was 79.4% at 5 years and 51.8% at 10 years. 28.5% of patients (n = 35) with ABO-incompatible and 25.5% (n = 54) with ABO-compatible grafts required reoperation. The mean time to reoperation in the iso group was 97.3 vs 90 months in the non-iso group.

In 17 years of research, we have not yet found a statistical significant difference in blood group incompatibility regarding overall event-free survival. In our opinion, there is no need to use ABO-compatible homografts for aortic valve replacement in adults. Histological and immunohistochemical assays are mandatory to confirm our results.