British societies guideline on the management of emergencies in implantable left ventricular assist device recipients in transplant centres.

An implantable left ventricular assist device (LVAD) is indicated as a bridge to transplantation or recovery in the United Kingdom (UK). The mechanism of action of the LVAD results in a unique state of haemodynamic stability with diminished arterial pulsatility. The clinical assessment of an LVAD recipient can be challenging because non-invasive blood pressure, pulse and oxygen saturation measurements may be hard to obtain. As a result of this unusual situation and complex interplay between the device and the native circulation, resuscitation of LVAD recipients requires bespoke guidelines. Through collaboration with key UK stakeholders, we assessed the current evidence base and developed guidelines for the recognition of clinical deterioration, inadequate circulation and time-critical interventions. Such guidelines, intended for use in transplant centres, are designed to be deployed by those providing immediate care of LVAD patients under conditions of precipitous clinical deterioration. In summary, the Joint British Societies and Transplant Centres LVAD Working Group present the UK guideline on management of emergencies in implantable LVAD recipients for use in advanced heart failure centres. These recommendations have been made with a UK resuscitation focus but are widely applicable to professionals regularly managing patients with implantable LVADs.

From 6-wk Lungs to 6 y: Increasing the Donor Pool for Pediatric Lung Transplantation.

BACKGROUND: Lung transplantation in the pediatric population is a challenge. With the donor pool being so small and lungs from young donors rare and precious, every organ available needs to be utilized to its best potential. CASE: Here, we describe the case of a 6-wk-old donor of double lungs to a 5-mo-old baby girl diagnosed with alveolar capillary dysplasia with misalignment of the pulmonary veins. The recipient is doing very well, 6 y after the transplant, now following normal growth. DISCUSSION: The challenges facing pediatric cardiothoracic transplantation in terms of organ supply and demand are enormous. CONCLUSIONS: In this article, we discuss some of the issues around the shortage of organs and alternatives to increase the organ donor pool.

Surgical intervention for left ventricular assist device outflow graft obstruction due to external compression.

Left ventricular assist device outflow graft obstruction is an uncommon but serious complication. The causes of left ventricular assist device outflow graft obstruction include thrombus, outflow graft kink or torsion and external compression. The HeartMate 3 left ventricular assist device was reported to have a low risk of thromboembolic events. However, the deposition of bio-debris between the semi-permeable left ventricular assist device outflow graft and the impermeable bend relief has been increasingly recognized as a cause of external compression. The potential treatment options include percutaneous insertion of a stent, surgical removal of the bio-debris, change of left ventricular assist device, and an urgent heart transplant. We report a case of left ventricular assist device outflow graft compression successfully treated by removal of the bio-debris via a subxiphoid approach.

The British Transplantation Society guidelines on cardiothoracic organ transplantation from deceased donors after circulatory death.

Maximising organ utilisation from donation after circulatory death (DCD) donors could help meet some of the shortfall in organ supply, but it represents a major challenge, particularly as organ donors and transplant recipients become older and more medically complex over time. Success is dependent upon establishing common practices and accepted protocols that allow the safe sharing of DCD organs and maximise the use of the DCD donor pool. The British Transplantation Society 'Guideline on transplantation from deceased donors after circulatory death' has recently been updated. This manuscript summarises the relevant recommendations from chapters specifically related to transplantation of cardiothoracic organs.

Graft function and incidence of cardiac allograft vasculopathy in donation after circulatory-determined death heart transplant recipients.

