Modifying risks to improve outcome in cardiac surgery: An anesthesiologist's perspective

The role of hemoadsorption in cardiac surgery - a systematic review

BACKGROUND

Extracorporeal blood purification has been widely used in intensive care medicine, nephrology, toxicology, and other fields. During the last decade, with the emergence of new adsorptive blood purification devices, hemoadsorption has been increasingly applied during CPB in cardiac surgery, for patients at different inflammatory risks, or for postoperative complications. Clinical evidence so far has not provided definite answers concerning this adjunctive treatment. The current systematic review aimed to critically assess the role of perioperative hemoadsorption in cardiac surgery, by summarizing the current knowledge in this clinical setting.

METHODS

A literature search of PubMed, Cochrane library, and the database provided by CytoSorbents was conducted on June 1st, 2023. The search terms were chosen by applying neutral search keywords to perform a non-biased systematic search, including language variations of terms "cardiac surgery" and "hemoadsorption". The screening and selection process followed scientific principles (PRISMA statement). Abstracts were considered for inclusion if they were written in English and published within the last ten years. Publications were eligible for assessment if reporting on original data from any type of study (excluding case reports) in which a hemoadsorption device was investigated during or after cardiac surgery. Results were summarized according to sub-fields and presented in a tabular view.

RESULTS

The search resulted in 29 publications with a total of 1,057 patients who were treated with hemoadsorption and 988 control patients. Articles were grouped and descriptively analyzed due to the remarkable variability in study designs, however, all reported exclusively on CytoSorb® therapy. A total of 62% (18/29) of the included articles reported on safety and no unanticipated adverse events have been observed. The most frequently reported clinical outcome associated with hemoadsorption was reduced vasopressor demand resulting in better hemodynamic stability.

CONCLUSIONS

The role of hemoadsorption in cardiac surgery seems to be justified in selected high-risk cases in infective endocarditis, aortic surgery, heart transplantation, and emergency surgery in patients under antithrombotic therapy, as well as in those who develop a dysregulated inflammatory response, vasoplegia, or septic shock postoperatively. Future large randomized controlled trials are needed to better define proper patient selection, dosing, and timing of the therapy.

PreScheck Team Study: prehabilitation clinic as an effective patient management tool in elective cardiac surgery

INTRODUCTION

The main purpose of the study was to assess the impact of preoperative interdisciplinary assessment by the PreScheck Team on optimization of the final selection for elective cardiac surgery.

MATERIAL AND METHODS

This is a single-centre prospective observational study. The examined population consisted of 933 adult patients planned for cardiac surgery. After the exclusion of urgent operations, the study group consisted of 288 patients planned for elective cardiac surgery within 3 months from 1.01.2023 with PreScheck assessment (PreScheck Team group 2) and a control group of 311 patients scheduled for elective cardiac surgery between 1.03.2022 and 30.06.2022 (4 months), without preoperative interdiscipli-nary assessment (No PreScheck Team group 2).

RESULTS

Fifty-two patients (18.06%) from the study group were finally excluded from the surgery on the scheduled date. In 46 patients (88.46%) the temporary or permanent exclusion from surgery was a result of PreScheck Team assessment. In the control group 42 patients (13.5%) did not undergo surgery on the scheduled date. Twenty-seven of those patients (8.97%) were permanently excluded from cardiac surgery after admission to the hospital and required additional tests before the final clinical decision, with total hospitalization time of 146 days.

CONCLUSIONS

Pre Surgery Check (PreScheck) Team is an original concept that combines classical preoperative assessment and an outpatient prehabilitation clinic. The approach we are proposing here should be a complementary stage in the process of selection for elective cardiac surgery, in addition to the Heart Team recommendation. This two-step decision-making enables real individual risk assessment, selection of the most suitable intervention and better use of medical resources.

