Clinical Outcomes In Cardiac Surgery Research Articles

Machine learning in cardiac surgery: a narrative review.

Machine learning (ML) is increasingly being utilized to provide data driven solutions to challenges in medicine. Within the field of cardiac surgery, ML methods have been employed as risk stratification tools to predict a variety of operative outcomes. However, the clinical utility of ML in this domain is unclear. The aim of this review is to provide an overview of ML in cardiac surgery, particularly with regards to its utility in predictive analytics and implications for use in clinical decision support. We performed a narrative review of relevant articles indexed in PubMed since 2000 using the MeSH terms "Machine Learning", "Supervised Machine Learning", "Deep Learning", or "Artificial Intelligence" and "Cardiovascular Surgery" or "Thoracic Surgery". ML methods have been widely used to generate pre-operative risk profiles, consistently resulting in the accurate prediction of clinical outcomes in cardiac surgery. However, improvement in predictive performance over traditional risk metrics has proven modest and current applications in the clinical setting remain limited. Studies utilizing high volume, multidimensional data such as that derived from electronic health record (EHR) data appear to best demonstrate the advantages of ML methods. Models trained on post cardiac surgery intensive care unit data demonstrate excellent predictive performance and may provide greater clinical utility if incorporated as clinical decision support tools. Further development of ML models and their integration into EHR's may result in dynamic clinical decision support strategies capable of informing clinical care and improving outcomes in cardiac surgery.

Platelet Transfusion After Cardiac Surgery

To investigate the independent association of platelet transfusion with hospital mortality and key relevant clinical outcomes in cardiac surgery. A single-center, propensity score-matched, retrospective, cohort study. At an American tertiary teaching hospital data from the Medical Information Mart for Intensive Care III and IV databases from 2001 to 2019. Consecutive adults undergoing coronary artery bypass graft and/or cardiac valvular surgery. Platelet transfusion during perioperative intensive care unit (ICU) admission. Overall, 12,043 adults met the study inclusion criteria. Of these, 1,621 (13.5%) received apheresis-leukoreduced platelets, with a median of 1.19 units per recipient (IQR: 0.93-1.19) at a median of 1.78 hours (IQR: 0.75-4.25) after ICU admission. The platelet count was measured in 1,176 patients (72.5%) before transfusion, with a median count of 120×109/L (IQR: 89.0-157.0), and only 53 (3.3%) had platelet counts below 50×109/L. After propensity matching of 1,046 platelet recipients with 1,046 controls, perioperative platelet transfusion carried no association with in-hospital mortality (odds ratio [OR]: 1.28; 99% CI: 0.49-3.35; p=0.4980). However, it was associated with a pattern of decreased odds of suspected infection (eg, respiratory infection, urinary tract infection, septicaemia, or other; OR: 0.70; 99% CI: 0.50-0.97; p=0.0050), days in the hospital (adjusted mean difference [AMD]: 0.86; 99% CI: -0.27 to 1.98; p=0.048), or days in intensive care (AMD 0.83; 99% CI: -0.15 to 1.82; p=0.0290). Platelet transfusion was not associated with hospital mortality, but it was associated with decreased odds of suspected infection and with shorter ICU and hospital stays.

Clinical presentation and in-hospital outcomes of intraoperative red blood cell transfusion in non-anemic patients undergoing elective valve replacement.

