Perioperative Characteristics and Outcomes of Fontan Versus Non-Fontan Patients Undergoing Combined Heart-Liver Transplantation: A Retrospective Cohort Study.

OBJECTIVES: Combined heart-liver transplantation (CHLT) is becoming increasingly frequent as a maturing population of patients with Fontan-palliated congenital heart disease develop advanced liver fibrosis or cirrhosis. The authors present their experience with CHLT for congenital and noncongenital indications, and identify characteristics associated with poor outcomes that may guide intervention in high-risk patients. DESIGN: This was a single-center retrospective cohort study. SETTING: This study was conducted at Vanderbilt University Medical Center in Nashville, Tennessee. PARTICIPANTS: The study included 16 consecutive adult recipients of CHLT at the authors' institution between April 2017 and February 2022. INTERVENTIONS: Eleven patients underwent transplantation for Fontan indications, and 5 were transplanted for non-Fontan indications. MEASUREMENTS AND MAIN RESULTS: Compared with non-Fontan patients, Fontan recipients had longer cardiopulmonary bypass duration (199 v 119 minutes, p =m0.002), operative times (786 v 599 minutes, p = 0.01), and larger blood product transfusions (15.4 v 6.3 L, p = 0.18). Six of 16 patients required extracorporeal membrane oxygenation (ECMO), of whom 4 were Fontan patients who subsequently died. Patients who required ECMO had lower 5-hour lactate clearance (0.0 v 3.5 mmol/L, p = 0.001), higher number of vasoactive infusions, lower pulmonary artery pulsatility indices (0.58 v 1.77, p = 0.03), and higher peak inspiratory pressures (28.0 v 18.5 mmHg, p = 0.01) after liver reperfusion. CONCLUSIONS: Combined heart-liver transplantation in patients with Fontan-associated end-organ disease is particularly challenging and associated with higher recipient morbidity compared with non-Fontan-related CHLT. Early hemodynamic intervention for signs of ventricular dysfunction may improve outcomes in this growing high-risk population.

Thoraco-abdominal normothermic regional perfusion for thoracic transplantation in the United States: current state and future directions.

PURPOSE OF REVIEW: To provide an update regarding the state of thoracoabdominal normothermic regional perfusion (taNRP) when used for thoracic organ recovery. RECENT FINDINGS: taNRP is growing in its utilization for thoracic organ recovery from donation after circulatory death donors, partly because of its cost effectiveness. taNRP has been shown to yield cardiac allograft recipient outcomes similar to those of brain-dead donors. Regarding the use of taNRP to recover donor lungs, United Network for Organ Sharing (UNOS) analysis shows that taNRP recovered lungs are noninferior, and taNRP has been used to consistently recover excellent lungs at high volume centers. Despite its growth, ethical debate regarding taNRP continues, though clinical data now supports the notion that there is no meaningful brain perfusion after clamping the aortic arch vessels. SUMMARY: taNRP is an excellent method for recovering both heart and lungs from donation after circulatory death donors and yields satisfactory recipient outcomes in a cost-effective manner. taNRP is now endorsed by the American Society of Transplant Surgeons, though ethical debate continues.

Association of Intraoperative Red Blood Cell Transfusions With Venous Thromboembolism and Adverse Outcomes After Cardiac Surgery.

OBJECTIVE: We determined whether intraoperative packed red blood cell (PRBC) transfusion was associated with a higher incidence of hospital-acquired venous thromboembolic (HA-VTE) complications and adverse outcomes after isolated coronary artery bypass grafting (CABG) surgery. BACKGROUND: Intraoperative PRBC has been associated with increased risk for postoperative deep venous thrombosis after cardiac surgery, but validation of these findings in a large, multi-institutional, national cohort of cardiac surgery patients has been lacking. METHODS: A registry-based cohort study of 751,893 patients with isolated CABG between January 1, 2015, to December 31, 2019. Using propensity score-weighted regression analysis, we analyzed the effect of intraoperative PRBC on the incidence of HA-VTE and adverse outcomes. RESULTS: Administration of 1, 2, 3, and ≥4 units of PRBC transfusion was associated with increased odds for HA-VTE [odds ratios (ORs): 1.27 (1.22-1.32), 1.21 (1.16-1.26), 1.93 (1.85-2.00), 1.82 (1.75-1.89)], deep venous thrombosis [ORs: 1.39 (1.33-1.46), 1.38 (1.32-1.44), 2.18 (2.09-2.28), 1.82 (1.74-1.91], operative mortality [ORs: 1.11 (1.08-1.14), 1.16 (1.13-1.19), 1.29 (1.26-1.32), 1.47 (1.43-1.50)], readmission within 30 days [ORs: 1.05 (1.04-1.06), 1.16 (1.13-1.19), 1.29 (1.26-1.32), 1.47 (1.43-1.50)], and a prolonged postoperative length of stay [mean difference in days, 0.23 (0.19-0.27), 0.34 (0.30-0.39), 0.69 (0.64-0.74), 0.77 (0.72-0.820]. The odds of pulmonary venous thromboembolism were lower for patients transfused with 1 or 2 units [ORs: 0.98 (0.91-1.06), 0.75 (0.68-0.81)] of PRBC but remained significantly elevated for those receiving 3 and ≥4 units [ORs: 1.19 (1.09-1.29), 1.35 (1.25-1.48)]. CONCLUSIONS: Intraoperative PRBC transfusion was associated with HA-VTE and adverse outcomes after isolated CABG surgery.

