The Rise and Fall of Antithrombin Supplementation in Cardiac Surgery.

Various cohort studies, both retrospective and prospective, showed that low antithrombin levels after cardiac surgery (at the arrival in the intensive care unit and during the next days) were associated with a number of adverse outcomes, including surgical reexploration and thromboembolic events, eventually leading to prolonged stay in the intensive care. Values lower than 58% to 64% of antithrombin activity were indicative of this higher morbidity with good sensitivity and specificity. The scenario generated the hypothesis that low antithrombin levels needed to be corrected by supplementation to improve postoperative outcome.

Monitoring the Evolution of Asynchrony between Mean Arterial Pressure and Mean Cerebral Blood Flow via Cross-Entropy Methods.

Cerebrovascular control is carried out by multiple nonlinear mechanisms imposing a certain degree of coupling between mean arterial pressure (MAP) and mean cerebral blood flow (MCBF). We explored the ability of two nonlinear tools in the information domain, namely cross-approximate entropy (CApEn) and cross-sample entropy (CSampEn), to assess the degree of asynchrony between the spontaneous fluctuations of MAP and MCBF. CApEn and CSampEn were computed as a function of the translation time.

Comparison of Causal and Non-causal Strategies for the Assessment of Baroreflex Sensitivity in Predicting Acute Kidney Dysfunction After Coronary Artery Bypass Grafting.

Coronary artery bypass graft (CABG) surgery may lead to postoperative complications such as the acute kidney dysfunction (AKD), identified as any post-intervention increase of serum creatinine level. Cardiovascular control reflexes like the baroreflex can play a role in the AKD development. The aim of this study is to test whether baroreflex sensitivity (BRS) estimates derived from non-causal and causal approaches applied to spontaneous systolic arterial pressure (SAP) and heart period (HP) fluctuations can help in identifying subjects at risk of developing AKD after CABG and which BRS estimates provide the best performance.

Causality analysis reveals the link between cerebrovascular control and acute kidney dysfunction after coronary artery bypass grafting.

Background: Patients undergoing coronary artery bypass graft (CABG) surgery might experience postoperative complications and some of them, such as acute kidney dysfunction (AKD), are the likely consequence of hypoperfusion. We hypothesized that an impaired cerebrovascular control is a hallmark of a vascular damage that might favor AKD after CABG.

Objective: Our aim is to characterize cerebrovascular control in CABG patients through the assessment of the relationship between mean arterial pressure (MAP) and mean cerebral blood flow velocity (MCBFV) and to check whether markers describing MCBFV-MAP dynamical interactions could identify subjects at risk to develop postoperative AKD.

Short-term multiscale complexity analysis of cardiovascular variability improves low cardiac output syndrome risk stratification after coronary artery bypass grafting.

Background: Low cardiac output syndrome (LCOS) is a myocardial dysfunction leading to systemic hypoperfusion, favored by particular conditions of the autonomic nervous system. LCOS is one of the adverse events that might occur after cardiac surgery.

Objective: The aim is to test the hypothesis that short-term multiscale complexity (MSC) analysis of heart period (HP) and systolic arterial pressure (SAP) variability series in the frequency bands typical of cardiovascular control could be fruitfully exploited in identifying subjects at risk of developing LCOS after coronary artery bypass graft (CABG).

A gender-based analysis of the obesity paradox in cardiac surgery: height for women, weight for men?

Objectives: In cardiac surgery, obesity is associated with a lower mortality risk. This study aims to investigate the association between body mass index (BMI) and operative mortality separately in female patients and male patients undergoing cardiac surgery and to separate the effects of weight and height in each gender-based cohort of patients.

Methods: A retrospective cohort study including 7939 consecutive patients who underwent cardiac surgery was conducted.

Bloodstream infections during post-cardiotomy extracorporeal membrane oxygenation: Incidence, risk factors, and outcomes.

Introduction: Veno-arterial extracorporeal membrane oxygenation after heart surgery is a relatively common procedure. It is easily applicable but associated with a number of complications, including bloodstream infections. The aim of this study is to determine the current rate and the risk factors related to bloodstream infections acquired during post-cardiotomy veno-arterial extracorporeal membrane oxygenation.