Intraoperative transfusion is associated with adverse clinical outcomes in cardiac surgery. However, few studies have shown the impact of intraoperative red blood cell (RBC) transfusion on non-anemic patients undergoing cardiac surgery. We assessed the in-hospital clinical outcomes of non-anemic patients undergoing isolated valve replacements and investigated the predictors associated with intraoperative RBC transfusion. We enrolled 345 non-anemic patients undergoing isolated valve replacements in our department from January 2015 to December 2019. The patients were stratified by the receipt of intraoperative RBC transfusion. Baseline characteristics were compared between groups and multiple logistic regression was used to identify the predictors for intraoperative RBC transfusion. The association between intraoperative RBC transfusion and in-hospital outcomes was also evaluated. Intraoperative RBC transfusion developed in 84 of the 345 enrolled patients (24.3%). Three independent predictors for intraoperative RBC transfusion of non-anemic patients undergoing isolated valve replacements were identified by multivariate logistic analysis, including female, iron deficiency and hemoglobin level. When the two groups were compared, a significant tendency of higher in-hospital mortality (6.0% vs. 1.1%, P = 0.033) and higher incidence of postoperative hypoxemia (9.5% vs. 2.7%, P = 0.007) were observed in the intraoperative RBC transfusion group. After adjustment, the presence of intraoperative RBC transfusion was associated with an increase in postoperative hypoxemia (OR = 3.36, 95% CI: 1.16-9.71, P = 0.026). Intraoperative RBC transfusion was associated with poorer clinical outcomes in non-anemic adults undergoing isolated valve replacements, which significantly increased the risk of postoperative hypoxemia. The independent predictors of intraoperative RBC transfusion, such as iron deficiency and female, were identified, which may be helpful for risk assessment and perioperative management.

Restrictive versus liberal transfusion in patients with diabetes undergoing cardiac surgery: An open-label, randomized, blinded outcome evaluation trial.

To characterize the association between diabetes and transfusion and clinical outcomes in cardiac surgery, and to evaluate whether restrictive transfusion thresholds are harmful in these patients. The multinational, open-label, randomized controlled TRICS-III trial assessed a restrictive transfusion strategy (haemoglobin [Hb] transfusion threshold <75 g/L) compared with a liberal strategy (Hb <95 g/L for operating room or intensive care unit; or <85 g/L for ward) in patients undergoing cardiac surgery on cardiopulmonary bypass with a moderate-to-high risk of death (EuroSCORE ≥6). Diabetes status was collected preoperatively. The primary composite outcome was all-cause death, stroke, myocardial infarction, and new-onset renal failure requiring dialysis at 6months. Secondary outcomes included components of the composite outcome at 6 months, and transfusion and clinical outcomes at 28 days. Of the 5092 patients analysed, 1396 (27.4%) had diabetes (restrictive, n=679; liberal, n=717). Patients with diabetes had more cardiovascular disease than patients without diabetes. Neither the presence of diabetes (OR [95% CI] 1.10 [0.93-1.31]) nor the restrictive strategy increased the risk for the primary composite outcome (diabetes OR [95% CI] 1.04 [0.68-1.59] vs. no diabetes OR 1.02 [0.85-1.22]; Pinteraction =.92). In patients with versus without diabetes, a restrictive transfusion strategy was more effective at reducing red blood cell transfusion (diabetes OR [95% CI] 0.28 [0.21-0.36]; no diabetes OR [95% CI] 0.40 [0.35-0.47]; Pinteraction =.04). The presence of diabetes did not modify the effect of a restrictive transfusion strategy on the primary composite outcome, but improved its efficacy on red cell transfusion. Restrictive transfusion triggers are safe and effective in patients with diabetes undergoing cardiac surgery.

The Outcomes of Patients Incidentally Confirmed with Covid-19 After Cardiac Surgery

The aim of this study was to investigate the clinical outcomes of cardiac surgery in patients who were incidentally diagnosed with Covid-19 in the postoperative period. We performed 826 open cardiac surgeries in five tertiary centers. Most of the surgeries were elective coronary artery bypass grafting (CABG) (93.8%). A preoperative RT-PCR test and transcutaneous oxygen saturation were routinely investigated prior to surgery. We also investigated whether the patients already received Covid-19 treatment or had any contact with a Covid-19 patient in the last two weeks. We analyzed high sensitive C-reactive protein (hs-CRP), d-dimer, and fibrinogen, which plays a main role in the activation of procoagulant state after surgeries. Acute lung injury related to Covid-19 activation was observed in 48 out of 826 patients (5.8%). The median age of 48 patients was 63.9±12.4 years. Euro-Score and body mass index (BMI) were 6.1±1.1 and 29.2±4.1kg/m², respectively. RT-PCR test results were positive in 29 patients (60.4%). We performed thoracic computed tomography (CT) in all patients with or without positive RT-PCR test results. Thoracic CT images showed that there was a different degree of ARDS (mild, moderate, and serious). The median time of extracorporeal circulation (ECC) was 93.2±14.6 min. in on-pump surgery (IQR, 68-155 min.). Common symptoms included dyspnea (N = 22; 45.8%) and fever (N = 12; 25%). Eleven patients needed readmission to ICU. Compared with non-admitted to ICU patients, ICU patients were higher comorbidities and severe laboratory abnormalities (eg, high blood d-dimer and fibrinogen). We also detected significantly low oxygen saturation, hypercapnia, and severe acidosis in readmitted patients. Radiologic investigations showed that there were severe ARDS with bilateral pneumonic infiltration resistant to medical treatment in 6 out of 11 patients who died (54.5%). Diffuse pneumonic infiltration related to Covid-19 may develop in asymptomatic cardiac surgery patients with negative RT-PCR test results. Immunologic disorders resulting from ECC, physiologic distress, and anesthesia may activate Covid-19 during the incubation period. We need randomized clinical trials to explain Covid-19 activation in the latent period of the virus, and clinical outcomes in cardiac surgery.