Adult Cardiac Surgery-Associated Acute Kidney Injury: Joint Consensus Report

OBJECTIVES

Acute kidney injury (AKI) is increasingly recognized as a source of poor patient outcomes after cardiac surgery. The purpose of the present report is to provide perioperative teams with expert recommendations specific to cardiac surgery-associated AKI (CSA-AKI).

METHODS

This report and consensus recommendations were developed during a joint, in-person, multidisciplinary conference with the Perioperative Quality Initiative and the Enhanced Recovery After Surgery Cardiac Society. Multinational practitioners with diverse expertise in all aspects of cardiac surgical perioperative care, including clinical backgrounds in anesthesiology, surgery and nursing, met from October 20 to 22, 2021, in Sacramento, California, and used a modified Delphi process and a comprehensive review of evidence to formulate recommendations. The quality of evidence and strength of each recommendation were established using the Grading of Recommendations Assessment, Development, and Evaluation methodology. A majority vote endorsed recommendations.

RESULTS

Based on available evidence and group consensus, a total of 13 recommendations were formulated (4 for the preoperative phase, 4 for the intraoperative phase, and 5 for the postoperative phase), and are reported here.

CONCLUSIONS

Because there are no reliable or effective treatment options for CSA-AKI, evidence-based practices that highlight prevention and early detection are paramount. Cardiac surgery-associated AKI incidence may be mitigated and postsurgical outcomes improved by focusing additional attention on presurgical kidney health status; implementing a specific cardiopulmonary bypass bundle; using strategies to maintain intravascular euvolemia; leveraging advanced tools such as the electronic medical record, point-of-care ultrasound, and biomarker testing; and using patient-specific, goal-directed therapy to prioritize oxygen delivery and end-organ perfusion over static physiologic metrics.

Physical performance tests and in-hospital outcomes in elective open chest heart surgery

Background

Physical performance tests are essential for a comprehensive health assessment, and have been described as predictors of disability and muscle mass decline after open chest heart surgery (OHS). We evaluated the association between physical performance tests with clinical outcomes after OHS in younger and older patients. Moreover, the ability of physical performance tests and European System for Cardiac Operative Risk Evaluation (Euroscore II) to predict death was assessed.

Methods

Elective OHS patients were evaluated before surgery with handgrip strength (HGS), 30-s Chair-Stand Test (30sCST), and timed up and go test (TUGT). The outcomes were post-surgical complications, total length of stay (LOS), time to walk (TW), time in invasive mechanical ventilation (TIMV), and in-hospital mortality. Data were stratified between patients < 60 (younger) and ≥ 60 years old (older).

Results

A total of 166 patients were included in the study (older, n = 89). The only physical test associated with mortality in the adjusted models was HGS in older patients (p = 0.03). Among older patients, both Euroscore II (AUC = 0.77) and HGS (AUC = 0.80) demonstrated good ability to predict death. Combining HGS and Euroscore II did not increase accuracy for mortality prediction (AUC = 0.83).

Conclusion

HGS performance was comparable to a well-established surgical risk score in evaluating in-hospital mortality after OHS, only in older patients. Functional testing before OHS could be a tool to improve risk stratification in these patients. Future intervention studies aiming to improve functional capacity before elective OHS can further clarify the impact of physical fitness in surgical recovery.

