Soluble ST2 is associated with postoperative atrial fibrillation after cardiac surgery in postmenopausal women.

BACKGROUND: Postoperative atrial fibrillation (POAF) represents the most common complication following cardiac surgery. Approximately one-third of patients experiencing POAF transition to atrial fibrillation within a year, challenging the notion of POAF as merely a transient event. Soluble ST2 (sST2) is an established biomarker regarding fibrosis and myocardial stretch, however, its role in predicting the onset of POAF remains unclear. METHODS: Preoperative sST2 levels have been assessed in 496 individuals with no prior history of AF who underwent elective cardiac surgery, including valve, coronary artery bypass graft surgery, or a combined procedure. RESULTS: The average age was 70 years, and 29.4 % were female. Overall, 42.3 % developed POAF. sST2 levels were found to be significantly higher in patients with POAF. Interestingly, sST2 was only predictive of POAF in females with an adjusted OR of 1.894 (95 %CI:1.103-3.253; p = 0.021) and not males (OR:1.091; 95 %CI:0.849-1.402; p = 0.495). Furthermore, within a linear regression model it was observed that for every 1 ng/mL increase in sST2 levels, the average POAF duration extended by 39.5 min (95 %CI:15.8-63.4 min; p = 0.001). CONCLUSION: sST2 predicts the onset of POAF in women but not men undergoing cardiac surgery. Furthermore, sST2 levels were associated with the subsequent burden of POAF. Thus, assessment of sST2 in addition to clinical risk factors could improve risk stratification for development of POAF following elective cardiac surgery.

Is the T2MR Candida Panel a suitable alternative to the SeptiFast for the rapid diagnosis of candidemia in routine clinical practice?

OBJECTIVES: The diagnosis of invasive Candida infection remains challenging because of tests with slow turnaround times or mediocre performance. T2magnetic resonance imaging is a new diagnostic tool. We investigated the diagnostic accuracy of the T2Candida panel (T2) in comparison with blood culture (BC) and the SeptiFast (SF) for the detection of five different Candida species among high-risk intensive care unit patients with suspected candidemia. METHODS: We analysed blood samples collected from patients with suspected candidemia (177 samples from 138 patients) from August 2018 to April 2020. Blood samples were collected and analysed concurrently by BC, SF, and T2Candida. Subsequently, based on clinical and microbiological findings, patient samples were assigned to specific risk categories (proven, probable, and no candidemia). RESULTS: Twenty-two samples from 17 patients were classified as proven candidemia, and 15 samples from 14 patients were classified as probable candidemia. A sensitivity of 68.2% (95% CI, 45-86%) was observed for the BC and the SF, and a sensitivity of 63.6% (95% CI, 41-83%) was observed for the T2 when only cases with proven candidemia were evaluated. For proven and probable candidemia, the sensitivity was 40.5% (95% CI, 23-58%) for BC, 81.1% (95% CI, 65-92%) for SF, and 73.0% (95% CI, 56-86%) for T2. DISCUSSION: The diagnostic performance of SF and T2 was similar. For samples with proven/probable candidemia, SF and T2 had a higher sensitivity compared to BC. Used in conjunction with other diagnostic methods, T2 can replace the no longer available SF for the diagnosis of candidemia, enabling the timely initiation of targeted antifungal therapy.

Hemodynamic and Rhythmologic Effects of Push-Dose Landiolol in Critical Care-A Retrospective Cross-Sectional Study.

BACKGROUND: The highly ß1-selective beta-blocker Landiolol is known to facilitate efficient and safe rate control in non-compensatory tachycardia or dysrhythmia when administered continuously. However, efficacy and safety data of the also-available bolus formulation in critically ill patients are scarce. METHODS: We conducted a retrospective cross-sectional study on a real-life cohort of critical care patients, who had been treated with push-dose Landiolol due to sudden-onset non-compensatory supraventricular tachycardia. Continuous hemodynamic data had been acquired via invasive blood pressure monitoring. RESULTS: Thirty patients and 49 bolus applications were analyzed. Successful heart rate control was accomplished in 20 (41%) cases, rhythm control was achieved in 13 (27%) episodes, and 16 (33%) applications showed no effect. Overall, the heart rate was significantly lower (145 (130-150) vs. 105 (100-125) bpm, p < 0.001) in a 90 min post-application observational period in all subgroups. The median changes in blood pressure after the bolus application did not reach clinical significance. Compared with the ventilation settings before the bolus application, the respiratory settings including the required FiO2 after the bolus application did not differ significantly. No serious adverse events were seen. CONCLUSIONS: Push-dose Landiolol was safe and effective in critically ill ICU patients. No clinically relevant impact on blood pressure was noted.

