Effect of 4% Albumin Solution vs Ringer Acetate on Major Adverse Events in Patients Undergoing Cardiac Surgery With Cardiopulmonary Bypass: A Randomized Clinical Trial

IMPORTANCE

In cardiac surgery, albumin solution may maintain hemodynamics better than crystalloids and reduce the decrease in platelet count and excessive fluid balance, but randomized trials are needed to compare the effectiveness of these approaches in reducing surgical complications.

OBJECTIVE

To assess whether 4% albumin solution compared with Ringer acetate as cardiopulmonary bypass prime and perioperative intravenous volume replacement solution reduces the incidence of major perioperative and postoperative complications in patients undergoing cardiac surgery.

DESIGN, SETTING, AND PARTICIPANTS

A randomized, double-blind, single-center clinical trial in a tertiary university hospital during 2017-2020 with 90-day follow-up postoperatively involving patients undergoing on-pump coronary artery bypass grafting; aortic, mitral, or tricuspid valve surgery; ascending aorta surgery without hypothermic circulatory arrest; and/or the maze procedure were randomly assigned to 2 study groups (last follow-up was April 13, 2020).

INTERVENTIONS

The patients received in a 1:1 ratio either 4% albumin solution (n = 693) or Ringer acetate solution (n = 693) as cardiopulmonary bypass priming and intravenous volume replacement intraoperatively and up to 24 hours postoperatively.

MAIN OUTCOMES AND MEASURES

The primary outcome was the number of patients with at least 1 major adverse event: death, myocardial injury, acute heart failure, resternotomy, stroke, arrhythmia, bleeding, infection, or acute kidney injury.

RESULTS

Among 1407 patients randomized, 1386 (99%; mean age, 65.4 [SD, 9.9] years; 1091 men [79%]; 295 women [21%]) completed the trial. Patients received a median of 2150 mL (IQR, 1598-2700 mL) of study fluid in the albumin group and 3298 mL (IQR, 2669-3500 mL) in the Ringer group. The number of patients with at least 1 major adverse event was 257 of 693 patients (37.1%) in the albumin group and 234 of 693 patients (33.8%) in the Ringer group (relative risk albumin/Ringer, 1.10; 95% CI, 0.95-1.27; P = .20), an absolute difference of 3.3 percentage points (95% CI, -1.7 to 8.4). The most common serious adverse events were pulmonary embolus (11 [1.6%] in the albumin group vs 8 [1.2%] in the Ringer group), postpericardiotomy syndrome (9 [1.3%] in both groups), and pleural effusion with intensive care unit or hospital readmission (7 [1.0%] in the albumin group vs 9 [1.3%] in the Ringer group).

CONCLUSIONS AND RELEVANCE

Among patients undergoing cardiac surgery with cardiopulmonary bypass, treatment with 4% albumin solution for priming and perioperative intravenous volume replacement solution compared with Ringer acetate did not significantly reduce the risk of major adverse events over the following 90 days. These findings do not support the use of 4% albumin solution in this setting.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02560519.

Effect and safety of 4% albumin in the treatment of cardiac surgery patients: study protocol for the randomized, double-blind, clinical ALBICS (ALBumin In Cardiac Surgery) trial

Background

In cardiac surgery with cardiopulmonary bypass (CPB), large amounts of fluids are administered. CPB priming with crystalloid solution causes marked hemodilution and fluid extravasation. Colloid solutions may reduce fluid overload because they have a better volume expansion effect than crystalloids. The European Medicines Agency does not recommend the use of hydroxyethyl starch solutions (HES) due to harmful renal effects. Albumin solution does not impair blood coagulation but the findings on kidney function are conflicting. On the other hand, albumin may reduce endothelial glycocalyx destruction and decrease platelet count during CPB. No large randomized, double-blind, clinical trials have compared albumin solution to crystalloid solution in cardiac surgery.

