Complication Of Cardiac Surgery Research Articles

Association between preoperative arterial stiffness and postoperative atrial fibrillation

Postoperative atrial fibrillation (POAF) is the most frequent cardiac surgery complication, associated with poor morbid-mortality. POAF pathophysiology remains unclear. Aortic stiffness has been demonstrated to increase after aortic valve replacement (AVR). Moreover, atrial fibrillation incidence has been demonstrated to be correlated with aortic stiffness in the context of AF ablation and in the general population. Our goal was to test the association between preoperative aortic stiffness indexes and postoperative atrial fibrillation onset after cardiac surgery. We explored consecutive patients referred for surgical aortic valve replacement for symptomatic, severe aortic stenosis with or without coronary bypass at the University Hospital CHU Lille. Aortic tree properties were characterized non-invasively thanks to the Sphygmocor® at the preoperative time. Postoperative atrial fibrillation was assessed by EKG monitoring from the end of surgery to hospital discharge. POAF occurred in 40 (31.2%) patients among the 128 included from January 2019 to June 2022. Preoperative aortic stiffness indexes were different between POAF and sinus rhythm (SR) patients regarding pulse wave velocity 12.3 ± 1.3 m/s vs. 10.8 ± 0.9 m/s P = 0.0002, and reflection magnitude (respectively 76 ± 7% vs. 75 ± 8%; P = 0.56). Preoperative aortic compliance was also different between SR and POAF patients (1.7 ± 0.6 mL/mmHg vs. 1.3 ± 0.7 mL/mmHg respectively; P = 0.017). Peripheral vascular resistances were 1570 ± 430 dyn.s.cm−5 in SR vs. 1640 ± 450 dyn.s.cm-5 in POAF (P = 0.0.04). There is a higher aortic stiffness in preoperative period for patient who underwent POAF after aortic valve replacement.

Effect of angiography timing on acute kidney injury after cardiac surgery in patients with preoperative renal dysfunction

BackgroundCardiac surgery-associated acute kidney injury (AKI) is one of the common complications of cardiac surgery. Preoperative angiography helps assess heart disease but may increase the risk of AKI. Although more and more patients with preoperative renal dysfunction can undergo cardiac surgery with the advances in surgical techniques, there is little research on the effect of angiography on postoperative AKI in these patients. This study investigates whether angiography increases the risk of AKI after cardiac surgery in patients with preoperative renal dysfunction (15 ≤ eGFR < 60 ml/min/1.73m2).MethodsPatients with preoperative renal dysfunction (15 ≤ eGFR < 60 ml/min/1.73m2) who underwent angiography and cardiac surgery successively from January 2015 to December 2020 were retrospectively enrolled in this study. The primary outcome was postoperative AKI, defined as the Kidney Disease: Improving Global Outcomes Definition and Staging (KDIGO) criteria. Univariate analysis and multivariate regression were performed to identify the association between angiography timing and AKI.ResultsA total of 888 consecutive eligible patients with preoperative renal dysfunction (15 ≤ eGFR < 60 ml/min/1.73m2) were enrolled in this study. The incidence of AKI was 48.31%. Male (OR = 1.903), the interval between angiography and surgery (0-2d OR = 2.161; 3-6d OR = 3.291), cross-clamp duration (OR = 1.009), were identified as predictors for AKI. The interval between angiography and surgery was also associated with AKI in the patients with 15 ≤ eGFR < 30ml/min/1.73m2 (0-2d OR = 4.826; 3-6d OR = 5.252), 30 ≤ eGFR < 45 ml/min/1.73m2 (0-2d OR = 2.952; 3-6d OR = 3.677), but not associated with AKI in patients with 45 ≤ eGFR < 60 ml/min/1.73m2.ConclusionsIn patients with preoperative renal dysfunction, the interval between angiography and cardiac surgery (0-2d and 3-6d) was associated with AKI. For patients with poorer preoperative renal function, the interval between angiography and cardiac surgery is of great concern.