Relationship of Fibroblast Growth Factor 23 With Hospitalization for Heart Failure and Cardiovascular Outcomes in Patients Undergoing Cardiac Surgery.

Background Fibroblast growth factor 23 (FGF-23) is crucial in regulating phosphate and vitamin D metabolism and is moreover associated with an increased cardiovascular risk. The specific objective of this study was to investigate the influence of FGF-23 on cardiovascular outcomes, including hospitalization for heart failure (HHF), postoperative atrial fibrillation, and cardiovascular death, in an unselected patient population after cardiac surgery. Methods and Results Patients undergoing elective coronary artery bypass graft and/or cardiac valve surgery were prospectively enrolled. FGF-23 blood plasma concentrations were assessed before surgery. A composite of cardiovascular death/HHF was chosen as primary end point. A total of 451 patients (median age 70 years; 28.8% female) were included in the present analysis and followed over a median of 3.9 years. Individuals with higher FGF-23 quartiles showed elevated incidence rates of the composite of cardiovascular death/HHF (quartile 1, 7.1%; quartile 2, 8.6%; quartile 3, 15.1%; and quartile 4, 34.3%). After multivariable adjustment, FGF-23 modeled as a continuous variable (adjusted hazard ratio for a 1-unit increase in standardized log-transformed biomarker, 1.82 [95% CI, 1.34-2.46]) as well as using predefined risk groups and quartiles remained independently associated with the risk of cardiovascular death/HHF and the secondary outcomes, including postoperative atrial fibrillation. Reclassification analysis indicated that the addition of FGF-23 to N-terminal pro-B-type natriuretic peptide provides a significant improvement in risk discrimination (net reclassification improvement at the event rate, 0.58 [95% CI, 0.34-0.81]; P<0.001; integrated discrimination increment, 0.03 [95% CI, 0.01-0.05]; P<0.001). Conclusions FGF-23 is an independent predictor of cardiovascular death/HHF and postoperative atrial fibrillation in individuals undergoing cardiac surgery. Considering an individualized risk assessment, routine preoperative FGF-23 evaluation may improve detection of high-risk patients.

Soluble urokinase plasminogen activator receptor and survival in elective cardiac surgery.

BACKGROUND: The study investigated the prognostic value of soluble urokinase plasminogen activator receptor (suPAR) in patients undergoing cardiac surgery and calculated a simplified biomarker score comprising suPAR, N-terminal pro B-type natriuretic peptide (NT-proBNP) and age. METHODS AND RESULTS: Biomarkers were assessed in a cohort of 478 patients undergoing elective cardiac surgery. After a median follow-up of 4.2 years, a total of 72 (15.1%) patients died. SuPAR, NT-proBNP and age were independent prognosticators of mortality in a multivariable Cox regression model after adjustment for EuroScoreII. We then calculated a simplified biomarker score comprising age, suPAR and NT-proBNP, which had a superior prognostic value compared to EuroScoreII (Harrel's C of 0.76 vs. 0.72; P for difference = 0.02). Besides long-term mortality, the biomarker score had an excellent performance predicting one-year mortality and hospitalization due to heart failure. CONCLUSION: The biomarker suPAR and NT-proBNP were strongly and independently associated with mortality in patients undergoing cardiac surgery. A simplified biomarker score comprising only three variables (age, suPAR and NT-proBNP) performed better than the established EuroScoreII with respect to intermediate and long-term outcome as well as hospitalization due to heart failure. As such, integration of established and upcoming biomarkers in clinical practice may provide improved decision support in cardiac surgery.

Galectin-3 is an independent predictor of postoperative atrial fibrillation and survival after elective cardiac surgery.

