Increasing obesity is associated with lower postoperative bleeding in coronary bypass patients.

OBJECTIVE: Despite inherent comorbidities, obese cardiac surgical patients paradoxically had shown lower morbidity and mortality, although the nature of this association is still unclear. Thus, the authors intended in this large registry-based study to investigate the impact of obesity on short- and long-term postoperative outcomes, focusing on bleeding and transfusion requirements. DESIGN: Retrospective registry study. SETTING: Three university hospitals. PARTICIPANTS: A cohort of 12,330 prospectively compiled data from coronary bypass grafting patients undergoing surgery between 2007 to 2020 were retrieved from the Western Denmark Heart Registry. INTERVENTIONS: The parameters were analyzed to assess the association between body mass index (BMI) and the selected outcome parameters. MEASUREMENTS AND MAIN RESULTS: The crude data showed a clear statistically significant association in postoperative drainage from 637 (418-1108) mL in underweight patients with BMI <18.5 kg/m2 to 427 (295-620) mL in severely obese patients with BMI ≥40 kg/m2 (p < 0.0001, Kruskal-Wallis). Further, 50.0% of patients with BMI <18.5 received an average of 451 mL/m2 in red blood cell transfusions, compared to 16.7% of patients with BMI >40 receiving 84 mL/m2. The obese groups were less often submitted to reexploration due to bleeding, and fewer received perioperative hemostatics, inotropes, and vasoconstrictors. The crude data showed increasing 30-day and 6-month mortality with lower BMI, whereas the one-year mortality showed a V-shaped pattern, but BMI had no independent impact on mortality in logistic regression analysis. CONCLUSION: Patients with high BMI may carry protection against postoperative bleeding after cardiac surgery, probably secondary to an inherent hypercoagulable state, whereas underweight patients carry a higher risk of bleeding and worse outcomes.

Fewer transfusions are still more-red blood cell transfusions affect long-term mortality in cardiac surgery.

OBJECTIVES: Previous studies indicated higher long-term mortality after the transfusion of allogeneic red blood cells (RBC); newer recommendations emphasize lower transfusion rates. The consequences of the transfusion of RBCs in cardiac surgery are unclear because later studies focused on transfusion triggers and short-term outcomes. Reports on long-term complications after cardiac surgery are few. MATERIAL AND METHODS: The mandatory Western Denmark Heart Registry was used to identify all adult cardiac operations performed in 4 centres from 2000 to 2019. Patients with multiple entries or previous cardiac operations, special/complex procedures, dying within 30 days and not eligible for follow-up were excluded. RESULTS: A total of 32,581 adult cardiac operations performed in 4 centres from 2000 to 2019 were included. The Kaplan-Meier survival plot for low-risk patients undergoing simple cardiac operations showed a significantly lower 15-year survival (0.384 vs 0.661) of patients who received perioperative RBC transfusions [odds ratio 2.43 (confidence level 2.23-2.66)]. The risk decreased with increasing comorbidity or age. No difference was found in high-risk patients. The adjusted risk ratio after an RBC transfusion, including age, sex, comorbidity and surgery, was 1.62 (1.48-1.77). CONCLUSIONS: Despite reduced transfusion rates, long-term follow-up on especially low-risk patients undergoing comparable cardiac operations still demonstrates substantially more deaths of patients receiving perioperative RBC transfusions. Even transfusion of 1-2 units is associated with increased long-term mortality.

Differences in diagnostication, and revascularisation of ischaemic heart disease in Western Denmark.

INTRODUCTION: In Denmark, the incidence of and mortality from ischaemic heart disease (IHD) has been declining. In this context, it is of interest to assess any regional differences in diagnostication and invasive treatment of IHD. METHODS: We intended to describe the diagnostication and invasive treatment of IHD in Western Denmark at the regional/municipal level using the Western Denmark Heart Registry. Coronary angiography (CAG), percutaneous coronary intervention (PCI) and coronary arterial bypass grafting were registered from 2000 through 2019; cardiac multislice computed tomography (CMCT), from 2015 through 2019. RESULTS: Concerning the use of revascularisation for acute coronary syndrome (ACS), we found comparable regional activity levels but significant differences between individual municipalities. Furthermore, the use of CAG for chronic coronary syndrome (CCS) was significantly higher and the use of CMCT significantly lower in the North Denmark Region than in the Central and South Denmark Regions. CONCLUSION: We found differences in the rates of PCI for ACS at the municipal level but not between the Western Denmark regions. Furthermore, at the regional level, evaluation of chronic IHD differed regarding use of elective CAG and CMCT, and use of CMCT was not paralleled by a reduction in the number of CAG procedures. This may possibly prompt discussions on the strategy for invasive and non-invasive diagnosis of CCS and on targeted preventive measures. FUNDING: none TRIAL REGISTRATION. not relevant.

