Antibody-Mediated Rejection in Heart Transplantation: Case Presentation with a Review of Current International Guidelines

Antibody-mediated rejection (AMR) (humoral rejection) of cardiac allografts remains difficult to diagnose and treat. Interest in AMR of cardiac allografts has increased over the last decade as it has become apparent that untreated humoral rejection threatens graft and patient survival. An international and multidisciplinary consensus group has formulated guidelines for the diagnosis and treatment of AMR and established that identification of circulating or donor-specific antibodies is not required and that asymptomatic AMR, that is, biopsy-proven AMR without cardiac dysfunction is a real entity with worsened prognosis. Strict criteria for the diagnosis of cardiac AMR have not been firmly established, although the diagnosis relies heavily on tissue pathological findings. Therapy remains largely empirical. We review an unfortunate experience with one of our patients and summarize recommended criteria for the diagnosis of AMR and potential treatment schemes with a focus on current limitations and the need for future research and innovation

Blunt trauma as a suspected cause of delayed constrictive pericarditis: a case report

<p>Abstract</p> <p>Introduction</p> <p>Constrictive pericarditis is a heterogeneous disease with many causes. Traumatic hemopericardium is an uncommon initiating cause. We report the case of a man developing constrictive pericarditis after blunt chest trauma, in order to highlight an approach to diagnosing the condition and to raise awareness of the possibility of this condition developing after blunt trauma.</p> <p>Case presentation</p> <p>A 72-year-old Caucasian man presented initially to our outpatient clinic with a one-year history of progressively worsening dyspnea, and recent onset of edema of the legs. He was later taken to the emergency department and admitted to hospital. He had previously received unsuccessful treatment from his local primary physicians for suspected respiratory disorder and cellulitis of his legs. Echocardiography showed evidence of pericardial constriction, and computed tomography revealed nodular, lobulated thickening of the pericardium and pleura bilaterally. Interventional biopsies were taken, but gave inconclusive results. Thus, as pericarditis and/or advanced malignancy were suspected, diagnostic video-assisted thoracoscopic surgery was performed to take biopsies from the abnormal lung and pericardial tissue. Examination of these supported the diagnosis of pericarditis, as acute and chronic inflammation and fibrous thickening were found, with no evidence of malignancy. Our patient underwent cardiac catheterization, which revealed three-vessel coronary artery disease. Emergency total pericardiectomy and coronary bypass were performed. Having excluded other common initiating factors, we considered that a blunt trauma that our patient had previously sustained to his chest was the potential cause of the constrictive pericarditis.</p> <p>Conclusion</p> <p>This was an interesting case of blunt chest trauma followed by progressive pericardial and pleural thickening. Subsequent development of chronic constrictive pericarditis occurred, requiring treatment by surgical pericardiectomy, as the clinical course of constrictive pericarditis is usually progressive without surgical intervention. Diagnosis of constrictive pericarditis remains challenging. Although uncommon, blunt trauma should be considered as a possible initiating cause. Delayed presentation of constrictive pericarditis should also be considered as a possible morbidity in a patient who has sustained blunt chest trauma. Our case also highlights the importance of performing echocardiography promptly in patients experiencing ongoing symptoms of congestive heart failure to allow earlier diagnosis of constrictive pericarditis or other cardiac disorders, and avoid unnecessary treatments.</p

Outcomes from elective colorectal cancer surgery during the SARS-CoV-2 pandemic

This study aimed to describe the change in surgical practice and the impact of SARS-CoV-2 on mortality after surgical resection of colorectal cancer during the initial phases of the SARS-CoV-2 pandemic

Mechanical ventilation and the total artificial heart: optimal ventilator trigger to avoid post-operative autocycling - a case series and literature review

<p>Abstract</p> <p>Many patients with end-stage cardiomyopathy are now being implanted with Total Artificial Hearts (TAHs). We have observed individual cases of post-operative mechanical ventilator autocycling with a flow trigger, and subsequent loss of autocycling after switching to a pressure trigger. These observations prompted us to do a retrospective review of all TAH devices placed at our institution between August 2007 and May 2009. We found that in the immediate post-operative period following TAH placement, autocycling was present in 50% (5/10) of cases. There was immediate cessation of autocycling in all patients after being changed from a flow trigger of 2 L/minute to a pressure trigger of 2 cm H₂O. The autocycling group was found to have significantly higher CVP values than the non-autocycling group (P = 0.012). Our data suggest that mechanical ventilator autocycling may be resolved or prevented by the use of a pressure trigger rather than a flow trigger setting in patients with TAHs who require mechanical ventilation.</p

Plasmapheresis During Cardiopulmonary Bypass: A Proposed Treatment For Presensitized Cardiac Transplantation Patients

Potential thoracic organ transplantation recipients who have positive cytotoxic antibody screens as quantified panel reactive antibodies (PRA) are at risk for immediate or long-term immunologic events that may affect the donor organ. The patient population at risk includes those who are supported with cardiac assist devices, multiparous women, and individuals receiving numerous homologous blood products. We treated three highly positive PRA patients with intraoperative plasmapheresis coupled to the cardiopulmonary bypass system to remove sufficient cytotoxic antibody. Upon the availability of donor hearts of an unknown HLA type, intraoperative plasmapheresis was performed using a Cobe Spectra Plasmapheresis system coupled to a Terumo CXSX18 oxygenator system. Three plasma volume exchanges of fresh frozen plasma (FFP) were performed while the patients were on cardiopulmonary bypass. One to one and one-half plasma volume exchange plasmaphereses were performed with a declining schedule for the next 30 days post-transplantation in combination with aggressive B-cell specific immunosuppressive therapy. The three patients are NYHA functional class I and free of rejection at 6 months post-transplantation. In conclusion, intraoperative plasmapheresis is effective and safe for the patient who would not be otherwise transplanted because of markedly elevated PRAs