BACKGROUND: Postoperative atrial fibrillation (POAF) is a frequent complication after heart surgery and is associated with thromboembolic events, prolonged hospital stay, and adverse outcomes. Inflammation and fibrosis are involved in the pathogenesis of atrial fibrillation. OBJECTIVE: The purpose of this study was to assess whether galectin-3, which reflects preexisting atrial fibrosis, has the potential to predict POAF and mortality after cardiac surgery. METHODS: Four hundred seventy-five consecutive patients (mean age 67.4 ± 11.8 years; 336 (70.7%) male) undergoing elective heart surgery at the Medical University of Vienna were included in this prospective single-center cohort study. Galectin-3 plasma levels were assessed on the day before surgery. RESULTS: The 200 patients (42.1%) who developed POAF had significantly higher galectin-3 levels (9.60 ± 6.83 ng/mL vs 7.10 ± 3.54 ng/mL; P < .001). Galectin-3 significantly predicted POAF in multivariable logistic regression analysis (adjusted odds ratio per 1-SD increase 1.44; 95% confidence interval 1.15-1.81; P = .002). During a median follow-up of 4.3 years (interquartile range 3.4-5.4 years), 72 patients (15.2%) died. Galectin-3 predicted all-cause mortality in multivariable Cox regression analysis (adjusted hazard ratio per 1-SD increase 1.56; 95% confidence interval 1.16-2.09; P = .003). Patients with the highest-risk galectin-3 levels according to classification and regression tree analysis (>11.70 ng/mL) had a 3.3-fold higher risk of developing POAF and a 4.4-fold higher risk of dying than did patients with the lowest-risk levels (≤5.82 ng/mL). CONCLUSION: The profibrotic biomarker galectin-3 is an independent predictor of POAF and mortality after cardiac surgery. This finding highlights the role of the underlying arrhythmogenic substrate in the genesis of POAF. Galectin-3 may help to identify patients at risk of POAF and adverse outcome after cardiac surgery.

The impact of left atrial mechanics on adverse events and clinical outcome after cardiac surgery.

OBJECTIVES: Postoperative atrial fibrillation (POAF) represents a common complication after cardiac surgery that is associated with unfavourable clinical outcome. Identifying patients at risk for POAF is crucial but challenging. This study aimed to investigate the prognostic potential of speckle-tracking echocardiography on POAF and fatal adverse events from a long-term perspective. METHODS: A total of 124 patients undergoing elective cardiac surgery were prospectively enrolled and underwent preoperative speckle-tracking echocardiography. Patients were followed prospectively for the occurrence of POAF within the entire hospitalization and reaching the secondary end points cardiovascular and all-cause mortality. RESULTS: Within the study population 43.5% (n = 53) of enrolled individuals developed POAF. After a median follow-up of 3.9 years, 25 (20.2%) patients died. We observed that patients presenting with POAF had lower global peak atrial longitudinal strain (PALS) values compared to the non-POAF arm {POAF: 14.8% [95% confidence interval (CI): 10.9-17.8] vs non-POAF: 19.4% [95% CI: 14.8-23.5], P < 0.001}. Moreover, global PALS was a strong and independent predictor for POAF [adjusted odds ratio per 1 standard deviation: 0.37 (95% CI: 0.22-0.65), P < 0.001] and independently associated with mortality [adjusted hazard ratio per 1 standard deviation: 0.63 (95% CI: 0.40-0.99), P = 0.048]. Classification and Regression Tree analysis revealed a cut-off value of <17% global PALS as high risk for both POAF and mortality. CONCLUSIONS: Global PALS is associated with the development of POAF following surgery in an unselected patient population undergoing CABG and/or valve surgery. Since patients with global PALS <17% face a poor long-term prognosis, routine assessment of global PALS needs to be considered in terms of proper secondary prevention in the era of personalized medicine.

A Prospective Observational Study on Multiplate®-, ROTEM®- and Thrombin Generation Examinations Before and Early After Implantation of a Left Ventricular Assist Device (LVAD).

