Cardiac transplantation with hearts from donors after circulatory declaration of death: haemodynamic and biochemical parameters at procurement predict recovery following cardioplegic storage in a rat model

OBJECTIVES: Donation after circulatory declaration of death (DCDD) could significantly improve the number of cardiac grafts for transplantation. Graft evaluation is particularly important in the setting of DCDD given that conditions of cardio-circulatory arrest and warm ischaemia differ, leading to variable tissue injury. The aim of this study was to identify, at the time of heart procurement, means to predict contractile recovery following cardioplegic storage and reperfusion using an isolated rat heart model. Identification of reliable approaches to evaluate cardiac grafts is key in the development of protocols for heart transplantation with DCDD. METHODS: Hearts isolated from anaesthetized male Wistar rats (n = 34) were exposed to various perfusion protocols. To simulate DCDD conditions, rats were exsanguinated and maintained at 37°C for 15-25 min (warm ischaemia). Isolated hearts were perfused with modified Krebs-Henseleit buffer for 10 min (unloaded), arrested with cardioplegia, stored for 3 h at 4°C and then reperfused for 120 min (unloaded for 60 min, then loaded for 60 min). Left ventricular (LV) function was assessed using an intraventricular micro-tip pressure catheter. Statistical significance was determined using the non-parametric Spearman rho correlation analysis. RESULTS: After 120 min of reperfusion, recovery of LV work measured as developed pressure (DP)-heart rate (HR) product ranged from 0 to 15 ± 6.1 mmHg beats min(-1) 10(-3) following warm ischaemia of 15-25 min. Several haemodynamic parameters measured during early, unloaded perfusion at the time of heart procurement, including HR and the peak systolic pressure-HR product, correlated significantly with contractile recovery after cardioplegic storage and 120 min of reperfusion (P < 0.001). Coronary flow, oxygen consumption and lactate dehydrogenase release also correlated significantly with contractile recovery following cardioplegic storage and 120 min of reperfusion (P < 0.05). CONCLUSIONS: Haemodynamic and biochemical parameters measured at the time of organ procurement could serve as predictive indicators of contractile recovery. We believe that evaluation of graft suitability is feasible prior to transplantation with DCDD, and may, consequently, increase donor heart availability.

Efficacy of mechanical postconditioning following warm, global ischaemia depends on circulating fatty acid levels in an isolated, working rat heart model†

OBJECTIVES The number of heart transplantations is limited by donor organ availability. Donation after circulatory determination of death (DCDD) could significantly improve graft availability; however, organs undergo warm ischaemia followed by reperfusion, leading to tissue damage. Laboratory studies suggest that mechanical postconditioning [(MPC); brief, intermittent periods of ischaemia at the onset of reperfusion] can limit reperfusion injury; however, clinical translation has been disappointing. We hypothesized that MPC-induced cardioprotection depends on fatty acid levels at reperfusion. METHODS Experiments were performed with an isolated rat heart model of DCDD. Hearts of male Wistar rats (n = 42) underwent working-mode perfusion for 20 min (baseline), 27 min of global ischaemia and 60 min reperfusion with or without MPC (two cycles of 30 s reperfusion/30 s ischaemia) in the presence or absence of high fat [(HF); 1.2 mM palmitate]. Haemodynamic parameters, necrosis factors and oxygen consumption (O2C) were assessed. Recovery rate was calculated as the value at 60 min reperfusion expressed as a percentage of the mean baseline value. The Kruskal-Wallis test was used to provide an overview of differences between experimental groups, and pairwise comparisons were performed to compare specific time points of interest for parameters with significant overall results. RESULTS Percent recovery of left ventricular (LV) work [developed pressure (DP)-heart rate product] at 60 min reperfusion was higher in hearts reperfused without fat versus with fat (58 ± 8 vs 23 ± 26%, P < 0.01) in the absence of MPC. In the absence of fat, MPC did not affect post-ischaemic haemodynamic recovery. Among the hearts reperfused with HF, two significantly different subgroups emerged according to recovery of LV work: low recovery (LoR) and high recovery (HiR) subgroups. At 60 min reperfusion, recovery was increased with MPC versus no MPC for LV work (79 ± 6 vs 55 ± 7, respectively; P < 0.05) in HiR subgroups and for DP (40 ± 27 vs 4 ± 2%), dP/dtmax (37 ± 24 vs 5 ± 3%) and dP/dtmin (33 ± 21 vs 5 ± 4%; P < 0.01 for all) in LoR subgroups. CONCLUSIONS Effects of MPC depend on energy substrate availability; MPC increased recovery of LV work in the presence, but not in the absence, of HF. Controlled reperfusion may be useful for therapeutic strategies aimed at improving post-ischaemic recovery of cardiac DCDD grafts, and ultimately in increasing donor heart availability.