Comparison of free arterial and saphenous vein grafting in outcomes after coronary bypass surgery.

Objectives. The goal of this study was to examine whether the use of free arterial grafts could reduce the need for repeated revascularization and all-cause mortality in patients undergoing coronary artery grafting. Design. The cohort study included 17,354 consecutive adults with isolated coronary artery grafting from 2000 to 2016 in three cardiac surgery centers. Data were obtained from the Western Denmark Heart Registry. Propensity matching with 24 factors was used to establish comparable groups of patients receiving either vein grafts (n = 1019) or free arterial grafts (n = 1019) for outcome analysis. Results. The need for repeated revascularization and all-cause mortality was similar in both graft groups at 10 years of follow-up. Creatine-Kinase MB Isoenzyme >100 µg/L increased the risk of repeated revascularization rate after 1, 5 and 10 years. Conclusions. Long-term outcomes in revascularization and survival are comparable after free arterial or saphenous vein grafting.

ICU Nurses-An Impact Factor on Patient Turnover in Cardiac Surgery in Western Denmark?

OBJECTIVE: The aim of this study was to describe changes in performance indicators such as length of stay [LOS] in the intensive care unit [ICU] and ventilation time, during the last six years in an attempt to identify associations between patient and systemic performance indicators, including the impact of nurse turnover. DESIGN: A retrospective study of prospectively registered data (2013-2018). Propensity- score matching was performed to establish comparable groups. SETTING: Three Danish university hospitals. PARTICIPANTS: The study included a total of 12,404 adult cardiac surgical patients registered in the Western Denmark Heart Registry. The cohort was divided into an "early" group (2013-2016) and a "late" group (2017-2018). INTERVENTIONS: An analysis of dynamics in patient indicators and systemic performance indicators, including the impact from selected performance parameters and nurse turnover. MEASUREMENTS AND MAIN RESULTS: Comorbidity, calculated from the European System for Cardiac Operative Risk Evaluation, and the mean age were stable in the study period. Strong predictors of long LOS in the ICU included postoperative use of inotropes, re-exploration surgery, high postoperative drainage, and the "late" time group. Time parameters (relative risks) were all significantly longer in the "late" time group": ventilation time 1.21 (1.05-1.39), length of stay ICU 1.28 (1.11-1.48), and in-hospital time 1.36 (1.19-1.57). ICU nurse turnover increased from four (2013-2014) to 52 (2017-2018). CONCLUSION: No single patient factor, such as age or comorbidity, could explain the decrease in patient turnover in the ICU. In the same period, the turnover of ICU nurses increased. Patient turnover is complex and affected by a mix of patient and systemic performance factors.

A Descriptive Study of Perioperative Hemodynamics in Open Cardiac Surgery Patients.

OBJECTIVES: The purpose of the present study was to describe how the perioperative hemodynamic profile before and after cardiopulmonary bypass during cardiac surgery is influenced by age and to describe the association between postoperative hemodynamics and one-year mortality. DESIGN: A retrospective registry-based study. SETTING: University Hospital of Aarhus, Denmark. PARTICIPANTS: The study comprised 6,595 patients undergoing elective on-pump cardiac surgery from 2006 to 2016. MEASUREMENTS AND MAIN RESULTS: Perioperative hemodynamic values were derived from computerized anesthesia and intensive care reports, including mean arterial pressure, cardiac index, and oxygenation saturation from mixed venous blood in the pulmonary artery, during the perioperative period. Perioperative hemodynamic values were stratified according to age. Logistic regression was applied to predict the crude probability of death within one year from surgery according to hemodynamic values at six hours after surgery, stratified by age and use of inotropic agents, respectively. Lower values for cardiac index and mixed venous blood in the pulmonary artery with increasing age, across all points in time in the perioperative course, were observed. Higher probability of death was associated with lower hemodynamic values in the postoperative phase, and the probability of death was modified by age and the need for inotropic agents. DISCUSSION: This is a large registry based study describing the perioperative hemodynamic profile of patients undergoing cardiac surgery and the results enhance our understanding of age-differentiated values of CI and SvO2 in this specific population.