Experience in donation after circulatory-determined death (DCD) heart transplantation (HTx) is expanding. There is limited information on the functional outcomes of DCD HTx recipients. We sought to evaluate functional outcomes in our cohort of DCD recipients. We performed a single-center, retrospective, observational cohort study comparing outcomes in consecutive DCD and donation after brain death (DBD) HTx recipients between 2015 and 2019. Primary outcome was allograft function by echocardiography at 12 and 24 months. Secondary outcomes included incidence of cardiac allograft vasculopathy, treated rejection, renal function, and survival. Seventy-seven DCD and 153 DBD recipients were included. There was no difference in left ventricular ejection fraction at 12 months (59% vs 59%, P = .57) and 24 months (58% vs 58%, P = .87). There was no significant difference in right ventricular function at 12 and 24 months. Unadjusted survival between DCD and DBD recipients at 5 years (85.7% DCD and 81% DBD recipients; P = .45) was similar. There were no significant differences in incidence of cardiac allograft vasculopathy (odds ratio 1.59, P = .21, 95% confidence interval 0.77-3.3) or treated rejection (odds ratio 0.60, P = .12, 95% confidence interval 0.32-1.15) between DBD and DCD recipients. Post-transplant renal function was similar at 1 and 2 years. In conclusion, cardiac allografts from DCD donors perform similarly to a contemporary population of DBD allografts in the medium term.

The international experience of in-situ recovery of the DCD heart: a multicentre retrospective observational study.

Background: Heart transplantation is an effective treatment offering the best recovery in both quality and quantity of life in those affected by refractory, severe heart failure. However, transplantation is limited by donor organ availability. The reintroduction of heart donation after the circulatory determination of death (DCD) in 2014 offered an uplift in transplant activity by 30%. Thoraco-abdominal normothermic regional perfusion (taNRP) enables in-situ reperfusion of the DCD heart. The objective of this paper is to assess the clinical outcomes of DCD donor hearts recovered and transplanted from donors undergoing taNRP. Method: This was a multicentre retrospective observational study. Outcomes included functional warm ischaemic time, use of mechanical support immediately following transplantation, perioperative and long-term actuarial survival and incidence of acute rejection requiring treatment. 157 taNRP DCD heart transplants, performed between February 2, 2015, and July 29, 2022, have been included from 15 major transplant centres worldwide including the UK, Spain, the USA and Belgium. 673 donations after the neurological determination of death (DBD) heart transplantations from the same centres were used as a comparison group for survival. Findings: taNRP resulted in a 23% increase in heart transplantation activity. Survival was similar in the taNRP group when compared to DBD. 30-day survival was 96.8% ([92.5%-98.6%] 95% CI, n = 156), 1-year survival was 93.2% ([87.7%-96.3%] 95% CI, n = 72) and 5-year survival was 84.3% ([69.6%-92.2%] 95% CI, n = 13). Interpretation: Our study suggests that taNRP provides a significant boost to heart transplantation activity. The survival rates of taNRP are comparable to those obtained for DBD transplantation in this study. The similar survival may in part be related to a short warm ischaemic time or through a possible selection bias of younger donors, this being an uncontrolled observational study. Therefore, our study suggests that taNRP offers an effective method of organ preservation and procurement. This early success of the technique warrants further investigation and use. Funding: None of the authors have a financial relationship with a commercial entity that has an interest in the subject.

Comparing Cardiac Mechanics and Myocardial Fibrosis in DBD and DCD Heart Transplant Recipients.