Prediction of new onset postoperative atrial fibrillation using a simple Nomogram

BackgroundNew onset postoperative atrial fibrillation (POAF) is the most common complication of cardiac surgery, with an incidence ranging from 15 to 50%. This study aimed to develop a new nomogram to predict POAF using preoperative and intraoperative risk factors.MethodsWe retrospectively analyzed the data of 2108 consecutive adult patients (> 18 years old) who underwent cardiac surgery at our medical institution. The types of surgery included isolated coronary artery bypass grafting, valve surgery, combined valve and coronary artery bypass grafting (CABG), or aortic surgery. Logistic regression or machine learning methods were applied to predict POAF incidence from a subset of 123 parameters. We also developed a simple nomogram based on the strength of the results and compared its predictive ability with that of the CHA2DS2-VASc and POAF scores currently used in clinical practice.ResultsPOAF was observed in 414 hospitalized patients. Logistic regression provided the highest area under the receiver operating characteristic curve (ROC) in the validation cohort. A simple bedside tool comprising three variables (age, left atrial diameter, and surgery type) was established, which had a discriminative ability with a ROC of 0.726 (95% CI 0.693–0.759) and 0.727 (95% CI 0.676–0.778) in derivation and validation subsets respectively. The calibration curve of the new model was relatively well-fit (p = 0.502).ConclusionsLogistic regression performed better than machine learning in predicting POAF. We developed a nomogram that may assist clinicians in identifying individuals who are prone to POAF.

Metabolomic interplay between gut microbiome and plasma metabolome in cardiac surgery-associated acute kidney injury.

Cardiac surgery-associated acute kidney injury (CSA-AKI) is a prevalent complication of cardiac surgery, which may be associated with a great risk of developing chronic kidney disease and mortality. This study aimed to investigate the possible links between gut microbiota metabolism and CSA-AKI. A prospective cohort of patients who underwent cardiac surgery was continuously recruited, who were further divided into CSA-AKI group and Non-AKI group based on clinical outcomes. Their faecal and plasma samples were collected before surgery and were separately analysed by nontargeted and targeted metabolomics. The differential metabolites related to CSA-AKI were screened out using statistical methods, and altered metabolic pathways were determined by examining the Kyoto Encyclopedia of Genes and Genomes database. Nearly 1000 faecal metabolites were detected through high-resolution mass spectrometry (MS) and bioinformatics at high and mid confidence levels, and 49 differential metabolites at high confidence level may perform essential biological functions and provide potential diagnostic indicators. Compared with the Non-AKI group, the patients in the CSA-AKI group displayed dramatic changes in gut microbiota metabolism, including amino acid metabolism, nicotinate and nicotinamide metabolism, purine metabolism and ATP-binding cassette (ABC) transporters. Meanwhile, 188 plasma metabolites were identified and quantified by tandem MS, and 34 differential plasma metabolites were screened out between the two groups using univariate statistical analysis. These differential plasma metabolites were primarily enriched in the following metabolic pathways: sulphur metabolism, amino acid biosynthesis, tryptophan metabolism and ABC transporters. Furthermore, the content of indole metabolites in the faecal and plasma samples of the CSA-AKI group was higher than that of the Non-AKI group. Patients with CSA-AKI may have dysbiosis of their intestinal microbiota and metabolic abnormalities in their gut system before cardiac surgery. Thus, some metabolites and related metabolic pathways may be potential biomarkers and new therapeutic targets for the disease.

Post-operative atrial fibrillation after cardiac surgery: Challenges throughout the patient journey.

Atrial fibrillation (AF) is the most common complication of cardiac surgery, occurring in up to half of patients. Post-operative AF (POAF) refers to new-onset AF in a patient without a history of AF that occurs within the first 4 weeks after cardiac surgery. POAF is associated with short-term mortality and morbidity, but its long-term significance is unclear. This article reviews existing evidence and research challenges for the management of POAF in patients who have had cardiac surgery. Specific challenges are discussed in four phases of care. Pre-operatively, clinicians need to be able to identify high-risk patients, and initiate prophylaxis to prevent POAF. In hospital, when POAF is detected, clinicians need to manage symptoms, stabilize hemodynamics and prevent increases in length of stay. In the month after discharge, the focus is on minimizing symptoms and preventing readmission. Some patients require short term oral anticoagulation for stroke prevention. Over the long term (2-3 months after surgery and beyond), clinicians need to identify which patients with POAF have paroxysmal or persistent AF and can benefit from evidence-based therapies for AF, including long-term oral anticoagulation.