Impact of perioperative course during cardiac surgery on outcomes in patients 80 years and older.

OBJECTIVE: To describe the associations among preoperative characteristics, intraoperative and postoperative factors, and mortality and morbidity after open-heart surgery in patients age ≥80 years. METHODS: This retrospective multicenter register study was based on prospectively collected data of all patients age ≥80 years undergoing open-heart surgery in western Denmark between 1999 and 2016. Logistic regression was used to estimate the associations among preoperative characteristics, intraoperative and postoperative factors, and morbidity and mortality. Bonferroni correction was used for multiple comparisons. RESULTS: The study population included 2342 patients age ≥80 years undergoing open-heart surgery. We observed an association between severely impaired preoperative renal function and death within 1-year postsurgery (odds ratio [OR], 4.6; 95% confidence interval [CI], 2.7-7.2). Furthermore, renal clearance <40 mL/min and prolonged cardiopulmonary bypass time of >180 minutes were associated with a >50% probability of death within 1 year. The adjusted OR for death within 1 year was increased significantly with a postoperative length of stay in intensive care of ≥3 days (OR, 5.9; 95% CI, 4.1-8.6) and a duration of postoperative mechanical ventilation ≥2 days (OR, 7.5; 95% CI, 4.1-13.9). Various preoperative and intraoperative characteristics were associated with in-hospital dialysis, in particular cardiopulmonary bypass time >180 minutes (OR, 11.6; 95% CI, 4.7-28.5). CONCLUSIONS: Our findings emphasize the importance of careful referral regarding the procedural burden for very elderly patients and may provide support for informed patient discussions about prognosis and recovery.

Fast-track cardiac anaesthesia protocols: Is quality pushed to the edge?

Background: The quest for methods expediting rapid postoperative patient turnover has triggered implementation of various fast-track cardiac anaesthesia protocols. Using three different fast-track protocols in randomized controlled studies (RCT) conducted 2010-2016 we found minimal achievements in ventilation time together with actual and eligible length of stay in cardiac recovery unit. The comparable control group patients were evaluated in this retrospective post hoc analysis, for an association between above mentioned parameters and quality parameters, to assess whether the marginal gains have been at the expense of quality of recovery and patient comfort. Method: 90 control patients from three RCT with comparable demographic parameters and receiving standard department treatment were evaluated using time parameters and an objective/semi-objective Intensive Care Unit (ICU) score system (IDS score). Results: Ventilation time was statistical significant lower in latest study (C) than the early (A) and intermedium (B) studies (A=293, B=261, C=205 minutes; P=0.04). The IDS was lower at extubation and all time points in the early study compared to other studies (P < 0.001;). The average IDS in latest study were the double of previous studies at the end of observations, and marginally above the acceptable score for discharge. The postoperative morphine requirement A=15.0, B=10.0 and C=26.5 mg; P=0.002) was statistical significant higher in the latest study compared to previous studies. Conclusion: The implementation of strict fast-track protocols resulting in shorter ventilation time did not convert to earlier eligibility to discharge from the ICU. However, the quality of recovery appears challenged.

The Major Decrease in Resource Utilization in Recent Decades Seems Guided by Demographic Changes: Fast Tracking-Real Concept or Demographics.

OBJECTIVE: To identify dynamics of associations and potential areas for optimization of patient turnover between various patient profile and comorbidity indicators and selected system performance indicators such as ventilation time, length of stay in the intensive care unit, and in-hospital stay. DESIGN: Retrospective study of prospectively registered data (2000-2017). SETTING: Three university hospitals. PARTICIPANTS: The study comprised 38,100 adult cardiac surgical patients registered in the Western Denmark Heart Registry. INTERVENTIONS: Analysis of dynamics in patient indicators and system performance indicators, including effect on the selected performance parameters. MEASUREMENTS AND MAIN RESULTS: Comorbidity, calculated from EuroSCORE, decreased from 2.5 ± 2.2 to 1.5 ± 2.0 (p < 0.001), whereas the average age of patients increased from 65.1 ± 9.9 years to 67.6 ± 10.8 years (p < 0.001). Median ventilation time decreased from 380 to 275 minutes (p < 0.0001). The mean length of stay in the intensive care unit demonstrated a statistically significant decrease from 35.1 hours between 2000 to 2002 to 31.8 hours between 2015 to 2017 (p = 0.004), and the median time was unchanged at 22.0 hours throughout the observation period. The median in-hospital stay decreased from 6.5 to 5.1 days (p < 0.001) and the mean in-hospital stay from 8.7 days (2003-2005) to 7.0 days (2015-2017; p < 0.001). Logistic regression analysis of performance factors showed a statistically significant negative independent effect on most comorbidity and surgical factors. CONCLUSION: The increase in performance parameters appears to be highly associated with decreased comorbidities and fast-tracking protocols and may only offer limited effect in additional patient turnover.

