Disparities in donor heart acceptance between the USA and Europe: clinical implications

BACKGROUND AND AIMS

Given limited evidence and lack of consensus on donor acceptance for heart transplant (HT), selection practices vary widely across HT centres in the USA. Similar variation likely exists on a broader scale-across countries and HT systems-but remains largely unexplored. This study characterized differences in heart donor populations and selection practices between the USA and Eurotransplant-a consortium of eight European countries-and their implications for system-wide outcomes.

METHODS

Characteristics of adult reported heart donors and their utilization (the percentage of reported donors accepted for HT) were compared between Eurotransplant (n = 8714) and the USA (n = 60 882) from 2010 to 2020. Predictors of donor acceptance were identified using multivariable logistic regression. Additional analyses estimated the impact of achieving Eurotransplant-level utilization in the USA amongst donors of matched quality, using probability of acceptance as a marker of quality.

RESULTS

Eurotransplant reported donors were older with more cardiovascular risk factors but with higher utilization than in the USA (70% vs. 44%). Donor age, smoking history, and diabetes mellitus predicted non-acceptance in the USA and, by a lesser magnitude, in Eurotransplant; donor obesity and hypertension predicted non-acceptance in the USA only. Achieving Eurotransplant-level utilization amongst the top 30%-50% of donors (by quality) would produce an additional 506-930 US HTs annually.

CONCLUSIONS

Eurotransplant countries exhibit more liberal donor heart acceptance practices than the USA. Adopting similar acceptance practices could help alleviate the scarcity of donor hearts and reduce waitlist morbidity in the USA.

Population Pharmacokinetics of Caspofungin and Dose Simulations in Heart Transplant Recipients

The effect of heart transplantation (HTx) on the pharmacokinetics (PK) of caspofungin is not well-characterized. The aim of this study was to investigate the population PK of caspofungin in HTx and non-HTx patients and to identify covariates that may affect the PK of caspofungin. Seven successive blood samples were collected before administration and at 1, 2, 6, 10, 16, and 24 h after the administration of caspofungin for at least 3 days. This study recruited 27 HTx recipients and 31 non-HTx patients with 414 plasma concentrations in total. A nonlinear mixed-effects model was used to describe the population PK of caspofungin. The PK of caspofungin was best described by a two-compartment model. The clearance (CL) and volume of the central compartment (V_c) of caspofungin were 0.385 liter/h and 4.27 liters, respectively. The intercompartmental clearance (Q) and the volume of the peripheral compartment (V_p) were 2.85 liters/h and 6.01 liters, respectively. In the final model, we found that albumin (ALB) affected the CL of caspofungin with an adjustment factor of -1.01, and no other covariates were identified. In this study, HTx was not found to affect the PK of caspofungin. Based on the simulations, the dose of caspofungin should be proportionately increased in patients with decreased ALB levels.

Benefits of the Modified Bicaval Anastomosis Technique for Orthotopic Heart Transplantation From a Size-Mismatched Marginal Donor

BACKGROUND

Size-mismatched heart transplantation (HTx) is associated with a risk of stenosis of the caval anastomosis site or low cardiac output syndrome. We developed a modified bicaval anastomosis technique (mBCAT) that achieved an adjustable caval anastomosis to compensate for size mismatch. This study was performed to validate the rationale of the mBCAT for size-mismatched HTx.Methods and Results:This institutional consecutive series involved 106 patients who underwent HTx with the mBCAT during an 18-year period. The cohort was divided into 3 groups according to the donor-to-recipient body weight ratio: <0.8, undersized group (n=17); 0.8-1.3, size-matched group (n=68); and >1.3, oversized group (n=21); outcomes were compared. The undersized, size-matched, and oversized groups showed no significant differences in the rate of mild or worse echocardiographic tricuspid regurgitation at 1 month [1 (5.8%), 7 (10.2%), and 1 (4.8%), respectively; P=0.87] or the survival rate at 10 years [100%, 93.9%, and 100%, respectively; P=0.25]. The right heart catheter study revealed no pressure gradient across the orifices of both cavae in any patient. Additionally, the cardiac index immediately post-HTx was significantly low in the undersized group (P=0.008), but was similar to the other groups at 6 months post-HTx (P=0.16).

CONCLUSIONS

The mBCAT prevented caval anastomosis-related complications in size-mismatched HTx and achieved excellent hemodynamics regardless of donor size.

Three-dimensional replica of corrected transposition of the great arteries for successful heart transplantation

A 59-year-old man who had been previously diagnosed with congenitally corrected transposition of the great arteries at the age of 35 years became a candidate for heart transplantation. At the age of 57 years, he was referred to our hospital and underwent implantation of a left ventricular assist device (EVAHEART; Sun Medical Technology Research Corp., Suwa City, Japan) because of worsening ventricular function and was listed as a heart transplant candidate. A donor appeared when the patient was 59 years. A three-dimensional replica was made using data from computed tomography angiography. The three-dimensional replica was made of soft rubber (crossMedical, Inc., Kyoto, Japan), which enabled the surgeons to understand the relationship between the great arteries and chambers. After repeated dry laboratories using this replica, the patient underwent successful heart transplantation.

Off-pump coronary artery bypass grafting for a left main lesion due to cardiac allograft vasculopathy in Japan: first report of a case

Cardiac allograft vasculopathy (CAV) is a major cause of mortality after transplantation. We treated a 44-year-old female with off-pump coronary artery bypass grafting (OPCAB) 4 years after heart transplantation. Annual examinations, including coronary angiography and intravenous ultrasound (IVUS), revealed a severe lesion in the left main trunk. The left internal mammary artery was successfully anastomosed to the left anterior descending artery in an off-pump manner. To ensure that patients have a good long-term outcome after heart transplantation, routine examinations, including IVUS, are crucial, because of the nature of CAV. OPCAB is a good option for a left main trunk lesion due to CAV.