Hyperbilirubinaemia after cardiac surgery: the point of no return

Hepatic function markers as prognostic factors in patients with acute kidney injury undergoing continuous renal replacement therapy

Acute kidney injury (AKI) requiring continuous renal replacement therapy (CRRT), secondary to cardiovascular disease and sepsis, is associated with high in-hospital mortality. Although studies have examined cardiovascular disease and sepsis in AKI, the association between AKI and hepatic functional impairment remains unclear. We hypothesized that hepatic function markers would predict mortality in patients undergoing CRRT. We included 1,899 CRRT patients from a multi-centre database. In Phase 1, participants were classified according to the total bilirubin (T-Bil) levels on the day of, and 3 days after, CRRT initiation: T-Bil < 1.2, 1.2 ≤ T-Bil < 2, and T-Bil ≥ 2 mg/dL. In Phase 2, propensity score matching (PSM) was performed to examine the effect of a T-Bil cutoff of 1.2 mg/dL (supported by the Sequential Organ Failure Assessment score); creating two groups based on a T-Bil cutoff of 1.2 mg/dL 3 days after CRRT initiation. The primary endpoint was total mortality 90 days after CRRT initiation, which was 34.7% (n = 571). In Phase 1, the T-Bil, aspartate transaminase (AST), alanine transaminase (ALT), and AST/ALT (De Ritis ratio) levels at CRRT initiation were not associated with the prognosis, while T-Bil, AST, and the De Ritis ratio 3 days after CRRT initiation were independent factors. In Phase 2, T-Bil ≥1.2 mg/dL on day 3 was a significant independent prognostic factor, even after PSM [hazard ratio: 2.41 (95% CI; 1.84-3.17), p < 0.001]. T-Bil ≥1.2 mg/dL 3 days after CRRT initiation predicted 90-day mortality. Changes in hepatic function markers in acute renal failure may enable stratification of high-risk patients.

Bilirubin Elevation During Hospitalization Post Radiofrequency Catheter Ablation of Persistent Atrial Fibrillation: Variation Trend, Related Factors, and Relevance to 1-Year Recurrence

Background

The role of total bilirubin (TBIL) in cardiovascular disease has been increasingly recognized in recent decades. Studies have shown a correlation between total bilirubin levels and the prognosis of patients after heart surgery. This study aimed to investigate the clinical significance of bilirubin elevation in persistent atrial fibrillation (PAF) patients who received radiofrequency catheter ablation (RFCA).

Methods and Results

A total of 184 patients with PAF who received RFCA were retrospectively studied. Laboratory examinations and demographic data were analyzed to identify independent predictors of TBIL elevation. The relationship between TBIL and prognosis was further investigated. Our results indicated that TBIL increased significantly after RFCA. Multiple linear regression analysis showed that TBIL elevation owned a negative correlation with the percentile of low voltage areas (LVAs) in left atria (β=-0.490, P<0.001). In contrast, a positive correlation was observed with the white blood cell (WBC) ratio (β=0.153, P=0.042) and left atrial diameter (LAD) (β=0.232, P=0.025). It was found that postoperative TBIL levels increased and then gradually decreased to baseline within 5 days without intervention. The bilirubin ratio <1.211 indicated the possibility of 1-year AF recurrence after ablation with a predictive value of 0.743 (specificity = 75.00%, sensitivity = 66.67%).

Conclusion

Bilirubin elevation post PAF RFCA was a common phenomenon and was associated with 1-year recurrence of AF in PAF patients after RFCA.

Carboxyhemoglobin in Cardiac Surgery Patients and Its Association with Risk Factors and Biomarkers of Hemolysis

BACKGROUND

Cardiac surgery with cardiopulmonary bypass (CPB) is associated with hemolysis. Yet, there is no easily available and frequently measured marker to monitor this hemolysis. However, carboxyhemoglobin (CO-Hb), formed by the binding of carbon monoxide (a product of heme breakdown) to hemoglobin, may reflect such hemolysis. We hypothesized that CO-Hb might increase after cardiac surgery and show associations with operative risk factors and indirect markers for hemolysis.

METHODS

We conducted a retrospective descriptive cohort study of data from on-pump cardiac surgery patients. We analyzed temporal changes in CO-Hb levels and applied a generalized linear model to assess patient characteristics associated with peak CO-Hb levels. Additionally, we examined their relationship with red blood cell (RBC) transfusion and bilirubin levels.