Methods/design

In this single-center, double-blind, randomized controlled trial comprising 1386 adult cardiac surgery patients, 4% albumin solution will be compared to Ringer’s acetate solution in CPB priming and volume replacement up to 3200 mL during surgery and the first 24 h of intensive care unit stay. The primary efficacy outcome is the number of patients with at least one major adverse event (MAE) during 90 postoperative days (all-cause death, acute myocardial injury, acute heart failure or low output syndrome, resternotomy, stroke, major arrhythmia, major bleeding, infection compromising post-procedural rehabilitation, acute kidney injury). Secondary outcomes are total number of MAEs, incidence of major adverse cardiac events (MACE; cardiac death, acute myocardial injury, acute heart failure, arrhythmia), amount of each type of blood product transfused (red blood cells, fresh frozen plasma, platelets), total fluid balance at the end of the intervention period, total measured blood loss, development of acute kidney injury, days alive without mechanical ventilation in 90 days, days alive outside intensive care unit at 90 days, days alive at home at 90 days, and 90-day mortality.

Discussion

The findings of this study will provide new evidence regarding efficacy and safety of albumin solution in adult patients undergoing cardiac surgery with CPB.

Trial registration

EudraCT (clinicaltrialsregister.eu) 2015–002556-27 Registered 11 Nov 2016 and ClinicalTrials.gov NCT02560519. Registered 25 Sept 2015.

The origin of plasma neutrophil gelatinase-associated lipocalin in cardiac surgery

Background

Acute kidney injury (AKI) is common after heart surgery. Neutrophil gelatinase-associated lipocalin (NGAL) is produced in injured kidney. NGAL has been used as an early plasma biomarker for AKI in patients undergoing heart surgery. Neutrophils contain all isoforms (25-kDa, 45-kDa and 145-kDa) but the kidney produces almost exclusively the 25-kDa isoform of NGAL. We investigated first, whether there is association between NGAL and neutrophil activation, and second whether activated neutrophils are a significant source of circulating NGAL in plasma in patients undergoing cardiac surgery.

Methods

Two separate patient cohorts were studied: 1) the “kinetic cohort” (n = 29) and 2) the “FINNAKI cohort” (n = 306). As NGAL is strictly co-localized with lactoferrin in neutrophils, NGAL and lactoferrin were measured with enzyme-linked immunosorbent assay in all patients. In sixty-one patients of the “FINNAKI cohort” Western blot was used to separate NGAL isoforms according to their molecular size. Mann-Whitney U, Kruskal-Wallis H, Pearson’s and Spearman’s tests were used as appropriate.

Results

There was strong intraoperative association between NGAL and lactoferrin at all four time-points in the “kinetic cohort”. In the “FINNAKI cohort”, NGAL and lactoferrin concentrations correlated preoperatively (R = 0.59, p < 0.001) and at admission to the intensive care unit (R = 0.69, p < 0.001). At admission to intensive care unit, concentrations of NGAL and lactoferrin were higher in AKI than in non-AKI patients (NGAL: p < 0.001; lactoferrin: p < 0.029). In Western blot analyses, neutrophil specific 45-kDa isoform (median 41% [IQR 33.3–53.1]) and mostly neutrophil derived 145-kDa isoform (median 53.5% [IQR 44.0–64.9%]) together represented over 90% of total NGAL in plasma. Potentially kidney derived NGAL isoform (25-kDa) accounted for only 0.9% (IQR 0.3 – 3.0%) of total NGAL in plasma. There were no statistically significant differences in the distribution of NGAL isomers between AKI and non-AKI patients.

Conclusions

Plasma NGAL during cardiac surgery is associated with neutrophil activation. Based on molecular size, the majority of circulating NGAL is derived from neutrophils. Neutrophil activation is a confounding factor when interpreting increased plasma NGAL in cardiac surgery.

Epicardial delivery of autologous atrial appendage micrografts during coronary artery bypass surgery-safety and feasibility study

Background

The atrial appendages are a tissue reservoir for cardiac stem cells. During on-pump coronary artery bypass graft (CABG) surgery, part of the right atrial appendage can be excised upon insertion of the right atrial cannula of the heart-lung machine. In the operating room, the removed tissue can be easily cut into micrografts for transplantation. This trial aims to assess the safety and feasibility of epicardial transplantation of atrial appendage micrografts in patients undergoing CABG surgery.

