Cytokine Hemoadsorption During Cardiac Surgery Versus Standard Surgical Care for Infective Endocarditis (REMOVE): Results From a Multicenter Randomized Controlled Trial.

BACKGROUND: Cardiac surgery often represents the only treatment option in patients with infective endocarditis (IE). However, IE surgery may lead to a sudden release of inflammatory mediators, which is associated with postoperative organ dysfunction. We investigated the effect of hemoadsorption during IE surgery on postoperative organ dysfunction. METHODS: This multicenter, randomized, nonblinded, controlled trial assigned patients undergoing cardiac surgery for IE to hemoadsorption (integration of CytoSorb to cardiopulmonary bypass) or control. The primary outcome (change in sequential organ failure assessment score [ΔSOFA]) was defined as the difference between the mean total postoperative SOFA score, calculated maximally to the 9th postoperative day, and the basal SOFA score. The analysis was by modified intention to treat. A predefined intergroup comparison was performed using a linear mixed model for ΔSOFA including surgeon and baseline SOFA score as fixed effect covariates and with the surgical center as random effect. The SOFA score assesses dysfunction in 6 organ systems, each scored from 0 to 4. Higher scores indicate worsening dysfunction. Secondary outcomes were 30-day mortality, duration of mechanical ventilation, and vasopressor and renal replacement therapy. Cytokines were measured in the first 50 patients. RESULTS: Between January 17, 2018, and January 31, 2020, a total of 288 patients were randomly assigned to hemoadsorption (n=142) or control (n=146). Four patients in the hemoadsorption and 2 in the control group were excluded because they did not undergo surgery. The primary outcome, ΔSOFA, did not differ between the hemoadsorption and the control group (1.79±3.75 and 1.93±3.53, respectively; 95% CI, -1.30 to 0.83; P=0.6766). Mortality at 30 days (21% hemoadsorption versus 22% control; P=0.782), duration of mechanical ventilation, and vasopressor and renal replacement therapy did not differ between groups. Levels of interleukin-1ß and interleukin-18 at the end of integration of hemoadsorption to cardiopulmonary bypass were significantly lower in the hemoadsorption than in the control group. CONCLUSIONS: This randomized trial failed to demonstrate a reduction in postoperative organ dysfunction through intraoperative hemoadsorption in patients undergoing cardiac surgery for IE. Although hemoadsorption reduced plasma cytokines at the end of cardiopulmonary bypass, there was no difference in any of the clinically relevant outcome measures. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT03266302.

Right Mini-Thoracotomy for Aortic Plus Mitral with or without Tricuspid Valve Surgery.

OBJECTIVES: Minimally invasive surgery is increasingly performed for isolated aortic or mitral valve procedures. However, combined minimally invasive aortic and mitral valve surgery is rare. We report our initial experience performing multiple valve procedures through a right-sided mini-thoracotomy (RMT) compared with sternotomy. METHODS: A total of 264 patients underwent aortic and mitral with or without tricuspid valve surgery through RMT (n = 25) or sternotomy (n = 239). Propensity score matching was used for outcome comparisons. RESULTS: Of the 264 patients, 25 (age: 72 ± 10 years; 72% male) underwent double (n = 19) and triple valve surgery (n = 6) through RMT and 239 (age: 71 ± 11 years; 54% male) underwent double (n = 176) and triple valve surgery (n = 63) through sternotomy. Sternotomy patients had more co-morbidities and preoperative risk factors (EuroSCORE II 10.25 ± 10.89 vs. RMT 3.58. ± 4.98; p < 0.001). RMT procedures were uneventful without intraoperative complications or conversions to sternotomy. After propensity score matching, surgical procedures were comparable between groups with a higher valve repair rate in RMT. Despite longer cardiopulmonary bypass times in RMT, there was no evidence for differences in 30-day mortality (RMT: n = 2 vs. sternotomy: n = 2) and there were no significant differences in other outcomes. During 5-year follow-up, reoperation was required in sternotomy patients only (n = 2). Follow-up echocardiography showed durable results after valve surgery. RMT patients showed higher survival probability compared with sternotomy, although this difference was not significant (hazard ratio = 0.33; 95% confidence interval: 0.06-1.65; p = 0.18). CONCLUSION: Combined aortic plus mitral with or without tricuspid valve surgery can safely be performed through a RMT with a trend toward better mid-term outcomes.

Predictors of Outcome for Aortic Valve Reimplantation Including the Surgeon-A Single-Center Experience.