RESULTS

We studied 38,487 CO-Hb measurements in 1735 patients. CO-Hb levels increased significantly after cardiac surgery, reaching a peak CO-Hb level 2.1 times higher than baseline (P < .001) at a median of 17 hours after the initiation of surgery. Several factors were independently associated with higher peak CO-Hb, including age (P < .001), preoperative respiratory disease (P = .001), New York Heart Association Class IV (P = .019), the number of packed RBC transfused (P < .001), and the duration of CPB (P = .002). Peak CO-Hb levels also significantly correlated with postoperative total bilirubin levels (Rho = 0.27, P < .001).

CONCLUSIONS

CO-Hb may represent a readily obtainable and frequently measured biomarker that has a moderate association with known biomarkers of and risk factors for hemolysis in on-pump cardiac surgery patients. These findings have potential clinical implications and warrant further investigation.

A novel interpretative tool for early prediction of low cardiac output syndrome after valve surgery: online machine learning models

OBJECTIVE

Low cardiac output syndrome (LCOS) is a severe complication after valve surgery, with no uniform standard for early identification. We developed interpretative machine learning (ML) models for predicting LCOS risk preoperatively and 0.5 h postoperatively for intervention in advance.

METHODS

A total of 2218 patients undergoing valve surgery from June 2019 to Dec 2021 were finally enrolled to construct preoperative and postoperative models. Logistic regression, support vector machine (SVM), random forest classifier, extreme gradient boosting, and deep neural network were executed for model construction, and the performance of models was evaluated by area under the curve (AUC) of the receiver operating characteristic and calibration curves. Our models were interpreted through SHapley Additive exPlanations, and presented as an online tool to improve clinical operability.

RESULTS

The SVM algorithm was chosen for modeling due to better AUC and calibration capability. The AUCs of the preoperative and postoperative models were 0.786 (95% CI 0.729-0.843) and 0.863 (95% CI 0.824-0.902), and the Brier scores were 0.123 and 0.107. Our models have higher timeliness and interpretability, and wider coverage than the vasoactive-inotropic score, and the AUC of the postoperative model was significantly higher. Our preoperative and postoperative models are available online at http://njfh-yxb.com.cn:2022/lcos.

CONCLUSIONS

The first interpretable ML tool with two prediction periods for online early prediction of LCOS risk after valve surgery was successfully built in this study, in which the SVM model has the best performance, reserving enough time for early precise intervention in critical care.

A novel survival rat model of hyperkalemia and landiolol induced cardioplegic arrest and resuscitation via cardiopulmonary bypass

OBJECTIVE

A small animal model would be an effective tool for research on the pathophysiology of cardiopulmonary bypass (CPB). However, numerous CPB models do not involve myocardial arrest and resuscitation. The aim of this research is to establish an easily achievable myocardial arrest and resuscitation CPB model through hyperkalemia and landiolol, simulating clinical cardiac surgery.

MATERIALS AND METHODS

Ten Sprague-Dawley rats were chosen for CPB. Rats underwent sevoflurane inhalation induction anesthesia and were sustained in an anesthesia state by intubation and intraperitoneal injection's of esketamine and propofol. The entire CPB circuit include a reservoir, a membrane oxygenator and a roller pump, which were connected into a complete loop via silicon tubes and infusion tube.After CPB was established through the tail artery and internal jugular vein, cardioplegic arrest was induced and maintained for 5 min at a rectum temperature of 28.5 ± 0.5°C with hyperkalemia and landiolol. Calcium chloride, epinephrine and insulin were then used for resuscitation.

RESULT

All rats successfully finished cardioplegic arrest, resuscitation procedure and survived 2 h postoperatively. Mean hematocrit during CPB was significantly lower than physiologic values of the baseline. The mean time of arrest-resuscitation and CPB was 5.4 ± 0.8 min and 98.5 ± 5.0 min. The blood gas at each detection point were in range with the normal standard requirement of CPB.

CONCLUSION

The establishment of cardioplegic arrest and resuscitation procedure via hyperkalemia and landiolol during CPB of WD rat could be achieved successfully. This animal model could be an alternative organ injury research on organ injury of patients undergoing cardiac surgery.