Patients’ pre- and postoperative expectations as predictors of clinical outcomes six months after cardiac surgery

ABSTRACT The aim of this study was to investigate not only preoperative expectations (as shown previously), but also postoperative expectations of patients predict clinical outcomes six months after cardiac surgery. Furthermore, the study sought to examine illness behavior as a possible pathway through which expectations may affect postoperative well-being. Seventy patients scheduled for cardiac surgery were examined one day before surgery, ~7–10 days after surgery, and six months after surgery. Regression analyses indicated that disability at follow-up (primary outcome) was significantly predicted by postoperative (β = −.342, p = .008), but not by preoperative expectations (β = −.213, p = .069). Similar results were found for the secondary outcomes, i.e. quality of life and depressive symptoms. A bootstrapped mediation analysis showed that although both postoperative expectations and illness behavior had significant unique effects on disability, there was no significant mediation effect. While previous studies have mainly focused on patients’ preoperative expectations, the present is the first to emphasize the predictive value of patients’ expectations a few days after surgery, pointing to the potential of interventions targeting postoperative expectations. However, given the non-significant results of the mediation analysis, it remains unclear how exactly patients’ expectations affect clinical outcomes in cardiac surgery.

Night-time care routine interaction and sleep disruption in adult cardiac surgery.

To explore the context and the influence of night-time care routine interactions (NCRIs) on night-time sleep effectiveness (NSE) and daytime sleepiness (DSS) of patients in the cardiac surgery critical-care and progressive-care units of a hospital. There exists a paucity of empirical data regarding the influence of NCRIs on sleep and associated outcomes in hospitalised adult cardiac surgery patients. An exploratory repeated-measures research design was employed on the data provided by 38 elective cardiac surgery patients (mean age 60.0±15.9years). NCRI forms were completed by the bedside nurses and patients completed a 9-item Visual Analogue Sleep Scale (100-mm horizontal lines measuring NSE and DSS variables). All data were collected during postoperative nights/days (PON/POD) 1 through 5 and analysed with IBM SPSS software. Patient assessment, medication administration and laboratory/diagnostic procedures were the top three NCRIs reported between midnight and 6:00 a.m. During PON/POD 1 through 5, the respective mean NSE and DSS scores ranged from 52.9±17.2 to 57.8±13.5 and from 27.0±22.6 to 45.6±16.5. Repeated-measures ANOVA showed significant changes in DSS scores (p<.05). NSE and DSS were negatively correlated (r=-.44, p<.05), but changes in NSE scores were not significant (p>.05). Finally, of 8 NCRIs, only 1 (postoperative exercises) was significantly related to sleep variables (r>.40, p<.05). Frequent NCRIs are a common occurrence in cardiac surgery units of a hospital. Further research is needed to make a definitive conclusion about the impact of NCRIs on sleep/sleep disruptions and daytime sleepiness in adult cardiac surgery. Worldwide, acute and critical-care nurses are well positioned to lead initiatives aimed at improving sleep and clinical outcomes in cardiac surgery.

Hematological predictors and clinical outcomes in cardiac surgery.