INTRODUCTION: Aortic valve reimplantation is considered technically demanding. We searched for predictors of long-term outcome including the surgeon as risk factor. METHODS: We selected all aortic valve reimplantations performed in our department between December 1999 and January 2017 and obtained a complete follow-up. The main indications were combined aortic aneurysm plus aortic valve regurgitation (AR), 69% and aortic dissections (15%). In 14%, valves were bicuspid. Cusp repair was performed in 27% of patients. One-third received additional procedures (coronary artery bypass grafting, mitral, or arch surgery). We performed multivariable analyses for independent risk factors of short- and long-term outcomes, including "surgeon" as variable. Twelve different surgeons operated on 193 patients. We created three groups: surgeons A and B with 84 and 64 procedures, respectively, and surgeon C (10 surgeons for 45 patients). RESULTS: Cardiopulmonary bypass and clamp times were 176 ± 45 and 130 ± 24 minutes, respectively. In-hospital mortality was 2%. Postoperatively, 5% had mild and 0.5% had moderate AR. Kaplan-Meier's survival estimates, freedom from reoperation, and freedom from severe AR at 12 years were 97 ± 1, 93 ± 2, and 91 ± 3%, respectively. Age and chronic obstructive pulmonary disease appeared as risk factors for perioperative complications by univariate analysis. Age, coronary artery disease, and duration of cardiopulmonary bypass, but not surgeon, presented as risk factors by multivariable analysis. CONCLUSION: The results suggest that if a David procedure is performed successfully, long-term durability may be excellent. They also suggest that good and durable results are possible even with limited experience of the operating surgeon.

Lost in circulation.

BACKGROUND: Device complications in complex percutaneous coronary interventions are rare but potentially deadly. Surgical removal is often required. However, an evaluation of surgical therapy beyond case reports is practically not existent. METHODS: We prospectively followed all cases of retained guide wires and/or other devices referred to us for surgical removal between 2015 and 2019 and retrospectively searched our database for such cases between 2010 and 2014. RESULTS: From 2015 on, eight cases were referred for surgical removal from six different cardiology departments. In the 5 years before, there was not a single case. Six patients were operated emergently. Patients were 60.5 ± 5.42 years old, overweight (body mass index 30.1 ± 3.77) and except for one case (left ventricular-assist device) showed preserved ejection fraction (EF) (mean EF 57 ± 18.01). The retained devices were mostly located in the right coronary artery (50%), followed by the circumflex artery (37.5%) and diagonal branch (12.5%). The devices were remnants of guide wires (n = 4), balloon catheters (n = 3), and in one case a rotablator. Full sternotomy was performed in six patients and two received a left-sided minithoracotomy (n = 2). The operations were performed on-pump in five (62.5%) and off-pump in three patients. Complete extraction of the foreign bodies was possible in all patients. Two patients died; one in unrelated multiorgan failure and one due to retained-device-related right heart failure. The other patients survived and had uneventful postoperative courses. CONCLUSIONS: Retained foreign bodies from cardiac interventions can be completely removed surgically using individualized approaches. There appears to be a trend toward a rising incidence of such interventional complications.

Do We Need Basic Research in Cardiac Surgery?

Thinking about the daily practice of cardiac surgery, genetically altered mouse models, polymerase chain reactions, western blots, and other laboratory tools are the last that comes to mind. It is, therefore, not surprising that the pursuit of such basic science activities by practicing surgeons and those in training is often limited. However, there is an innate connection between these two seemingly different disciplines. To address and visualize this connection, we propose the following three hypotheses. First, cardiac surgery would not be at its present level of expertise without fundamental contributions of basic science. Second, without practicing cardiac surgeons performing basic research and translating their results to clinical practice next to their daily work, our ability to care for cardiac surgery patients would be poorer. Third, basic science training for those aiming to become practicing cardiac surgeons improves their ability to properly care for their patients. Finally, we will discuss some potentially even unexpected implications for our currently changing daily clinical practice.

Valve-in-valve transcatheter aortic valve implantation: the new playground for prosthesis-patient mismatch.