Inhaled milrinone in cardiac surgical patients: pharmacokinetic and pharmacodynamic exploration

Mean arterial pressure to mean pulmonary arterial pressure ratio (mAP/mPAP) has been identified as a strong predictor of perioperative complications in cardiac surgery. We therefore investigated the pharmacokinetic/pharmacodynamic (PK/PD) relationship of inhaled milrinone in these patients using this ratio (R) as a PD marker. Following approval by the ethics and research committee and informed consent, we performed the following experiment. Before initiation of cardiopulmonary bypass in 28 pulmonary hypertensive patients scheduled for cardiac surgery, milrinone (5 mg) was nebulized, plasma concentrations measured (up to 10 h) and compartmental PK analysis carried out. Baseline (R0) and peak (Rmax) ratios as well as magnitude of peak response (∆Rmax-R0) were measured. During inhalation, individual area under effect-time (AUEC) and plasma concentration–time (AUC) curves were correlated. Potential relationships between PD markers and difficult separation from bypass (DSB) were explored. In this study, we observed that milrinone peak concentrations (41–189 ng ml−1) and ΔRmax-R0 (− 0.12–1.5) were obtained at the end of inhalation (10–30 min). Mean PK parameters agreed with intravenous milrinone published data after correction for the estimated inhaled dose. Paired comparisons yielded a statistically significant increase between R0 and Rmax (mean difference, 0.58: 95% CI 0.43–0.73; P < 0.001). Individual AUEC correlated with AUC (r = 0.3890, r2 = 0.1513; P = 0.045); significance increased after exclusion of non-responders (r = 4787, r2 = 0.2292; P = 0.024). Individual AUEC correlated with ∆Rmax-R0 (r = 5973, r2 = 0.3568; P = 0.001). Both ∆Rmax-R0 (P = 0.009) and CPB duration (P < 0.001) were identified as predictors of DSB. In conclusion, both magnitude of peak response of the mAP/mPAP ratio and CPB duration were associated with DSB.

Left atrial dissection after a supra-annular mitral valve replacement for endocarditis

BackgroundLeft atrial dissection is a rare and a potentially fatal complication of cardiac surgery. Multi-modal imagery is helpful for the diagnosis and to guide the treatment.Case presentationWe report the case of a 66-year-old female patient who underwent a combined mitral and aortic valve replacement for degenerative valvular disease. She presented an infectious endocarditis revealed by a third-degree atrioventricular bloc and had a redo mitral- and aortic valve replacement. Mitral valve was inserted in supra-annular position due to annular destruction. Post-operative course was marked by a refractory acute heart failure explained by a left atrial wall dissection confirmed by transoesophageal echocardiography and synchronized cardiac CT-scan. Surgical treatment was theoretically indicated but considering the high risk of a third surgery, a palliative care support was collegially decided.ConclusionsLeft atrial dissection can occur after a redo surgery and supra-annular mitral valve implantation. Multi-modal imagery including transoesophageal echocardiography and cardiac CT-scan is helpful for the diagnosis.

Gut Microbiota in Patients with Postoperative Atrial Fibrillation Undergoing Off-Pump Coronary Bypass Graft Surgery.

Post-operative atrial fibrillation (POAF) is one of the most common complications of cardiac surgery. However, the underlying mechanism is not well understood. Alterations in the gut microbiota are associated with the development of atrial fibrillation (AF). The aim of this study was to explore the relationship between gut microbiota and POAF. Fecal samples were collected before surgery from 45 patients who underwent coronary artery bypass grafting with POAF and 90 matched patients without POAF (1:2). 16S rRNA sequencing was used to detect the microbiome profiles of 45 POAF patients and 89 matched patients (one sample in the no-POAF group was deleted owing to low quality after sequencing). Plasma 25-hydroxy vitamin D level was measured by ELISA. Compared to the patients without POAF, gut microbiota composition was remarkably changed in the patients with POAF, with an increase in Lachnospira, Acinetobacter, Veillonella and Aeromonas, and a decrease in Escherichia-Shigella, Klebsiella, Streptococcus, Brevundimonas and Citrobacter. Furthermore, plasma 25-hydroxy vitamin D levels were decreased in POAF patients and negatively correlated with an abundance of Lachnospira. The gut microbiota composition between patients with and without POAF is significantly different, implying that gut microbiota may play a role in the pathogenesis of POAF. Further studies are needed to fully clarify the role of gut microbiota in the initiation of AF.

A Practical Approach to Systemic Mastocytosis Complications in Cardiac Surgery: A Case Report and Systematic Review of the Literature.