BACKGROUND: Heart transplantation (HTx) after donation after circulatory death (DCD) is an expanding practice but is associated with increased warm ischemic time. The impact of DCD HTx on cardiac mechanics and myocardial fibrosis has not been reported. We aimed to compare cardiac mechanics and myocardial fibrosis using cardiovascular magnetic resonance (CMR) imaging in donation after brain death (DBD) and DCD HTx recipients and healthy controls. METHODS AND RESULTS: Consecutive HTx recipients between March 2015 and March 2021 who underwent routine surveillance CMR imaging were included. Cardiac mechanics were assessed using CMR feature tracking to compute global longitudinal strain, global circumferential strain, and right ventricular free-wall longitudinal myocardial strain. Fibrosis was assessed using late gadolinium enhancement imaging and estimation of extracellular volume. There were 82 (DBD n = 42, DCD n = 40) HTx recipients (aged 53 years, interquartile range 41-59 years, 24% female) who underwent CMR imaging at median of 9 months (interquartile range 6-14 months) after transplantation. HTx recipients had increased extracellular volume (29.7 ± 3.6%) compared with normal ranges (25.9%, interquartile range 25.4-26.5). Myocardial strain was impaired after transplantation compared with controls (global longitudinal strain -12.6 ± 3.1% vs -17.2 ± 1.8%, P < .0001; global circumferential strain -16.9 ± 3.1% vs -19.2 ± 2.0%, P = .002; right ventricular free-wall longitudinal strain -15.7 ± 4.5% vs -21.6 ± 4.7%, P < .0001). There were no differences in fibrosis burden (extracellular volume 30.6 ± 4.4% vs 29.2 ± 3.2%; P = .39) or cardiac mechanics (global longitudinal strain -13.1 ± 3.0% vs -12.1 ± 3.1%, P = .14; global circumferential strain -17.3 ± 2.9% vs -16.6 ± 3.1%, P = .27; right ventricular free-wall longitudinal strain -15.9 ± 4.9% vs -15.5 ± 4.1%, P = .71) between DCD and DBD HTx. CONCLUSIONS: HTx recipients have impaired cardiac mechanics compared with controls, with increased myocardial fibrosis. There were no differences in early CMR imaging characteristics between DBD and DCD heart transplants, providing further evidence that DCD and DBD HTx outcomes are comparable.

Adult heart procurement following circulatory determined death from a donor on venous-venous extracorporeal membrane oxygenation: A case report.

Donation after circulatory death in the context of heart transplants is attracting interest and becoming popular in clinical practice. Activity is growing in the United Kingdom, Australia, and the United States. We believe that a prolonged warm ischemic time (time from asystole to reperfusion of the heart on an ex vivo perfusion system) is a primary indicator of adverse outcomes. However, 1.5 liters of blood must be retrieved from the right atrium following sternotomy prolonging warm ischemic time. The patient in the following case report was supported by veno-venous extra-corporeal membrane oxygenation following drowning, further complicated by aspiration-related lung failure. Following circulatory death and a mandatory five-minute stand-off period, 1.5 liters of blood was drained from the circuit as sternotomy began. Surgeons then proceeded to direct procurement of the heart, aiming for least functional warm ischemic time. Following standard implantation, the patient's postoperative recovery has been unremarkable to date.

Lactate during ex-situ heart perfusion does not predict the requirement for mechanical circulatory support following donation after circulatory death (DCD) heart transplants.

BACKGROUND: Ex-situ heart perfusion (ESHP) is commonly used for the reanimation and preservation of hearts following donation after circulatory determined death (DCD). The only commercially available existing ESHP device promotes perfusate lactate levels for assessment of heart viability. The reliability of this marker is yet to be confirmed for DCD heart transplantation. METHODS: This is a single center, retrospective study examining DCD heart transplants from March 1, 2015 to June 30, 2020. Recipients were divided into 2 groups dependent upon their requirement for or absence of mechanical circulatory support post-transplant. Lactate profiles obtained during ESHP were analyzed. Hearts were procured using the direct procurement and perfusion (DPP) method. RESULTS: Fifty-one DCD heart transplant recipients were studied, of which 20 (39%) were dependent on mechanical circulatory support (MCS) following transplantation, (2% Ventricular Assist Device (VAD), 16% Extra Corporeal Membrane Oxygenation (ECMO) and 21% Intra-aortic balloon pumps (IABP). There was no difference in arterial lactate profiles on ESHP at any time point for those dependent upon MCS support (MCS) and those that were not (no MCS) post-transplant. After 3 hours of ESHP, the arterial lactate was >5mmol/L in 80% upon MCS vs 62% no MCS, p = .30. There was also no difference in ESHP rising arterial lactate concentrations, (15% MCS vs 13% non MCS, p = 1.00). CONCLUSION: For DCD hearts transplants retrieved using the DPP technique, lactate profiles do not seem to be a reliable predictor of mechanical circulatory support requirement post-transplant.