To jump or not to jump? A multicentre propensity-matched study of sequential vein grafting of the heart†.

OBJECTIVES: In this propensity-matched study we investigated the outcome after grafting with either a single vein or a sequential vein grafting strategy. Outcomes were primarily risk of reintervention and death in the short, intermediate and long term (10 years). MATERIALS: In the period from 2000 to 2016, data from 24 742 patients undergoing coronary artery bypass grafting were extracted from the Western Denmark Heart Registry, where data are registered perioperatively. We used a propensity-matched study in which the study groups were matched on parameters primarily from the EuroSCORE. The numbers of patients in both groups after matching were 3380. RESULTS: Single grafts resulted in significantly more postoperative bleeding and were more time-consuming. No differences were seen regarding in-hospital events such as stroke, acute myocardial infarction, dialysis or arrhythmias. After 30 days, patients in the jump graft group showed an increased rate of reintervention due to ischaemia after adjusting for confounding factors [hazard ratio (HR) 2.08, 95% confidence interval 1.01-4.34]. In addition, after adjusting for known confounders, sequential grafts were found to increase the risk of mortality at 6 months (HR 1.51, 95% confidence limits 1.07-2.11) and 5 years (HR 1.23, 95% confidence limits 1.04-1.46). CONCLUSIONS: This propensity-matched analysis suggested, although discretely, that a jump graft as a grafting strategy is associated with a slightly increased risk of mortality and early graft failure and that a single grafting strategy to the coronary arteries should be preferred when feasible.

Blood cardioplegia benefits only patients with a long cross-clamp time.

INTRODUCTION: A clear advantage of blood versus crystalloid cardioplegia has not yet been observed in smaller population studies. The purpose of this article was to further investigate the clinical outcomes of blood versus crystalloid cardioplegia in a large propensity-matched cohort of patients who underwent cardiac surgery. METHODS: The study was a single-centre study. Data was withdrawn from the Western Denmark Heart Registry, which comprises a perfusion section for each procedure. A total of 4,852 patients were propensity matched into crystalloid (CC) vs blood cardioplegia (BC) groups. The primary end points were creatinine kinase-MB (CKMB) elevation, acute myocardial infarction (AMI), stroke, dialysis, coronary angiography (CAG) and mortality (30 days and 6 months). RESULTS: We found lower odds ratio in 30-day mortality in the BC group (OR 0.21; CI 0.06-0.68), but no difference in overall 6-month mortality. There was no difference in CKMB elevation, AMI, dialysis or stroke. Several end points were further analysed for different cross-clamp times. In the CC group, ventilation time above 600 minutes was seen more often in almost all cross-clamp time intervals (23.5 % vs 12.2 %; p<0.0001; χ2-test) and 6-month mortality was significantly higher when the cross-clamp time exceeded 210 minutes (64.3 vs 23.8; p=0.018; χ2-test). CONCLUSIONS: We did not find clear evidence of superiority of either type in the uncomplicated patient. When prolonged cross-clamp time or postoperative ventilation is expected, this study indicates that blood cardioplegia might be preferable.

The association between a three-day ticagrelor discontinuation and perioperative bleeding complications.