Early Assessment of Cardiac Allograft Vasculopathy Risk Among Recipients of Hepatitis C Virus-infected Donors in the Current Era.

BACKGROUND: Transplantation of hearts from hepatitis C virus (HCV)-positive donors has increased substantially in recent years following development of highly effective direct-acting antiviral therapies for treatment and cure of HCV. Although historical data from the pre-direct-acting antiviral era demonstrated an association between HCV-positive donors and accelerated cardiac allograft vasculopathy (CAV) in recipients, the relationship between the use of HCV nucleic acid test-positive (NAT+) donors and the development of CAV in the direct-acting antiviral era remains unclear. METHODS AND RESULTS: We performed a retrospective, single-center observational study comparing coronary angiographic CAV outcomes during the first year after transplant in 84 heart transplant recipients of HCV NAT+ donors and 231 recipients of HCV NAT- donors. Additionally, in a subsample of 149 patients (including 55 in the NAT+ cohort and 94 in the NAT- cohort) who had serial adjunctive intravascular ultrasound examination performed, we compared development of rapidly progressive CAV, defined as an increase in maximal intimal thickening of ≥0.5 mm in matched vessel segments during the first year post-transplant. In an unadjusted analysis, recipients of HCV NAT+ hearts had reduced survival free of CAV ≥1 over the first year after heart transplant compared with recipients of HCV NAT- hearts. After adjustment for known CAV risk factors, however, there was no significant difference between cohorts in the likelihood of the primary outcome, nor was there a difference in development of rapidly progressive CAV. CONCLUSIONS: These findings support larger, longer-term follow-up studies to better elucidate CAV outcomes in recipients of HCV NAT+ hearts and to inform post-transplant management strategies.

Preemptive Pharmacogenetic-Guided Metoprolol Management for Postoperative Atrial Fibrillation in Cardiac Surgery: The Preemptive Pharmacogenetic-Guided Metoprolol Management for Atrial Fibrillation in Cardiac Surgery Pilot Trial.

OBJECTIVES: To test the hypothesis that implementation of a cytochrome P-450 2D6 (CYP2D6) genotype-guided perioperative metoprolol administration will reduce the risk of postoperative atrial fibrillation (AF), the authors conducted the Preemptive Pharmacogenetic-Guided Metoprolol Management for Atrial Fibrillation in Cardiac Surgery pilot study. DESIGN: Clinical pilot trial. SETTING: Single academic center. PARTICIPANTS: Seventy-three cardiac surgery patients. MEASUREMENTS AND MAIN RESULTS: Patients were classified as normal, intermediate, poor, or ultrarapid metabolizers after testing for their CYP2D6 genotype. A clinical decision support tool in the electronic health record advised providers on CYP2D6 genotype-guided metoprolol dosing. Using historical data, the Bayesian method was used to compare the incidence of postoperative AF in patients with altered metabolizer status to the reference incidence. A logistic regression analysis was performed to study the association between the metabolizer status and postoperative AF while controlling for the Multicenter Study of Perioperative Ischemia AF Risk Index. Of the 73 patients, 30% (n = 22) developed postoperative AF; 89% (n = 65) were normal metabolizers; 11% (n = 8) were poor/intermediate metabolizers; and there were no ultrarapid metabolizer patients identified. The estimated rate of postoperative AF in patients with altered metabolizer status was 30% (95% CI 8%-60%), compared with the historical reference incidence (27%). In the risk-adjusted analysis, there was insufficient evidence to conclude that modifying metoprolol dosing based on poor/intermediate metabolizer status was associated significantly with the odds of postoperative AF (odds ratio 0.82, 95% CI 0.15-4.55, p = 0.82). CONCLUSIONS: A CYP2D6 genotype-guided metoprolol management was not associated with a reduction of postoperative AF after cardiac surgery.