Inflammatory Mediated Chronic Anemia in Patients Supported with a Mechanical Circulatory Assist Device

It is widely accepted and clinically anticipated that the patient implanted with a mechanical circulatory assist device (MCAD) will develop a state of chronic anemia that will last throughout the duration of MCAD support. Large-scale hemolysis mediated by the high sheer stress transmitted to the erythrocytes (RBCs) from the mechanical action of most MCAD systems is the accustomed mechanism responsible for this anemic status. MCAD patients exhibiting chronic anemia require frequent blood transfusions placing the patients at a high infectious risk to maintain an acceptable hematocrit. It is also acknowledged that the biomaterial interaction of the MCAD with the immune system precipitates a chronic inflammatory state in this patient population. Taken together, we hypothesize that inflammatory mediation of the erythropoiesis pathway at multiple sites—limiting the replacement of lysed RBCs—dictates the extent of chronic anemia in MCAD patients more than mechanical trauma to the blood. Hematological parameters were retrospectively analyzed for 78 patients implanted with a mechanical circulatory assist device for greater than 30 days at the University of Arizona Health Sciences Center between the years 1996 to 2002. Analysis demonstrates that the rate of hemolysis slows after MCAD implantation, marked by a progressively decreasing plasma hemoglobin concentration. In addition, the absolute reticulocyte count, a marker of juvenile RBC production, increases and remains above maximum normal values after MCAD implantation. Furthermore, the mean cell hemoglobin concentration indicates sufficient substrate for RBC development and maturation. However, hematocrit, a conventional marker of anemia, drops and remains below minimum normal value throughout the measured time period. A state of anemia in the MCAD supported patient results initially from the effect of hemolysis associated with the mechanical action of the MCAD, then chronically persists as the result of another undetermined mechanism. Given the state of chronic inflammation in the patient population, immunological activation most likely limits the full production of RBCs to their mature state

High Molecular Weight von Willebrand Factor Multimer Loss and Bleeding in Patients with Short-Term Mechanical Circulatory Support Devices: A Case Series

Acquired von Willebrand syndrome (VWS) due to loss of high-molecular-weight multimers (HMWMs) has been reported with longer term mechanical devices and is associated with mucosal bleeding, a primary hemostasis type of bleeding. However, little is known whether a similar defect occurs in patients with short-term mechanical circulatory support (STMCS) devices. We reviewed von Willebrand factor (VWF) profiles in patients with STMCS devices who underwent VWS workup from December 2015 to March 2017 at an academic quaternary care hospital. There were a total of 18 patients (57.0 ± 12.7 years old; 83.3% male) including nine with mucosal bleeding and nine with decreasing hemoglobin. The STMCS devices included Impella (n = 11), Impella and right ventricular assist device (n = 2), and an extracorporeal membrane oxygenator (n = 5). The mean HMWM by quantitative VWF multimer analysis was 3.6% ± 1.3% (normal cutoff: 18–34%). In all 10 cases in which VWF activity, fibrinogen, factor VIII, or VWF antigen level were obtained, they were either normal or elevated. All cases demonstrated high normal or elevated levels of low molecular weight multimers (LMWMs). These findings are consistent with type 2 VWS (qualitative defect). This is the first study that quantitatively describes STMCS device–associated HMWM loss, which may contribute to mucosal bleeding. This finding may have implications for intraoperative management during implantation of longer term devices or heart transplantation or other surgery while on STMCS

Platelet Mapping by Thromboelastography and Whole Blood Aggregometry in Adult Patients Supported by Mechanical Circulatory Support Device on Aspirin Therapy

Patients on mechanical circulatory support (MCS) devices are placed on aspirin and may require platelet function testing (PFT) to monitor the adequacy of therapy. Routine laboratory PFT is performed using whole blood aggregation (WBA) which typically has a long turnaround time (4–5 hours) and may not be readily available. By contrast, platelet mapping by thromboelastography (TPM) can provide results within 45 minutes. The objective of this study was to compare the results of TPM with WBA. We compared platelet mapping maximal amplitude (MA) by TPM with that of arachidonic acid (AA) to WBA with AA by impedance. We analyzed paired samples where both TPM and WBA were available. Of 45 paired samples, 34 were from 29 MCS patients and 11 were from non-MCS patients. When applying institutional interpretation guidelines with an MAActivator cutoff of ≤40 mm, WBAAA vs TPM MAAA in non-MCS and MCS patients correlated well with an accuracy of 100 and 94.4%, respectively. MAActivator >40 had poor correlation with an accuracy of 37.5%. Irrespective of MAActivator value, TPM AA inhibition expressed in percent of inhibition had poor accuracy. When used with proper guidelines for interpretation, specifically when MAActivator ≤ 40 mm, TPM is a suitable and reliable test to use for MCS patients on aspirin