OBJECTIVES: Dual antiplatelet therapy at the time of cardiac surgery is associated with excessive perioperative bleeding. International guidelines, therefore, recommended discontinuing oral adenosine diphosphate receptor antagonists prior to non-emergency surgery. In this study, we analysed whether a 3-day ticagrelor discontinuation was sufficient to avoid major bleeding complications. METHODS: This study is a retrospective cohort analysis of 3377 patients undergoing coronary artery bypass or single-valve surgery from January 2013 to September 2017. Patients exposed to ticagrelor prior to surgery were compared with control patients exposed to aspirin only. Outcome measures included transfusion requirements, bleeding volumes, the need for re-exploration and the composite outcome major bleeding complication. Data were retrieved from the the Western Denmark Heart Registry. RESULTS: During the study period, 101 patients were preoperatively exposed to ticagrelor, whereas 3276 patients were exposed to aspirin only. Propensity-score matching resulted in 90 pairs of patients. Overall, ticagrelor exposure was associated with a greater risk of major bleeding complications compared with control patients [31 vs 12%, relative risk 2.6, 95% confidence interval (CI) 1.4-4.8]. While ticagrelor exposure within 0-72 h before surgery (n = 42) was associated with a substantially increased risk of major bleeding complications (48 vs 10%, relative risk 5.0, 95% CI 1.9-13.4), ticagrelor exposure 72-120 h before surgery (n = 48) showed no statistically significant association (17 vs 15%, relative risk 1.1, 95% CI 0.4-2.9). CONCLUSIONS: In our historical cohort, ticagrelor exposure 0-72 h prior to cardiac surgery was associated with an increased risk of major bleeding complications. On the other hand, ticagrelor exposure 72-120 h prior to surgery was not associated with a clinically relevant increase in major bleeding complications.

The Western Denmark Heart Registry: Its Influence on Cardiovascular Patient Care.

The WDHR (Western Denmark Heart Registry) is a seminational, multicenter-based registry with longitudinal registration of detailed patient and procedure data since 1999. The registry includes as of January 1, 2017 approximately 240,000 coronary angiographies, 90,000 percutaneous coronary interventions, 60,000 cardiac computed tomographies, 40,000 cardiac operations, and 2,000 transcatheter aortic valve replacements. Positron emission tomography/computed tomography, single-photon emission computed tomography, and magnetic resonance imaging are soon to be added. Each procedure is registered with 50 to 200 administrative, patient, and procedure variables. Lesion data are also registered for percutaneous coronary intervention, and cardiac surgeries also include variables for EuroSCORE, anesthesia, perfusion, and intensive care. The registry has high completeness and accuracy. The Danish registry infrastructure allows for complete follow-up for medical events and mortality, which greatly enhances the research potential of the data. This review describes why the WDHR is a unique data resource and how it continues to influence cardiovascular patient care.

Intraoperative milrinone versus dobutamine in cardiac surgery patients: a retrospective cohort study on mortality.

BACKGROUND: Several choices of inotropic therapy are available and used in relation to cardiac surgery. Comparisons are necessary to select optimal therapy. In Denmark, dobutamine and milrinone are the two inotropic agents most commonly used to treat post-bypass low cardiac output syndrome. This study compares all-cause mortality with these drugs. METHODS: In a retrospective observational study we investigated 10,700 consecutive patients undergoing cardiac surgery from 1 April 2006 to 31 December 2013 at Aarhus and Aalborg University Hospitals in the Central and Northern Denmark Region. Prospectively entered data in the Western Danish Heart Registry on intraoperative use of inotropes were used to identify 952 patients treated with milrinone, 418 patients treated with dobutamine, and 82 patients receiving a combination of the two inotropes. All-cause mortality among patients receiving dobutamine was compared to all-cause mortality among milrinone receivers. Multiple logistic regression analyses including preoperative and intraoperative variables along with g-formula analyses were used to model 30-day and 1-year mortality risks. Reported were standardized mortality risk differences between the treatment groups. RESULTS: Among patients receiving intraoperative dobutamine, 18 (4.3%) died within 30 days and 49 (11.7%) within 1 year. Corresponding 30-day and 1-year mortality for milrinone receivers were 81 (8.5%) and 170 (17.9%). Risk of death within 30 days and 1 year was increased for intraoperative milrinone compared to dobutamine with a standardized risk difference of 4.06% (confidence interval (CI) 1.23; 6.89, p = 0.005) and 4.77% (CI 0.39; 9.15, p = 0.033), respectively. Sensitivity analyses including adjustment for milrinone preference, hemodynamic instability prior to cardiopulmonary bypass, and separate analyses on hospital level all confirmed a sign toward increased mortality among milrinone receivers. CONCLUSIONS: Intraoperative use of milrinone in cardiac surgery may be associated with an increase in all-cause mortality compared to use of dobutamine.

Lower Dose of Sufentanil Does Not Enhance Fast Track Significantly-A Randomized Study.

