Heart transplant outcomes in patients with mechanical circulatory support: cold storage versus normothermic perfusion organ preservation.

OBJECTIVES: Patients with mechanical circulatory support bridged to a heart transplant (HTx) are at higher risk of postoperative graft dysfunction. In this subset, a mode of graft preservation that shortens graft ischaemia should be beneficial. METHODS: The outcomes of 38 patients on mechanical circulatory support (extracorporeal life support, left ventricular assist device and biventricular assist device) who received a HTx between 2015 and 2020 were analysed according to the method of graft preservation: cold storage (CS) group, 24 (63%) or ex vivo perfusion (EVP) group, 14 (37%). RESULTS: The median age was 57 (range 30-73) vs 64 (35-75) years (P = 0.10); 88% were men (P = 0.28); extracorporeal life support was more frequent in the CS group (54% vs 36%; P = 0.27) versus left ventricular and biventricular assist devices in the EVP group (46% vs 64%; P = 0.27). Clamping time was shorter in the EVP group (P < 0.001) and ischaemic time >4 h was higher in the CS group (P = 0.01). Thirty-day mortality was 13% (0-27%) in the CS group and 0% (P = 0.28) in the EVP group. A significantly lower primary graft failure [7% (0-23%) vs 42% (20-63%); P = 0.03] was observed in the EVP group. Survival at 1 year was 79 ± 8% (63-95%) in the CS group and 84 ± 10% (64-104%) in the EVP group (P = 0.95). CONCLUSIONS: Our results support the use of ex vivo graft perfusion in patients on mechanical circulatory support as a bridge to a HTx. This technique, by shortening graft ischaemic time, seems to improve post-HTx outcomes.

Continuous monitoring of membrane lung carbon dioxide removal during ECMO: experimental testing of a new volumetric capnometer.

BACKGROUND: Extracorporeal membrane oxygenation constitutes a complex support modality, and accurate monitoring is required. An ideal monitoring system should promptly detect ECMO malfunctions and provide real-time information to optimize the patient-machine interactions. We tested a new volumetric capnometer which enables continuous monitoring of membrane lung carbon dioxide removal (V'CO2ML), to help in estimating the oxygenator performance, in terms of CO2 removal and oxygenator dead space (VDsML). METHODS: This study was conducted on nine pigs undergoing veno-arterial ECMO due to cardiogenic shock after induced acute myocardial infarction. The accuracy and reliability of the prototype of the volumetric capnometer (CO2RESET™, by Eurosets srl, Medolla, Italy) device was evaluated for V'CO2ML and VDsML measurements by comparing the obtained measurements from the new device to a control capnometer with the sweep gas values. Measurements were taken at five different levels of gas flow/blood flow ratio (0.5-1.5). Agreement between the corresponding measurements was taken with the two methods. We expected that 95% of differences were between d - 1.96s and d + 1.96s. RESULTS: In all, 120 coupled measurements from each device were obtained for the V'CO2ML calculation and 40 for the VDsML. The new capnometer mean percentage bias (95% confidence interval limits of agreement) was 3.86% (12.07-4.35%) for V'CO2ML and 2.62% (8.96-14.20%) for VDsML. A negative proportional bias for V'CO2ML estimation with the new device was observed with a mean of 3.86% (12.07-4.35%). No correlations were found between differences in the coupled V'CO2ML and VDsML measurements and the gas flow/blood flow ratio or temperature. Coupled measurements for V'CO2ML showed strong correlation (rs = 0.991; p = 0.0005), as did VDsML calculations (rs = 0.973; p = 0.0005). CONCLUSION: The volumetric capnometer is reliable for continuous monitoring of CO2 removal by membrane lung and VDsML calculations. Further studies are necessary to confirm these data.

Coronary Dissection Discovered During Ex Vivo Organ Preservation: Avoiding a Fatal Complication.

This report describes the case of undiagnosed posttraumatic coronary artery dissection in a young multiorgan donor. Ex vivo preservation with the Organ Care System (TransMedics, Inc, Andover, MA) revealed the presence of coronary disease and avoided transplantation of an organ at high risk for failure.