MONOCYTIC MYELOID-DERIVED SUPPRESSOR CELL EXPANSION AFTER CARDIAC SURGERY WITH CARDIOPULMONARY BYPASS INDUCES LYMPHOCYTE DYSFUNCTION.

ABSTRACT: Cardiac surgery with cardiopulmonary bypass (CPB) is associated with an immune paresis that predisposes to the development of postoperative infections and sepsis. Among factors responsible for CPB-induced immunosuppression, circulating myeloid-derived suppressor cells (MDSCs) have been found to induce early lymphocyte apoptosis and lymphocyte proliferation inhibition. However, the mechanisms involved are not fully understood. In this study, we found that the main lymphocyte subsets decreased significantly 24 h after cardiac surgery with CBP. As expected, cardiac surgery with CPB induced a monocytic MDSC expansion associated with an increased T-cell apoptosis and decreased proliferation capacity. Noteworthy, granulocytic MDSCs remain stable. Myeloid-derived suppressor cell depletion restored the ability of T-cell to proliferate ex vivo . After CPB, indoleamine 2,3-dioxygenase activity and IL-10 plasma level were increased such as programmed death-ligand 1 monocytic expression, whereas plasma level of arginine significantly decreased. Neither the inhibition of indoleamine 2,3-dioxygenase activity nor the use of anti-programmed death-ligand 1 or anti-IL-10 blocking antibody restored the ability of T-cell to proliferate ex vivo . Only arginine supplementation restored partially the ability of T-cell to proliferate.

The impact of iron store on red blood cell transfusion: a multicentre prospective cohort study in cardiac surgery.

BACKGROUND: Anaemia is common prior to cardiac surgery and contributes to perioperative morbidity. Iron deficiency is the main cause of anaemia but its impact remains controversial in the surgical setting. We aimed to estimate the impact of iron deficiency on in-hospital perioperative red blood cell transfusion for patients undergoing elective and urgent cardiac surgery. Secondary objectives were to identify risk factors associated with in-hospital red blood cell transfusion. METHODS: We conducted a prospective multicentre observational study in three university hospitals performing cardiac surgery. We determined iron status prior to surgery and collected all transfusion data to compare iron-deficient and iron-replete patients during hospital stay. We performed a multivariable logistic regression to compare transfusion among groups. RESULTS: Five hundred and two patients were included. A trend of low haemoglobin levels associated with iron deficiency persisted until discharge. Red blood cell transfusion was significantly higher in the group of iron deficient patients during surgery (22% vs 13%, p = 0.017), however the incidence during the whole hospital stay was 31% in the iron-deficient group, not significantly different with the non-deficient group (26%, p = 0.28). Iron deficiency was not independently associated with in-hospital red blood cell transfusion (adjusted OR = 0.85 [0.53-1.36], p = 0.49). CONCLUSIONS: In-hospital red blood cell transfusion was not significantly higher in iron-deficient patients and iron deficiency was not associated with in-hospital red blood cell transfusion in patients undergoing elective and urgent cardiac surgery. Iron deficiency was the main cause of anaemia and anaemia was a strong driver of red blood cell transfusion. Further studies should identify sub-population of iron-deficient patients which may benefit from preoperative iron deficiency management and explore the long-term impact of lower haemoglobin levels at discharge in the iron deficient population.

Successful heart transplantation for COVID-19-associated post-infectious fulminant myocarditis.

Various clinical presentations of the 2019 coronavirus disease (COVID-19) have been described, including post-infectious acute and fulminant myocarditis. Here, we describe the case of a young patient admitted for COVID-19-associated post-infectious fulminant myocarditis. Despite optimal pharmacologic management, haemodynamic status worsened requiring support by veno-arterial extracorporeal membrane oxygenation. Emergent heart transplantation was required at Day 11 given the absence of cardiac function improvement. The diagnosis of post-infectious COVID-19-associated myocarditis was made from both pathologic examination of the explanted heart and positive SARS-CoV-2 serology.

Impact of Preoperative Iron Deficiency on Blood Transfusion in Elective Cardiac Surgery.