(1) Background: Systemic mastocytosis is a rare, non-curable disease with potential life-threatening complications in patients receiving cardiac surgery. (2) Methods: This systematic review of the literature was prompted by the case of a life-threatening anaphylactic reaction during cardiac surgery related to systemic mastocytosis. The search of all types of studies, using several databases (Pubmed, Scopus and Web of Science), was conducted through September 2022 to identify the relevant studies. (3) Results: Twelve studies were included describing cases of patients undergoing cardiac surgery who were diagnosed with systemic mastocytosis. An adverse effect, namely anaphylaxis, has happened in three cases. Different strategies of premedication, intraoperative and postoperative management were used. In our case, the patient was admitted for elective biological aortic valve replacement due to severe aortic stenosis. Intraoperatively, the patient developed an anaphylactic shock during the administration of protamine after separation from the cardiopulmonary bypass. This anaphylaxis reaction was a complication of the pre-existing systemic mastocytosis and could be successfully managed by the administration of epinephrine, antihistamines and corticosteroids. (4) Conclusions: This systematic literature search and case report highlight the importance of careful preoperative planning, as well as coordination between cardiac surgeons, anesthesiologists and hemato-oncological specialists, in patients with rare but complication-prone diseases such as systemic mastocytosis.

Abstract WP80: The Heart-brain Connection: Implementing Strategies To Reduce The Rate Of Perioperative Stroke For Patients Undergoing Coronary Artery Bypass Graft Surgery

Background: Stroke is a known complication of cardiac surgery. The objective of this study was to implement a systemwide strategy to reduce perioperative stroke after isolated coronary artery bypass graft (CABG) surgery utilizing best practices from cardiothoracic surgery and neurology expertise. Methods: A prospective, quality improvement study of all isolated CABG patients at three hospitals within a multicenter academic healthcare system, in a large metropolitan area, was completed from January 1, 2021 to June 30, 2022. Utilizing Lean methodology, a multidisciplinary team of cardiothoracic surgeons, neurologists, anesthesiologists, certified stroke nurses, and process improvement specialists conducted a gap analysis to identify interventions to decrease the observed to expected (O/E) ratio of risk-adjusted perioperative strokes. The team developed a pre-operative evaluation process for patients with a history of stroke, formalized the utilization of intra-operative epiaortic ultrasound, and deployed education on BE-FAST symptoms and the purpose of stroke alerts to providers, nurses, and ancillary staff caring for the patient population. Results: During the study period, 1175 patients underwent isolated CABG. Risk adjusted perioperative stroke rates in the first 6 months of 2021 compared to 2022 declined from an O/E ratio of 1.32 to 0.78. Among patients with new post-operative stroke symptoms, the time frame from last known well to symptom recognition decreased from 704 to 486 minutes. Following the implementation of the protocol, one site saw the utilization of inpatient stroke alerts after CABG increase from 81.3% to 100% for patients with new BE-FAST symptoms. Conclusion: Multidisciplinary implementation of best practices was associated with lower risk adjusted perioperative stroke rates, reductions in time to new symptom recognition, and increased utilization of inpatient stroke alert processes. Further study is needed to monitor the effects of the pre-operative evaluation process and the standardization of epiaortic ultrasound. Future goals are to standardize the methods and assess the benefit to other types of cardiac surgery.

Leveraging artificial intelligence for the management of postoperative delirium following cardiac surgery

BACKGROUND Postoperative delirium is a highly relevant complication of cardiac surgery. It is associated with worse outcomes and considerably increased costs of care. A novel approach of monitoring patients with machine learning enabled prediction software could trigger pre-emptive implementation of mitigation strategies as well as timely intervention. OBJECTIVE This study evaluates the predictive accuracy of an artificial intelligence (AI) model for anticipating postoperative delirium by comparing it to established standards and measures of risk and vulnerability. DESIGN Retrospective predictive accuracy study. SETTING Records were gathered from a database for anaesthesia quality assurance at a specialised heart surgery centre in Germany. PATIENTS Between January and July 2021, 131 patients had been enrolled into the database and had data available for AI prediction modelling. After exclusion of incomplete follow-ups, a subset of 114 was included in the statistical analysis. MAIN OUTCOME MEASURES Delirium was diagnosed with the Confusion Assessment Method for the ICU (CAM-ICU) over three days postoperatively with specific follow-up visits. AI predictions were also compared with risk assessment through a frailty screening, a Shulman Clock Drawing Test, and using a checklist of predisposing factors including comorbidity, reduced mobility, and substance abuse. RESULTS Postoperative delirium was diagnosed in 23.7% of patients. Postoperative AI screening exhibited reasonable performance with an area under the receiver operating curve (AUROC) of 0.79, 95% confidence interval (CI), 0.69–0.87. But pre-operative prediction was weak for all methods (AUROC range from 0.55 to 0.66). There were significant associations with postoperative delirium: open heart surgery versus endovascular valve replacement (33.3% vs. 10.4%, P &lt; 0.01), postinterventional hospitalisation (12.8 vs. 8.6 days, P &lt; 0.01), and length of ICU stay (1.7 vs. 0.3 days, P &lt; 0.01) were all significantly associated with postoperative delirium. CONCLUSION AI is a promising approach with considerable potential and delivered noninferior results compared with the usual approach of structured evaluation of risk factors and questionnaires. Since these established methods do not provide the desired confidence level, improved AI may soon deliver a better performance. TRIAL REGISTRATION None.