Hemoadsorption in Complex Cardiac Surgery-A Single Center Experience

(1) Background: Cardiac surgery may evoke a generalized inflammatory response, typically magnified in complex, combined, redo, and emergency procedures with long aortic cross-clamp times. Various treatment options have been introduced to help regain control over post-cardiac surgery hyper-inflammation, including hemoadsorptive immunomodulation with CytoSorb^®. (2) Methods: We conducted a single-center retrospective observational study of patients undergoing complex cardiac surgery. Patients intra-operatively treated with CytoSorb^® were compared to a control group. The primary outcome was the change in the vasoactive-inotropic score (VIS) from pre-operatively to post-operatively. (3) Results: A total of 52 patients were included in the analysis, where 23 were treated with CytoSorb^® (CS) and 29 without (controls). The mean VIS increase from pre-operative to post-operative values was significantly lower in the CS group compared to the control group (3.5 vs. 5.5, respectively, p = 0.05). In-hospital mortality in the control group was 20.7% (6 patients) and 9.1% (2 patients) in the CS group (p = 0.26). Lactate level changes were comparable, and the median intensive care unit and hospital lengths of stay were similar between groups. (4) Conclusions: Despite notable imbalances between the groups, the signals revealed point toward better hemodynamic stability with CytoSorb^® hemoadsorption in complex cardiac surgery and a trend of lower mortality.

A Multicenter, Randomized, Double-Blind, Placebo-Controlled Trial of Preoperative Antithrombin Supplementation in Patients at Risk for Antithrombin Deficiency After Cardiac Surgery

BACKGROUND

Antithrombin (AT) activity is reduced during cardiac operations with cardiopulmonary bypass (CPB), which is associated with adverse outcomes. Preoperative AT supplementation, to achieve >58% and <100% AT activity, may potentially reduce postoperative morbidity and mortality in cardiac operations with CPB. This prospective, multicenter, randomized, double-blind, placebo-controlled study was designed to evaluate the safety and efficacy of preoperative treatment with AT supplementation in patients at risk for low AT activity after undergoing cardiac surgery with CPB.

METHODS

A total of 425 adult patients were randomized (1:1) to receive either a single dose of AT (n = 213) to achieve an absolute increase of 20% above pretreatment AT activity or placebo (n = 212) before surgery. The study duration was approximately 7 weeks. The primary efficacy end point was the percentage of patients with any component of a major morbidity composite (postoperative mortality, stroke, acute kidney injury [AKI], surgical reexploration, arterial or venous thromboembolic events, prolonged mechanical ventilation, and infection) in the 2 groups. Secondary end points included AT activity, blood loss, transfusion requirements, duration of intensive care unit (ICU), and hospital stays. Safety was also assessed.

RESULTS

Overall, 399 patients (men, n = 300, 75.2%) with a mean (standard deviation [SD]) age of 66.1 (11.7) years, with the majority undergoing complex surgical procedures (n = 266, 67.9%), were analyzed. No differences in the percentage of patients experiencing morbidity composite outcomes between groups were observed (AT-treated 68/198 [34.3%] versus placebo 58/194 [29.9%]; P = .332; relative risk, 1.15). After AT infusion, AT activity was significantly higher in the AT group (108% [42-143]) versus placebo group (76% [40-110]), and lasted up to postoperative day 2. At ICU, the frequency of patients with AT activity ≥58% in the AT group (81.5%) was significantly higher (P < .001) versus placebo group (43.2%). Secondary end point analysis did not show any advantage of AT over placebo group. There were significantly more patients with AKI (P < .001) in the AT group (23/198; 11.6%) than in the placebo group (5/194, 2.6%). Safety results showed no differences in treatment-emergent adverse events nor bleeding events between groups.

CONCLUSIONS

AT supplementation did not attenuate adverse postoperative outcomes in our cohort of patients undergoing cardiac surgery with CPB.

Surgical Procedure Time and Mortality in Patients with Infective Endocarditis Caused by Staphylococcus aureus or Streptococcus Species