Discrimination and calibration properties of the hypotension probability indicator during cardiac and vascular surgery.

Background: Hypotension during surgery is linked to postoperative complications. Recently, a new hemodynamic algorithm intended to predict hypotensive events (hypotension probability indicator [HPI]) has been developed. The aim of the present study is to test the discrimination and calibration properties of the HPI.

Comparison of Different Strategies to Assess Cardiac Baroreflex Sensitivity Based on Transfer Function Technique in Patients Undergoing General Anesthesia.

Baroreflex sensitivity (BRS) can be noninvasively assessed from heart period (HP) and arterial pressure (AP) variability series via the estimation of the gain of the transfer function (TF) in the low frequency (LF, 0.04-0.15 Hz) band.

Platelet function after cardiac surgery and its association with severe postoperative bleeding: the PLATFORM study.

Platelet dysfunction after cardiac surgery is a determinant of postoperative bleeding. The existing guidelines suggest the use of desmopressin and/or platelet concentrate transfusions in case of platelet dysfunction in bleeding patients, but no cut-off values for platelet activity exist in the literature. The Platelet Function in the Operating Room (PLATFORM) study aims to identify the relationship between platelet function after cardiopulmonary bypass and severe bleeding, finding adequate predictive values of platelet function for severe bleeding.

Validation of renal-risk models for the prediction of non-renal replacement therapy cardiac surgery-associated acute kidney injury.

Background: Cardiac surgery-associated acute kidney injury (AKI) is a serious complication of cardiac surgery, even when renal replacement therapy (RRT) is not required. The existing risk models for cardiac surgery associated AKI are designed to predict AKI requiring RRT (RRT-AKI). The aim of this study is to validate three risk models for the prediction of RRT-dependent and non-RRT AKI after cardiac surgery.

Goal-directed perfusion to reduce acute kidney injury: A randomized trial.

Objective: To determine whether a goal-directed perfusion (GDP) strategy aimed at maintaining oxygen delivery (DO) at ≥280 mL·min·m reduces the incidence of acute kidney injury (AKI).

Methods: This multicenter randomized trial enrolled a total of 350 patients undergoing cardiac surgery in 9 institutions. Patients were randomized to receive either GDP or conventional perfusion.

Correction: Baroreflex sensitivity and outcomes following coronary surgery.

[This corrects the article DOI: 10.1371/journal.pone.

Model-based directional analysis of cardiovascular variability identifies patients developing atrial fibrillation after coronary artery bypass grafting.

Background: Postoperative atrial fibrillation (AF) might be favored by cardiovascular control impairment. We hypothesize that cardiovascular regulation indexes derived from directional model-based analysis of the spontaneous fluctuations of heart period (HP) and systolic arterial pressure (SAP) can identify subjects at risk to develop AF after coronary artery bypass graft (CABG) surgery.

Methods: Beat-to-beat HP and SAP series were derived from electrocardiogram (ECG) and invasive arterial pressure recorded for 5 min just before CABG surgery in conscious condition.

Separating arterial pressure increases and decreases in assessing cardiac baroreflex sensitivity via sequence and bivariate phase-rectified signal averaging techniques.

Cardiac baroreflex (cBR) is activated by both arterial pressure (AP) increases and decreases. Sequence method, a widely utilized tool assessing cBR sensitivity (cBRS) from spontaneous heart period (HP) and systolic AP (SAP) variations, allows the separated computation of cBRS from positive and negative SAP variations. The recently proposed phase-rectified signal averaging (PRSA) method has the same feature but it has been applied so far solely to positive SAP variations.

Towards the identification of subjects prone to develop atrial fibrillation after coronary artery bypass graft surgery via univariate and multivariate complexity analysis of heart period variability.