Transcatheter aortic valve implantation (TAVI) has become an established procedure for patients with aortic valve stenosis and significant comorbidities. One option offered by this technique is the implantation of a transcatheter valve inside a surgically implanted bioprosthesis. Many reports address the feasibility but also the pitfalls of these valve-in-valve (VIV) procedures. Review articles provide tables listing which valve sizes are appropriate based on the size of the initially implanted bioprosthesis. However, we previously argued that the hemodynamic performance of a prosthetic tissue valve is in large part a result of the dimensions of the bioprosthesis in relation to the patient's aortic outflow dimensions. Thus, the decision if a VIV TAVI procedure is likely to be associated with a favorable hemodynamic result cannot safely be made by looking at premade sizing tables that do not include patient dimensions and do not inquire about the primary cause for bioprosthetic valve stenosis. Prosthesis-patient mismatch (PPM) may therefore be more frequent than expected after conventional aortic valve replacement. Importantly, it may be masked by a potentially flawed method assessing its relevance. Such PPM may therefore impact significantly on hemodynamic outcome after VIV TAVI. Fifteen percent of currently published VIV procedures show only a minimal reduction of pressure gradients. We will address potential pitfalls in the current determination of PPM, outline the missing links for reliable determination of PPM, and present a simplified algorithm to guide decision making for VIV TAVI.

Novel thoughts on patient-prosthesis mismatch in aortic valve replacement: the rationale for the PAR I trial.

The hemodynamic performance of prosthetic tissue valves is influenced by valve design and valve-specific sizing strategies. Design determines the actual geometric opening area (GOA) of the prosthetic valve and sizing strategy its actual chosen size. Currently, hemodynamic performance is assessed by determining the effective orifice area (EOA; derived from the continuity equation by relating flow velocities with the area of the left ventricular outflow tract [LVOTA]). The question whether a valve is too small (patient-prosthesis mismatch [PPM]) is currently addressed by relating EOA to body surface area (EOA index [EOAi]). However, this relation may not be appropriate because the EOAi relates flow velocity to patient-specific anatomic parameters twice (i.e., LVOTA and body surface area). This potential confounder may explain the controversies regarding PPM. However, intuitively, leaving a gradient behind after aortic valve replacement cannot be irrelevant. PPM becomes even more relevant with transcatheter valve-in-valve implantation, where a second prosthesis is taking up inner space of a valve that may have already been too small initially. Thus, a reliable method to determine the presence of PPM is needed. The Prosthesis-to-Annulus Relation I (PAR I) trial is a German multicenter study assessing the relation between the prosthetic GOA and the LVOTA as a potentially new parameter for the prediction of hemodynamic outcome. The results may possibly guide future valve size selection and may allow prediction of functionally relevant PPM. Here, we will demonstrate the shortcomings of the currently applied EOAi for the assessment of hemodynamic relevance and present the rationale for the PARI trial, which recently started recruiting patients.

Antithrombotic Therapy in Patients With Infective Endocarditis: A Systematic Review and Meta-Analysis.

Background: Antithrombotic therapy (ATT) in patients with infective endocarditis (IE) is challenging. Objectives: The authors evaluated the impact of anticoagulant and antiplatelet therapy on clinical endpoints in IE patients. Methods: We performed a systematic review and meta-analysis comparing IE patients with prior and/or ongoing use of ATT vs those without any ATT during IE course. Primary outcome was reported in-hospital cerebrovascular events. Secondary outcomes were in-hospital mortality, intracranial hemorrhage (ICH), systemic thromboembolism (ST), and mortality within 6 months. Results: Twelve studies, with a total of 12,151 patients, were included. The primary endpoint was not different comparing 10,115 IE patients with or without prior anticoagulation (OR: 1.10; 95% CI: 0.56-2.17; P = 0.77) or comparing 838 IE patients with or without prior antiplatelet (OR: 0.90; 95% CI: 0.61-1.33; P = 0.61). In-hospital mortality was lower in IE patients with prior anticoagulation compared to those without (OR: 0.74; 95% CI: 0.57-0.96; P = 0.03). There was no difference in reported ICH rates between patients with or without prior anticoagulation (OR: 0.54; 95% CI: 0.27-1.09; P = 0.09) or between patients with or without prior antiplatelet (OR: 0.35; 95% CI: 0.11-1.10; P = 0.07). The rate of ST was lower in IE patients with prior antiplatelet therapy compared to those without (OR: 0.53; 95% CI: 0.38-0.72; P < 0.01). Conclusions: ATT in IE patients was not associated with higher frequency of cerebrovascular events or ICH. Moreover, we found that the use of anticoagulation was associated with decreased in-hospital mortality and the use of antiplatelets was associated with decreased ST. Due to the limitations of this study, these results should be interpreted cautiously showing the necessity of a randomized setup.

Predictive Value of Serial Model of End-Stage Liver Disease Score Determination in Patients with Postcardiotomy Extracorporeal Membrane Oxygenation.