Methods/design

Autologous cardiac micrografts are made from leftover right atrial appendage during CABG of 6 patients. Atrial appendage is mechanically processed to micrografts consisting of atrial appendage-derived cells (AADCs) and their extracellular matrix (ECM). The micrografts are epicardially transplanted in a fibrin gel and covered with a tissue-engineered ECM sheet. Parameters including echocardiography—reflecting cardiac insufficiency—are studied pre- and post-operatively as well as at 3 and 6 months of the follow-up. Cardiac functional magnetic resonance imaging is performed preoperatively and at 6-month follow-up. The primary outcome measures are patient safety in terms of hemodynamic and cardiac function over time and feasibility of therapy administration in a clinical setting. Secondary outcome measures are left ventricular wall thickness, change in the amount of myocardial scar tissue, changes in left ventricular ejection fraction, plasma concentrations of N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels, New York Heart Association class, days in hospital, and changes in the quality of life. Twenty patients undergoing routine CAGB surgery will be recruited to serve as a control group.

Discussion

This study aims to address the surgical feasibility and patient safety of epicardially delivered atrial appendage micrografts during CABG surgery. Delivery of autologous micrografts and AADCs has potential applications for cell and cell-based gene therapies.

Trial registration

ClinicalTrials.gov Identifier: NCT02672163. Date of registration: 02.02.2016

Cost-utility of venoarterial extracorporeal membrane oxygenation in cardiogenic shock and cardiac arrest

BACKGROUND

The use of venoarterial extracorporeal membrane oxygenation in cardiogenic shock keeps increasing, but its cost-utility is unknown.

METHODS

We studied retrospectively the cost-utility of venoarterial extracorporeal membrane oxygenation in a five-year cohort of consequent patients treated due to refractory cardiogenic shock or cardiac arrest in a transplant centre in 2013-2017. In our centre, venoarterial extracorporeal membrane oxygenation is considered for all cardiogenic shock patients potentially eligible for heart transplantation, and for selected postcardiotomy patients. We assessed the costs of the index hospitalization and of the one-year hospital costs, and the patients' health-related quality of life (response rate 71.7%). Based on the data and the population-based life expectancies, we calculated the amount and the costs of quality-adjusted life years gained both without discount and with an annual discount of 3.5%.

RESULTS

The cohort included 102 patients (78 cardiogenic shock; 24 cardiac arrest) of whom 67 (65.7%) survived to discharge and 66 (64.7%) to one year. The effective costs per one hospital survivor were 242,303€. Median in-hospital costs of the index hospitalization per patient were 129,967€ (interquartile range 150,340€). Mean predicted number of quality-adjusted life years gained by the treatment was 20.9 (standard deviation 9.7) without discount, and the median cost per quality-adjusted life year was 7474€ (interquartile range 10,973€). With the annual discount of 3.5%, 13.0 (standard deviation 4.8) quality-adjusted life years were gained with the cost of 12,642€ per quality-adjusted life year (interquartile range 15,059€).

CONCLUSIONS

We found the use of venoarterial extracorporeal membrane oxygenation in refractory cardiogenic shock and cardiac arrest justified from the cost-utility point of view in a transplant centre setting.

Albumin Infusion and Blood Loss After Cardiac Surgery

BACKGROUND

In the recent ALBICS (ALBumin In Cardiac Surgery) trial, 4% albumin used for cardiopulmonary bypass priming and volume replacement increased perioperative bleeding compared with Ringer acetate. In the present exploratory study, albumin-related bleeding was further characterized.

METHODS

Ringer acetate and 4% albumin were compared in a randomized, double-blinded fashion in 1386 on-pump adult cardiac surgery patients. The study end points for bleeding were the Universal Definition of Perioperative Bleeding (UDPB) class and its components.