Normothermic regional perfusion for donation after circulatory death donors.

PURPOSE OF REVIEW: This review is intended to provide an update on the logistics, technique, and outcomes associated with normothermic regional perfusion (NRP), as well as provide a discussion of the associated ethical issues. RECENT FINDINGS: There has been renewed interest in utilizing NRP to increase quality and availability of organs from donation after circulatory death (DCD) donors. Our institution has increasing experience with thoraco-abdominal NRP (TA-NRP) in controlled DCD donors (cDCD), whereas abdominal NRP (A-NRP) has been used with success in both cDCD and uncontrolled DCD (uDCD). There is increasing evidence that NRP can be conducted in a practical and cost-efficient manner, and that the organ yield may be of better quality than standard direct procurement and perfusion (DPP). SUMMARY: NRP is increasingly successful and will likely prove to be a superior method for cDCD recovery. However, before TA-NRP can be widely accepted the ethical debate surrounding this technique must be settled. VIDEO ABSTRACT: http://links.lww.com/COOT/A11.

Simulation Versus Interactive Mobile Learning for Teaching Extracorporeal Membrane Oxygenation to Clinicians: A Randomized Trial.

OBJECTIVES: Extracorporeal membrane oxygenation has become integral to critical care. Data informing optimal extracorporeal membrane oxygenation education modalities are lacking. We aimed to compare the effect of high-fidelity simulation versus interactive mobile learning on extracorporeal membrane oxygenation knowledge acquisition and retention among clinicians. DESIGN: Observer-blinded, randomized controlled trial. SETTING: A single academic medical center. SUBJECTS: Forty-four critical care clinicians with limited extracorporeal membrane oxygenation experience. INTERVENTIONS: Participants were randomized to receive: 1) simulation: three high-fidelity training scenarios, 2) QuizTime: 15 total multiple-choice questions delivered over 3 weeks via mobile device, or 3) experiential: no formal training. Participants completed a survey, written knowledge examination, and simulation assessment prior to randomization, immediately following the intervention, and 4 month postintervention. MEASUREMENTS AND MAIN RESULTS: The primary outcome was knowledge about extracorporeal membrane oxygenation assessed by score on the immediate postintervention written examination. Secondary outcomes included performance in extracorporeal membrane oxygenation simulation postintervention and 4 months later assessed by a rater blinded to group assignment. Clinicians randomized to simulation (n = 15), QuizTime (n = 14), and experiential (n = 15) had similar baseline characteristics. Adjusting for baseline knowledge, postintervention examination scores were higher in the simulation group (90.0%; interquartile range, 85.0-90.0%) than the QuizTime group (70.0%; interquartile range, 65.0-80.0%; p = 0.0003) and the experiential group (75.0%; interquartile range, 65.0-80.0%; p = 0.001). Scores did not differ between the groups at 4 months (p > 0.05 in all analyses). In postintervention extracorporeal membrane oxygenation simulations, the simulation group demonstrated shorter time to critical action compared with QuizTime (80.0 s [interquartile range, 54.0-111.0 s] vs 300.0 s [interquartile range 85.0-300.0 s]; p = 0.02) and compared with both QuizTime (45.0 s [interquartile range, 34.0-92.5 s] vs 255.5 s [interquartile range, 102.0-300.0 s]; p = 0.008) and experiential (300.0 s [interquartile range, 58.0-300.0 s]; p = 0.009) at 4 months. CONCLUSIONS: Simulation was superior to QuizTime and experiential learning with regard to extracorporeal membrane oxygenation knowledge acquisition. Further studies are needed to ascertain the effect of these interventions on knowledge retention, clinical performance, and patient outcomes.

Left Ventricular Unloading During Extracorporeal Life Support: Current Practice.