(1) Background: The use of extracorporeal membrane oxygenation (ECMO) in low cardiac output states after cardiac surgery may aid in patient recovery. However, in some patients, the clinical state may worsen, resulting in multiple organ failure and high mortality rates. In these circumstances, calculating a model of end-stage liver disease (MELD) score was shown to determine organ dysfunction and predicting mortality. (2) Methods: We evaluated whether serial MELD score determination increases mortality prediction in patients with postcardiotomy ECMO support. (3) Results: Statistically, a cutoff of a 2.5 MELD score increase within 48 h of ECMO initiation revealed an AUC of 0.722. Further, we found a significant association between hospital mortality and 48 h MELD increase (HR: 2.5, 95% CI: 1.33-4.75, p = 0.005) after adjustment for possible confounders. (4) Conclusions: Therefore, serial MELD score determinations on alternate days may be superior to single measurements in this special patient cohort.

Deactivation of LVAD support for myocardial recovery-surgical perspectives.

Left ventricular assist devices (LVADs) are excellent therapies for advanced heart failure patients either bridged to transplant or for lifetime use. LVADs also allow for reverse remodeling of the failing heart that is often associated with functional improvement. Indeed, growing enthusiasm exists to better understand this population of patients, whereby the LVAD is used as an adjunct to mediate myocardial recovery. When patients achieve benchmarks suggesting that they no longer need LVAD support, questions related to the discontinuation of LVAD therapy become front and center. The purpose of this review is to provide a surgical perspective on the practical and technical issues surrounding LVAD deactivation.

Pacemaker implantation after concomitant tricuspid valve repair in patients undergoing minimally invasive mitral valve surgery: Results from the Mini-Mitral International Registry.

Objective: Randomized evidence suggests a high risk of pacemaker implantation for patients undergoing mitral valve (MV) surgery with concomitant tricuspid valve repair (cTVR). We investigated the impact of cTVR on outcomes in the Mini-Mitral International Registry. Methods: From 2015 to 2021, 7513 patients underwent minimally invasive MV with or without cTVR in 17 international centers (MV: n = 5609, cTVR: n = 1113). Propensity matching generated 1110 well-balanced pairs. Multivariable analysis was applied. Results: Patients with cTVR were older and had more comorbidities. Propensity matching eliminated most differences except for more TR in patients who underwent cTVR (77.2% vs 22.1% MV, P < .001). Mean matched age was 71 years, and 45% were male. European System for Cardiac Operative Risk Evaluation II was still 2.68% (interquartile range [IQR], 0.80-2.63) vs 1.9% (IQR, 1.12-3.9) in matched MV (P < .001). MV replacement (30%) and atrial fibrillation surgery (32%) were similar in both groups. Cardiopulmonary bypass (161 minutes [IQR, 133-203] vs MV: 130 minutes [IQR, 103-166]; P < .001) and crossclamp times (93 minutes [IQR, 66-123] vs MV: 83 minutes [IQR, 64-107]; P < .001) were longer with cTVR. Although in-hospital mortality was similar (cTVR: 3.3% vs MV: 2.2%; P = .5), postoperative pacemaker implantations (9% vs MV: 5.8%; P = .02), low cardiac output syndrome (7.7% vs MV: 4.4%; P = .02), and acute kidney injury (13.8% vs MV: 10%; P = .01) were more frequent with cTVR. cTVR eliminated relevant TR in most patients (greater-than-moderate TR: 6.8%). Multivariable analysis identified MV replacement, atrial fibrillation, and cTVR as risk factors of postoperative pacemaker implantation. Conclusions: cTVR in minimally invasive MV surgery is an independent risk factor for pacemaker implantation in this international registry. It is also associated with more bleeding, low output syndrome, and acute kidney injury. It remains unclear whether technical or patient factors (or both) explain these differences.

Is There a Future for Minimal Access and Robots in Cardiac Surgery?

Minimally invasive techniques in cardiac surgery have found increasing use in recent years. Both patients and physicians often associate smaller incisions with improved outcomes (i.e., less risk, shorter hospital stay, and a faster recovery). Videoscopic and robotic assistance has been introduced, but their routine use requires specialized training and is associated with potentially longer operating times and higher costs. Randomized evidence is scarce and transcatheter treatment alternatives are increasing rapidly. As a result, the concept of minimally invasive cardiac surgery may be viewed with skepticism. In this review, we examine the current status and potential future perspectives of minimally invasive and robotic cardiac surgery.