The present study was to investigate if five values that are part of the hemogram analysis routinely checked before heart surgeries can be used as a high-quality, quick, low-cost, and easy-to-use outcome predictor. This investigation was a retrospective, observational, cross-sectional study. Univariate and multivariate logistic regression was used to identify independent predictors for combined adverse events. We enrolled 1500 consecutive patients who underwent elective, on-pump, open-heart surgery from 2011 to 2014. Preoperative hemogram evaluation, red cell distribution width (RDW), mean platelet volume (MPV), platelet-to-lymphocyte ratio (PLR), and neutrophil-to-lymphocyte ratio (NLR) were recorded. We classified combined adverse events (CAE) as (1) myocardial infarction, (2) cardiac reoperation, (3) prolonged mechanical ventilation, (4) prolonged hospital stay, (5) rehospitalization, or (6) mortality. It was found that several parameters obtained as part of the hemogram, namely RDW, MPV, PLR, and NLR, can predict, individually or in combinations, the outcomes in open-heart surgery patients. It was found that the prediction success of NLR (4.8 fold) was higher compared to RDW (1.8 fold) and MPV (1.5 fold). When the prediction success of the combined parameters was investigated, the NLR-RDW (4.7 fold) pair was found higher in the prediction of CAE occurrence. The predictive success of the triple combination of NLR-MPV-RDW (5.5 fold) was higher than other combinations. The triple combination of parameters obtained as part of the hemogram, NLR-RDW-MPV, indicated a much more predictive power than two parameters coupled. This combination of three parameters, NLR-RDW-MPV, is to be considered as a sensitive, high-quality, low-cost outcome prediction marker for cardiac surgery patients that is less time consuming and easy to use.

Microvascular reactivity and clinical outcomes in cardiac surgery.

IntroductionMicrovascular reactivity is decreased in patients with septic shock; this is associated with worse clinical outcomes. The objectives of the present study were to investigate microvascular reactivity in cardiac surgery patients and to assess any association with clinical outcomes.MethodsWe retrospectively analyzed a prospectively collected registry. In total, 254 consecutive adult patients undergoing cardiac and thoracic aortic surgeries from January 2013 through May 2014 were analyzed. We performed a vascular occlusion test (VOT) by using near-infrared spectroscopy to measure microvascular reactivity. VOT was performed three times per patient: prior to the induction of anesthesia, at the end of surgery, and on postoperative day 1. The primary endpoint was a composite of major adverse complications, including death, myocardial infarction, acute kidney injury, acute respiratory distress syndrome, and persistent cardiogenic shock.ResultsVOT recovery slope decreased during the surgery. VOT recovery slope on postoperative day 1 was significantly lower in patients with composite complications than those without (3.1 ± 1.6 versus 4.0 ± 1.5 %/s, P = 0.001), although conventional hemodynamic values, such as cardiac output and blood pressure, did not differ between the groups. On multivariable regression and linear analyses, low VOT recovery slope on postoperative day 1 was associated with increases of composite complications (odds ratio 0.742; 95 % confidence interval (CI) 0.584 to 0.943; P = 0.015) and hospital length of stay (regression coefficient (B) −1.276; 95 % CI −2.440 to −0.112; P = 0.032).ConclusionMicrovascular reactivity largely recovered on postoperative day 1 in the patients without composite complications, but this restoration was attenuated in patients with composite complications.Trial registrationClinicalTrials.gov NCT01713192. Registered 22 October 2012.Electronic supplementary materialThe online version of this article (doi:10.1186/s13054-015-1025-3) contains supplementary material, which is available to authorized users.