Venoarterial extracorporeal life support (VA-ECLS) is a powerful tool that can provide complete cardiopulmonary support for patients with refractory cardiogenic shock. However, VA-ECLS increases left ventricular (LV) afterload, resulting in greater myocardial oxygen demand, which can impair myocardial recovery and worsen pulmonary edema. These complications can be ameliorated by various LV venting strategies to unload the LV. Evidence suggests that LV venting improves outcomes in VA-ECLS, but there is a paucity of randomized trials to help guide optimal strategy and the timing of venting. In this review, we discuss the available evidence regarding LV venting in VA-ECLS, explain important hemodynamic principles involved, and propose a practical approach to LV venting in VA-ECLS.

Early United States experience with liver donation after circulatory determination of death using thoraco-abdominal normothermic regional perfusion: A multi-institutional observational study.

Mortality on the liver waitlist remains unacceptably high. Donation after circulatory determination of death (DCD) donors are considered marginal but are a potentially underutilized resource. Thoraco-abdominal normothermic perfusion (TA-NRP) in DCD donors might result in higher quality livers and offset waitlist mortality. We retrospectively reviewed outcomes of the first 13 livers transplanted from TA-NRP donors in the US. Nine centers transplanted livers from eight organ procurement organizations. Median donor age was 25 years; median agonal phase was 13 minutes. Median recipient age was 60 years; median lab MELD score was 21. Three patients (23%) met early allograft dysfunction (EAD) criteria. Three received simultaneous liver-kidney transplants; neither had EAD nor delayed renal allograft function. One recipient died 186 days post-transplant from sepsis but had normal presepsis liver function. One patient developed a biliary anastomotic stricture, managed endoscopically; no recipient developed clinical evidence of ischemic cholangiopathy (IC). Twelve of 13 (92%) patients are alive with good liver function at 439 days median follow-up; one patient has extrahepatic recurrent HCC. TA-NRP DCD livers in these recipients all functioned well, particularly with respect to IC, and provide a valuable option to decrease deaths on the waiting list.

An Unusual Finding in a Patient Presenting for Pulmonary Thromboendarterectomy: Pulmonary Venous Thrombosis.

Pulmonary venous thrombosis (PVT) is a rare but potentially devastating disease state with a largely unknown incidence. The most common etiologies of PVT are secondary to complications of lung surgery, malignancy, catheter ablation for atrial fibrillation, and idiopathic causes. Diagnosis can be challenging because presenting symptoms often are vague and nonspecific, or even asymptomatic, and traditional diagnostic modalities, such as chest radiography and arterial phase computed tomography scans, are poor techniques for diagnosis. The authors present a case of a patient presenting for pulmonary thromboendarterectomy for a presumed diagnosis of chronic thromboembolic pulmonary hypertension who was found incidentally to have a PVT, on intraoperative transesophageal echocardiography. Due to significant thrombus burden, the new finding of PVT, and known association of PVT and malignancy, a biopsy of mediastinal lymph nodes was obtained, which revealed metastatic cervical carcinoma. The pulmonary endarterectomy procedure was aborted.

Limited Balloon Atrial Septostomy for Left Ventricular Unloading in Peripheral Extracorporeal Membrane Oxygenation.

BACKGROUND: This study describes the authors' experience with a limited balloon atrial septostomy technique, using a median balloon size of 15 mm, as a left ventricular (LV) unloading strategy in venoarterial extracorporeal membrane oxygenation (VA-ECMO). There has been increasing use of VA-ECMO in cardiogenic shock. Although LV unloading strategies have been suggested to improve outcomes, it is unclear which strategy is optimal. METHODS AND RESULTS: We performed a retrospective study of patients who underwent a limited balloon atrial septostomy for LV unloading in peripheral VA-ECMO at a single center. The goal of this study was to define the procedural outcomes and clinical characteristics of these patients. Of the 12 patients identified, none had complications related to the procedure. There was a significant decrease in the mean left atrial pressure and the majority of patients had radiologic improvement in pulmonary vascular congestion. Of the 12 patients, 58.3% survived to discharge. CONCLUSIONS: Limited BAS is an elegant and safe method for unloading the LV in peripheral VA-ECMO.

Predicting Length of Stay of Coronary Artery Bypass Grafting Patients Using Machine Learning.