Background: Heart failure patients are frequently on coagulation-active medications before LVAD implantation and perioperative bleeding is a frequent complication after left ventricular assist device (LVAD) implantation. The role of point-of-care coagulation tests in assessing bleeding risk for LVAD implantation and the early postoperative time course of these tests is not well established. Methods: We prospectively enrolled 25 patients with terminal heart failure undergoing LVAD implantation. Study related TRAP-, ASPI- and ADP- tests of Multiplate® platelet aggregometry, ROTEM® rotational thromboelastometry (INTEM, EXTEM, FIBTEM), thrombin generation assay and conventional laboratory studies were measured at 11 predefined time-points during the first 21 postoperative days. We examined if preoperative TRAP-, ASPI-, ADP- and ROTEM values are correlated with estimated total blood loss (primary outcome parameter) during the first 21 days after LVAD implantation and compared the baseline values of these measurements between patients with a bleeding event to those without. We performed Spearman's correlation and non-parametric tests for paired and non-paired comparisons. Results: 7 out of 25 (28%) patients experienced a bleeding event of which 4 required surgical revision. Of the preoperatively performed measurements the TRAP test [Spearman's Rho (ρ) = -0.5, p = 0.01], INTEM CFT (ρ = 0.72, p < 0.001), INTEM alpha (-0.7, p < 0.001), EXTEM MCF (ρ = -0.63; p < 0.001), EXTEM alpha (ρ = -0.67; p < 0.001), FIBTEM MCF (ρ = -0.41; p = 0.042), Fibrinogen (Clauss) (ρ = -0.5; p = 0.011), Anti-thrombin activity (ρ = -0.49; p = 0.013) and platelet count (ρ = -0.42; p = 0.034) were significantly correlated to total blood loss. Patients undergoing a surgical bleeding revision had significantly reduced values in TRAP-[31.5 IQR (17.25-43.5U) vs. 69 IQR (52.5-87U); p = 0.004], ASPI-[16.5 IQR (5.5-35.7U) vs. 39 IQR (24.5-62.5U); p = 0.038], ADP-[30 IQR (22-69U) vs. 12.5 IQR (8.7-21.5U); p = 0.01], EXTEM MCF-[63 IQR (57.7-63.7) vs. 67 IQR (65-75.5); p = 0.019] and EXTEM alpha [74 IQR (68.75-74) vs. 79 IQR (78-80.5); p = 0.002] values before LVAD implantation. Conclusion: Multiplate® and ROTEM® measurements before LVAD implantation may identify LVAD candidates with platelet dysfunction and alterations of the primary hemostasis and could guide anesthetists and intensive care practitioners in bleeding risk stratification and in the perioperative clinical management.

The Prognostic Impact of Anti-thrombotic Treatment Strategies After Biological Aortic Valve Replacement.

PURPOSE: Optimal antithrombotic therapy in patients who underwent surgical biological aortic valve replacement (AVR) represents an issue of ongoing discussion. Additionally, the prognostic impact of anti-thrombotic treatment strategies after biological AVR and real-life data on anticoagulation strategies (AC) of patients presenting with short-term postoperative atrial fibrillation (POAF) has not clearly been investigated so far. Therefore, this study aimed to investigate the impact of therapeutic AC after biological AVR on patient outcome and whether the presence of POAF affects decision making on anti-thrombotic management. METHODS: Within this prospective observational study, 200 individuals that underwent biological AVR surgery were enrolled. Participants were followed prospectively until the primary study endpoint was reached. Multivariate logistic regression analysis was performed to elucidate the effect of therapeutic AC on outcome. RESULTS: Overall, 106 individuals received therapeutic AC at the time of discharge. The fraction of patients presenting with POAF was balanced between individuals receiving AC and the non-AC subgroup (p = 0.617). After a median follow-up time of 1418 days, 31 (15.5%) individuals died, referring to 15 (13.9%) POAF-free patients and 16 (17.4%) with POAF. We observed a strong inverse association of therapeutic AC and cardiovascular mortality, which remained stable after adjustment for potential confounders showing a HR of 0.437 (95% CI 0.202-0.943; p = 0.035), while bleeding risk was comparable (p = 0.680). CONCLUSION: Within this investigation, therapeutic AC showed a strong and independent inverse association with long-term mortality in patients that underwent biological AVR. Although POAF is associated with thromboembolic adverse events, the development of this arrhythmia did not affect decision-making of the anti-thrombotic management.

Perioperative Risk Factors for Intensive Care Unit Readmissions and Mortality After Cardiac Surgery.