The Relationship Between Fibrinogen Levels After Cardiopulmonary Bypass and Large Volume Red Cell Transfusion in Cardiac Surgery

Coagulopathy leading to excessive blood loss and large volume red cell transfusion is a frequent complication of cardiac surgery with cardiopulmonary bypass (CPB) that may be caused by low perioperative fibrinogen levels. We explored the relationship between post-CPB fibrinogen levels and large volume red cell transfusion. Patients who underwent cardiac surgery with CPB from 2005 to 2011 at a single institution and had a fibrinogen level measured after CPB were included in this retrospective observational study. The relationship between post-CPB fibrinogen levels and large volume red cell transfusion (defined as ≥5 units transfused on the day of or the day after surgery) was assessed by cubic spline function and receiver operating characteristic analyses. The independent relationship between fibrinogen levels and large volume transfusion was assessed by multivariable logistic regression and propensity score analyses. In the 4606 patients included, the probability of large volume transfusion increased when fibrinogen levels decreased below approximately 2.0 g/L. Using <2.0 g/L as the threshold for low fibrinogen, 1918 (42%) were categorized into the low fibrinogen group, of whom 363 (18.9%) had large volume transfusion compared with 164 (13.5%) of the 2688 patients whose fibrinogen level was ≥2.0 g/L (P < 0.0001). In the low fibrinogen group, the unadjusted odds ratio (95% confidence interval) for large volume transfusion was 1.5 (1.3-1.7). The risk-adjusted odds ratio obtained by logistic regression was 1.8 (1.4-2.2) and by propensity score methods was 1.5 (1.2-2.0). While this study was not equipped to detect the critical fibrinogen level in bleeding patients, its results suggest that current recommendations that fibrinogen replacement not be initiated in bleeding patients unless fibrinogen levels decrease below 0.8 to 1.0 g/L may be too conservative. Randomized trials are needed to determine whether maintaining higher fibrinogen levels in bleeding patients can reduce blood loss and transfusions and by that means improve clinical outcomes in cardiac surgery.

Preoperative Cerebral Oxygen Saturation and Clinical Outcomes in Cardiac Surgery

Preoperative Cerebral Oxygen Saturation and Clinical Outcomes in Cardiac Surgery

Preoperative Cerebral Oxygen Saturation and Clinical Outcomes in Cardiac Surgery

The current study was designed to determine the relation between preoperative cerebral oxygen saturation (Sco2), variables of cardiopulmonary function, mortality, and morbidity in a heterogeneous cohort of cardiac surgery patients. In this study, 1,178 consecutive patients scheduled for on-pump surgery were prospectively studied. Preoperative Sco2, demographics, N-terminal pro-B-type natriuretic peptide, high-sensitive troponin T, clinical outcomes, and 30-day and 1-yr mortality were recorded. Median additive EuroSCORE was 5 (range: 0-19). Thirty-day and 1-yr mortality and major morbidity (at least two major complications and/or a high-dependency unit stay of at least 10 days) were 3.5%, 7.7%, and 13.3%, respectively. Median minimal preoperative oxygen supplemented Sco2 (Sco2min-ox) was 64% (range: 15-92%). Sco2min-ox was correlated (all: P value <0.0001) with N-terminal pro-B-type natriuretic peptide (ρ: -0.35), high-sensitive troponin T (ρ: -0.28), hematocrit (ρ: 0.34), glomerular filtration rate (ρ: 0.19), EuroSCORE (τ: 0.20), and left ventricular ejection fraction class (τ: 0.12). Thirty-day nonsurvivors had a lower Sco2min-ox than survivors (median 58% [95% CI, 50.7-62%] vs. 64% [95% CI, 64-65%]; P < 0.0001). Receiver-operating curve analysis of Sco2min-ox and 30-day mortality revealed an area-under-the-curve of 0.71 (95% CI, 0.68-0.73%; P < 0.0001) in the total cohort and an area-under-the-curve of 0.77 (95% CI, 0.69-0.86%; P < 0.0001) in patients with a EuroSCORE more than 10. Logistic regression based on different EuroSCORE categories (0-2; 3-5, 6-10, >10), Sco2min-ox, and duration of cardiopulmonary bypass showed that a Sco2min-ox equal or less than 50% is an independent risk factor for 30-day and 1-yr mortality. Preoperative Sco2 levels are reflective of the severity of cardiopulmonary dysfunction, associated with short- and long-term mortality and morbidity, and may add to preoperative risk stratification in patients undergoing cardiac surgery.