OBJECTIVE: Adjustment in the doses of opioids has been a focus of interest for achieving better fast-track conditions in cardiac anesthesia, but relatively sparse information exists on the potential effect of psychologic and behavioral factors, such as stress, anxiety, and type of personality, on anesthesia requirements and patient turnover in the cardiac recovery unit (CRU); to the authors' knowledge, this particular focus has not been systematically investigated. In this randomized study, the authors tested the hypothesis that low-dose sufentanil, compared with a standard dose, can improve fast-track parameters and the overall quality of recovery. Opioid requirements related to personality type, pain sensitivity, and preoperative stress and anxiety also were assessed. DESIGN: A randomized, prospective study. PARTICIPANTS: The study comprised 60 patients scheduled for elective coronary artery bypass grafting with or without aortic valve replacement. SETTING: A university hospital. INTERVENTIONS: Patients were randomly assigned to receive either a standard dose (bolus 0.5 µg/kg) or low dose (bolus 0.25 µg/kg) of sufentanil combined with propofol. MEASUREMENTS AND MAIN RESULTS: The primary outcome variables were ventilation time and eligible time to discharge from the CRU. The secondary objective was to evaluate the relationship between opioid requirements and personality type, pain sensitivity, and preoperative stress and anxiety. The groups were comparable in selected demographics and perioperative parameters. There was no difference between groups in ventilation time (low dose: 191 [163-257] v standard dose: 205 [139-279] min; p = 0.405); eligible CRU discharge time (10.3 ± 5.0 v 10.3 ± 4.2 h; p = 0.978); or administration of postoperative morphine (25 [11-34) v 27 [10-39] g; p = 0.790). There was no difference between groups in total sufentanil administration and various preoperative psychologic and behavioral test levels nor in the time to reach bispectral index <50 during induction, except that personality type A demonstrated a longer induction time of 10 (8-12) minutes versus 6 (4-8) minutes in low-score patients. CONCLUSION: A lower dose of sufentanil, compared with a standard dose, does not enhance fast-track conditions significantly.

Quality assurance of the Western Denmark Heart Registry, a population-based healthcare register.

INTRODUCTION: During the past decade, the mandatory population-based healthcare database, the Western Denmark Heart Registry (WDHR), has provided the data for several research projects. As in most clinical registries, the data quality has not been validated thoroughly. This study was undertaken to evaluate the quality of registrations in the WDHR. METHODS: The audit supervised procedures from involved departments that were performed in 2013. An experienced research nurse completed data collection, and an experienced consultant evaluated the agreement between the WDHR and patient records. Indistinct data from patient records were determined after consulting a specialist from the department in question. Patient files were double-checked in case of disagreements between the involved systems. RESULTS: The total proportion of errors in the referral date was 16.4% in surgery, 9.8% in percutaneous invasive procedures (PCI), 16.1% in coronary angiography (CAG) and 19.5% in computed tomography (CT)-CAG, while the errors in inhospital dates were slightly lower. In the cardiac surgery registries, the proportion of errors was 3.3% in the history and EuroSCORE module, 1.0% in the procedure module and 2.8% in the discharge module. For PCI procedures, the errors were 3.8% in the history module, 2.2% in the procedure module and 1.6% in the discharge module. CAG and CT-CAG had slightly more errors. CONCLUSIONS: The quality control of the WDHR revealed that overall data errors were lower than 3% and for procedure-specific registrations including indications and complications, the error rate was below 1.5%. The WDHR is valid and may be used in contemporary epidemiological studies. FUNDING: none. TRIAL REGISTRATION: not relevant.

Re-exploration due to bleeding is not associated with severe postoperative complications.

