Is primary graft failure still a challenge in time of venoarterial extracorporeal membrane oxygenation?

Introduction

Primary graft failure (PGF) is the leading cause of early mortality after heart transplantation (HT). Its increasing incidence during the last decade may be triggered by the disbalance between receptors and donors that forces the acceptance of suboptimal organs.

Purpose

The aim of our work was to analyse the mechanical circulatory support (MCS) with VA-ECMO in refractory to inotropes PGF and determinate its impact in terms of graft function recovery and survival.

Methods

A retrospective study, analyzing our database of circulatory assist devices between 2009 and 2019. During this period, 252 devices have been implanted (154 ECMOs and 98 ventricular assist devices) and 201 patients have received a HT. We describe the characteristics and evolution of all PGF cases managed with VA-ECMO.

Results

Thirty nine patients (19.4%) developed PGF, defined as significant left, right or biventricular systolic dysfunction in the first 24 hours after HT, associated with hemodynamic instability and requiring high dose of inotropes, intra-aortic balloon pump (IABP) or VA-ECMO. Twenty two cases (56.4%) underwent a VA-ECMO implantation by peripheral cannulation as a bridge to recovery.

The median age was 50.8 (44.3–57.3) years and 77% were male. Biventricular dysfunction was observed in 50% and isolated right ventricular dysfunction in the remaining 50%. At the time of implantation, 59% had IABP and the median of inotropic score was 24 (8–40). Two complications occurred during implantation (one because of a complex vascular access and one due to a malposition of the venous cannula). Anticoagulation was started after a median of 19 hours (10–28; 59% sodic heparin and 36% bivalirudin).

The median support duration was 6.2 days (3–9.2). Graft function was recovered in 90%, making it possible to withdraw the device successfully in 82% of patients. The remaining 18% deceased during the support (2 because of multiorgan failure and 2 due to absence of function recovery).The median hospital length of stay was 63 days (33–93) and hospital and 1-year survival was 68.1%.

Conclusion

The support with VA-ECMO allowed graft function recovery in 90% of severe PGF cases, with a similar survival rate to other centres with MCS. In a scenario with a mortality rate superior to 50%, the MCS programs have managed to increase survival, avoid retransplantation in times of donor shortage and handle the use of suboptimal donors with better chances of success.

Funding Acknowledgement

Type of funding source: None

Restudy of the original marker X family

Restudy of the original marker-X family confirmed recent observations that this XLMR disorder is associated with large testes and slightly abnormal ears. However, other aspects of the phenotype were variable and a distinct facies was not evident. Significant differences in marker-X frequency between two laboratories processing the same samples were observed. Possibly, the combination of more cells and a longer culture time in one laboratory led to a greater depletion of critical nutrients and a higher frequency of the marker-X, but additional studies are needed. No evidence was found of a diminishing frequency of the marker-X over a 15 year period.

A large kindred with X-linked mental retardation, marker X and macroorchidism

Thirty-eight members of a black kindred with mental retardation and the Marker X were studied. Ten of 14 affected males, 6 of 6 affected females, 18 carriers or possible carriers, and 7 normal males were examined. Eight of 9 affected males who could be measured had macroorchidism, but their ears and mandibles were not prominent. No distinct facies were evident, although minor anomalies, such as a slight pectus, were present in some. Clinical diagnosis in the absence of a strongly positive family history may be even more difficult among prepubertal black children than in whites. The risk of retardation among children of carriers was estimated at 20-40%.

Studies on the oligosaccharide chains of human alpha 1-protease inhibitor. II. Structure of oligosaccharides

Human alpha 1-protease inhibitor has three oligosaccharide side chains attached to 3 separate asparaginyl residues of the protein by N-glycosyl linkages. Two of the three asparaginyl residues link mostly to the A-type oligosaccharide chains which consist of Man3, Gal2, (GlcNAc)4 and (NeuAc)2. One of the three asparaginyl residues also attaches to a B-type oligosaccharide chain, which consists of Man3, Gal3, (GlcNAc)5, and (NeuAc)3. The ratio of A-chain to B-chain in this particular position is about 2:1. The structures of A- and B-chains of the glycoprotein were examined by periodate oxidation, sequential glycosidase digestion, and permethylation. The results unequivocally revealed the following structure for A-chains. (Formula: see text). B-type oligosaccharide chains have an additional trisaccharide, i.e. NeuAc 2 alpha leads to 3 Gal 1 beta leads to 4 GlcNAc attached to mannose at the (a) and/or (b) position of A-type chains by a beta 1 leads to 4 linkage. The sialic acid of human alpha 1-protease inhibitor was determined to be N-acetylneuraminic acid.

Studies on the oligosaccharide chains of human alpha 1-protease inhibitor. I. Isolation of glycopeptides

Cyanogen bromide fragments of alpha 1-protease inhibitor (PI) were chromatographed on Sephadex G-75. Three fragments (CNBr-I, -II, and -III) contained carbohydrates with nearly the same composition, i.e. Man3, Gal2-3, (GlcNAc)4-5, and (NeuAc)2-3. These three fragments were digested with pronase, and the glycopeptides were purified by column chromatography on Sephadex G-50, Bio-Gel P-4, and DEAE-cellulose. The carbohydrate and amino acid compositions of the glycopeptides obtained by these treatments demonstrated that oligosaccharide side chains are attached to three asparaginyl residues which are located in separate regions of the polypeptide chain, and that the carbohydrate chains are made of two different carbohydrate compositions. The A-chain consists of Man3, Gal2, (GlcNAc)4, and (NeuAc)2, and the B-chain consists of Man3, Gal3, (GlcNAc)5, and (NeuAc)3. CNBr-III contained only A-type oligosaccharide while CNBr-II contained both A-type and B-type oligosaccharides in a ratio of about 2:1. CNBr-I, derived from the NH2 terminus of PI, contained mainly A-type, but also some B-type oligosaccharide.