OBJECTIVE: The aim of this study was to identify perioperative risk factors associated with intensive care unit readmission and in-hospital death after cardiac surgery. DESIGN: Retrospective analysis using a multivariate regression model to identify independent risk factors for intensive care unit [ICU] readmission and in-hospital mortality. SETTING: The study was carried out in a single tertiary-care hospital. PARTICIPANTS: This was an analysis of 2,789 adult patients. INTERVENTIONS: All patients underwent cardiac surgery and were admitted to the intensive care unit perioperatively at the General Hospital Vienna. MEASUREMENTS AND MAIN RESULTS: Among the 2,789 patients included in the analysis, 167 (6%) were readmitted to the intensive care unit during the same hospital stay. Preoperative risk factors associated with ICU readmission included end-stage renal failure (odds ratio [OR] 2.80, 95% CI: 1.126-6.964), arrhythmia (OR 1.59, 95% CI: 1.019-2.480), chronic obstructive pulmonary disease (OR 1.51, 95% CI: 1.018-2.237), age >80 (OR 2.55, 95% CI: 1.189-5.466), and European System for Cardiac Operative Risk Evaluation II >8 (OR 1.40, 95% CI: 1.013-1.940). Readmitted patients were more likely to die than nonreadmitted patients (OR 5.3, 95% CI: 3.284-8.558). In-hospital mortality in readmitted patients was 19.2%, whereas that in the nonreadmitted study population was 5.1%. CONCLUSION: Preoperative risk assessment is crucial for identifying cardiac surgery patients at risk of ICU readmission and in-hospital death. The potentially modifiable risk factors pinpointed by this study call for the optimization of care before surgery and after ICU discharge.

The Prognostic Potential of Growth Differentiation Factor-15 on Bleeding Events and Patient Outcome after Cardiac Surgery-A Prospective Cohort Study.

BACKGROUND: GDF-15 (growth/differentiation factor 15) is induced by myocardial stretch, volume overload, inflammation, and oxidative stress. Its expression is tightly linked with cardiovascular events as well as the risk for major bleeding and all-cause mortality. The present study aimed to elucidate the prognostic potential of GDF-15 in patients after cardiac surgery. METHODS: A total of 504 patients undergoing elective cardiac valve and/or coronary artery bypass graft surgery were prospectively enrolled. GDF-15 levels were measured prior to surgery to evaluate the impact on bleeding events, thromboembolic events, and mortality. RESULTS: Preoperative GDF-15 was associated with the primary endpoint of intra- and postoperative red blood cell transfusion (for bleeding risk factors adjusted [adj] OR [odds ratio] per 1-SD [standard deviation] of 1.62 [95% confidence interval [CI]: 1.31-2.00]; p < 0.001). Higher concentrations of GDF-15 were observed in patients reaching the secondary endpoint of major or clinically relevant minor bleeding (for bleeding risk factors adj. OR per 1-SD of 1.70 [95% CI: 1.05-2.75]; p = 0.030) during the first postoperative year, but not for thromboembolic events. GDF-15 was a predictor for cardiovascular mortality (for comorbidities adj. HR [hazard ratio] per 1-SD of 1.67 [95% CI: 1.23-2.27]; p = 0.001) and all-cause mortality (for comorbidities adj. HR per 1-SD of 1.55 [95% CI: 1.19-2.01]; p = 0.001). A combined risk model of GDF-15 and EuroSCORE II outperformed the EuroSCORE II alone for long-term survival (C-index: 0.75 [95% CI: 0.70-0.80], p = 0.046; net reclassification improvement: 33.6%, p < 0.001). CONCLUSION: Preoperative GDF-15 concentration is an independent predictor for intra- and postoperative major bleeding, major bleeding during the first year, and for long-term cardiovascular or all-cause mortality after cardiac surgery.

Can Heparin-Coated ECMO Cannulas Induce Thrombocytopenia in COVID-19 Patients?

Extracorporeal membrane oxygenation (ECMO) is often used in the management of COVID-19-related severe respiratory failure. We report the first case of a patient with COVID-19-related ARDS on ECMO support who developed symptoms of heparin-induced thrombocytopenia (HIT) in the absence of heparin therapy. A low platelet count of 61 G/L was accompanied by the presence of circulating HIT antibodies 12 days after ECMO initiation. Replacement of the ECMO system including cannulas resulted in the normalization of the platelet count. However, the clinical situation did not improve, and the patient died 9 days later. Careful consideration of anticoagulant therapy and ECMO circuit, as well as routine HIT antibody testing, may prevent a fatal course in ECMO-supported COVID-19 patients.