OBJECTIVES: In cardiac surgery, postoperative bleeding remains a frequent complication with various possible adverse outcomes. Re-exploration due to bleeding is frequent in this type of patient. Sternal wound infection is an infrequent but serious and devastating complication. Whether re-exploration due to bleeding significantly affects the incidence of sternal wound infection is uncertain. There is no consensus on allowed severity of bleeding and timing of intervention. METHODS: A retrospective, observational cohort study of 15 350 consecutive patients who underwent cardiac surgical procedures from 1 April 2006 through 31 December 2013 in 3 different university hospitals in Denmark was performed. Re-exploration due to postoperative bleeding occurred in 873 patients. To adjust for possible confounders, propensity score matching and logistic regression analyses were performed based on the centre, EuroSCORE I/II factors, extracorporeal circulation time, drugs affecting bleeding and coagulation, postoperative bleeding and units of blood transfusions. Patients were matched into 2 groups of 779 patients each for further analysis. The short-term outcomes were sternum infection, 30-day mortality and acute renal failure needing dialysis. The long-term outcome was the number of deaths 6 months after surgery. RESULTS: The incidence of re-exploration was 5.7%. In the raw data, sternal infection was higher in the re-exploration group (2.4% vs 1.4; P = 0.020). After propensity score matching, no differences in sternal infection or other measured outcomes were found between the groups, either by crude or adjusted analyses. CONCLUSIONS: Our study indicates that re-exploration is not associated with a higher frequency of severe postoperative complications. Probably the time of intervention for bleeding is important.

Colloids in Cardiac Surgery-Friend or Foe?

OBJECTIVE: The right choice of fluid replacement still is a matter of debate. Recently, two large-scale studies on the use of hydroxyethyl starches (HES) in the intensive care setting have been published, which have caused a huge shift in the daily practice of volume therapy. These results have been applied to patients outside intensive care. The aim of this study was to evaluate the impact this change has had on the outcomes in a large population of cardiac surgery patients, with a focus on the type of colloid infusion. DESIGN: A prospective, registered, observational study, using propensity score matching. SETTING: Cohort study from 3 university hospitals using a common registry. PARTICIPANTS: The study comprised 17,742 patients who were referred for cardiac surgery from 2007 to 2014. INTERVENTIONS: Patients were divided in groups according to perioperative fluid replacement with either crystalloids or colloids. The colloid group was further divided into HES or human albumin (HA). Analyses were based on the following 3 subsections: HES versus crystalloids, HA versus crystalloids, and HES versus HA, with use of propensity score matching or direct matching of cases. Primary outcome parameters were 30-day and 6-month mortality, new postoperative renal replacement therapy, and new cardiac ischemic events. MEASUREMENTS AND MAIN RESULTS: The groups were fully comparable in individual analyses. The use of HES had no impact on new dialysis and 30-day mortality. A Cox proportional regression analysis showed that HES had no impact on 6-month mortality and new postoperative ischemic events. When comparing HA with crystalloid use, a significantly increased risk in crude analysis was demonstrated on all outcome parameters; and when comparing HA with HES, a significantly higher risk was observed in HA patients in mortality parameters and new postoperative, but after adjustment, only the risk of new postoperative dialysis persisted. CONCLUSION: This study underlined the difficulties in establishing hardcore outcome data, even in large cohort studies. The findings seemed to diminish the magnitude of risk when using HES in cardiac surgery patients and seriously questioned the choice of HA when a plasma expander is needed.

Storage time of intraoperative transfused allogeneic red blood cells is not associated with new-onset postoperative atrial fibrillation in cardiac surgery.

BACKGROUND: Allogeneic red blood cell (RBC) transfusion has been associated with new-onset postoperative atrial fibrillation (POAF) following cardiac surgery. Prolonged storage time of RBC may increase the risk. The primary aim of the study was to evaluate whether the storage time of RBC is associated with development of POAF. MATERIALS AND METHODS: Pre-, per- and postoperative data were retrieved from the Western Denmark Heart Registry and local blood banks regarding patients who underwent coronary artery bypass surgery, valve surgery or combined procedures in Aalborg or Aarhus University Hospital during 2010-2014. Multiple logistic regression was used to determine the risk of POAF according to transfusion of RBC on the day of surgery. Furthermore, we determined trend in storage time of RBC according to risk of POAF using restricted cubic splines. Patients with a history of preoperative atrial fibrillation, patients who received transfusions preoperative and patients who died at the day of surgery were among excluded patients. RESULTS: A total of 2,978 patients with a mean age of 66.4 years were included and 609 patients (21%) received RBC transfusion on the day of surgery. POAF developed in 752 patients (25%) and transfused patients were at an increased risk compared with non-transfused patients (adjusted Odds Ratios for patients receiving RBC: 1.37; 95% CI: 1.11-1.69, P-value = 0.004). However, RBC transfusion was not necessarily the cause of POAF and may only be a marker for development of POAF. There was no significant association between storage time of RBC and POAF. CONCLUSIONS: In contrast to intraoperative allogeneic RBC transfusion in general, increased storage time of RBC is not associated with development of POAF in cardiac surgery.