RESULTS

The UDPB bleeding grades were higher in the albumin group than the Ringer group: "insignificant" (albumin vs Ringer: 47.5% vs 62.9%), "mild" (12.7% vs 8.9%), "moderate" (28.7% vs 24.4%), "severe" (10.2% vs 3.2%), and "massive" (0.9% vs. 0.6%; P < .001). Patients in the albumin group received red blood cells (45.2% vs 31.5%; odds ratio [OR], 1.80; 95% CI, 1.44-2.24; P < .001), platelets (33.3% vs 21.8%; OR, 1.79; 95% CI, 1.41-2.28; P < .001), and fibrinogen (5.6% vs 2.6%; OR, 2.24; 95% CI, 1.27-3.95; P < .05), and underwent resternotomy (5.3% vs 1.9%; OR, 2.95; 95% CI, 1.55-5.60, P < .001) more often than patients in the Ringer group. The strongest predictors of bleeding were albumin group allocation (OR, 2.18; 95% CI, 1.74-2.74) and complex (OR, 2.61; 95% CI, 2.02-3.37) and urgent surgery (OR, 1.63; 95% CI, 1.26-2.13). In interaction analysis, the effect of albumin on the risk of bleeding was stronger in patients on preoperative acetylsalicylic acid.

CONCLUSIONS

Perioperative administration of albumin, compared with Ringer's acetate, resulted in increased blood loss and higher UDBP class. The magnitude of this effect was similar to the complexity and urgency of the surgery.

Epicardial Transplantation of Autologous Cardiac Micrografts During Coronary Artery Bypass Surgery

Background: Cardio-regenerative cell therapies offer additional biologic support to coronary artery bypass surgery (CABG) and are aimed at functionally repairing the myocardium that suffers from or is damaged by ischemia. This non-randomized open-label study assessed the safety and feasibility of epicardial transplantation of atrial appendage micrografts (AAMs) in patients undergoing CABG surgery. Methods: Twelve consecutive patients destined for CABG surgery were included in the study. Six patients received AAMs during their operation and six patients were CABG-operated without AAMs transplantation. Data from 30 elective CABG patients was collected for a center- and time-matched control group. The AAMs were processed during the operation from a biopsy collected from the right atrial appendage. They were delivered epicardially onto the infarct scar site identified in preoperative late gadolinium enhancement cardiac magnetic resonance imaging (CMRI). The primary outcome measures at the 6-month follow-up were (i) patient safety in terms of hemodynamic and cardiac function over time and (ii) feasibility of therapy administration in a clinical setting. Secondary outcome measures were left ventricular wall thickness, change in myocardial scar tissue volume, changes in left ventricular ejection fraction, plasma concentrations of N-terminal pro-B-type natriuretic peptide levels, NYHA class, number of days in hospital and changes in the quality of life. Results: Epicardial transplantation of AAMs was safe and feasible to be performed during CABG surgery. CMRI demonstrated an increase in viable cardiac tissue at the infarct site in patients receiving AAMs treatment. Conclusions and Relevance: Transplantation of AAMs shows good clinical applicability as performed during cardiac surgery, shows initial therapeutic effect on the myocardium and has the potential to serve as a delivery platform for cardiac gene therapies. Trial Registration:ClinicalTrials.gov, identifier: NCT02672163.

Noninvasive Neuromonitoring of Hypothermic Circulatory Arrest in Aortic Surgery

BACKGROUND AND AIMS

Circulatory arrest carries a high risk of neurological damage, but modern monitoring methods lack reliability, and is susceptible to the generalized effects of both anesthesia and hypothermia. The objective of this prospective, explorative study was to research promising, reliable, and noninvasive methods of neuromonitoring, capable of predicting neurological outcome after hypothermic circulatory arrest.

MATERIALS AND METHODS

Thirty patients undergoing hypothermic circulatory arrest during surgery of the thoracic aorta were recruited in a single center and over the course of 4 years. Neuromonitoring was performed with a four-channel electroencephalogram montage and a near-infrared spectroscopy monitor. All data were tested off-line against primary neurological outcome, which was poor if the patient suffered a significant neurological complication (stroke, operative death).

RESULTS

A poor primary neurological outcome seen in 10 (33%) patients. A majority (63%) of the cases were emergency surgery, and thus, no neurological baseline evaluation was possible. The frontal hemispheric asymmetry of electroencephalogram, as measured by the brain symmetry index, predicted primary neurological outcome with a sensitivity of 79 (interquartile range; 62%-88%) and specificity of 71 (interquartile range; 61%-84%) during the first 6 h after end of circulatory arrest.