OBJECTIVE: To evaluate the incidence and consequences of preoperative iron deficiency in elective cardiac surgery. DESIGN: A prospective observational study. SETTING: The cardiac surgery unit of a university hospital, from November 2016 to February 2017. PARTICIPANTS: All patients presenting for elective cardiac surgery during the study period, with the exclusion of noncardiac thoracic surgeries, surgeries of the descending aorta, endovascular procedures, and patients affected by an iron-metabolism disease. INTERVENTIONS: Transferrin saturation and serum ferritin levels were systematically assessed before surgery, and the care of patients was maintained as usual. MEASUREMENTS AND MAIN RESULTS: Routine analyses, clinical data, and the number of blood transfusions were recorded during the hospital stay. Among the 272 patients included, 31% had preoperative iron deficiency and 13% were anemic. Patients with iron deficiency had significantly lower hemoglobin levels throughout the hospital stay and received blood transfusions more frequently during surgical procedures (31% v 19%, p = 0.0361). Detailed analysis showed that patients with iron deficiency received more red blood cell units. There were no differences in postoperative bleeding, morbidity, or mortality. CONCLUSIONS: Iron deficiency appears to be related to lower hemoglobin levels and more frequent transfusions in elective cardiac surgery. Assessing iron status preoperatively and correcting any iron deficiencies should be one of the numerous actions involved in patient blood management for such surgeries, with the aim of reducing morbidity associated with both anemia and transfusion.

Impact of Low-Dose Hydrocortisone on the Incidence of Atrial Fibrillation in Patients With Septic Shock: A Propensity Score-Inverse Probability of Treatment Weighting Cohort Study.

PURPOSE: Atrial fibrillation (AF) is common in the intensive care unit (ICU), notably in patients with septic shock for whom inflammation is an already identified risk factor. The aim of this study was to evaluate the effect of low-dose hydrocortisone on AF occurrence in patients with septic shock. METHODS: We performed a prospective nonrandomized observational study in 5 academic ICUs in France. From November 2012 to June 2014, all patients ≥16 years having septic shock were included, except those who had a history of AF, had a pacemaker, and/or experienced AF during hospitalization before the onset of shock or in whom the onset of shock occurred prior to admission to the ICU. Hydrocortisone was administered at the discretion of the attending physician. The incidence of AF was compared among patients who received hydrocortisone, and the effect of low-dose hydrocortisone on AF was estimated using the inverse probability treatment weighting method based on propensity scores. RESULTS: A total of 261 patients were included (no-hydrocortisone group, n = 138; hydrocortisone group, n = 123). Atrial fibrillation occurred in 57 (22%) patients. Atrial fibrillation rates were 33 (24%) and 24 (19%) in no-hydrocortisone patients and hydrocortisone patients, respectively. In the weighted sample, the proportion of patients who developed AF was 28.8% in the no-hydrocortisone group and 16.8% in the hydrocortisone group (difference: -11.9%; 95% confidence interval: -23.4% to -0.5%; P = .040). CONCLUSION: In patients with septic shock, low-dose hydrocortisone was associated with a lower risk of developing AF during the acute phase.

Immune Dysfunction After Cardiac Surgery with Cardiopulmonary Bypass: Beneficial Effects of Maintaining Mechanical Ventilation.

UNLABELLED: Cardiac surgery with cardiopulmonary bypass (CPB) induces postoperative immunosuppression and impaired pulmonary function. Maintaining mechanical ventilation (MV) during CPB improves pulmonary function and diminishes postoperative systemic inflammation. However, there are no data about the influence of maintaining MV during CPB on postoperative immune dysfunction. METHODS: Fifty patients were prospectively divided into two groups: without MV during bypass (n = 25) and dead space MV with positive end-expiratory pressure (n = 25). PaO2 (arterial oxygen tension)/FIO2 (inspired oxygen fraction) ratio, CXCL10 (C-X-C motif chemokine 10), CCL2 (chemokine ligand 2), tumor necrosis factor α (TNF-α), interleukin 10 (IL-10), human leukocyte antigen-DR antigen (HLA-DR), monocytic myeloid-derived suppressor cells (Mo-MDSCs, CD14HLA-DR monocytes), and blood cell count were collected before and after surgery. RESULTS: Cardiopulmonary bypass induced a marked immunosuppression with a significant increase in plasmatic levels of TNF-α and IL-10 and a significant decrease in HLA-DR monocytic expression. The postoperative proportion of Mo-MDSCs was subsequently significantly increased. Maintaining MV during CPB significantly improved PaO2/FIO2 ratio and decreased postoperative plasmatic levels of TNF-α and IL-10 compared with patients without MV during CPB. Furthermore, nonventilated patients had a lower lymphocyte count after surgery compared with patients with MV during CPB. CONCLUSION: Our study suggests that maintaining MV during CPB for cardiac surgery decreases postoperative immune dysfunction and could be an interesting strategy to diminish the occurrence of postoperative nosocomial infection without hampering the surgical procedure. However, these findings have to be confirmed in a clinical trial using the incidence of nosocomial infection as an endpoint.