The impact of invasive respiratory support on the development of postoperative atrial fibrillation following cardiac surgery.

STUDY OBJECTIVE: Postoperative atrial fibrillation (POAF) is a frequent complication after cardiac valve- or coronary artery bypass (CABG) surgery and is associated with increased mortality. While it is known that prolonged postoperative invasive ventilation triggers POAF, the impact of ventilatory settings on POAF development has not been studied yet. DESIGN: Prospective observational study. SETTING: Postoperative Intensive Care Unit. PATIENTS: Patients having undergone elective CABG and/or cardiac valve surgery. MEASUREMENTS: Screening for the development of POAF. Patients' clinical data and postoperative ventilatory settings (driving pressure, controlled pressure above positive endexpiratory pressure (PEEP), respiration rate, and FiO2) were investigated to elucidate their impact on POAF. MAIN RESULTS: Out of 441 enrolled individuals, a total of 192 participants developed POAF (43.5%). We observed that POAF patients received a higher peak driving pressure, and a higher peak respiration rate than non-POAF individuals. Within the multivariate regression model, plateau pressure (adjusted OR 1.199 [1.038-1.661], p = 0.019), driving pressure (adjusted OR 1.244 [1.103-1.713], p = 0.021), and peak respiration rate (adjusted OR 1.206 [1.005-1.601], p = 0.040) proved to be independently associated with the development of POAF. CART analysis revealed a cut-off of ≥17.5 cmH2O of plateau pressure, ≥11.5 cmH2O of driving pressure and ≥ 17 respirations per minute as high-risk for POAF development. CONCLUSIONS: The ventilatory settings of plateau pressure, driving pressure, and respiration rate after cardiac surgery influence POAF occurrence probability. Optimized postoperative care such as lung-protective ventilation and increased awareness towards postoperative ventilatory efforts should be considered to prevent POAF development and poor patient outcome.

Pseudothrombocytopenia Inducing Nonindicated Platelet Transfusion after Cardiac Surgery.

Pseudothrombocytopenia (PTCP) is an in vitro phenomenon of low platelet count caused by the agglutination of platelets, leading to false low platelet counts in automated cell counting. Typically, ethylenediaminetetraacetic acid (EDTA) mediates this platelet clumping. PTCP has little clinical significance, but misdiagnosis may lead to unnecessary diagnostic tests and treatment. In this case report, we present a 65-year-old Caucasian female suffering from multiple complications during and after cardiac surgery. During her postoperative stay at the ICU, she was diagnosed with thrombocytopenia and an inadequate response to platelet supplementation.

The Prognostic Potential of Atrial Natriuretic Peptide on the Development of Postoperative Atrial Fibrillation after Cardiac Surgery.

BACKGROUND: Postoperative atrial fibrillation (POAF) represents a common complication after cardiac surgery associated with major adverse events and poor patient outcome. Tools for risk stratification of this arrhythmia remain scarce. Atrial natriuretic peptide (ANP) represents an easily assessable biomarker picturing atrial function and strain; however, its prognostic potential on the development of POAF has not been investigated so far. METHODS: Within the present investigation, 314 patients undergoing elective cardiac surgery were prospectively enrolled. Preoperative mid-region proANP (MR-proANP) values were assessed before the surgical intervention. Patients were followed prospectively and continuously screened for the development of arrhythmic events. RESULTS: A total of 138 individuals (43.9%) developed POAF. Median concentrations of MR-proANP were significantly higher within the POAF group (p < 0.001). MR-proANP showed a strong association with the development of POAF with a crude odds ratio (OR) of 1.68 per 1 standard deviation (1-SD; 95% confidence interval [CI]: 1.31-2.15; p < 0.001), which remained stable after comprehensive adjustment for confounders with an adjusted OR of 1.74 per 1-SD (95% CI: 1.17-2.58; p = 0.006). The discriminatory power of MR-proANP for the development of POAF was validated by the category-free net reclassification improvement (0.23 [95% CI: 0.0349-0.4193]; p = 0.022) and integrated discrimination increment (0.02 [95% CI: 0.0046-0.0397], p = 0.013). CONCLUSION: MR-proANP proved to be a strong and independent predictor of the development of POAF. Considering a personalized diagnostic and prognostic preoperative work-up, a standardized preoperative evaluation of MR-proANP levels might help to identify patients at risk for development of POAF after cardiac surgery.