A Case of Post-operative Jaundice After Cardiac Surgery

Hyperbilirubinemia is a common gastrointestinal complication seen post-cardiac surgery. Here, we describe a case of a 72-year-old male with a past medical history of chronic obstructive pulmonary disease, chronic kidney disease (CKD), pulmonary hypertension, and valvular heart disease with severe aortic stenosis, severe mitral and tricuspid regurgitations who underwent elective aortic valve replacement (AVR), mitral valve replacement (MVR), and tricuspid valve (TV) repair; in addition, he required left thoracotomy for the repair of pulmonary artery perforation from a Swan-Ganz catheter that resulted in a large left pleural bleed. Post-operatively, he developed severe jaundice, which was predominantly conjugated that peaked at 24 mg/dL. He also required multiple blood products' transfusion in the perioperative period and was supported temporarily with hemodialysis for acute kidney injury superimposed on his CKD. He underwent extensive evaluation for jaundice, which included ultrasound of the liver, hepatobiliary iminodiacetic (HIDA) scan, and magnetic resonance cholangiopancreatography (MRCP), which were all normal. The patient eventually got better and was discharged from the hospital. The hyperbilirubinemia slowly got better without any specific therapy and on his follow-up visit to the office following discharge, his bilirubin level was found completely normalized. Although most cases of post-cardiac surgery hyperbilirubinemia resolve without any specific therapy, the occurrence is not completely benign since it can increase morbidity and mortality. It is paramount that intensivists and cardiothoracic surgeons caring for these patients are aware of this occurrence to prevent unnecessary diagnostic evaluation. Most early cases of hyperbilirubinemia are transient and do not usually increase morbidity and mortality. In the late cases, infectious etiology resulting in sepsis needs to be entertained early and treated aggressively.

The prognostic significance of postoperative hyperbilirubinemia in cardiac surgery: systematic review and meta-analysis

Background

Hyperbilirubinemia following cardiac surgery is a common phenomenon and is of emerging interest in prognostic factor research. This systematic review and meta-analysis evaluated the association between post-operative hyperbilirubinemia (PH) and mortality and morbidity in cardiac surgery patients.

Methods

Ovid Medline and Ovid Embase were searched from inception to July 2020 for studies evaluating the prognostic significance of PH following cardiac surgery. Maximally adjusted odds ratios (OR) with associated confidence intervals were obtained from each study and pooled using random effects inverse variance modelling to assess in-hospital mortality. Standardised mean differences were pooled to assess Intensive Care Unit (ICU) and hospital length of stay (LOS). Qualitative analysis was performed to assess ventilation requirements and long-term mortality. Meta-regression was used to assess inter- and intra-study heterogeneity.

Results

3251 studies satisfied the selection criteria, from which 12 studies incorporating 3876 participants were included. PH significantly predicted in-hospital mortality with a pooled OR of 7.29 (95% CI 3.53, 15.09). Multiple pre-defined covariates contributed to the prognostic significance of PH, however only aortic cross-clamp time (p < 0.0001) and number of transfusions (p = 0.0001) were significant effect modifiers. PH significantly predicted both ICU LOS (Mean difference 1.32 [95% CI 0.04–2.6]) and hospital LOS (Mean difference 1.79 [95% CI 0.36–3.21]). Qualitative analysis suggested PH is associated with increased post-operative ventilation requirements and reduced long-term survival rates.

Conclusions

Hyperbilirubinemia is a cost-effective, widely available prognostic marker of adverse outcomes following cardiac surgery, albeit with residual sources of heterogeneity.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13019-022-01870-2.

Risk factors of postoperative low cardiac output syndrome in children with congenital heart disease: A systematic review and meta-analysis

BACKGROUND

Low cardiac output syndrome (LCOS) is the most common complication after cardiac surgery, which is associated with the extension of postoperative hospital stay and postoperative death in children with congenital heart disease (CHD). Although there are some studies on the risk factors of LCOS in children with CHD, an unified conclusion is lack at present.

PURPOSES

To synthesize the risk factors of LCOS after CHD in children, and to provide evidence-based insights into the early identification and early intervention of LCOS.

METHODS

The databases of the China National Knowledge Infrastructure (CNKI), Wanfang Database, China Science and Technology Journal Database (VIP), PubMed, Cochrane Library, Embase and Web of Science were searched for relevant articles that were published between the establishing time of each database and January 2022. Based on retrospective records or cohort studies, the influencing factors of postoperative low cardiac output in children with congenital heart disease were included in Meta analysis.This study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The risk of bias was evaluated according to the Newcastle-Ottawa Scale (NOS). RevMan 5.4 software was used to conduct the meta-analysis.