Staphylococcus aureus (SA) and Streptococcus species (SS) show different clinical manifestations in infective endocarditis (IE), but the impact on the complexity of surgical treatment remains unclear. All patients with surgically treated IE due to SA or SS between July 2013 and December 2016 were extracted from a prospectively collected, single-center registry. Data on patient characteristics, surgical procedures, and postprocedural outcomes were collected. SA-IE was more common with prosthetic valves (26.3% vs. 7.3%, p = 0.04), cardiac devices (14.3% vs. 0%, p = 0.03), previous cardiac surgery (28.6% vs. 9.8%, p = 0.03), intravenous drug abuse (14.3% vs. 0%, p = 0.03), and embolic events (57.1% vs. 26.8%, p = 0.007). Preoperative CRP was significantly higher in SA-IE (median 96.1 mg/L vs. 42.4 mg/L, p = 0.002). Otherwise, SS-IE affected more cusps/leaflets (mean 2.4 vs. 1.8, p = 0.03) and led to more valve dysfunction (83.8% vs. 54.3%, p = 0.007). Surgery times did not differ between the groups, though patients with SA spent more time in the intensive care unit (median 7 vs. 4.5 days, p = 0.04). Hospital mortality did not differ, but patients with SA-IE had unfavorable long-term survival (p = 0.001). Future studies need to be larger and focus on the mechanism behind the reduced long-term survival to mitigate the deleterious effect of SA in surgically treated patients with IE.

Machine learning in perioperative medicine: a systematic review

Background

Risk stratification plays a central role in anesthetic evaluation. The use of Big Data and machine learning (ML) offers considerable advantages for collection and evaluation of large amounts of complex health-care data. We conducted a systematic review to understand the role of ML in the development of predictive post-surgical outcome models and risk stratification.

Methods

Following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines, we selected the period of the research for studies from 1 January 2015 up to 30 March 2021. A systematic search in Scopus, CINAHL, the Cochrane Library, PubMed, and MeSH databases was performed; the strings of research included different combinations of keywords: “risk prediction,” “surgery,” “machine learning,” “intensive care unit (ICU),” and “anesthesia” “perioperative.” We identified 36 eligible studies. This study evaluates the quality of reporting of prediction models using the Transparent Reporting of a Multivariable Prediction Model for Individual Prognosis or Diagnosis (TRIPOD) checklist.

Results

The most considered outcomes were mortality risk, systemic complications (pulmonary, cardiovascular, acute kidney injury (AKI), etc.), ICU admission, anesthesiologic risk and prolonged length of hospital stay. Not all the study completely followed the TRIPOD checklist, but the quality was overall acceptable with 75% of studies (Rev #2, comm #minor issue) showing an adherence rate to TRIPOD more than 60%. The most frequently used algorithms were gradient boosting (n = 13), random forest (n = 10), logistic regression (LR; n = 7), artificial neural networks (ANNs; n = 6), and support vector machines (SVM; n = 6). Models with best performance were random forest and gradient boosting, with AUC > 0.90.

Conclusions

The application of ML in medicine appears to have a great potential. From our analysis, depending on the input features considered and on the specific prediction task, ML algorithms seem effective in outcomes prediction more accurately than validated prognostic scores and traditional statistics. Thus, our review encourages the healthcare domain and artificial intelligence (AI) developers to adopt an interdisciplinary and systemic approach to evaluate the overall impact of AI on perioperative risk assessment and on further health care settings as well.

Prognostic Impact of Prediabetes on Patient Outcomes After Coronary Artery Bypass Grafting: A Single-center Cohort Study

BACKGROUND

Prediabetes, as a precursor stage, has an important role in development of overt diabetes as well as coronary artery disease (CAD). The aim of this study is to evaluate the association between prediabetes and adverse outcomes (major adverse cardiovascular and cerebrovascular events [MACCE] and all-cause mortality) in patients who underwent coronary artery bypass grafting (CABG).

METHODS

In this prospective study, we included 3754 patients with CAD who underwent elective isolated CABG between January 2016 to January 2020. Patients were categorized based on their glycemic status at the time of CABG as follows: diabetics (n = 2707), prediabetics (n = 471), and nondiabetics (n = 576). Primary endpoints were occurrence of all-cause mortality and MACCE.