The assessment of cardiovascular control complexity as derived from spontaneous heart period (HP) fluctuations can be improved by exploiting a multivariate (MV) approach. This work proposes the assessment of a normalized complexity index (NCI) of HP variability according to a k-nearest-neighbor approach based on local predictability performed in a MV nonuniform embedding space. The method allows the selection of the past components of HP, systolic arterial pressure (SAP) and respiration (R) most useful for the prediction of HP fluctuations.

The ACEF II Risk Score for cardiac surgery: updated but still parsimonious.

Aims: The age, creatinine, and ejection fraction (ACEF) score was introduced in 2009 and is presently included in the guidelines for myocardial revascularization of the European Society of Cardiology and Association for Cardio-Thoracic Surgery as a risk stratification tool for surgical and percutaneous myocardial revascularization. The present study introduces an updated version of the ACEF (ACEF II) inclusive of emergency surgery and pre-operative anaemia.

Methods And Results: The development series includes 7011 consecutive cardiac surgery patients operated at a single institution.

Baroreflex sensitivity and outcomes following coronary surgery.

Postoperative atrial fibrillation, acute kidney dysfunction and low cardiac output following coronary surgery are associated with morbidity and mortality. The purpose of this study is to determine if the preoperative autonomic control is a determinant of these postoperative complications. This is a prospective cohort study on 150 adult patients undergoing surgical coronary revascularization with cardiopulmonary bypass.

Cardiovascular interactions assessed via conditional joint transfer entropy in patients developing atrial fibrillation after coronary artery bypass graft surgery.

Assigned the universe of knowledge Ω as composed by one target and two exogenous signals, the conditional joint transfer entropy (CJTE), assessing the amount of information jointly transferred from the two sources to the target that can be uniquely linked to one of the two sources, was found useful to study cardiovascular control. We propose the assessment of CJTE from systolic arterial pressure (SAP) and respiration (R) to heart period (HP) conditioned on R (CJTESAP, R→HP|R) along the baroreflex, and from HP and R to SAP conditioned on R (CJTEHP, R→SAP|R) along the feedforward mechanical pathway, in 134 patients undergoing coronary artery bypass graft surgery before (PRE) and after (POST) the induction of general anesthesia. In this group 38 patients developed atrial fibrillation (AF) after surgery, while the remaining individuals did not (noAF, n=96).

Patterns and determinants of functional and absolute iron deficiency in patients undergoing cardiac rehabilitation following heart surgery.

Background Anaemia and iron deficiency are frequent following major surgery. The present study aims to identify the iron deficiency patterns in cardiac surgery patients at their admission to a cardiac rehabilitation programme, and to determine which perioperative risk factor(s) may be associated with functional and absolute iron deficiency. Design This was a retrospective study on prospectively collected data.

The effectiveness of 10 years of interventions to control postoperative bleeding in adult cardiac surgery.

Objectives: Postoperative bleeding in cardiac surgery remains an important complication, leading to increased morbidity and mortality. Different interventions are possible to prevent/treat postoperative bleeding. The present study aims to investigate the effectiveness of these interventions in a real-world scenario.

Fibrinogen Levels After Cardiac Surgical Procedures: Association With Postoperative Bleeding, Trigger Values, and Target Values.

Background: Low fibrinogen levels immediately after cardiac surgical procedures have been associated with postoperative bleeding and transfusions. However, no sound data on the adequate trigger values for fibrinogen supplementation and target values for fibrinogen concentration exist.

Methods: This retrospective study examined prospectively collected data, including data on 2,800 adult patients undergoing cardiac operations.

Retuning mortality risk prediction in paediatric cardiac surgery: the additional role of early postoperative metabolic and respiratory profile.

Objectives: The existing risk stratification scores for paediatric patients undergoing cardiac surgery include the Aristotle Basic Complexity (ABC) Score, the Risk Adjustment in Congenital Heart Surgery-1 (RACHS-1) Score and the Aristotle Comprehensive Complexity (ACC) Score. They are all based on the nature of the surgical operation (ABC and RACHS-1 Scores) with possible adjustment for a number of patient conditions (ACC Score). The present study investigates if the early postoperative parameters may be used to improve the preoperative mortality risk prediction.