RESULTS

A total of 1,886 records were screened, of which 18 were included in the final review. In total, 37 risk factors were identified in the systematic review. Meta- analysis showed that age, type of CHD, cardiac reoperation, biventricular shunt before operation, CPB duration, ACC duration, postoperative residual shunt, cTn-1 level 2 h after CPB > 14 ng/ml and postoperative 24 h MR-ProADM level > 1.5 nmol/l were independent risk factors of LCOS. Additionally, the level of blood oxygen saturation before the operation was found to have no statistically significant relationship with LOCS.

CONCLUSION

The risk factors of postoperative LCOS in children with CHD are related to disease condition, intraoperative time and postoperative related indexes, so early prevention should be aimed at high-risk children.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/prospero/, identifier: CRD42022323043.

Safety, Mortality, and Hemodynamic Impact of Patients with MitraClip Undergoing Left Ventricular Assist Device Implantation

The interactions and hemodynamic impact of transcatheter percutaneous mitral valve repair (TMR) have not yet been investigated in patients undergoing left ventricular assist device (LVAD) implantation, but hemodynamic adverse effects are feared in the combination of TMR and LVAD for altered mitral valve flow. This study investigated the hemodynamic interplay in combination of TMR and LVAD in 119 patients, and propensity score match analysis revealed no difference in both perioperative mortality and 2-year follow-up survival (p = 0.84). Nonetheless, postoperatively mean pulmonary arterial pressure, pulmonary capillary wedge pressure, and cardiac index improved, and multivariable cox regression analysis at 2 years identified preoperative total bilirubin and temporary right ventricular mechanical circulatory support as independent risk factors for all-cause mortality but not TMR. Prior TMR has no impact on mortality or cardiovascular complications in patients with LVAD.

Risk factors analysis of hyperbilirubinemia after off-pump coronary artery bypass grafting: a retrospective observational study

Background

Hyperbilirubinemia is a common complication after off-pump coronary artery bypass grafting (OPCAB), but the incidence and the risk factors are unclear. This study aimed to analyze the incidence and risk factors of postoperative hyperbilirubinemia in patients undergoing OPCAB.

Methods

From December 2016 to March 2019, a total of 416 consecutive patients undergoing OPCAB were enrolled in this single-center retrospective study. Patients were divided into the normal serum total bilirubin group and the hyperbilirubinemia group based on the serum total bilirubin levels. Perioperative variables between the two groups were compared by univariate logistic regression analysis. Then, multivariate binary logistic regression analysis was used to analyze the independent risk factors of developing hyperbilirubinemia in patients underwent OPCAB. P < 0.05 was considered as statistically significant.

Results

Thirty two of 416 (7.7%) patients developed postoperative hyperbilirubinemia. Univariate regression analysis showed significant differences in gender (73.96% vs. 93.75%, P = 0.012), preoperative total bilirubin levels (11.92 ± 4.52 vs. 18.28 ± 7.57, P < 0.001), perioperative IABP implantation (22.66% vs. 43.75%, P = 0.008), perioperative blood transfusion (37.50% vs. 56.25%, P = 0.037) between the two groups. Multivariate logistic regression analysis revealed that elevated preoperative serum total bilirubin levels (OR = 1.225, 95% CI 1.145–1.310, P < 0.001), perioperative blood transfusion (OR = 4.488, 95% CI 1.876–10.737, P = 0.001) and perioperative IABP implantation (OR = 4.016, 95% CI 1.709–9.439, P = 0.001) were independent risk factors for hyperbilirubinemia after OPCAB.

Conclusions

Hyperbilirubinemia is also a common complication after OPCAB. Elevated preoperative serum total bilirubin levels, perioperative blood transfusion, and perioperative IABP implantation were independent risk factors for patients developing hyperbilirubinemia after OPCAB. Further studies need to be conducted to confirm the risk factors of hyperbilirubinemia after OPCAB procedure.

Epigenetic-sensitive challenges of cardiohepatic interactions: clinical and therapeutic implications in heart failure patients