BACKGROUND: There is a growing need to identify which bits of information are most valuable for healthcare providers. The aim of this study was to search for the highest impact variables in predicting postsurgery length of stay (LOS) for patients who undergo coronary artery bypass grafting (CABG). MATERIALS AND METHODS: Using a single institution's Society of Thoracic Surgeons (STS) Registry data, 2121 patients with elective or urgent, isolated CABG were analyzed across 116 variables. Two machine learning techniques of random forest and artificial neural networks (ANNs) were used to search for the highest impact variables in predicting LOS, and results were compared against multiple linear regression. Out-of-sample validation of the models was performed on 105 patients. RESULTS: Of the 10 highest impact variables identified in predicting LOS, four of the most impactful variables were duration intubated, last preoperative creatinine, age, and number of intraoperative packed red blood cell transfusions. The best performing model was an ANN using the ten highest impact variables (testing sample mean absolute error (MAE) = 1.685 d, R2 = 0.232), which performed consistently in the out-of-sample validation (MAE = 1.612 d, R2 = 0.150). CONCLUSION: Using machine learning, this study identified several novel predictors of postsurgery LOS and reinforced certain known risk factors. Out of the entire STS database, only a few variables carry most of the predictive value for LOS in this population. With this knowledge, a simpler linear regression model has been shared and could be used elsewhere after further validation.

No survival benefit associated with waiting for non-lung donor heart transplants for adult recipients with congenital heart disease.

BACKGROUND: Adults with congenital heart disease (CHD) awaiting heart transplant (HT) have higher mortality and waitlist removal due to clinical deterioration than those without CHD. The selective use of non-lung donors (NLD) to recover donor pulmonary vasculature to assist in graft implantation may be a contributing factor and is supported by consensus statements despite the recent use of pericardium or graft material as an alternative in pulmonary vascular reconstruction. The impact of selecting NLD for CHD recipients on wait time and mortality has not been evaluated. METHODS/RESULTS: In the United Network for Organ Sharing (UNOS) Registry, 1271 HT recipients age ≥ 18 with CHD were identified between 1987 and 2016, 68% of which had NLDs. Prior to HT, NLD recipients were significantly less likely to be listed UNOS Status 1A, require mechanical ventilation, or intra-aortic balloon pump support. There was no difference in mean waitlist time (254 vs. 278 days, p = .31), 1-year mortality (82% vs. 80%, p = .81; adjusted odds ratio 1.32, 95% confidence interval [CI] 0.96-1.83, p = .08), or overall mortality (adjusted hazard ratio 1.08, 95% CI 0.86-1.36, p = .48) between recipients from NLD and concomitant lung donors. CONCLUSIONS: Adult CHD patients who are less critically ill or listed at a lower status are more likely to receive HT from NLD. There is no overall mortality benefit associated with this practice. While specific cases may necessitate waiting for NLD, programs need to re-evaluate whether this should remain a more widespread practice among CHD patients.

Adult Combined Heart-Liver Transplantation: The United States Experience.

Background: We aimed to review the indications and outcomes of adults undergoing combined heart-liver transplantation (CHLT) in the US using national registry data. Methods: Adult (≥18 years) CHLT recipients in the United Network for Organ Sharing database were included (09/1987-09/2020; era 1 = 1989-2000, era 2 = 2001-2010, era 3 = 2011-2020). Survival analysis was conducted by means of Kaplan-Meier method, log-rank test, and Cox regression. Results: We identified 369 adults receiving CHLT between 12/1989-08/2020. The number of adult CHLT recipients (R2 = 0.75, p < 0.001) and centers performing CHLT (R2 = 0.80, p < 0.001) have increased over the study period. The most common cardiac diagnosis in the first two eras was restrictive/infiltrative cardiomyopathy, while the most common in era 3 was congenital heart disease (p = 0.03). The 1-, 3-, and 5-years patient survival was 86.8, 80.1, and 77.9%, respectively. In multivariable analysis, recipient diabetes [adjusted hazard ratio (aHR) = 2.35, 95% CI: 1.23-4.48], CHLT between 1989-2000 compared with 2011-2020 (aHR = 5.00, 95% CI: 1.13-22.26), and sequential-liver first CHLT compared with sequential-heart first CHLT (aHR = 2.44, 95% CI: 1.15-5.18) were associated with increased risk of mortality. Higher left ventricular ejection fraction was associated with decreased risk of mortality (aHR = 0.96, 95% CI: 0.92-0.99). Conclusion: CHLT is being increasingly performed with evolving indications. Excellent outcomes can be achieved with multidisciplinary patient and donor selection and surgical planning.

Intraoperative venous congestion and acute kidney injury in cardiac surgery: an observational cohort study.

