Long-Term Structural Valve Degeneration in Cryopreserved Mitral and Aortic Homograft: Is Pregnancy a Factor?

Abstract

Objective: This study reports the outcomes of the cryopreserved mitral homograft in 119 patients prospectively followed with clinical, echocardiographic and structural valve deterioration assessments. Methods: 119 patients undergoing mitral and aortic homograft implantation. Patient's causes of mitral disease were: rheumatic disease (n = 75), endocarditis (n = 37) and others (n = 7). There were 40 partial homografts and 88 total homografts. Mitro-aortic homograft valve replacement was performed in 29 cases. Results: Mean follow-up was 9.8 ± 6.3 years (up to 19.2 yrs). There were 7 early (<3 months) and 16 late deaths. There have been 9 early (<3 months) and 35 late reoperations. Nine patients had an endocarditis and 6 had ischemic/haemorrhagic event. As compared to baseline, follow-up echography showed progression of MR grade (from 0.4 to 1.3 p < 0.001) with stenosis (elevated gradient: from 3.9 to 7.0 mmHg p < 0.001 and decreased valve area: from 2.3 to 1.7 cm 2 p < 0.001). Proportion of patients free from structural valve deterioration (SVD) was 90%, 76% and 65% at 5 years, 10 years and 15 years respectively. Pregnancy and endocarditis etiology were found to be the main determinants of SVD. Stenosis related to SVD was more pronounced for age < 40 years and ring size 30 mm. Mitro aortic homograft valve replacement was the preferred choice in complex infective endocarditis. Pathological analysis of the explanted homografts almost invariably showed dense fibrosis with calcification and no cellularity. Conclusion: Mitral homografting could be accomplished with early echographic results similar to those of valve repair. SVD produced mixed stenosis with insufficiency and its incidence was comparable to that of bioprostheses SVD. An improvement in the preservation mode of valvular homografts is warranted. Double cryopreserved homograft implantation in the context of infective endocarditis might be an effective strategy especially if the mitro-aortic continuity is involved. However, a par-* Corresponding author. F. Nappi et al. 278 ticular attention should be paid to in women in childbearing age because pregnancy might accelerate structural degeneration of the cryopreserved homografts.