Heart failure and liver dysfunction can coexist owing to complex cardiohepatic interactions including the development of hypoxic hepatitis and congestive hepatopathy in patients with heart failure as well as 'cirrhotic cardiomyopathy' in advanced liver disease and following liver transplantation. The involvement of liver dysfunction in patients with heart failure reflects crucial systemic hemodynamic modifications occurring during the evolution of this syndrome. The arterial hypoperfusion and downstream hypoxia can lead to hypoxic hepatitis in acute heart failure patients whereas passive congestion is correlated with congestive hepatopathy occurring in patients with chronic heart failure. Nowadays, liquid biopsy strategies measuring liver function are well established in evaluating the prognosis of patients with heart failure. Large randomized clinical trials confirmed that gamma-glutamyltransferase, bilirubin, lactate deihydrogenase, and transaminases are useful prognostic biomarkers in patients with heart failure after transplantation. Deeper knowledge about the pathogenic mechanisms underlying cardiohepatic interactions would be useful to improve diagnosis, prognosis, and treatments of these comorbid patients. Epigenetic-sensitive modifications are heritable changes to gene expression without involving DNA sequence, comprising DNA methylation, histone modifications, and noncoding RNAs which seem to be relevant in the pathogenesis of heart failure and liver diseases when considered in a separate way. The goal of our review is to highlight the pertinence of detecting epigenetic modifications during the complex cardiohepatic interactions in clinical setting. Moreover, we propose a clinical research program which may be useful to identify epigenetic-sensitive biomarkers of cardiohepatic interactions and advance personalized therapy in these comorbid patients.

Severe postoperative hyperbilirubinemia in congenital heart disease

PURPOSE

The purpose of our present study was to explore the characteristics and outcomes of congenital heart disease (CHD) patients with severe postoperative hyperbilirubinemia.

METHODS

All patients who underwent cardiopulmonary bypass surgical treatment for CHD and had severe postoperative hyperbilirubinemia (total bilirubin [TB] ≥85.5 μmol/L) in our center between January 2015 and December 2018 were retrospectively screened. Univariate and multivariate analyses were employed to identify risk factors for the study endpoints, including postoperative acute kidney injury (AKI), in-hospital mortality, and long-term mortality.

RESULTS

After screening, 86 patients were included in our present study. In-hospital mortality was 10.9%. Fifty-one (59.3%) patients experienced AKI, and four (4.7%) patients received continuous renal replacement therapy. Multivariate analysis identified that the peak TB concentration (P = 0.002) and duration of mechanical ventilation (P = 0.008) were independent risk factors for in-hospital mortality, and stage 3 AKI was an independent risk factor for long-term mortality. The optimal cutoff value for peak TB concentration was 125.9 μmol/L. Patients with a postoperative TB level ≥125.9 μmol/L had worse long-term survival.

CONCLUSION

Hyperbilirubinemia was a common complication after CHD surgery. CHD patients with severe postoperative hyperbilirubinemia ≥125.9 μmol/L and AKI had a higher risk of mortality.

Outcome of Organ Dysfunction in the Perioperative Period

While intraoperative mortality has diminished greatly over the last several decades, the risk of death within 30 days of surgery remains stubbornly high and is ultimately related to perioperative organ failure. Perioperative strokes, while rare (<2% in noncardiac surgery), are associated with a more than 10-fold increase in mortality. Rapid identification and treatment are key to maximizing long-term outcomes. Postoperative delirium (POD) and postoperative cognitive dysfunction (POCD) are separate but related perioperative neurological disorders, both of which are associated with poor long-term outcomes. To date, there are few known interventions that can ameliorate the risk of perioperative central nervous system dysfunction. Major adverse cardiac events (MACE) are a major contributor to adverse clinical outcomes following surgical procedures. Recently, advances in diagnostic strategies (eg, high-sensitivity cardiac troponin [hs-cTn] assays) have improved our understanding of MACE. Recently, the dabigatran in patients with myocardial injury after noncardiac surgery (MINS; Management of myocardial injury After NoncArdiac surGEry) trial demonstrated that a direct thrombin inhibitor could improve outcomes following MINS. While the risk of acute respiratory distress syndrome (ARDS) after surgery is approximately 0.2%, other less severe complications (eg, pneumonia, reintubation) are closer to 2%. While intensive care unit (ICU) concepts related to ARDS have migrated into the operating room, whether or not adverse pulmonary outcomes impact long-term outcomes in surgical patients remains a matter of debate. The standardization of acute kidney injury (AKI) definition has improved the ability of clinicians to measure and study the incidence of this important source of perioperative morbidity. AKI is associated with increased mortality as well as nonrenal morbidity (eg, myocardial infarction) after major surgery. Gastrointestinal complications after surgery range from ileus (common in abdominal procedures and associated with an increased length of stay) to less common complications such as mesenteric ischemia and gastrointestinal bleeding, both of which are associated with very high mortality. Outside of cardiothoracic surgery, the incidence of perioperative hepatic injury is not well described but, in this population, is associated with worsened long-term outcomes. Hyperglycemia is a common perioperative complication and occurs in patients undergoing both cardiac and noncardiac surgery. Both hyper- and hypoglycemia are associated with worsened long-term outcomes in cardiac and noncardiac surgery. Better diagnosis and increased understanding of perioperative organ injury has led to an increased appreciation for the specific role that particular organ systems play in poor long-term outcomes and has set the stage for targeted therapeutic interventions.