Transfusion Association With Adverse Clinical Outcomes in Cardiac Surgery: An Analysis of a Large Patient Cohort

Abstract 3158 Poster Board III-95 Background Previous studies have demonstrated significant variation in red cell transfusion in cardiac surgery. Allogeneic red cell transfusion has been reported as associated with adverse post-operative outcomes in this setting, whilst there is conflicting evidence on potential adverse effects of platelets. We investigated the variation in transfusion practice (including red cell, platelets and plasma transfusion) across six large cardiac surgery centres and whether peri-operative transfusion was independently associated with clinical outcomes. Methods Data were prospectively collected on 9363 cardiac surgery patients at six major Australian hospitals from January 2005 to December 2008 through the Australasian Society of Cardiac and Thoracic Surgeons (ASCTS) Cardiac Surgery Database. The independent association of transfusion (including red cells, platelets and plasma) with clinical outcomes was determined by stepwise logistic regression analysis. Patient factors (including co-morbidities and medication use such as anticoagulants and anti-platelet agents) and surgical factors (including type of procedure, previous cardiothoracic intervention, urgency of surgery, cardiopulmonary bypass time, cross-clamp time, return to theatre and other peri-operative complications) were included in the analysis. Results Procedure types were: coronary artery bypass graft (CABG) surgery in 60%, valve surgery in 14%, CABG and valve in 10% and other procedure in 16%. There was significant variation in transfusion of all blood components between the six hospitals, which was not accounted for by patient or surgery related factors. The adjusted odds ratio (OR) for the risk of receiving a transfusion of red cells varied between the hospitals from 0.22 to 1.98, for platelets from 0.39 to 3.3 and for plasma from 0.27 to 2.0. Transfusion of red cells, platelets and plasma were each associated with all outcome measures. In multiple logistic regression analysis, red cell transfusion was independently associated with multi-system failure (OR, 2.97; 95% confidence interval [CI], 1.41 - 6.28; p = 0.004), peri-operative myocardial infarction (OR, 2.63; 95% CI, 1.45 - 4.77; p = 0.001), stroke (OR, 1.76; 95% CI, 1.13 - 2.72; p = 0.012), prolonged ventilation (OR, 2.6; 95% CI, 2.19 - 3.06; p Conclusion There was significant variation in transfusion practice for red cells, platelets and plasma across these six major hospitals that was not accounted for by patient or surgery related factors. Peri-operative transfusions of red cells, platelets and plasma, after adjusting for established clinical risk factors, were each independently associated with an increased risk of adverse events. These findings from a large cohort of patients are in keeping with previous reports of adverse events associated with red cell transfusion in cardiac surgery and support the need for further research into the effects of transfusion on patient outcomes. An improved understanding of factors contributing to the significant variation in transfusion practice is also required as this may have important implications for patient outcomes. Disclosures No relevant conflicts of interest to declare.

Preoperative creatinine clearance as a predictor of short-term outcomes after cardiac surgery: a cohort study for the comparison between the Cockroft–Gault and modification of diet in renal disease formulae

Preoperative renal function is an important risk factor in cardiac surgery for long-term and short-term outcomes. Renal function is best assessed by measuring or calculating the glomerular filtration rate (GFR). Several algorithms using the endogenous marker serum creatinine have been developed to estimate renal function. These include the Cockcroft and Gault and the modification of diet in renal disease (MDRD) formulae. The aim of this study was to compare the predictive power of the two formulae towards short-term outcomes after cardiac surgery, such as the length of intensive care unit (ICU) stay, the length of mechanical ventilation time, and the length of in-hospital stay. One hundred and fifty patients undergoing cardiac surgery and not affected by renal failure were followed up until hospital discharge. We collected data before, during and after surgery. Before surgery data consisted of date of birth, sex, height, weight, plasma creatinine level; during surgery data consisted of type of intervention (including number of bypasses, if any), cardiopulmonary bypass time and aortic cross-clamp time; after surgery data consisted of length of ICU stay, mechanical ventilation time, length of in-hospital stay after intensive-care discharge (ward stay), incidence of acute renal failure (expressed as the need for dialysis) and mortality. The dataset was analyzed using Cox regression. The average mechanical ventilation time, ICU stay and ward stay were 11 h, 49 h and 10 days, respectively. After having adjusted for chronic obstructive pulmonary disease, diabetes and postsurgical dialysis, the GFR calculated with the Cockcroft and Gault formula appeared to be a predictor of ICU stay and mechanical ventilation time with very strong evidence (P = 0.002 and <0.001, respectively) and a predictor of ward stay with some evidence (P = 0.062). After an identical case-mix adjustment, the GFR calculated with the MDRD formula appeared to be a predictor of ICU stay with strong evidence (P = 0.007), a predictor of mechanical ventilation time with some evidence (P = 0.075) and it has shown no evidence of predicting ward stay (P = 0.197). There is an indication that the Cockcroft and Gault formula could be more powerful than the MDRD formula for the preoperative prediction of early postoperative clinical outcomes in cardiac surgery, in patients not affected by renal failure. Further research is needed to confirm this result.