Case report: Ultrasound-guided bilateral serratus anterior plane block in intensive care unit—An alternative to opioid-sparing postoperative analgesia after sternotomy in infants

IntroductionThe high-opioid technique was applied in the setting of congenital cardiac surgery on the belief of severe pain management and analgesic limitation in children along with delayed extubation time and other side effects. Thoracic nerve blockade demonstrated superior postoperative analgesia and stable hemodynamics and lower perioperative opioid consumption and related complications in cardiac surgery. SAPB is a fascial plane block technique that is considered an alternative to paravertebral block for perioperative thoracic pain relief, targeting intercostal never.Cases presentationWe present 3 cases to describe the efficacy of SAPB as an alternative to opioid-sparing analgesia performed in infant patients after sternotomy in pediatric cardiac intensive care units. It was successfully used as a part of perioperative pain management. All patients were extubated early and recovered soon with no other complications.ConclusionSAPB lowers perioperative opioid consumption and related complications in cardiac surgery with satisfactory postoperative analgesia and stable hemodynamics.

Effect of Patient Sex on Neurocognitive Decline after Cardiac Surgery.

Neurocognitive decline (NCD) is a common complication of cardiac surgery. Understanding risk factors helps surgeons counsel patients pre- and perioperatively about risk, prevention, and treatment. Patients undergoing cardiac surgery using cardiopulmonary bypass underwent pre- and postoperative neurocognitive testing. Neurocognitive data are presented as a change from baseline to either postoperative day 4 or to 1 month. The score is standardized with respect to age. Eighty-four patients underwent surgery and completed postoperative neurocognitive testing. There was no significant difference in baseline neurocognitive function. NCD was more common in female patients (71%) than male patients (26.4%) on postoperative day 4. By 1 month, the incidence of NCD is similar between female (15.0%) and male patients (14.3%). Of note, female patients differed from male patients in preoperative hematocrit, preoperative creatinine, and type of surgery. In the acute postoperative period, female patients are both more likely to experience NCD and experience a more severe change from baseline cognitive function. This difference between male and female patients resolves by the 1 month follow-up point. Female patients had a lower preoperative hematocrit and were more likely to receive intraoperative and perioperative blood transfusion. Lower preoperative hematocrit appears to mediate the difference in NCD between male and female patients.

Neurological complications in cardiac surgery: a new view on an old problem

In modern conditions, it is necessary to take into account many factors that affect both the course of the underlying disease and the course of postoperative rehabilitation and long-term results of surgical treatment to improve the results of treatment in cardiac surgery patients. One of these factors is neurological complications associated with cardiac surgery. The article represents a clinical classification of neurological complications of cardiac surgery with a description of the main pathophysiological mechanisms of their development, and the reasoning of a neurologist’s role expansion in the examination and treatment of cardiac surgery patients. Ranging patients according to the risk of developing neurological complications, working out individual protocols of neuroprotection, as well as the further study of pathophysiological mechanisms of nervous tissue damage with the identification of triggers for their prevention, will improve the results of cardiac surgery patients’ treatment and reduce the time of their postoperative recovery.

Cost-effectiveness of Fibrinogen Concentrate vs Cryoprecipitate for Treating Acquired Hypofibrinogenemia in Bleeding Adult Cardiac Surgical Patients