Investigation of Risk Factors Related to the Development of Hepatic Dysfunction in Patients with a Low and Moderate Cardiac Risk During Open-Heart Surgeries

Objective

To determine the possible risk factors associated with hepatic dysfunction during open-heart surgeries.

Methods

After excluding 71 patients, 307 patients with possible low and moderate cardiac risk who underwent either coronary artery bypass graft surgery (CABG) (n=176) or valve repair surgery (mitral valve, mitral and aortic valves and/or tricuspid valve) (n=131) were investigated prospectively during a 6-month period. Hyperbilirubinemia is defined as an occurrence of a plasma total bilirubin concentration >34 µmol/L (2 mg/dL) in any measurement during the postoperative period; the patients were divided into groups with or without postoperative hyperbilirubinemia. The collected parameters were: alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP), total bilirubin (TBil), gamma-glutamyl transpeptidase (GGT) and albumin. The parameters were collected preoperatively and postoperatively on days 1, 3 and 7. Preoperative, intraoperative, and postoperative risk factors were investigated. Logistic regression analysis was performed to identify the risk factors for postoperative hyperbilirubinemia.

Results

Postoperative hyperbilirubinemia was observed in 7 of 176 patients (4%) who underwent CABG, and in 11 of 131 patients (8.4%) who underwent valve replacement surgeries. Independent risk factors for early postoperative hyperbilirubinemia were found as: ejection fraction (EF), aortic cross-clamp (ACC) time, intensive care unit stay and extubation time (P<0.001). In comparison to CABG procedures, postoperative hyperbilirubinemia was observed more frequently in patients undergoing valve surgeries (P=0.027).

Conclusion

Low EF and prolonged ACC time are significant independent risk factors for early postoperative hyperbilirubinemia during open-heart surgeries with cardiopulmonary bypass. Valve surgeries show a higher incidence of hyperbilirubinemia in comparison to CABG.

Bilirubin adsorption for the treatment of severe hyperbilirubinemia after cardiac surgery: A retrospective cohort study

OBJECTIVE

Severe hyperbilirubinemia after cardiac surgery increases in-hospital and 1-year mortality. Our present study aimed to analyze the safety and efficacy of bilirubin adsorption (BA) in patients with post-cardiac-surgery severe hyperbilirubinemia.

METHODS

We retrospectively included patients who underwent BA due to severe hyperbilirubinemia after cardiac surgery in our center between January 2015 and December 2018. The change of serum bilirubin, alanine aminotransferase, aspartate aminotransferase, and 30-day and 1-year mortality were assessed as endpoints. Univariate and multivariate analyses were employed to identify the risk factors of patient 30-day mortality.

RESULT

A total of 25 patients with 44 BA treatments were included. One BA treatment reduced total bilirubin (TB) concentration from 431.65 ± 136.34 to 324.83 ± 129.44 µmol/L (p < 0.001), with a reduction rate of 24.8%. No clinically relevant thrombosis of the extracorporeal circuit occurred during the BA treatment. The 30-day and 1-year mortality rates were 68% (n = 18) and 84% (n = 21), respectively. Multivariate analysis identified that TB level before BA treatment (odds ratio [OR] 1.010, 95% confidence interval [CI] 1.000-1.019; p = 0.043) was an independent risk factor of 30-day mortality.

CONCLUSIONS

BA treatment should be considered as an effective and safe method for the reduction of serum bilirubin in patients with post-cardiac-surgery severe hyperbilirubinemia. Patients with higher TB level before BA treatment had a relatively increased risk of 30-day mortality. Further studies are needed to evaluate the timing of BA for severe hyperbilirubinemia after cardiac surgery.

Bilirubin and lactate: easy to determine and valuable to predict outcome in cardiac surgery

BACKGROUND

Cardiopulmonary bypass during cardiac surgery is associated with metabolic changes after operation and results inter alia in increased levels of lactate and bilirubin. Since prediction of the course after operation has become very important for the management of an ICU and the patients themselves, we evaluated easily assessable markers (lactate and bilirubin), regarding their potential to predict mortality 90 days after surgery and the length of stay in ICU.