Outcomes of Concomitant Coronary Artery Bypass Grafting in Patients With Infective Endocarditis: A Systematic Review and Meta-Analysis.

It is current practice to perform concomitant coronary artery bypass grafting (CABG) in patients with infective endocarditis who have relevant coronary artery disease. However, CABG may add complexity to the operation. We performed a systematic review and a meta-analysis of studies that presented outcomes from patients who underwent valve surgery because of infective endocarditis with or without concomitant CABG. Three databases were assessed. Perioperative mortality was the primary outcome. Long-term mortality and postoperative stroke were the secondary outcomes. Inverse variance method and random model were performed. Five studies with a total of 5,408 patients were included. Mean follow-up was 8.2 years. Just 1 study addressed exclusively patients with documented coronary artery disease. Perioperative mortality did not differ between patients with or without concomitant CABG (odds ratio 1.53, 95% confidence interval 0.52 to 4.48, p = 0.44). Long-term mortality did not differ between patients who received and those who did not receive concomitant CABG (odds ratio 1.79, confidence interval 0.88 to 3.65, p = 0.11). Only 1 study from a multicenter registry reported data on the occurrence of postoperative stroke, which demonstrated that its incidence after adjustment was 26% in patients with concomitant CABG versus 21% in patients without concomitant CABG (p = 0.003). The results suggest that in endocarditis patients, adding CABG to valve surgery does not affect perioperative or long-term mortality. Data available on the impact of concomitant CABG on neurologic outcomes are limited to a retrospective multicenter registry and suggest that concomitant CABG may be associated with higher postoperative stroke.

Intraoperative Cell Savage, Infection and Organ Failure in Infective Endocarditis Patients-A Retrospective Single Center Evaluation.

Surgery is indicated in about 50% of infective endocarditis patients, and bleeding or the transfusion of blood a common finding. The intraoperative use of cell salvage may reduce the perioperative transfusion requirement, but its use is limited in the underlying disease. In this retrospective study, we therefore evaluated n = 335 patients fulfilling the modified Duke criteria for infective endocarditis characterized by the use of intraoperative cell salvage with autologous blood retransfusion. Inflammation markers and organ dysfunction, including catecholamine dependency, were evaluated by using linear regression analysis. Between 2015 and 2020, 335 patients underwent surgery for left-sided heart valve endocarditis. Intraoperative cell salvage was used in 40.3% of the cases, especially in complex scenarios and reoperation. Intraoperative cell salvage significantly altered the white blood cell count after surgery. On average, leucocytes were 3.0 Gpt/L higher in patients with intraoperative cell salvage compared to patients without after adjustment for confounders (95% CI: 0.39-5.54). Although the difference in WBC was statistically significant, i.e., higher in the ICS group compared to the no-ICS group, this difference may be clinically unimportant. Organ dysfunction, including hemodynamic instability and lactate values, were comparable between groups. In conclusion, intraoperative cell salvage enhanced the re-transfusion of autologous blood, with minor effects on the postoperative course of inflammatory markers, but was not associated with increased hemodynamic instability or organ dysfunction in general. The restriction of intraoperative cell salvage in surgery for infective endocarditis should be re-evaluated, and more prospective data in this topic are needed.

Impact of preoperative mitral regurgitation on left ventricular assist device patients: propensity score-matched analysis of the EUROMACS dataset.

OBJECTIVES: Mitral regurgitation (MR) is frequently observed in patients undergoing left ventricular assist device implantation. We investigated the impact of preoperative MR on left ventricular assist device patients. METHODS: A retrospective propensity score-matched analysis of adult patients enrolled in the EUROMACS registry between 1 January 2011 and 30 November 2021 was performed. Patients were divided into 2 groups according to the grade of preoperative MR: none-to-mild (MR 0-II) or moderate-to-severe (MR III-IV). RESULTS: Following 1:1 propensity score matching, each group consisted of 914 patients. Incidence of postoperative temporary right ventricular support, reoperation for bleeding and dialysis was similar. MR III-IV demonstrated shorter median intensive care unit stay [14 days (6; 27.8) vs 10 days (5; 22), P = 0.004] and ventilation time [72 h (22, 320) vs 31 h (18, 150), P < 0.001]. Mortality was lower for MR III-IV patients [subdistribution hazard ratio: 0.66, 95% confidence interval (CI): 0.59-0.73, P < 0.001]. The 1-year survival was 68.1% (95% CI: 65.1-71.3%) in MR 0-II and 75% (95% CI: 72.1-78%) in MR III-IV. A lower incidence of total complications [odds ratio (OR): 0.93 (0.89-0.98), P = 0.003] and trend towards a lower risk of neurological dysfunction (subdistribution hazard ratio: 0.79; 95% CI: 0.61-1.01, P = 0.063) and sustained ventricular tachycardia [OR: 0.93 (0.54-1.03), P = 0.074] were demonstrated for MR III-IV. The risk of fatal stroke and pump thrombosis was similar. CONCLUSIONS: Moderate-to-severe MR in patients undergoing left ventricular assist device implantation is associated with better mid-term survival and lower incidence of total major adverse events and complications. The incidence of severe postoperative complications including fatal stroke and device thrombosis was similar.