Validation of predicted heart mass equations by measurement of donor heart mass at time of heart transplantation.

Predicted heart mass (PHM) equations may be used in donor-recipient size matching in heart transplantation. We compared PHM and actual heart mass in 25 consecutive DBD heart transplants. There was a moderate positive correlation between actual heart mass and PHM. There was a similar moderate correlation between actual heart mass and donor weight or donor body surface area but not donor height. PHM was lower than actual heart mass for all donor hearts. Bland-Altman analysis showed a systematic bias between PHM and actual heart mass, with a mean difference of 190.9 ± 66.4 g. The utility of PHM equations is likely to be part of a multi-parametric assessment of the relative differences between donor and recipient, so the absolute difference is likely to be unimportant.

Pediatric heart transplantation following donation after circulatory death, distant procurement, and ex-situ perfusion.

BACKGROUND: Limited availability of suitable donor hearts remains a challenge to pediatric heart transplantation, contributing to waitlist mortality. Controlled donation after circulatory death (DCD) has demonstrated success in adults. Early series of pediatric DCD heart transplantation using cold storage alone reported significant early mortality. We report a collaboration between 2 centers in the United Kingdom, combining expertise in adult DCD organ retrieval and pediatric transplantation. METHODS: This retrospective series comprises 6 children (4 male, all >20 kg) undergoing DCD heart transplantation at Great Ormond Street Hospital between 1 February and 30 September 2020, following retrieval with direct procurement and perfusion using portable normothermic machine perfusion by the Royal Papworth Hospital service. Baseline characteristics and 1-year follow-up were compared to 9 children who underwent donation after brain death (DBD) transplants contemporaneously. RESULTS: Mean DCD donor age was 24.67 years and mean DCD recipient age was 13.83 years. Mean functional warm ischemic time was 28.5 minutes and ex-situ heart perfusion time was 280 minutes. Median ICU and hospital stay were 9 and 17 days, respectively. All children survived to 1-year post-transplant. Survival and ICU and hospital stay were similar between the DCD and DBD cohorts. Performing DCD transplants resulted in a 66.7% increase in transplants for children >20 kg at GOSH during the study. CONCLUSIONS: This series demonstrates that DCD heart transplant can be performed safely with excellent short-term survival in children. Although the cohort is small, there was no significant difference in major outcomes compared to a DBD cohort.

Heart transplantation from an extended criteria donation after circulatory death donor.

Transplantation of donation after circulatory death (DCD) donor hearts is gaining acceptance. However, DCD heart selection has been understandably cautious. We report a case of reconditioning a DCD heart using thoraco-abdominal normothermic regional perfusion in a 46-year-old donor who suffered irreversible brain injury following emergency type-A aortic dissection repair. The DCD heart was procured with cold preservation and directly transplanted into a 63-year-old male who was bridged to transplant with extracorporeal life support. The recipient required a brief period of mechanical circulatory support post-transplant but made a good recovery. To our knowledge, this is the first report of successful heart transplantation from such an extended criteria DCD donor.

Preoperative Atrial Fibrillation is associated with long-term morTality in patients undergoing suRgical AortiC valvE Replacement.