RESULTS

We studied 3754 patients for a median of 32.25 months after CABG. MACCE occurred in 474 (12.6%) patients. After adjusting for potential confounders, diabetic patients had a higher risk of MACCE (hazard ratio [HR] 1.69; 95% confidence intervals [CI], 1.24-2.29) and death (HR 2.33, 95% CI, 1.45-3.7) compared with nondiabetic and prediabetic ones. However, patients with prediabetes had lower HR of MACCE, but the association was nonsignificant (HR 1.02; 95% CI, 0.67-1.56).

CONCLUSIONS

Diabetes is significantly associated with higher risk of mortality and MACCE; however, prediabetes did not show a prognostic impact in terms of overall and MACCE-free survival.

Sarcopenia predicts adverse outcomes in an elderly population with coronary artery disease: a systematic review and meta-analysis

Background

The development of sarcopenia is attributed to normal aging and factors like type 2 diabetes, obesity, inactivity, reduced testosterone levels, and malnutrition, which are factors of poor prognosis in patients with coronary artery disease (CAD). This study aimed to perform a meta-analysis to assess whether preoperative sarcopenia can be used to predict the outcomes after cardiac surgery in elderly patients with CAD.

Methods

PubMed, Embase, the Cochrane library, and Web of Science were searched for available papers published up to December 2020. The primary outcome was major adverse cardiovascular outcomes (MACE). The secondary outcomes were mortality and heart failure (HF)-related hospitalization. The random-effects model was used. Hazard ratios (HRs) with 95% confidence intervals (95%CIs) were estimated.

Results

Ten studies were included, with 3707 patients followed for 6 months to 4.5 ± 2.3 years. The sarcopenia population had a higher rate of MACE compared to the non-sarcopenia population (HR = 2.27, 95%CI: 1.58–3.27, P < 0.001; I² = 60.0%, P_{heterogeneity} = 0.02). The association between sarcopenia and MACE was significant when using the psoas muscle area index (PMI) to define sarcopenia (HR = 2.86, 95%CI: 1.84–4.46, P < 0.001; I² = 0%, P_{heterogeneity} = 0.604). Sarcopenia was not associated with higher late mortality (HR = 2.15, 95%CI: 0.89–5.22, P = 0.090; I² = 91.0%, P_{heterogeneity} < 0.001), all-cause mortality (HR = 1.35, 95%CI: 0.14–12.84, P = 0.792; I² = 90.5%, P_{heterogeneity} = 0.001), and death, HF-related hospitalization (HR = 1.37, 95%CI: 0.59–3.16, P = 0.459; I² = 62.0%, P_{heterogeneity} = 0.105). The sensitivity analysis revealed no outlying study in the analysis of the association between sarcopenia and MACE after coronary intervention.

Conclusion

Sarcopenia is associated with poor MACE outcomes in patients with CAD. The results could help determine subpopulations of patients needing special monitoring after CAD surgery. The present study included several kinds of participants; although non-heterogeneity was found, interpretation should be cautious.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-021-02438-w.

Performance of the AusSCORE II and STS Score for Coronary Artery Bypass Grafting in a New Zealand Population

BACKGROUND

The updated Australian System for Cardiac Operative Risk Evaluation (AusSCORE II) and the Society of Thoracic Surgeons (STS) Score are well-established tools in cardiac surgery for estimating operative mortality risk. No validation analysis of both risk models has been undertaken for a contemporary New Zealand population undergoing isolated coronary bypass surgery. We therefore aimed to assess the efficacy of these models in predicting mortality for New Zealand patients receiving isolated coronary artery bypass grafting (CABG).

MATERIAL AND METHODS

A prospective database was maintained of patients undergoing isolated CABG at a major tertiary referral centre in New Zealand between September 2014 and September 2017. This database collected the patients' demographic, clinical, biochemical, operative and mortality data. The primary outcome measure was the correlation between the predicted AusSCORE II and STS Score mortality risks and the observed 30-day mortality events for all patients in the database using discrimination and calibration statistics. Discrimination and calibration were assessed using receiver operating characteristic (ROC) curves and the Hosmer-Lemeshow test respectively.

