Donation after circulatory death hearts recipients compared to donation after brain death heart recipients have comparable systolic left ventricular function and better myocardial strain at 1 year

Purpose

Cardiac transplantation from donation after circulatory death (DCD) has been implemented at our hospital since February 2015. Despite encouraging results some concerns may be raised about the impact of the warm ischemia and reperfusion injury on the myocardium status at longer follow-up. Therefore, we aimed to analyse systolic performance of the left ventricle at 1 year follow in DCD and donation after brain death (DBD) cardiac recipients, as assessed by echocardiography with myocardial deformation imaging.

Methods

We identified 46 consecutive DCD cardiac recipients who were transplanted from February 2015 to August 2018 and we matched them with 46 DBD cardiac recipients. Six and 7 patients from DCD and DBD group, respectively, died in the first-year post transplant. In the remaining patients we have compared the classical echocardiographic measurements as well as global longitudinal strain (GLS) and global circumferential strain (GCS) at 1-year follow-up.

Results

DCD and DBD patients did not present with differences in terms of classical echocardiographic parameters of left ventricular (LV) structure and systolic function at one-year follow-up. LVEDV was similar in DCD and DBD patients (101±24 vs. 95±32 ml, p=0.4 respectively), as well as LVESV (42±13 vs. 42±16 ml, p=0.9, respectively), LV ejection fraction (58±6 vs. 56±8%, p=0.22) and LV mass (156±39 vs. 163±38 gr, p=0.2, respectively). In contrast, myocardial deformation parameters, such as GLS and GCS, were better in DCD than in DBD (16.1 vs. −14.5%, p<0.01; and −25.2 vs. 22.3%, p<0.05, respectively). The diastolic LV function parameters were similar in DCD and DBD group, as evidenced by E wave velocity, A wave velocity and deceleration time of mitral inflow, however E over E prime was lower in DCD than in DBD recipients (7.7±8.7, p<0.05). Fractional area change of the right ventricle was higher in DCD in comparison with DBD (46±7 vs. 40±7%, p<0.01) while right atrial volume index was lower in DCD than in DBD (25±8 vs. 29±9 ml/m2, p<0.01). Other parameters of RV function (systolic excursion of the tricuspid annulus, TAPSE) were similar in both groups.

Conclusion

DCD and DBD heart recipients present with similar systolic LV function at 1-year follow, as assessed by classical echocardiographic parameters. DCD cardiac recipients have better myocardial deformation parameters as assessed by the speckle tracking, better systolic right ventricular function and lower filling pressures of the left ventricle.

Funding Acknowledgement

Type of funding source: None

Investigation of the safety and feasibility of AAV1/SERCA2a gene transfer in patients with chronic heart failure supported with a left ventricular assist device - the SERCA-LVAD TRIAL

The SERCA-LVAD trial was a phase 2a trial assessing the safety and feasibility of delivering an adeno-associated vector 1 carrying the cardiac isoform of the sarcoplasmic reticulum calcium ATPase (AAV1/SERCA2a) to adult chronic heart failure patients implanted with a left ventricular assist device. The SERCA-LVAD trial was one of a program of AAV1/SERCA2a cardiac gene therapy trials including CUPID1, CUPID 2 and AGENT trials. Enroled subjects were randomised to receive a single intracoronary infusion of 1 × 10¹³ DNase-resistant AAV1/SERCA2a particles or a placebo solution in a double-blinded design, stratified by presence of neutralising antibodies to AAV. Elective endomyocardial biopsy was performed at 6 months unless the subject had undergone cardiac transplantation, with myocardial samples assessed for the presence of exogenous viral DNA from the treatment vector. Safety assessments including ELISPOT were serially performed. Although designed as a 24 subject trial, recruitment was stopped after five subjects had been randomised and received infusion due to the neutral result from the CUPID 2 trial. Here we describe the results from the 5 patients at 3 years follow up, which confirmed that viral DNA was delivered to the failing human heart in 2 patients receiving gene therapy with vector detectable at follow up endomyocardial biopsy or cardiac transplantation. Absolute levels of detectable transgene DNA were low, and no functional benefit was observed. There were no safety concerns in this small cohort. This trial identified some of the challenges of performing gene therapy trials in this LVAD patient cohort which may help guide future trial design.

Control of Diatraea saccharalis by the endophytic Pantoea agglomerans 33.1 expressing cry1Ac7

Despite the fact that Bacillus thuringiensis (Bt) is found in more than 90 % of the products used against insects, it has some difficulty reaching the internal regions where the larvae feed. To solve this problem, many genetically modified microorganisms that colonize the same pests have been developed. Thus, the endophytic bacterium Pantoea agglomerans (33.1), which has been recently described as a promising sugarcane growth promoter, was genetically modified with the pJTT vector (which carries the gene cry1Ac7) to control the sugarcane borer, Diatraea saccharalis. Firstly, the bioassays for D. saccharalis control by 33.1:pJTT were conducted with an artificial diet. A new in vivo methodology was also developed, which confirmed the partial control of larvae by 33.1:pJTT. The 33.1:pJTT strain was inoculated into sugarcane stalks containing the D. saccharalis larvae. In the sugarcane stalks, 33.1:pJTT was able to increase the mortality of D. saccharalis larvae, impair larval development and decrease larval weight. Sugarcane seedlings were inoculated with 33.1:pJTT, and re-isolation confirmed the capacity of 33.1:pJTT to continuously colonize the sugarcane. These results prove that P. agglomerans (33.1), a sugarcane growth promoter, can be improved by expressing the Cry protein, and the resulting strain is able to control the sugarcane borer.