CONCLUSION

The hemispheric asymmetry of frontal electroencephalogram is inherently resistant to generalized dampening effects and is predictive of primary neurological outcome. The brain symmetry index provides an easy-to-use, noninvasive neuromonitoring method for surgery of the thoracic aorta and postoperative intensive care.

Prevalence and impact of hazardous alcohol use in intensive care cohort: A multicenter, register-based study

BACKGROUND

Reports of the prevalence and impact of hazardous alcohol use among intensive care unit (ICU) patients are contradictory. We aimed to study the prevalence of hazardous alcohol use among ICU patients and its association with ICU length of stay (LOS) and mortality.

METHODS

Finnish ICUs have been using the Alcohol Use Disorder Identification Test-Consumption (AUDIT-C) to evaluate and record patients' alcohol use into the Finnish Intensive Care Consortium's Database (FICC). We retrieved data from the FICC from a 3-month period. We excluded data from centers with an AUDIT-C recording rate of less than 70% of admissions. We defined hazardous alcohol use as a score of 5 or more for women and 6 or more for men from a maximum score of 12 points.

RESULTS

Two thousand forty-five patients were treated in the 10 centers with an AUDIT-C recording rate of 70% or higher. AUDIT-C was available for 1576 (77%) patients and indicated hazardous alcohol use for 334 (21%) patients who were more often younger (median age 55 [interquartile range 42-65] vs 67 [57-74] [P < .001]) and male (78.1% vs 61.3% [P < .001]) compared to other patients. We found no difference in LOS or hospital mortality between hazardous and non-hazardous alcohol users. Among the non-abstinent, risk of death within a year increased with increasing AUDIT-C scores adjusted odds ratio 1.077 (95% confidence interval, 1.006-1.152) per point.

CONCLUSION

The prevalence of hazardous alcohol use in Finnish ICUs was 21%. Patients with hazardous alcohol use were more often younger and male compared with non-hazardous alcohol users.

Albumin and Cardioprotection in On-Pump Cardiac Surgery-A Post Hoc Analysis of a Randomized Trial

OBJECTIVES

To study the quantitative potency of plasma albumin on cardioprotection in terms of creatinine kinase-myocardial band mass (CK-MBm) in on-pump cardiac surgery.

DESIGN

Post hoc analysis of a double-blinded randomized clinical trial.

SETTING

Single-center study in the Helsinki University Hospital.

PARTICIPANTS

A total of 1,386 adult on-pump cardiac surgical patients.

INTERVENTION

Administration of 4% albumin (n = 693) or Ringers acetate (n = 693) for cardiopulmonary bypass priming and volume replacement intraoperatively and postoperatively during the first 24 hours.

MEASUREMENTS AND MAIN RESULTS

Albumin concentration was measured preoperatively and intraoperatively (after protamine administration), and CK-MBm on the first postoperative morning. Multivariate linear regression analyses were measured in the whole cohort and the Ringer group. Plasma albumin concentration did not differ between the groups preoperatively (Ringer v albumin: 38.3 ± 5.0 g/L v 38.6 ± 4.5 g/L; p = 0.171) but differed intraoperatively (29.5 ± 5.2 g/L v 41.5 ± 6.0 g/L; p < 0.001). Creatinine kinase-myocardial band mass was higher in the Ringer (32.0 ± 34.8 μg/L) than in the albumin group (24.3 ± 33.0 μg/L) (p < 0.001). Aortic cross-clamping time associated with CK-MBm in the whole cohort (standardized β = 0.376 [95% CI 0.315-0.437], p < 0.001) and the Ringer group (β = 0.363 [0.273-0.452]; p < 0.001). Albumin administration in the whole cohort (β = -0.156 [-0.201 to -0.111]; p < 0.001) and high intraoperative albumin concentration in the Ringer group (β = -0.07 [-0.140 to -0.003]; p = 0.04) associated with reduced CK-MBm. Compared with ischemia-induced increase in CK-MBm, albumin's potency to reduce CK-MBm was 41% in the whole cohort (β-value ratio of -0.156/0.376) and 19% in the Ringer group (β-value ratio of -0.07/0.363).

