Faculty Bibliography

OBJECTIVE:This pilot study sought to evaluate the feasibility of our donation after circulatory death (DCD) heart transplantation protocol using cardiopulmonary bypass (CPB) for normothermic regional reperfusion (NRP). METHODS:Suitable local DCD candidates were transferred to our institution. Life support was withdrawn in the operating room (OR). On declaration of circulatory death, sternotomy was performed, and the aortic arch vessels were ligated. CPB was initiated with left ventricular venting. The heart was reperfused, with correction of any metabolic abnormalities. CPB was weaned, and cardiac function was assessed at 30-minute intervals. If accepted, the heart was procured with cold preservation and transplanted into recipients in a nearby OR. RESULTS:Between January 2020 and January 2021, a total of 8 DCD heart transplants were performed: 6 isolated hearts, 1 heart-lung, and 1 combined heart and kidney. All donor hearts were successfully resuscitated and weaned from CPB without inotropic support. Average lactate and potassium levels decreased from 9.39 ± 1.47 mmol/L to 7.20 ± 0.13 mmol/L and 7.49 ± 1.32 mmol/L to 4.36 ± 0.67 mmol/L, respectively. Post-transplantation, the heart-lung transplant recipient required venoarterial extracorporeal membrane oxygenation for primary lung graft dysfunction but was decannulated on postoperative day 3 and recovered uneventfully. All other recipients required minimal inotropic support without mechanical circulatory support. Survival was 100% with a median follow-up of 304 days (interquartile range, 105-371 days). CONCLUSIONS:DCD heart transplantation outcomes have been excellent. Our DCD protocol is adoptable for more widespread use and will increase donor heart availability in the United States.

INTRODUCTION/BACKGROUND:ImmuKnow, an immune cell function assay that quantifies overall immune system activity can assist in post-transplant immunosuppression adjustment. However, the utility of pre-transplant ImmuKnow results representing a patient's baseline immune system activity is unknown. This study sought to assess if pre-transplant ImmuKnow results are predictive of rejection at the time of first biopsy in our cardiac transplant population. METHODS:This is a single center, retrospective observational study of consecutive patients from January 1, 2018 to October 1, 2020 who underwent orthotopic cardiac transplantation at NYU Langone Health. Patients were excluded if a pre-transplant ImmuKnow assay was not performed. ImmuKnow results were categorized according to clinical interpretation ranges (low, moderate, and high activity), and patients were divided into two groups: a low activity group versus a combined moderate-high activity group. Pre-transplant clinical characteristics, induction immunosuppression use, early postoperative tacrolimus levels, and first endomyocardial biopsy results were collected for all patients. Rates of clinically significant early rejection (defined as rejection ≥ 1R/1B) were compared between pre-transplant ImmuKnow groups. RESULTS:Of 110 patients who underwent cardiac transplant, 81 had pre-transplant ImmuKnow results. The low ImmuKnow activity group was comprised of 15 patients, and 66 patients were in the combined moderate-high group. Baseline characteristics were similar between groups. Early rejection occurred in 0 (0%) patients with low pre-transplant ImmuKnow levels. Among the moderate- high pre-transplant ImmuKnow group, 16 (24.2%) patients experienced early rejection (P = .033). The mean ImmuKnow level in the non-rejection group was the 364.9 ng/ml of ATP compared to 499.3 ng/ml of ATP for those with rejection (P = .020). CONCLUSION/CONCLUSIONS:Patients with low pre-transplant ImmuKnow levels had lower risk of early rejection when compared with patients with moderate or high levels. Our study suggests a possible utility in performing pre-transplant ImmuKnow to identify patients at-risk for early rejection who may benefit from intensified upfront immunosuppression as well as to recognize those where slower calcineurin inhibitor initiation may be appropriate.

BACKGROUND:Specific aetiologies of cardiomyopathy can significantly impact treatment options as well as appropriateness and prioritisation for advanced heart failure therapies such as ventricular assist device (VAD) or orthotopic heart transplantation (OHT). We reviewed the tissue diagnoses of patients who underwent advanced therapies for heart failure (HF) to identify diagnostic discrepancies. METHODS:This study presents a retrospective cohort of the aetiology of cardiomyopathy in 118 patients receiving either durable VAD or OHT. Discrepancies between the preoperative aetiological diagnosis of cardiomyopathy with the pathological diagnosis were recorded. Echocardiographic and haemodynamic data were reviewed to examine differences in patients with differing aetiological diagnoses. RESULTS:Twelve (12) of 118 (12/118) (10.2%) had a pathological diagnosis that was discordant with pre-surgical diagnosis. The most common missed diagnoses were infiltrative cardiomyopathy (5) and hypertrophic cardiomyopathy (3). Patients with misidentified aetiology of cardiomyopathy had smaller left ventricular (LV) dimensions on echocardiography than patients with dilated cardiomyopathy (5.8±0.9 vs 6.7±1.1 respectively p=0.01). CONCLUSIONS:Most HF patients undergoing VAD and OHT had a correct diagnosis for their heart failure prior to treatment, but a missed diagnosis at time of intervention (VAD or OHT) was not uncommon. Smaller LV dimension on echocardiogram in a patient with a non-ischaemic cardiomyopathy warrants further workup for a more specific aetiology.

Purpose: In the U.S., heart transplantation from donation after circulatory death (DCD) is increasing. We present our institutional experience of DCD transplantation by using a thoracoabdominal-normothermic regional perfusion (TA-NRP) protocol and compare the results to a cohort concomitantly transplanted, from standard brain death (