Ozgur Ersoy

HLA Sensitization in End-Stage Heart Failure Patients Supported By Extracorporeal Membrane Oxygenation

Introduction Human leukocyte antigen (HLA) sensitization of heart recipients increases the risk for dysfunction of the cardiac allograft. HLA sensitization rates on extracorporeal membrane oxygenation (ECMO) are unclear. In this retrospective study, we sought to define the possible factors that may induce HLA sensitization in the heart transplant recipients where ECMO bridge to transplantation was employed. Materials and Methods This was a single-center retrospective review in which 23 patients who were supported with ECMO were analyzed. Data on pre-transplant ECMO patients (14-51 years) included: age; diagnosis, duration of mechanical support; use of blood products, volume of transfusion; level of screening panel-reactive antibodies (PRAs); and outcome. PRA>25% was used to define HLA sensitization in both HLA type I and II while PRA>90% was used for highly-sensitized patients. Results 8 patients (34%) became sensitized after ECMO support. The duration of ECMO showed variation between 5 was 21 days. The volume of blood products transfused was 294 ml. Factors like; diagnosis, age and duration of mechanical support did not appear to be linked to HLA sensitization. However, the volume of transfused blood products has been found to be associated and could give rise to HLA sensitization. Conclusion Different studies have shown an increased risk for acute graft failure among patients with elevated pre-transplant anti-HLA antibodies, but others have not. HLA sensitization does occur rarely in ECMO supported patients and may be associated with the large amounts of blood products received during ECMO. Although sensitization may occur, successful transplantation is possible without any evidence of rejection. With increasing number of patients being bridged to heart transplantation, further research is needed to clearly define the significance of allosensitization on ECMO and establish a clear etiology of all factors related.

Left Ventricular Assist Device Management Strategy

Introduction Heart transplantation is the gold standard treatment for end-stage heart failure. The use of left ventricular assist devices (LVAD) is increasing due to the large number of transplant candidates and donor organ limitation. In the final consensus, the LVAD velocities are adjusted according to the interventricular septum position and aortic valve opening frequency. In this study, we aim to present the parameters that we use in patients with LVAD and to find out the answer to the question whether we can recognize in advance the development of right ventricular failure, especially in the context of these parameters. Materials and Methods 62 patients who had LVAD implantation in our clinic between April 2013 and November 2017 were evaluated. Our routine LVAD follow-up includes physical examination findings (hepatomegaly and pretibial edema), LVAD parameters (speed, power, flow), renal and liver function tests, and prothrombin time. Interventricular septum position, right ventricular end diastolic (RVED) and end-systolic diameters and volumes, right ventricle (RV) diastolic and systolic areas, ratio of the short axis of the RV to the long axis of the RV, RV fractional areas, inferior vena cava diameter and association with respiration, tricuspid annular plane systolic excursion (TAPSE), left ventricular end-diastolic (LVED) and end-systolic diameters and volumes and aortic valve expansions were assessed by echocardiography. Results We decided not to use only septum position and aortic valve opening parameters in order to adjust the LVAD rate but looking at all of the parameters mentioned above. In a patient with a volumetric load, although the septum is in the midline, we have found that the LVED diameters and volumes and RVED diameters and volumes have increased compared to the previous findings. Instead of increasing pump flow rates in these patients, we arranged diuretic treatments. The increase in the ratio of the short axis to the long axis of the RV, the RV fractional area and the inferior vena cava diameter was determined as cautionary parameters for developing right ventricular failure. Discussion Various invasive and non-invasive methods are available for optimal adjustment of the speed of the LVAD. Echocardiography is one of the non-invasive methods. Intermittent aortic valve opening and septum position are assessed with echocardiography when LVAD velocity is set. However, these parameters alone may not be enough to evaluate the right ventricular failure that may occur due to long-term use of the device (destination therapy), and may lead to missed sight. Conclusion A complete patient follow-up chart including aortic valve opening and septum position together with LVED volumes and diameters and RV parameters helps to reduce the error margin to a minimum and helps us to organize our treatment strategy.

Unusual Treatment of Unusual Complication: Stenting of Left Ventricular Assist Device Outflow Graft Stenosis

Due to the increase in the number of patients waiting for heart transplantation and shortage of heart donors, both the use of mechanical assist devices and their associated complications increase. Here we present the case of a stenosis occurring in a patient at aortic outflow graft anastomosis for whom we applied a left ventricular assist device, followed by a discussion of the diagnosis, approach, and the treatment we offer in our clinic.