A new universal, standardized implant database for product identification: a unique tool for arthroplasty registries.

INTRODUCTION Every joint registry aims to improve patient care by identifying implants that have an inferior performance. For this reason, each registry records the implant name that has been used in the individual patient. In most registries, a paper-based approach has been utilized for this purpose. However, in addition to being time-consuming, this approach does not account for the fact that failure patterns are not necessarily implant specific but can be associated with design features that are used in a number of implants. Therefore, we aimed to develop and evaluate an implant product library that allows both time saving barcode scanning on site in the hospital for the registration of the implant components and a detailed description of implant specifications. MATERIALS AND METHODS A task force consisting of representatives of the German Arthroplasty Registry, industry, and computer specialists agreed on a solution that allows barcode scanning of implant components and that also uses a detailed standardized classification describing arthroplasty components. The manufacturers classified all their components that are sold in Germany according to this classification. The implant database was analyzed regarding the completeness of components by algorithms and real-time data. RESULTS The implant library could be set up successfully. At this point, the implant database includes more than 38,000 items, of which all were classified by the manufacturers according to the predefined scheme. Using patient data from the German Arthroplasty Registry, several errors in the database were detected, all of which were corrected by the respective implant manufacturers. CONCLUSIONS The implant library that was developed for the German Arthroplasty Registry allows not only on-site barcode scanning for the registration of the implant components but also its classification tree allows a sophisticated analysis regarding implant characteristics, regardless of brand or manufacturer. The database is maintained by the implant manufacturers, thereby allowing registries to focus their resources on other areas of research. The database might represent a possible global model, which might encourage harmonization between joint replacement registries enabling comparisons between joint replacement registries.

Efficacy of mechanical postconditioning following warm, global ischaemia depends on circulating fatty acid levels in an isolated, working rat heart model

Gebiet: Chirurgie Abstract: OBJECTIVES: – The number of heart transplantations is limited by donor organ availability. Donation after circulatory determination of death (DCDD) could significantly improve graft availability, however, organs undergo warm ischaemia followed by reperfusion, leading to tissue damage. Laboratory studies suggest that mechanical postconditioning [(MPC), brief, intermittent periods of ischaemia at the onset of reperfusion] can limit reperfusion injury, however, clinical translation has been disappointing. We hypothesized that MPC-induced cardioprotection depends on fatty acid levels at reperfusion. – – METHODS: – Experiments were performed with an isolated rat heart model of DCDD. Hearts of male Wistar rats (n = 42) underwent working-mode perfusion for 20 min (baseline), 27 min of global ischaemia and 60 min reperfusion with or without MPC (two cycles of 30 s reperfusion/30 s ischaemia) in the presence or absence of high fat [(HF), 1.2 mM palmitate]. Haemodynamic parameters, necrosis factors and oxygen consumption (O2C) were assessed. Recovery rate was calculated as the value at 60 min reperfusion expressed as a percentage of the mean baseline value. The Kruskal-Wallis test was used to provide an overview of differences between experimental groups, and pairwise comparisons were performed to compare specific time points of interest for parameters with significant overall results. – – RESULTS: – Percent recovery of left ventricular (LV) work [developed pressure (DP)-heart rate product] at 60 min reperfusion was higher in hearts reperfused without fat versus with fat (58 ± 8 vs 23 ± 26%, P < 0.01) in the absence of MPC. In the absence of fat, MPC did not affect post-ischaemic haemodynamic recovery. Among the hearts reperfused with HF, two significantly different subgroups emerged according to recovery of LV work: low recovery (LoR) and high recovery (HiR) subgroups. At 60 min reperfusion, recovery was increased with MPC versus no MPC for LV work (79 ± 6 vs 55 ± 7, respectively, P < 0.05) in HiR subgroups and for DP (40 ± 27 vs 4 ± 2%), dP/dtmax (37 ± 24 vs 5 ± 3%) and dP/dtmin (33 ± 21 vs 5 ± 4%, P < 0.01 for all) in LoR subgroups. – – CONCLUSIONS: – Effects of MPC depend on energy substrate availability, MPC increased recovery of LV work in the presence, but not in the absence, of HF. Controlled reperfusion may be useful for therapeutic strategies aimed at improving post-ischaemic recovery of cardiac DCDD grafts, and ultimately in increasing donor heart availability.