Initial Postoperative Hemoglobin Values Are Independently Associated With One-Year Mortality in Patients Undergoing Double-Lung Transplantation Requiring Intraoperative Transfusion.

OBJECTIVE: To evaluate the association of postoperative hemoglobin values and mortality in patients undergoing double- lung transplantation with intraoperative transfusion. DESIGN: Retrospective cohort study. SETTING: University hospital. PARTICIPANTS: Adult patients who underwent double-lung transplantation at the authors' institution, with intraoperative transfusion of packed red blood cells between 2009 and 2015. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Intraoperative transfusion requirements and general characteristics of 554 patients were collected. A generalized additive model, controlling for postoperative hemoglobin levels, number of transfused units of packed red blood cells, perioperative change in hemoglobin levels, disease leading to lung transplantation, and postoperative extracorporeal membrane oxygenation, was created to predict one-year mortality. A postoperative hemoglobin level of 11.3 g/dL was calculated as an optimal cutoff point. The patients were stratified according to this level. The end -point was all-cause one-year mortality after double-lung transplantation, assessed using the Kaplan-Meier analysis with log-rank test. All-cause mortality of the 554 patients was 17%. Postoperatively, 171 patients (31%) were categorized as being below the cutoff point. Improved survival was observed in the group with higher postoperative hemoglobin values (p = 0.002). CONCLUSION: Lower postoperative hemoglobin levels in double-lung transplantation recipients were associated with increased mortality during the first year after surgery. Confirmation of these findings in additional investigations could alter patient blood management for double-lung transplantation.

The impact of volume substitution on post-operative atrial fibrillation.

BACKGROUND: Post-operative atrial fibrillation (POAF) represents a common complication after cardiac valve or coronary artery bypass surgery. While strain of atrial tissue is known to induce atrial fibrillating impulses, less attention has been paid to potentially strain-promoting values during the peri- and post-operative period. This study aimed to determine the association of peri- and post-operative volume substitution with markers of cardiac strain and subsequently the impact on POAF development and promotion. RESULTS: A total of 123 (45.4%) individuals were found to develop POAF. Fluid balance within the first 24 hours after surgery was significantly higher in patients developing POAF as compared to non-POAF individuals (+1129.6 mL [POAF] vs +544.9 mL [non-POAF], P = .044). Post-operative fluid balance showed a direct and significant correlation with post-operative N-terminal pro-brain natriuretic peptide (NT-ProBNP) values (r = .287; P = .002). Of note, the amount of substituted volume significantly proved to be a strong and independent predictor for POAF with an adjusted odds ratio per one litre of 1.44 (95% CI: 1.09-1.31; P = .009). In addition, we observed that low pre-operative haemoglobin levels at admission were associated with a higher need of intraoperative transfusions and volume-demand. CONCLUSION: Substitution of larger transfusion volumes presents a strong and independent predictor for the development of POAF. Via the observed distinct association with NT-proBNP values, it can reasonably be assumed that post-operative atrial fibrillating impulses are triggered via increased global cardiac strain. Optimized pre-operative management of pre-existing anaemia should be considered prior surgical intervention in terms of a personalized patient care.

Interdependence of VA-ECMO output, pulmonary congestion and outcome after cardiac surgery.