INTRODUCTION: Atrial fibrillation (AF) is frequent after any cardiac surgery, but evidence suggests it may have no significant impact on survival if sinus rhythm (SR) is effectively restored early after the onset of the arrhythmia. In contrast, management of preoperative AF is often overlooked during or after cardiac surgery despite several proposed protocols. This study sought to evaluate the impact of preoperative AF on mortality in patients undergoing isolated surgical aortic valve replacement (AVR). METHODS: We performed a retrospective, single-center study involving 2628 consecutive patients undergoing elective, primary isolated surgical AVR from 2008 to 2018. A total of 268/2628 patients (10.1%) exhibited AF before surgery. The effect of preoperative AF on mortality was evaluated with univariate and multivariate analyses. RESULTS: Short-term mortality was 0.8% and was not different between preoperative AF and SR cohorts. Preoperative AF was highly predictive of long-term mortality (median follow-up of 4 years [Q1-Q3 2-7]; hazard ratio [HR]: 2.24, 95% confidence interval [CI]: 1.79-2.79, p < .001), and remained strongly and independently predictive after adjustment for other risk factors (HR: 1.54, 95% CI: 1.21-1.96, p < .001) compared with preoperative SR. In propensity score-matched analysis, the adjusted mortality risk was higher in the AF cohort (OR: 1.47, 95% CI: 1.04-1.99, p = .03) compared with the SR cohort. CONCLUSIONS: Preoperative AF was independently predictive of long-term mortality in patients undergoing isolated surgical AVR. It remains to be seen whether concomitant surgery or other preoperative measures to correct AF may impact long-term survival.

Prosthesis-Patient Mismatch Increases Early and Late Mortality in Low Risk Aortic Valve Replacement.

The concept of prosthesis-patient mismatch (PPM) has gained much attention since first described 40 years ago. Previous studies have shown conflicting evidence regarding increased early and late morbidity and mortality with PPM after aortic valve replacement (AVR). The aim of this study was to evaluate the effects of PPM on short- and long-term mortality in low-risk patients after isolated AVR. A retrospective, single-center study involving 1707 consecutive patients ≤80 years of age with preserved left ventricular systolic function who underwent elective, primary isolated AVR operations from 2008 to 2018. Patients were stratified into 2 groups according to the presence of PPM (n = 96), defined as effective orifice area index <0.85 cm2/m2 body surface area, and no-PPM (n = 1611). The effect of PPM on mortality was evaluated with univariate and multivariate analyses. 30-day mortality was 0.8% (4.2% in PPM group vs 0.6 in no-PPM group; P = 0.005). PPM occurred more in female gender, obese and older patients. PPM was highly associated with long-term all-cause mortality (median 4 years [Q1-Q3 2-7]; HR: 1.79, 95% CI: 1.27-2.55, P = 0.002), and remained strongly and independently associated after adjustment for other risk factors (HR: 1.60, 95% CI: 1.10-2.34, P = 0.014). In propensity score-matched analysis, the adjusted mortality risk was higher in PPM group (HR: 2.03, 95% CI: 1.22-3.39, P = 0.006) compared to no-PPM group. In a single-centre observational study, PPM increased early mortality and was independently associated with long-term all-cause mortality after low-risk, primary isolated AVR operations. Strategies to avoid PPM should be explored and implemented.

A 5-year single-center early experience of heart transplantation from donation after circulatory-determined death donors.

BACKGROUND: In an effort to address the increasing demand for heart transplantation within the United Kingdom (UK), we established a clinical program of heart transplantation from donation after circulatory-determined death (DCD) donors in 2015. After 5 years, we report the clinical early outcomes and impact of the program. METHODS: This is a single-center, retrospective, matched, observational cohort study comparing outcomes of hearts transplanted from DCD donors from March 1, 2015 to February 29, 2020 with those from matched donation after brain death (DBD) donors at Royal Papworth Hospital (RPH) (Cambridge, UK). DCD hearts were either retrieved using thoracoabdominal normothermic regional perfusion or the direct procurement and perfusion technique. All DBD hearts were procured using standard cold static storage. The primary outcomes were recipient 30-day and 1-year survival. RESULTS: During the 5-year study, DCD heart donation increased overall heart transplant activity by 48% (79 for DCD and 164 for DBD). There was no difference in survival at 30 days (97% for DCD vs 99% for DBD, p = 1.00) or 1 year (91% for DCD vs 89% for DBD, p = 0.72). There was no difference in the length of stay in the intensive care unit (7 for DCD vs 6 for DBD days, p = 0.24) or in the hospital (24 for DCD vs 25 for DBD days, p = 0.84). CONCLUSIONS: DCD heart donation increased overall heart transplant activity at RPH by 48%, with no difference in 30-day or 1-year survival in comparison with conventional DBD heart transplantations. DCD heart donation is set to make a dramatic difference in the number of patients who can benefit from heart transplantation.