Excessive bleeding requiring fibrinogen replacement is a serious complication of cardiac surgery. However, the relative cost-effectiveness of the 2 available therapies-fibrinogen concentrate and cryoprecipitate-is unknown. To determine cost-effectiveness of fibrinogen concentrate vs cryoprecipitate for managing active bleeding in adult patients who underwent cardiac surgery. A within-trial economic evaluation of the Fibrinogen Replenishment in Surgery (FIBERS) randomized clinical trial (February 2017 to November 2018) that took place at 4 hospitals based in Ontario, Canada, hospitals examined all in-hospital resource utilization costs and allogeneic blood product (ABP) transfusion costs incurred within 28 days of surgery. Participants included a subset of 495 adult patients from the FIBERS trial who underwent cardiac surgery and developed active bleeding and acquired hypofibrinogenemia requiring fibrinogen replacement. Fibrinogen concentrate (4 g per dose) or cryoprecipitate (10 units per dose) randomized (1:1) up to 24 hours postcardiopulmonary bypass. Effectiveness outcomes included number of ABPs administered within 24 hours and 7 days of cardiopulmonary bypass. ABP transfusion (7-day) and in-hospital resource utilization (28-day) costs were evaluated and a multivariable net benefit regression model built for the full sample and predefined subgroups. Patient level costs for 495 patients were evaluated (mean [SD] age 59.2 [15.4] years and 69.3% male.) Consistent with FIBERS, ABP transfusions and adverse events were similar in both treatment groups. Median (IQR) total 7-day ABP cost was CAD $2280 (US dollars [USD] $1697) (CAD $930 [USD $692]-CAD $4970 [USD $3701]) in the fibrinogen concentrate group and CAD $2770 (USD $1690) (IQR, CAD $1140 [USD $849]-CAD $5000 [USD $3723]) in the cryoprecipitate group. Median (interquartile range) total 28-day cost was CAD $38 180 (USD $28 431) $(IQR, CAD $26 350 [USD $19 622]-CAD $65 080 [USD $48 463]) in the fibrinogen concentrate group and CAD $38 790 (USD $28 886) (IQR, CAD $26 180 [USD $19 495]-CAD $70 380 [USD $52 409]) in the cryoprecipitate group. After exclusion of patients who were critically ill before surgery (11%) due to substantial variability in costs, the incremental net benefit of fibrinogen concentrate vs cryoprecipitate was positive (probability of being cost-effective 86% and 97% at $0 and CAD $2000 (USD $1489) willingness-to-pay, respectively). Net benefit was highly uncertain for nonelective and patients with critical illness. Fibrinogen concentrate is cost-effective when compared with cryoprecipitate in most bleeding adult patients who underwent cardiac surgery with acquired hypofibrinogenemia requiring fibrinogen replacement. The generalizability of these findings outside the Canadian health system needs to be verified.

Aprotinin does not Impair Vascular Function in Patients Undergoing Coronary Artery Bypass Graft Surgery.

Bleeding is a major complication in coronary artery bypass graft surgery. Antifibrinolytic agents like serine protease inhibitor aprotinin can decrease postoperative bleeding and complications of cardiac surgery. However, the effects of aprotinin on vascular function are not completely elucidated. We compared the ex vivo vascular function of left internal mammary arteries from patients undergoing coronary artery bypass graft surgery with and without intraoperative application of aprotinin using a Mulvany Myograph. Human internal mammary arteries were treated with aprotinin ex vivo and tested for changes in vascular function. We analyzed the impact of aprotinin on vascular function in rat aortic rings. Finally, impact of aprotinin on expression and activity of endothelial nitric oxide synthase was tested in human endothelial cells. Intraoperative application of aprotinin did not impair ex vivo vascular function of internal mammary arteries of patients undergoing coronary artery bypass graft surgery. Endothelium-dependent and -independent relaxations were not different in patients with or without aprotinin after nitric oxide synthase blockade. A maximum vasorelaxation of 94.5%±11.4vs. 96.1%±5.5% indicated a similar vascular smooth muscle function in both patient groups (n=13 each). Long-term application of aprotinin under physiological condition preserved vascular function of the rat aorta. In vitro application of increasing concentrations of aprotinin on human endothelial cells resulted in a similar expression and activity of endothelial nitric oxide synthase. In conclusion, intraoperative and ex vivo application of aprotinin does not impair the endothelial function in human internal mammary arteries and experimental models.

Risk Factors Associated with Ischemic Stroke in the Immediate Postoperative Period of Cardiac Surgery.

Stroke remains a major complication of cardiac surgery. Despite all efforts, the incidence of postoperative stroke remains as high as 6%. We aimed to investigate risk factors for ischemic stroke in a contemporary cohort of patients undergoing cardiac surgery. This is a retrospective cohort study of 678 consecutive adult patients who underwent cardiac surgery requiring cardiopulmonary bypass in a tertiary hospital in Brazil between July 1, 2011, and December 31, 2018. The primary outcome was the rate of early (perioperative and seven-day postoperative) stroke, defined as the occurrence of the outcome during the index admission. We developed a predictive model of stroke using the Poisson regression analysis with robust variance. Postoperative stroke occurred in 24 patients (3.5%), 23 (3.3%) were ischemic, and 21 (3.0%) were diagnosed in the first 72 hours after surgical procedure. After multivariate analysis, the following factors were significantly associated with stroke: previous stroke/transient ischemic attack (relative risk [RR]=2.75; 95% confidence interval [CI], 1.11-6.82), carotid artery disease (RR=4.0; 95% CI, 1.43-11.0), previous atrial fibrillation (RR=3.26, 95% CI, 1.31-8.1), and postoperative platelets > 200,000/mm3 (RR=2.26; 95% CI, 1.01-5.1). We developed a contemporary model to determine risk predictors for stroke after cardiac surgery. This model may help clinicians to identify patients at risk and could be useful in clinical practice.