BACKGROUND: Increased intravascular volume has been associated with protection from acute kidney injury (AKI), but in patients with congestive heart failure, venous congestion is associated with increased AKI. We tested the hypothesis that intraoperative venous congestion is associated with AKI after cardiac surgery. METHODS: In patients enrolled in the Statin AKI Cardiac Surgery trial, venous congestion was quantified as the area under the curve (AUC) of central venous pressure (CVP) >12, 16, or 20 mm Hg during surgery (mm Hg min). AKI was defined using Kidney Disease Improving Global Outcomes (KDIGO) criteria and urine concentrations of tissue inhibitor of metalloproteinase-2 and insulin-like growth factor binding protein 7 ([TIMP-2]⋅[IGFBP7]), a marker of renal stress. We measured associations between venous congestion, AKI and [TIMP-2]⋅[IGFBP7], adjusted for potential confounders. Values are reported as median (25th-75th percentile). RESULTS: Based on KDIGO criteria, 104 of 425 (24.5%) patients developed AKI. The venous congestion AUCs were 273 mm Hg min (81-567) for CVP >12 mm Hg, 66 mm Hg min (12-221) for CVP >16 mm Hg, and 11 mm Hg min (1-54) for CVP >20 mm Hg. A 60 mm Hg min increase above the median venous congestion AUC above each threshold was independently associated with increased AKI (odds ratio=1.06; 95% confidence interval [CI], 1.02-1.10; P=0.008; odds ratio=1.12; 95% CI, 1.02-1.23; P=0.013; and odds ratio=1.30; 95% CI, 1.06-1.59; P=0.012 for CVP>12, >16, and >20 mm Hg, respectively). Venous congestion before cardiopulmonary bypass was also associated with increased [TIMP-2]⋅[IGFBP7] measured during cardiopulmonary bypass and after surgery, but neither venous congestion after cardiopulmonary bypass nor venous congestion throughout surgery was associated with postoperative [TIMP-2]⋅[IGFBP7]. CONCLUSION: Intraoperative venous congestion was independently associated with increased AKI after cardiac surgery.

Impact of implantation time on early function of cardiac transplant.

BACKGROUND: Data on out-of-ice implantation ischemia in heart transplant are scarce. We examined implantation time's impact on allograft dysfunction. METHODS: We conducted a single-site retrospective review of all primary adult heart transplants from June 2012 to August 2019 for implantation warm ischemic time (WIT), defined as first atrial stitch to aortic crossclamp removal. Univariate regression was used to assess the relationship of perioperative variables to primary graft dysfunction (PGD) and to pulmonary artery pulsatility index (PAPi) at postoperative hour 24. A threshold of p < .10 was set for the inclusion of covariates in multivariate regression. Secondary analyses evaluated for consistency among alternative criteria for allograft dysfunction. A post hoc subgroup analysis examined WIT effect in prolonged total ischemia of 240 min or longer. RESULTS: Complete data were available for 201 patients. Baseline characteristics were similar between patients who did and did not have WIT documented. In univariate analysis, female gender, longer total ischemic time (TIT), longer bypass time, greater blood transfusions, and pretransplant intensive care unit (ICU) care were associated with PGD, whereas longer bypass time was associated with worse PAPi and pretransplant ICU care was associated with better PAPi. In multivariate analysis, longer bypass time predicted PGD, and worse PAPi and preoperative ICU admission predicted PGD and better PAPi. Results did not differ in secondary or subgroup analyses. CONCLUSIONS: This study is one of few examining the functional impact of cardiac implantation ischemia. Results suggest allograft implantation time alone may not impact postoperative graft function, which was driven by intraoperative bypass duration and by preoperative ICU care, instead.

Impact of increased donor distances following adult heart allocation system changes: A single center review of 1-year outcomes.

BACKGROUND: On October 18, 2018, several changes to the donor heart allocation system were enacted. We hypothesize that patients undergoing orthotopic heart transplantation (OHT) under the new allocation system will see an increase in ischemic times, rates of primary graft dysfunction, and 1-year mortality due to these changes. METHODS: In this single-center retrospective study, we reviewed the charts of all OHT patients from October 2017 through October 2019. Pre- and postallocation recipient demographics were compared. Survival analysis was performed using the Kaplan-Meier method. RESULTS: A total of 184 patients underwent OHT. Recipient demographics were similar between cohorts. The average distance from donor increased by more than 150 km (p = .006). Patients in the postallocation change cohort demonstrated a significant increase in the rate of severe left ventricle primary graft dysfunction from 5.4% to 18.7% (p = .005). There were no statistically significant differences in 30-day mortality or 1-year survival. Time on the waitlist was reduced from 203.8 to 103.7 days (p = .006). CONCLUSIONS: Changes in heart allocation resulted in shorter waitlist times at the expense of longer donor distances and ischemic times, with an associated negative impact on early post-transplantation outcomes. No significant differences in 30-day or 1-year mortality were observed.