RESULTS

A total of 933 patients underwent isolated CABG during the 3-year study period. There were seven deaths in the study cohort occurring within 30 days of surgery. Discrimination analysis demonstrated the area under the ROC curve (AUC) of the AusSCORE II and STS Score as 88.2% (95% CI: 85.9-90.2, p<0.0001) and 92.1% (95% CI: 90.2-93.7, p<0.0001) respectively. Calibration analysis revealed Hosmer-Lemeshow test p-values for the AusSCORE II and STS Score as 0.696 and 0.294 respectively.

DISCUSSION

ROC curve analysis produced very high and statistically significant AUC values for the AusSCORE II and STS Score. Hosmer-Lemeshow test analysis revealed that both risk scoring tools are well calibrated for our study cohort. Therefore, the AusSCORE II and STS Score are both strongly predictive of 30-day mortality for isolated coronary artery bypass grafting surgery in our New Zealand patient population. Both risk models have performed with excellent discrimination and calibration. There is, however, a need to consider the performance of these risk stratification models in other cardiac surgical procedures outside isolated coronary bypass surgery where appropriate.

Consensus Report on Patient Blood Management in Cardiac Surgery by Turkish Society of Cardiovascular Surgery (TSCVS), Turkish Society of Cardiology (TSC), and Society of Cardio-Vascular-Thoracic Anaesthesia and Intensive Care (SCTAIC)

Anemia, transfusion and bleeding independently increase the risk of complications and mortality in cardiac surgery. The main goals of patient blood management are to treat anemia, prevent bleeding, and optimize the use of blood products during the perioperative period. The benefit of this program has been confirmed in many studies and its utilization is strongly recommended by professional organizations. This consensus report has been prepared by the authors who are the task members appointed by the Turkish Society of Cardiovascular Surgery, Turkish Society of Cardiology (TSC), and Society of Cardio-Vascular-Thoracic Anaesthesia and Intensive Care to raise the awareness of patient blood management. This report aims to summarize recommendations for all perioperative blood- conserving strategies in cardiac surgery.

Patient Blood Management in Pediatric Cardiac Surgery: A Review

Efforts to reduce blood product transfusions and adopt blood conservation strategies for infants and children undergoing cardiac surgical procedures are ongoing. Children typically receive red blood cell and coagulant blood products perioperatively for many reasons, including developmental alterations of their hemostatic system, and hemodilution and hypothermia with cardiopulmonary bypass that incites inflammation and coagulopathy and requires systemic anticoagulation. The complexity of their surgical procedures, complex cardiopulmonary interactions, and risk for inadequate oxygen delivery and postoperative bleeding further contribute to blood product utilization in this vulnerable population. Despite these challenges, safe conservative blood management practices spanning the pre-, intra-, and postoperative periods are being developed and are associated with reduced blood product transfusions. This review summarizes the available evidence regarding anemia management and blood transfusion practices in the perioperative care of these critically ill children. The evidence suggests that adoption of a comprehensive blood management approach decreases blood transfusions, but the impact on clinical outcomes is less well studied and represents an area that deserves further investigation.

The spectrum of myocardial homeostasis mechanisms in the settings of cardiac surgery procedures (Review)

Classic cardiac surgery, determined through the function of cardiopulmonary bypass machine and myocardial cardioplegic arrest, represents the most controlled scenario for cardiomyocyte homeostatic disturbances due to systemic inflammatory response and myocardial reperfusion injury. An increasing number of studies have demonstrated that myocardial cell homeostasis in cardiac surgery procedures is a sequence of molecularly interrelated and overlapping mechanisms in the form of apoptosis, autophagy and necrosis, which are activated by a plethora of induced inflammatory mediators and gene-related signaling pathways. In this study, we outline the molecular mechanisms of the cardiomyocyte adaptive homeostatic process and the associated clinical implications, in the settings of classic cardiac surgery procedures.