1227. Candida Sternal Wound Infections After Cardiac Operations: Uncommon but Deadly

Abstract Background Sternal wound infections (SWI) are a devastating complication of cardiac surgery. The majority of SWI are bacterial infections; however, Candida species are a less common cause and have not been well described. The purposes of this study were (1) to describe clinical characteristics, management and outcomes of Candida SWI and (2) to compare the risk factors and outcomes for Candida to bacterial SWI. Methods Our study reviewed medical records of 41 patients with Candida SWI after cardiac surgeries between 2013 - 2020 at our medical center, then compared them to 76 patients with bacterial SWI during the same timeframe via univariate analysis. We defined superficial SWI as positive culture isolates involving the skin or subcutaneous tissues, deep SWI as involving deep soft tissues or bone, and mediastinitis as involving the mediastinum. Results Of the 41 Candida SWI patients, relevant comorbidities included previous cardiac surgery (46.3%), heart failure (65.9%), and diabetes (58.5%). Candida SWI was diagnosed at an average of 123.6 days after cardiac surgery, with the majority being deep SWI (70.7%). Candida albicans was most common (70.7%). Bacterial co-infections were found in 53.7% (Table 1). Longer bypass and operative times for the initial cardiac surgery were found to be positively correlated to disease severity. Clinical cure rate after completion of antimicrobial treatment was 100% in superficial SWI, 72.4% in deep SWI and 25.0% in mediastinitis. Overall mortality was 29.3%: 25%, 24.1% and 50.0%, respectively. When compared to bacterial SWI, factors significantly associated with Candida SWI included: previous cardiac surgery (46.3% vs. 7.9%, odds ratio (OR): 5.9; 95% confidence interval (CI): 2.2-15.9), heart failure (65.9% vs. 11.8%, OR: 5.6; 95% CI: 2.4-12.9), and &amp;gt;48 hours of postoperative antibiotics (39.0% vs. 3.0%, OR: 9.9; 95% CI: 2.7-35.9). Mortality rates were higher with Candida than with bacterial infections (29.3% vs. 1.3%, OR: 22.2, 95% CI 2.8-177.2) (Table 2). Conclusion This study showed Candida SWI as a serious complication of extensive cardiac surgery with higher mortality rates. Prior history of cardiac surgery and heart failure, prolonged surgeries, and complicated postoperative course were significant risk factors for the development of Candida SWI. Disclosures Barbara Trautner, MD, PhD, Genetech: Advisor/Consultant.