METHODS

All patients within a period of five years undergoing cardiac surgery were enrolled in the study. Among others peak levels of lactate and bilirubin within 48 hours after operation were recorded. A Cox proportional hazard model as well as a logistic regression model were used to predict mortality or rather length of stay in ICU.

RESULTS

Increased levels of bilirubin and lactate were associated with a significantly increase in mortality and length of stay in ICU (in a concentration-related manner). Interestingly, creatinine serum levels before operation showed a similar performance.

CONCLUSIONS

Three easily assessable and cheap laboratory parameters (bilirubin, lactate, and creatinine) are useful to predict 90-day mortality and length of stay in ICU. These findings might be helpful to give patients a reliable prediction about short and mid-term-survival and to improve the management of an ICU.

Risk factors of mortality in AAAD patients who had severe postoperative hyperbilirubinemia and received CRRT

OBJECTIVE

Severe acute kidney injury (AKI) and hyperbilirubinemia increase the morbidity and mortality risk in patients undergoing emergency surgery for acute type A aortic dissection (AAAD). Our purpose was to investigate the risk factors of mortality in AAAD surgery patients who had severe postoperative hyperbilirubinemia and AKI receiving continuous renal replacement therapy (CRRT).

METHODS

Patients who had severe hyperbilirubinemia and received CRRT after AAAD surgery in our center between January 2015 and December 2018 were retrospectively screened. Univariate and multivariate analyses were performed to identify the risk factors of in-hospital mortality. Kaplan-Meier curves were employed to evaluate the accumulated patient survival proportion.

RESULTS

After screening, 50 patients were included in our present study. The in-hospital mortality was 84%. The univariate logistic analysis showed that preoperative MAP (p = .017) and peak total bilirubin concentration (p < .001) were associated with in-hospital mortality in AAAD surgery patients who had severe postoperative hyperbilirubinemia and received CRRT. Multivariate logistic regression analysis revealed that the peak bilirubin concentration (odds ratio, 1.050; 95% confidence interval, 1.002-1.101; p = .041) after surgery was the only independent risk factor for in-hospital mortality. The optimal cutoff value of peak bilirubin for predicting in-hospital mortality was 134.4 μmol/L.

CONCLUSIONS

AAAD surgery patients with severe hyperbilirubinemia and AKI requiring CRRT had a poor prognosis. Increased postoperative peak bilirubin concentration strongly increased the risk of patient in-hospital mortality. Therefore, these patients should be closely monitored and treated aggressively when possible.

Time to peak bilirubin concentration and advanced AKI were associated with increased mortality in rheumatic heart valve replacement surgery patients with severe postoperative hyperbilirubinemia: a retrospective cohort study

BACKGROUND

Hyperbilirubinemia after heart valve surgery (HVS) with cardiopulmonary bypass is frequently observed and associated with worse outcomes. We investigated the characteristics and prognosis of patients with severe hyperbilirubinemia after HVS for rheumatic heart disease (RHD) to identify the clinical outcomes and potential risk factors.

METHODS

Between 2015 and 2018, patients who underwent HVS in the cardiac surgery intensive care unit of our hospital were retrospectively screened. Risk factors for acute kidney injury (AKI), the requirement for continuous renal replacement therapy (CRRT), and in-hospital and long-term mortality were identified by univariate and multivariate analyses. The patient survival proportion was graphically presented with the Kaplan-Meier method.

RESULTS

A total of 149 patients who underwent HVS for RHD and had severe postoperative hyperbilirubinemia were included. Of the included patients, 80.5% developed postoperative AKI, and 18.1% required CRRT. The in-hospital mortality was 30.2%. Backward logistic regression analysis showed that the time to peak TB concentration (odds ratio [OR] 1.557, 95% confidence interval [CI] 1.259-1.926; P < 0.001) and advanced AKI (stage 2 and 3 AKI) (OR 19.408, 95% CI 6.553-57.482; P < 0.001) were independent predictors for in-hospital mortality. The cutoff value of the time to peak TB levels for predicting in-hospital mortality was 5 postoperative days.

CONCLUSIONS

Severe postoperative hyperbilirubinemia is a life-threatening complication in patients who undergo HVS for RHD. Patients whose bilirubin levels continued to increase past the 5th postoperative day and who had advanced AKI (stages 2 and 3) were associated with a higher risk of mortality.