Mid-term clinical outcomes in cardiac surgery of Jehovah's witnesses

Surgical treatment of Jehovah's witnesses is a special challenge for cardiac surgery. The purpose of this study was to evaluate perioperative management and mid-term clinical outcome of Jehovah's witnesses who underwent cardiac surgery. Between January 1990 and June 2009, 34 Jehovah's witnesses (22 men, mean age 66 +/- 8 years) underwent cardiac surgery. Surgical procedures included 17 coronary artery bypass grafts (CABG): 3 CABG and aortic valve replacements (AVR); 1 CABG and mitral valve plasty (MVP); 6 AVR; 1 subaortic membrane resection; 2 mitral valve replacements (MVR) and 2 MVP; 1 mitro-aortic valve replacement; and 1 cardiac foreign body removal. There were four urgent operations; 14 patients had NYHA class II-III. Sixteen patients received erythropoietin preoperatively. Preoperative haemoglobin (Hb) value was 14.2 +/- 1.4 g/dl. Extracorporeal circulation time was 127 +/- 66 min, aortic cross-clamping 84 +/- 45 min. Haemoglobin value 24 h after surgery was 11.2 +/- 1.7 g/dl, haematocrit 34.1 +/- 5.2%. None required surgical reoperation for bleeding.Intensive care unit stay was 2.3 +/- 4.3 days, hospital stay 12.3 +/- 10.4 days; there was no hospital mortality. Postoperatively, erythropoietin was administered to 19 patients. Follow-up was completed in 100%. Reoperation was necessary 8 years later in one patient for mitral bioprosthesis degeneration; the patient died 8 months later. All other patients are alive 59 +/- 60 months after surgery; actuarial survival is 100% and 80 +/- 2% at 5 and 10 years, respectively. In our limited experience, early and late surgical results of Jehovah's witnesses patients are satisfactory. Appropriate preoperative management, optimization of Hb values, intraoperative measures to reduce the risk of bleeding and total blood loss recovery are the goals to achieve these results.

Transfusion Association with Adverse Clinical Outcomes in Cardiac Surgery: An Analysis of a Large Patient Cohort.