250 POST-PERICARDIOTOMY SINDROME: A DESCRIPTIVE ANALYSIS OF A NEGLECTED SYNDROME

Abstract Background Post-pericardiotomy syndrome (PPS) is a condition in which the surgical incision of the pericardium provokes the onset of pericardial and/or pleural effusion as a result of the inflammatory response inside the pericardial and/or the pleural space. PPS is a common complication following cardiac surgery (CS) and it has a significant impact on post-surgical patients’ management. Thus, it would be useful to find predictors in order to stratify patients in terms of risk of PPS and define tailored Cardiovascular Rehabilitation (CR) programmes. Purpose The aim of this study was to assess the incidence and to elucidate the features of PPS in a population of patients undergoing cardiac surgery. Secondly, the study was focused on the findings of likeable predictors of PPS and PPS’ relapse. Methods A prospective cohort study was performed on 156 patients who underwent cardiac surgery and then were admitted to the CR Unit of our institute. Among the 156-patients population, 26 patients developed post-pericardiotomy syndrome. Pre-operative and post-operative anamnestic and clinical data were collected to define the baseline characteristics of the population. The predictive role of anamnestic data, type of surgical procedure and laboratory parameters was evaluated. Treatment was then started in the PPS population, analysed and compared to the outcome. Data were collected during CR hospital stay and after discharge, during follow up check-ups. During CR hospital stay, the analysis regarded first and second line medical therapy, which was started in case of persistence, worsening or relapse of the pericardial and/or pleural effusion. After discharge, the analysis considered the outcome of the therapy at a defined deadline. Binary logistic regression analysis was performed to identify possible predictors of PPS and PPS’ relapse. All the variables with a univariate p-value &amp;lt;0.150 or clinically relevant were entered into the multivariate model. Results The population comprehends 156 patients. PPS patients presented with pleural effusion pre surgical intervention in 3 cases (11.5% vs 0%; p-value &amp;lt; 0.001) and showed more frequently pericardial effusion early after surgery (53.8% vs 8.5%; p-value &amp;lt; 0.001). In 3 patients (1.9%) drainage of pleural effusion was needed (7.7% vs 0.8%, p-value= 0.019). At admission in the CR Unit 26 patients (16.6%) presented or subsequently developed PPS. Pericardial effusion was classified as mild in 18 patients (69.2%), moderate in 7 patients (26.9%) and severe in 1 patient (3.8%); the median value of pericardial effusion at diagnosis was 7.5 mm, while the median value of the maximum pericardial effusion was 9.5 mm. During in-hospital stay, a first line medical therapy was administered to 26 PPS patients (100%): 13 patients (50%) needed a switch to a second line therapy, 4 patients (15.4%) needed invasive treatment of the effusion, 3 patients (11.5%) needed percutaneous pleural drainage and 2 patients (7.7%) needed percutaneous pericardial drainage. Medical therapy’ collateral effects occurred in 7 patients (26.95%). PPS therapy at discharge was administered to 22 patients (84.6%). At follow up, pericardial effusion occurred in 9 patients (36%), pleural effusion occurred in 3 patients (12%). Relapse of pleuro/pericardial effusion after therapy suspension occurred in 3 patients (12%) and consequently, pleuro/pericardial effusion resolution was obtained in 23 patients (92%). The median time of therapy interruption at follow up was 27 days (7–60). Binary logistic regression was performed to identify the clinical predictors of PPS and PPS’ relapse, the multivariate analysis did not find statistical significance for independent predictors of both conditions. Conclusion The PPS is a common complication of cardiac surgery. Further studies are needed to determine novel possible PPS predictors. Possible indicators of PPS relapse should be identified in patients with possible discontinuation of treatment.

3: PHASE 2 STUDY INTERIM RESULTS OF RBT-1 EFFECT ON POSTOPERATIVE COURSE IN ELECTIVE CABG/VALVE SURGERY

Introduction: Patients undergoing cardiac surgery are at risk of postoperative complications. RBT-1 is a novel drug with anti-inflammatory and antioxidant activity, which has shown broad organ protective activity in preclinical models. A Phase 2 randomized, double-blind, placebo-controlled study assessed the efficacy of RBT-1, as measured by cytoprotective preconditioning biomarkers, hospital course, and readmission rates. Methods: Eligible subjects undergoing elective coronary artery bypass graft and/or valve surgery on cardiopulmonary bypass were randomized 1:1:1 to receive placebo, low dose RBT-1, or high dose RBT-1 as preconditioning 24-48 hours before surgery. An interim analysis was performed once 60 subjects had completed 30 day follow up. The primary endpoint was to assess the efficacy of RBT-1 in generating a cytoprotective biomarker response. Key secondary/exploratory endpoints included ventilator and ICU days, incidence of acute kidney injury (AKI), hospital length of stay (LOS), and readmission rates. Results: The cytoprotective biomarker composite was significantly increased in response to both RBT-1 dose groups compared to placebo (p < 0.0001). Mean ventilator days in the placebo and combined RBT-1 groups were 3.2 and 1.2, respectively (p=0.03). Mean ICU days in the placebo and RBT-1 groups were 7.0 and 2.7, respectively (p=0.0375). AKI incidence was decreased by 52%, with a 27% and 13% incidence in the placebo and RBT-1 groups, respectively. Mean LOS in the placebo and RBT-1 groups were 10.9 and 8.9 days, respectively, resulting in a 2-day reduction. Hospital readmission at 30 days was reduced by 91%, with rates of 31.8% and 2.6% in the placebo and RBT-1 groups, respectively (p=0.0027). Treatment with RBT-1 was generally well tolerated. The most common treatment-related adverse event was photosensitivity. Conclusions: RBT-1 is a novel drug with cytoprotective preconditioning activity. Interim Phase 2 results suggest RBT-1 protects against postoperative complications of cardiac surgery. The improvements in renal complications, hospital course, and readmission rates are expected given the broad organ protective mechanism of RBT-1. Final results of this study are expected in 2023.