Combined heart-lung transplantation from a donation after circulatory death donor.

Combined heart-lung transplantation is the optimal treatment option for many patients with end-stage heart failure and fixed severe pulmonary hypertension. It offers the only possibility of long-term survival and a return to a normal quality of life. Unfortunately, it is rarely performed because of donor organ allocation policies. We present the case of a critically ill 24-year-old man, who after waiting for >100 days in-hospital on the urgent transplant list, deteriorated further and underwent the first successful heart-lung transplant with organs from a donation after circulatory death.

SARS-CoV-2 infection and early mortality of waitlisted and solid organ transplant recipients in England: A national cohort study.

Patients waitlisted for and recipients of solid organ transplants (SOT) are perceived to have a higher risk of contracting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and death; however, definitive epidemiological evidence is lacking. In a comprehensive national cohort study enabled by linkage of the UK transplant registry and Public Health England and NHS Digital Tracing services, we examined the incidence of laboratory-confirmed SARS-CoV-2 infection and subsequent mortality in patients on the active waiting list for a deceased donor SOT and recipients with a functioning SOT as of February 1, 2020 with follow-up to May 20, 2020. Univariate and multivariable techniques were used to compare differences between groups and to control for case-mix. One hundred ninety-seven (3.8%) of the 5184 waitlisted patients and 597 (1.3%) of the 46 789 SOT recipients tested positive for SARS-CoV-2. Mortality after testing positive for SARS-CoV-2 was 10.2% (20/197) for waitlisted patients and 25.8% (154/597) for SOT recipients. Increasing recipient age was the only variable independently associated with death after positive SARS-CoV-2 test. Of the 1004 transplants performed in 2020, 41 (4.1%) recipients have tested positive for SARS-CoV-2 with 8 (0.8%) deaths reported by May 20. These data provide evidence to support decisions on the risks and benefits of SOT during the coronavirus disease 2019 pandemic.

Vasoplegia following heart transplantation and left ventricular assist device explant is not associated with inferior outcomes.

BACKGROUND: Vasoplegia has been associated with inferior outcomes following heart transplantation (HTx). This observational study was designed to investigate outcomes in recipients with vasoplegia following left ventricular assist device (LVAD) explant HTx. METHODS: Patients undergoing LVAD explant followed by HTx from 01/2013-12/2018 at our centre were included. Vasoplegia was defined as the requirement for high dose vasopressor [noradrenaline (>0.5 µg/kg/min) and vasopressin (>1 U/h)] over the first 24 hours following HTx. Demographic and outcome data were retrieved from the transplant unit database. RESULTS: During the study period 24 patients underwent LVAD explant HTx. Of these, 13 (54.2%) developed vasoplegia. Both groups had similar duration of LVAD support (median 684 vs. 620 days P=0.62). There was a higher incidence of driveline infection in patients developing vasoplegia (69.2% vs. 18.2% P=0.02). HTx following donation after circulatory death (DCD) occurred in 9 (37.5%) patients and was not associated with a higher incidence of vasoplegia (P=0.21). Vasoplegia developed early following reperfusion and intensive care unit admission vasopressor-inotrope scores were significantly higher in patients with vasoplegia (P=0.002). Patients developing vasoplegia had similar ICU (P=0.79) and hospital (P=0.93) lengths of stay. Survival was equivalent both at 30-day (92.3% vs. 100% P=0.99) and 1-year (67.7% vs. 74.7% P=0.70). Our overall HTx 1-year survival was 89.3% over this period. CONCLUSIONS: Vasoplegia is seen with a high incidence in HTx recipients bridged with an LVAD. This appears to be associated with the presence of driveline infections. Early aggressive management is advocated, resulting in equivalent 1-year survival to those patients not developing vasoplegia.