Abstract 3158Poster Board III-95 BackgroundPrevious studies have demonstrated significant variation in red cell transfusion in cardiac surgery. Allogeneic red cell transfusion has been reported as associated with adverse post-operative outcomes in this setting, whilst there is conflicting evidence on potential adverse effects of platelets. We investigated the variation in transfusion practice (including red cell, platelets and plasma transfusion) across six large cardiac surgery centres and whether peri-operative transfusion was independently associated with clinical outcomes. MethodsData were prospectively collected on 9363 cardiac surgery patients at six major Australian hospitals from January 2005 to December 2008 through the Australasian Society of Cardiac and Thoracic Surgeons (ASCTS) Cardiac Surgery Database. The independent association of transfusion (including red cells, platelets and plasma) with clinical outcomes was determined by stepwise logistic regression analysis. Patient factors (including co-morbidities and medication use such as anticoagulants and anti-platelet agents) and surgical factors (including type of procedure, previous cardiothoracic intervention, urgency of surgery, cardiopulmonary bypass time, cross-clamp time, return to theatre and other peri-operative complications) were included in the analysis. ResultsProcedure types were: coronary artery bypass graft (CABG) surgery in 60%, valve surgery in 14%, CABG and valve in 10% and other procedure in 16%. There was significant variation in transfusion of all blood components between the six hospitals, which was not accounted for by patient or surgery related factors. The adjusted odds ratio (OR) for the risk of receiving a transfusion of red cells varied between the hospitals from 0.22 to 1.98, for platelets from 0.39 to 3.3 and for plasma from 0.27 to 2.0. Transfusion of red cells, platelets and plasma were each associated with all outcome measures. In multiple logistic regression analysis, red cell transfusion was independently associated with multi-system failure (OR, 2.97; 95% confidence interval [CI], 1.41 - 6.28; p = 0.004), peri-operative myocardial infarction (OR, 2.63; 95% CI, 1.45 - 4.77; p = 0.001), stroke (OR, 1.76; 95% CI, 1.13 - 2.72; p = 0.012), prolonged ventilation (OR, 2.6; 95% CI, 2.19 - 3.06; p < 0.001), pulmonary embolism (OR, 4.29; 95% CI, 1.4 - 13.16; p = 0.011), pneumonia (OR, 2.12; 95% CI, 1.8 - 2.72, p < 0.001) and septicaemia (OR, 2.29; 95% CI, 1.31 - 4.0; p = 0.004). Platelet transfusion was independently associated with multi-system failure (OR, 2.17; 95% CI, 1.3 - 3.63; p = 0.003) and pneumonia (OR, 1.25; 95% CI, 1.02 - 1.52; p = 0.03). Plasma transfusion was independently associated with in-hospital (OR, 2.46; 95% CI, 1.82 - 3.32; p < 0.001) and 30 day mortality (OR, 2.2; 95% CI, 1.61 - 2.99; p < 0.001), multi-system failure (OR, 1.97; 95% CI, 1.18-3.31; p = 0.010), prolonged ventilation (OR, 1.81; 95% CI, 1.55 - 2.13; p < 0.001) and septicaemia (OR, 1.83; 95% CI, 1.17 -2.85; p = 0.008). ConclusionThere was significant variation in transfusion practice for red cells, platelets and plasma across these six major hospitals that was not accounted for by patient or surgery related factors. Peri-operative transfusions of red cells, platelets and plasma, after adjusting for established clinical risk factors, were each independently associated with an increased risk of adverse events. These findings from a large cohort of patients are in keeping with previous reports of adverse events associated with red cell transfusion in cardiac surgery and support the need for further research into the effects of transfusion on patient outcomes. An improved understanding of factors contributing to the significant variation in transfusion practice is also required as this may have important implications for patient outcomes. DisclosuresNo relevant conflicts of interest to declare.

Canonical Correlation Analysis of Risk Factors and Clinical Outcomes in Cardiac Surgery

Assessment of the association between risk factors and outcomes in cardiac surgery is a complex problem. The aim of this study was to explore the relationship between possible risk factors and several clinical outcomes in cardiac surgery by using canonical correlation analysis (CCA). This retrospective study of 2605 consecutive adult patients who underwent cardiac surgery, evaluated 74 potential risk factors and up to 12 outcomes by canonical correlation analysis. For three serious outcomes, sternal wound complications/mediastinitis, cerebral complications, and perioperative myocardial infarctions, CCA was preceded by univariate analyses and backward stepwise multivariate logistic regression analyses. The CCA suggests that the major risk factors for complications in these models are intraoperative and postoperative risk factors. The power of risk prediction models developed with multivariate regression analysis can be enhanced by application of canonical correlation analysis, thereby offering new ways of analyzing and interpreting sets of potential risk factors in relation to sets of clinical outcomes.

Perioperative detection of brain oxygenation and clinical outcomes in cardiac surgery.

Awareness of the high incidence of subtle central nervous system dysfunction after cardiopulmonary bypass, when it leads to increased vigilance in monitoring and diagnosis, remains the most important factor in the detection of postoperative injury. Preliminary data from an ongoing prospective study indicates that the use of noninvasive cerebral oximetry may be associated with a decreased length of stay in patients who have had coronary artery bypass grafting.