Temporary Mechanical Circulatory Support in Cardiogenic Shock Patients after Cardiac Procedures: Selection Algorithm and Weaning Strategies.

Mechanical circulatory support has proven effective in managing postcardiotomy cardiogenic shock by stabilizing patients' hemodynamics and ensuring adequate organ perfusion. Among the available device modalities, the combination of extracorporeal life support and a microaxial flow pump for left ventricular unloading has emerged as a valuable tool in the surgical armamentarium. In this publication, we provide recommendations for the application and weaning of temporary mechanical circulatory support in cardiogenic shock patients, derived from a consensus among leading cardiac centers in German-speaking countries.

Diabetes Is an Independent Risk Factor for Cancer after Heart and/or Lung Transplantation.

Background: De novo cancers are feared complications after heart or lung transplantation. Recent data suggest that diabetes mellitus (DM) might also be a risk factor for cancer. We hypothesized that transplanted diabetic patients are at greater risk of developing cancer compared to non-diabetic ones. Methods: We reviewed 353 patients post-heart and/or -lung transplantation from our center between October 1999 and June 2021. Patients with follow-up <180 days (n = 87) were excluded from the analysis. The remaining 266 patients were divided into patients who had preoperative DM (n = 88) or developed it during follow-up (n = 40) and patients without DM (n = 138). Results: The diabetic cohort showed higher rates of malignancies in all patients (30.33 vs. 15.97%, p = 0.005) and in the matched population (31.9 vs. 16.1%, p < 0.001). There were also significantly more solid tumors (17.9 vs. 9.4%, p = 0.042; matched: 16.6 vs. 9.1%, p = 0.09) The presence of diabetes was associated with a 13% increased risk of cancer when compared to non-diabetic patients. New-onset post-transplant diabetes doubled the likelihood of cancer development. Conclusions: Pre-transplant diabetes mellitus increases the risk of cancer after heart and/or lung transplantation. However, new-onset diabetes after transplantation is associated with a much greater cancer risk. This information is relevant for screening during follow-up.

Association of liver dysfunction with outcomes after cardiac surgery-a meta-analysis.

OBJECTIVES: The aim of this study was to perform a meta-analysis of studies reporting outcomes in patients with liver dysfunction addressed by the model of end-stage liver disease and Child-Turcotte-Pugh scores undergoing cardiac surgery. METHODS: A systematic literature search was conducted to identify contemporary studies reporting short- and long-term outcomes in patients with liver dysfunction compared to patients with no or mild liver dysfunction undergoing cardiac surgery (stratified in high and low score group based on the study cut-offs). Primary outcome was perioperative mortality. Secondary outcomes were perioperative neurological events, prolonged ventilation, sepsis, bleeding and/or need for transfusion, acute kidney injury and long-term mortality. RESULTS: A total of 33 studies with 48 891 patients were included. Compared with the low score group, being in the high score group was associated with significantly higher risk of perioperative mortality [odds ratio (OR) 3.72, 95% confidence interval (CI) 2.75-5.03, P < 0.001]. High score group was also associated with a significantly higher rate of perioperative neurological events (OR 1.49, 95% CI 1.30-1.71, P < 0.001), prolonged ventilation (OR 2.45, 95% CI 1.94-3.09, P < 0.001), sepsis (OR 3.88, 95% CI 2.07-7.26, P < 0.001), bleeding and/or need for transfusion (OR 1.95, 95% CI 1.43-2.64, P < 0.001), acute kidney injury (OR 3.84, 95% CI 2.12-6.98, P < 0.001) and long-term mortality (incidence risk ratio 1.29, 95% CI 1.14-1.46, P < 0.001). CONCLUSIONS: The analysis suggests that liver dysfunction in patients undergoing cardiac surgery is independently associated with higher risk of short and long-term mortality and also with an increased occurrence of various perioperative adverse events.