CONCLUSION

Both endogenous and exogenous albumin appear to be cardioprotective regarding CK-MBm release in on-pump cardiac surgery.

Hazardous alcohol consumption and perioperative complications in a cardiac surgery patient. A retrospective study

BACKGROUND

We investigated the prevalence and effects of hazardous alcohol consumption on perioperative complications in cardiac surgery patients. Preoperative hazardous alcohol consumption has been associated with an increased risk of postoperative complications in noncardiac patient populations.

METHODS

We retrospectively collected data from the Finnish Intensive Care Consortium database and electronic patient records on all cardiac surgery patients treated in the intensive care units (ICUs) of Helsinki University Hospital (n = 919) during 2017. Data on preoperative alcohol consumption were routinely collected using the alcohol use disorder identification test consumption (AUDIT-C) questionnaire. We analyzed perioperative data and outcomes for any associations with hazardous alcohol consumption. Outcome measures were length of stay in the ICU, re-admissions to ICU, bleeding and infectious complications, and incidence of postoperative arrhythmias.

RESULTS

AUDIT-C scores were available for 758 (82.5%) patients, of whom 107 (14.1%) fulfilled the criteria for hazardous alcohol consumption (AUDIT-C score of 5/12 or higher for women and 6/12 or higher for men). Patients with hazardous alcohol consumption were younger, median age 59 (IQR 52.0-67.0) vs. 69.0 (IQR 63.0-74.0), p < .001, and more often men 93.5% vs. 71.9%, p < .001 than other patients and had an increased risk for ICU re-admissions [adjusted OR (aOR) 4.37 (95% CI, 1.60-11.95)] and severe postoperative infections aOR 3.26 (95% CI, 1.42-7.54).

CONCLUSION

Cardiac surgery patients with a history of hazardous alcohol consumption are younger than other patients and are predominantly men. Hazardous alcohol consumption is associated with an increased risk of severe postoperative infections and ICU re-admissions.

Comparison of 4% Albumin and Ringer's Acetate on Hemodynamics in On-pump Cardiac Surgery: An Exploratory Analysis of a Randomized Clinical Trial

OBJECTIVES

Compare hemodynamics between 4% albumin and Ringer's acetate.

DESIGN

Exploratory analysis of the double-blind randomized ALBumin In Cardiac Surgery trial.

SETTING

Single-center study in Helsinki University Hospital.

PARTICIPANTS

We included 1,386 on-pump cardiac surgical patients.

INTERVENTION

We used 4% albumin or Ringer's acetate administration for cardiopulmonary bypass priming, volume replacement intraoperatively and 24 hours postoperatively.

MEASUREMENTS AND MAIN RESULTS

Hypotension (time-weighted average mean arterial pressure of <65 mmHg) and hyperlactatemia (time-weighted average blood lactate of >2 mmol/L) incidences were compared between trial groups in the operating room (OR), and early (0-6 hours) and late (6-24 hours) postoperatively. Associations of hypotension and hyperlactatemia with the ALBumin In Cardiac Surgery primary outcome (≥1 major adverse event [MAE]) were studied. In these time intervals, hypotension occurred in 118, 48, and 17 patients, and hyperlactatemia in 313, 131, and 83 patients. Hypotension and hyperlactatemia associated with MAE occurrence. Hypotension did not differ between the groups (albumin vs Ringer's: OR, 8.8% vs 8.5%; early postoperatively, 2.7% vs 4.2%; late postoperatively, 1.2% vs 1.3%; all p > 0.05). In the albumin group, hyperlactatemia was less frequent late postoperatively (2.9% vs 9.1%; p < 0.001), but not earlier (OR, 22.4% vs 23.6%; early postoperatively, 7.9% vs 11.0%; both p > 0.025 after Bonferroni-Holm correction).

CONCLUSIONS

In on-pump cardiac surgery, hypotension and hyperlactatemia are associated with the occurrence of ≥1 MAE. Compared with Ringer's acetate, albumin did not decrease hypotension and decreased hyperlactatemia only late postoperatively. Albumin's modest hemodynamic effect is concordant with the finding of no difference in MAEs between albumin and Ringer's acetate in the ALBumin In Cardiac Surgery trial.