Prioritizing heart transplantation during the COVID-19 pandemic.

BACKGROUND: Coronavirus disease 2019 (COVID-19) has significantly impacted the healthcare landscape in the United States in a variety of ways including a nation-wide reduction in operative volume. The impact of COVID-19 on the availability of donor organs and the impact on solid organ transplant remains unclear. We examine the impact of COVID-19 on a single, large-volume heart transplant program. METHODS: A retrospective chart review was performed examining all adult heart transplants performed at a single institution between March 2020 and June 2020. This was compared to the same time frame in 2019. We examined incidence of primary graft dysfunction, continuous renal replacement therapy (CRRT) and 30-day survival. RESULTS: From March to June 2020, 43 orthotopic heart transplants were performed compared to 31 performed during 2019. Donor and recipient demographics demonstrated no differences. There was no difference in 30-day survival. There was a statistically significant difference in incidence of postoperative CRRT (9/31 vs. 3/43; p = .01). There was a statistically significant difference in race (23 W/8B/1AA vs. 30 W/13B; p = .029). CONCLUSION: We demonstrate that a single, large-volume transplant program was able to grow volume with little difference in donor variables and clinical outcomes following transplant. While multiple reasons are possible, most likely the reduction of volume at other programs allowed us to utilize organs to which we would not have previously had access. More significantly, our growth in volume was coupled with no instances of COVID-19 infection or transmission amongst patients or staff due to an aggressive testing and surveillance program.

Intraoperative Oxidative Damage and Delirium after Cardiac Surgery.

BACKGROUND: Mechanisms of postoperative delirium remain poorly understood, limiting development of effective treatments. We tested the hypothesis that intraoperative oxidative damage is associated with delirium and neuronal injury and that disruption of the blood-brain barrier modifies these associations. METHODS: In a prespecified cohort study of 400 cardiac surgery patients enrolled in a clinical trial of atorvastatin to reduce kidney injury and delirium, we measured plasma concentrations of F2-isoprostanes and isofurans using gas chromatography-mass spectrometry to quantify oxidative damage, ubiquitin carboxyl-terminal hydrolase isozyme L1 to quantify neuronal injury, and S100 calcium-binding protein B using enzyme-linked immunosorbent assays to quantify blood-brain barrier disruption before, during, and after surgery. We performed the Confusion Assessment Method for the Intensive Care Unit twice daily to diagnose delirium. We measured the independent associations between intraoperative F2-isoprostanes and isofurans and delirium (primary outcome) and postoperative ubiquitin carboxyl-terminal hydrolase isozyme L1 (secondary outcome), and we assessed if S100 calcium-binding protein B modified these associations. RESULTS: Delirium occurred in 109 of 400 (27.3%) patients for a median (10th, 90th percentile) of 1.0 (0.5, 3.0) days. In the total cohort, plasma ubiquitin carboxyl-terminal hydrolase isozyme L1 concentration was 6.3 ng/ml (2.7, 14.9) at baseline and 12.4 ng/ml (7.9, 31.2) on postoperative day 1. F2-isoprostanes and isofurans increased throughout surgery, and the log-transformed sum of intraoperative F2-isoprostanes and isofurans was independently associated with increased odds of postoperative delirium (odds ratio, 3.70 [95% CI, 1.41 to 9.70]; P = 0.008) and with increased postoperative ubiquitin carboxyl-terminal hydrolase isozyme L1 (ratio of geometric means, 1.42 [1.11 to 1.81]; P = 0.005). The association between increased intraoperative F2-isoprostanes and isofurans and increased postoperative ubiquitin carboxyl-terminal hydrolase isozyme L1 was amplified in patients with elevated S100 calcium-binding protein B (P = 0.049). CONCLUSIONS: Intraoperative oxidative damage was associated with increased postoperative delirium and neuronal injury, and the association between oxidative damage and neuronal injury was stronger among patients with increased blood-brain barrier disruption.

Mean platelet volume and cardiac-surgery-associated acute kidney injury: a retrospective study.