The correlation between bowel complications and cardiac surgery

Although advances in knowledge and technology have improved outcomes in surgical cardiac patients over the last decade, complications following cardiac operations still remain to be potentially fatal. Gastrointestinal complications, in particular, tend to have high rates of reintervention and mortality following cardiac surgery, with ischemia and hemorrhage being two of the commonest underlying causes. The intention of this review is to identify which risk factors play important roles in predisposing patients to such complications and to gain better insight into the pathogenesis of the sequelae. Furthermore, strategies for prevention have been discussed to educate and increase awareness of how adverse cardiac surgical outcomes can be minimized.

Characteristics and outcomes of Stanford type A aortic dissection patients with severe post-operation hyperbilirubinemia: a retrospective cohort study

BACKGROUND

Hyperbilirubinemia is one of the common complications after cardiac surgery and is associated with increased mortality. However, to the best of our knowledge, the reports on clinical significance of postoperative severe hyperbilirubinemia in Stanford type A aortic dissection (AAD) patients were limited.

METHODS

Patients who underwent surgical treatment for AAD in our center between January 2015 and December 2018 were retrospectively screened. In-hospital mortality, long-term mortality, acute kidney injury (AKI), and the requirement of continuous renal replacement therapy (CRRT) were assessed as endpoints. Univariate and multivariate regression models were employed to identify the risk factors of these endpoints.

RESULTS

After screening, 271 patients were included in our present study. Of the included patients, 222 (81.9%) experienced postoperative AKI, and 50 (18.5%) received CRRT. The in-hospital mortality was 30.3%. The 1-year, 2-year, and 3-year cumulative mortality were 32.9, 33.9, and 35.3%, respectively. Multivariate Logistic regression analysis indicated that age (P < 0.033), AKI stage 3 (P < 0.001), the amount of blood transfusion after surgery (P = 0.019), mean arterial pressure (MAP) in the first postoperative day (P = 0.012), the use of extracorporeal membrane oxygenation (ECMO) (P = 0.02), and the peak total bilirubin (TB) concentration (P = 0.023) were independent risk factors of in-hospital mortality. The optimal cut-off value of peak TB on predicting in-hospital mortality was 121.2 μmol/L. Patients with post-operation TB ≥ 121 μmol/L was associated with worse long-term survival as well.

CONCLUSIONS

Severe post-operation hyperbilirubinemia is a common clinical situation in patients had AAD repair. In AAD patients with severe post-operation hyperbilirubinemia, older age, lower MAP, increased blood transfusion, stage 3 AKI, the use of ECMO, and the increased peak TB lead to increase in-hospital mortality.

Hyperbilirubinaemia after cardiac surgery: the point of no return

Aims

The occurrence of hyperbilirubinaemia after heart surgery using cardiopulmonary bypass or post‐operative heart failure is fairly common. We investigated the incidence, predictive value, and post‐operative outcome of hyperbilirubinaemia after cardiac surgery in an effort to identify potential risk factors and significance on clinical outcome.

Methods and results

Between 2006 and 2016, 1272 (10.1%) out of 12 556 patients developed hyperbilirubinaemia, defined as bilirubin concentration >3 mg/dL, during post‐operative course at our institution. All patients who were operated using cardiopulmonary bypass were included. Hepatic dysfunction was diagnosed preoperatively in 200 patients (15.7%), whereas mean model of end‐stage liver disease score was 11.22 ± 4.99. Early mortality was 17.4% with age [hazard ratio (HR) 1.019, 95% confidence interval (CI) 1.008–1.029; P = 0.001], diabetes (HR 1.115, CI 1.020–1.220; P = 0.017), and emergent procedures (HR 1.315, CI 1.012–1.710) as multivariate predictors. Post‐operative predictors were low‐output syndrome (HR 3.193, 95% CI 2.495–4.086; P < 0.001), blood transfusion (HR 1.0, CI 1.0–1.0; P < 0.001), and time to peak bilirubin (HR 1.1, CI 1.0–1.1; P < 0.001). We found an increased correlation with mortality at 3.5 post‐operative day as well as an optimal cut‐off value for bilirubin of 5.35 mg/dL. A maximum bilirubin of 25.5 mg/dL was associated with 99% mortality. Survival analysis showed significantly decreased survival for patients who developed late, rather than early, hyperbilirubinaemia.

Conclusions

Post‐operative hyperbilirubinaemia is a prevalent threat after cardiopulmonary bypass, associated with high early mortality. The timing and amount of peak bilirubin concentration are linked to the underlying pathology and are predictors of post‐operative outcome. Patients with late development of steep hyperbilirubinaemia warrant meticulous post‐operative care optimizing cardiac and end organ functions before reaching the point of no return.