BACKGROUND: Venoarterial-extracorporeal membrane oxygenation (VA-ECMO) is a life-saving method for patients with low-output failure after cardiac surgery. However, VA-ECMO therapy may increase left ventricular afterload due to retrograde blood flow in the aorta, which may lead to progression of pulmonary congestion. We examined the predictive value of pulmonary congestion in patients that need VA-ECMO support after cardiovascular surgery. METHODS: We enrolled a total of 266 adult patients undergoing VA-ECMO support following cardiovascular surgery at a university-affiliated tertiary care centre into our single-center registry. Pulmonary edema was assessed on bedside chest X rays at day 0, 3, 5 after VA-ECMO implantation. RESULTS: Median age was 65 (57-72) years, 69% of patients were male and 30-day survival was 63%. At ICU-admission 20% of patients had mild, 54% had moderate and 26% showed severe pulmonary congestion. Pulmonary congestion at day 0 was not associated with outcome (adjusted HR 1.31; 95%-CI 0.89-1.93;P = 0.18), whereas pulmonary congestion at day 3 (adj. HR 2.81; 95%-CI 1.76-4.46;P<0.001) and day 5 (adj. HR 3.01;95%-CI 1.84-4.93;P<0.001) was significantly associated with survival. Linear regression revealed that out of left ventricular function, cardiac output, central venous saturation, maximum dobutamine and norepinephrine dose as well as fluid balance solely ECMO rotation was associated with the evolution of pulmonary congestion (P = 0.007). CONCLUSIONS: Pulmonary edema three and five days after ECMO implantation are associated with poor survival. Interestingly, a high VA-ECMO output was the most important determinant of worsening pulmonary congestion within the first five days.

CD8+CD28null T Lymphocytes are Associated with the Development of Atrial Fibrillation after Elective Cardiac Surgery.

BACKGROUND: Postoperative atrial fibrillation (POAF) is assumed as a complex and multifactorial interaction of different pathogenic factors. Data suggests an inflammatory process as the main trigger of this specific type of atrial fibrillation. CD8+ T lymphocytes that lack the surface protein CD28 were found to be crucially involved in chronic inflammatory processes within the cardiovascular system. Of utmost interest, these so-called CD8+CD28null T cells are known to present with autoaggressive behavior and deleterious cytotoxic effects on human tissue. METHODS: A total of 129 patients undergoing elective cardiac valve and/or coronary artery bypass graft surgery were enrolled. Fluorescence-activated cell sorting was performed to investigate lymphocyte subsets. Patients were stratified in two subgroups according to patients developing POAF (n = 60) and individuals free of POAF (n = 69). RESULTS: Comparing patients developing POAF to individuals free of POAF, the fraction of CD8+ lymphocytes was significantly higher in individuals developing POAF (30.5% [POAF] vs. 25.7% [no-POAF]; p = 0.021). Interestingly, also the fraction of CD8+CD28null T lymphocytes was significantly higher in the POAF subgroup (66.7% [POAF] vs. 61.6% [non-POAF]; p = 0.043). Multivariate logistic regression proved that the fraction of CD8+CD28null cells is a strong and independent prognosticator for the development of POAF with an adjusted odds ratio per 1 standard deviation of 3.21 (95% confidence interval 1.01-10.18; p = 0.048). CONCLUSION: We found that cytotoxic CD8+CD28null T lymphocytes proved to be a strong and independent predictor for the development of POAF after elective cardiac surgery. Our results potentially indicate an autoimmune impact of this preexisting, highly cytotoxic T cell subset in the pathogenesis of POAF.

An Extended Duration of the Pre-Operative Hospitalization is Associated with an Increased Risk of Healthcare-Associated Infections after Cardiac Surgery.

Nosocomial infections are a common complication in clinical practice with major impact on surgical success and patient outcome. The probability of nosocomial infections is rapidly increasing during hospitalization. Therefore, we investigated the impact of a prolonged pre-operative hospital stay on the development of post-operative infection. Within this prospective observational study, 200 patients scheduled for elective cardiac surgery were enrolled. Patients were followed during hospital admission and screened for the development of nosocomial infection. Logistic regression analysis was used to assess the impact of a prolonged pre-operative hospital stay on the development of infection. A total of 195 patients were suitable for the final analysis. We found a strong and direct association of the duration of pre-operative hospital stay and the number of patients developing infection (+23.5%; p = 0.006). Additionally, the length of patients' pre-operative hospital stay was independently associated with the development of post-operative nosocomial infection, with an adjusted OR per day of 1.38 (95%CI: 1.02-1.86; p = 0.036). A prolonged pre-operative hospital stay was significantly associated with the development of nosocomial infection after cardiac surgery. Those findings need to be considered in future clinical patient management in order to prevent unnecessary antibiotic use and potential harm to patients.