PURPOSE: Increased mean platelet volume (MPV) may indicate platelet activation, platelet aggregation, and a resulting prothrombotic state. Such changes in the postoperative period have been associated with organ injury and adverse outcomes. We hypothesized that changes in MPV after cardiac surgery are associated with both a higher risk of acute kidney injury (AKI) and mortality. METHODS: In this retrospective study, we evaluated consecutive patients undergoing adult cardiac surgery patients between 12 December 2011 and 5 June 2018. The change in MPV was derived by calculating the difference between the baseline MPV before surgery and the average postoperative MPV just prior to the occurrence of AKI. We defined postoperative AKI according to Kidney Disease: Improving Global Outcomes Clinical Practice Guideline for Acute Kidney Injury as either a ≥ 50% increase in serum creatinine in the first ten postoperative days, or an increase of ≥ 0.3 mg·dL-1 during any 48-hr window across the ten-day postoperative period. Multivariable logistic regression analysis was used to examine the association between MPV change and postoperative AKI and mortality. RESULTS: Of the 4,204 patients studied, 1,373 (32.7%) developed postoperative AKI, including 83 (2.0%) and 38 (0.9%) who developed stages II and III AKI, respectively. Compared with patients who had an increase in median postoperative MPV of 0.2 femtolitre (fL), those with an increase of 0.8 fL had an 80% increase in the odds of developing AKI (adjusted odds ratio [aOR], 1.80; 95% confidence interval [CI],1.36 to 2.38; P < 0.001) and were almost twice as likely to progress to a higher severity AKI (aOR, 1.66; 95% CI, 1.28 to 2.16; P < 0.001). Change in MPV was not associated with mortality (aOR,1.32; 95% CI, 0.92 to 1.89; P = 0.14). CONCLUSION: Increased MPV change in the postoperative period was associated with both increased risk and severity of AKI, but not mortality.

RéSUMé: OBJECTIF: Un volume plaquettaire moyen (VPM) augmenté peut être indicatif d'une activation plaquettaire, d'une agrégation plaquettaire, et de l'état prothrombotique qui en résulte. De tels changements en période postopératoire ont été associés à des lésions aux organes et à des devenirs défavorables. Nous avons émis l'hypothèse que des changements du VPM après une chirurgie cardiaque seraient associés à un risque plus élevé d'insuffisance rénale aiguë et de mortalité. MéTHODE: Dans cette étude rétrospective, nous avons évalué des patients adultes consécutifs subissant une chirurgie cardiaque entre le 12 décembre 2011 et le 5 juin 2018. Le changement de VPM a été dérivé en calculant la différence entre le VPM de base avant la chirurgie et le VPM postopératoire moyen juste avant la survenue de l'IRA. Nous avons défini une IRA postopératoire sur la base des Directives Kidney Disease: Improving Global Outcomes Clinical Practice Guideline for Acute Kidney Injury (Les maladies rénales: Guide d'exercice clinique pour améliorer les devenirs globaux pour l'insuffisance rénale aiguë) en tant qu'une augmentation ≥ 50 % de la créatine sérique au cours des dix premiers jours postopératoires, ou une augmentation de ≥ 0,3 mg·dL−1 pendant toute fenêtre de 48 h au cours des dix premiers jours postopératoires. Une analyse multivariée de régression logistique a été utilisée pour examiner l'association entre le changement de VPM et l'IRA postopératoire et la mortalité. RéSULTATS: Parmi les 4204 patients à l'étude, 1373 (32,7 %) ont souffert d'IRA postopératoire, y compris 83 (2,0 %) et 38 (0,9 %) qui ont développé des IRA de stade II et III, respectivement. Par rapport aux patients ayant manifesté une augmentation du VPM postopératoire médian de 0,2 femtolitre (fL), ceux affichant une augmentation de 0,8 fL ont démontré une augmentation de 80 % de la probabilité d'IRA (rapport de cotes ajusté [RCA], 1,80; intervalle de confiance [IC] 95 %, 1,36 à 2,38; P < 0,001) et couraient un risque pratiquement deux fois plus élevé de voir leur IRA progresser à un stade plus grave (RCA, 1,66; IC 95 %, 1,28 à 2,16; P < 0,001). Les changements de VPM n'étaient pas associés à la mortalité (RCA, 1,32; IC 95 %, 0,92 à 1,89; P = 0,14). CONCLUSION: Une augmentation accrue du VPM en période postopératoire a été associée à un risque et une gravité accrus d'IRA, mais pas à la mortalité.