Acute normovolemic hemodilution in cardiac surgery: rationale and design of a multicenter randomized trial

BACKGROUND: Minimizing the use of blood component can reduce known and unknown blood transfusion risks, preserve blood bank resources, and decrease healthcare costs. Red Blood Cell (RBC) transfusion is common after cardiac surgery and associated with adverse perioperative outcomes, including mortality. Acute normovolemic hemodilution (ANH) may reduce bleeding and the need for blood product transfusion after cardiac surgery. However, its blood-saving effect and impact on major outcomes remain uncertain. METHODS: This is a single-blinded, multinational, pragmatic, randomized controlled trial with a 1:1 allocation ratio conducted in Tertiary and University hospitals. The study is designed to enroll patients scheduled for elective cardiac surgery with planned cardiopulmonary bypass (CPB). Patients are randomized to receive ANH before CPB or the best available treatment without ANH. We identified an ANH volume of at least 650 mL as the critical threshold for clinically relevant benefits. Larger ANH volumes, however, are allowed and tailored to the patient's characteristics and clinical conditions. RESULTS: The primary outcome is the percentage of patients receiving RBCs transfusion from randomization until hospital discharge, which we hypothesize will be reduced from 35% to 28% with ANH. Secondary outcomes are all-cause 30-day mortality, acute kidney injury, bleeding complications, and ischemic complications. CONCLUSION: The trial is designed to determine whether ANH can safely reduce RBC transfusion after elective cardiac surgery with CPB. STUDY Registration: This trial was registered on ClinicalTrials.gov in April 2019 with the trial identification number NCT03913481.

Effect of volatile anesthetics on myocardial infarction after coronary artery surgery: a post hoc analysis of a randomized trial

OBJECTIVE: To investigate the effect of volatile anesthetics on the rates of postoperative myocardial infarction (MI) and cardiac death after coronary artery bypass graft (CABG). DESIGN: A post hoc analysis of a randomized trial. SETTING: Cardiac surgical operating rooms. PARTICIPANTS: Patients undergoing elective, isolated CABG. INTERVENTIONS: Patients were randomized to receive a volatile anesthetic (desflurane, isoflurane, or sevoflurane) or total intravenous anesthesia (TIVA). The primary outcome was hemodynamically relevant MI (MI requiring high-dose inotropic support or prolonged intensive care unit stay) occurring within 48 hours from surgery. The secondary outcome was 1-year death due to cardiac causes. Measurements and main Results: A total of 5,400 patients were enrolled between April 2014 and September 2017 (2,709 patients randomized to the volatile anesthetics group and 2,691 to TIVA). The mean age was 62 ± 8.4 years, and the median baseline ejection fraction was 57% (50-67), without differences between the 2 groups. Patients in the volatile group had a lower incidence of MI with hemodynamic complications both in the per-protocol (14 of 2,530 [0.6%] v 27 of 2,501 [1.1%] in the TIVA group; p = 0.038) and as-treated analyses (16 of 2,708 [0.6%] v 29 of 2,617 [1.1%] in the TIVA group; p = 0.039), but not in the intention-to-treat analysis (17 of 2,663 [0.6%] v 28 of 2,667 [1.0%] in the TIVA group; p = 0.10). Overall, deaths due to cardiac causes were lower in the volatile group (23 of 2,685 [0.9%] v 40 of 2,668 [1.5%] than in the TIVA group; p = 0.03). CONCLUSIONS: An anesthetic regimen, including volatile agents, may be associated with a lower rate of postoperative MI with hemodynamic complication in patients undergoing CABG. Furthermore, it may reduce long-term cardiac mortality.

Volatile Anesthetics versus Total Intravenous Anesthesia for Cardiac Surgery

BACKGROUND: Volatile (inhaled) anesthetic agents have cardioprotective effects, which might improve clinical outcomes in patients undergoing coronary-artery bypass grafting (CABG). METHODS: We conducted a pragmatic, multicenter, single-blind, controlled trial at 36 centers in 13 countries. Patients scheduled to undergo elective CABG were randomly assigned to an intraoperative anesthetic regimen that included a volatile anesthetic (desflurane, isoflurane, or sevoflurane) or to total intravenous anesthesia. The primary outcome was death from any cause at 1 year. RESULTS: A total of 5400 patients were randomly assigned: 2709 to the volatile anesthetics group and 2691 to the total intravenous anesthesia group. On-pump CABG was performed in 64% of patients, with a mean duration of cardiopulmonary bypass of 79 minutes. The two groups were similar with respect to demographic and clinical characteristics at baseline, the duration of cardiopulmonary bypass, and the number of grafts. At the time of the second interim analysis, the data and safety monitoring board advised that the trial should be stopped for futility. No significant difference between the groups with respect to deaths from any cause was seen at 1 year (2.8% in the volatile anesthetics group and 3.0% in the total intravenous anesthesia group; relative risk, 0.94; 95% confidence interval [CI], 0.69 to 1.29; P = 0.71), with data available for 5353 patients (99.1%), or at 30 days (1.4% and 1.3%, respectively; relative risk, 1.11; 95% CI, 0.70 to 1.76), with data available for 5398 patients (99.9%). There were no significant differences between the groups in any of the secondary outcomes or in the incidence of prespecified adverse events, including myocardial infarction. CONCLUSIONS: Among patients undergoing elective CABG, anesthesia with a volatile agent did not result in significantly fewer deaths at 1 year than total intravenous anesthesia. (Funded by the Italian Ministry of Health; MYRIAD ClinicalTrials.gov number, NCT02105610.). (AU)

Effect of Levosimendan on Renal Outcome in Cardiac Surgery Patients With Chronic Kidney Disease and Perioperative Cardiovascular Dysfunction: A Substudy of a Multicenter Randomized Trial.

OBJECTIVE: Acute kidney injury (AKI) occurs frequently after cardiac surgery. Levosimendan might reduce the incidence of AKI in patients undergoing cardiac surgery. The authors investigated whether levosimendan administration could reduce AKI incidence in a high-risk cardiac surgical population. DESIGN: Post hoc analysis of a multicenter randomized trial. SETTING: Cardiac surgery operating rooms and intensive care units of 14 centers in 3 countries. PARTICIPANTS: The study comprised 90 patients who underwent mitral valve surgery with an estimated glomerular filtration rate <60 mL/min/1.73 m2 and perioperative myocardial dysfunction. INTERVENTIONS: Patients were assigned randomly to receive levosimendan (0.025-0.2 µg/kg/min) or placebo in addition to standard inotropic treatment. MEASUREMENTS AND MAIN RESULTS: Forty-six patients were assigned to receive levosimendan and 44 to receive placebo. Postoperative AKI occurred in 14 (30%) patients in the levosimendan group versus 23 (52%) in the placebo group (absolute difference -21.8; 95% confidence interval -41.7 to -1.97; p = 0.035). The incidence of major complications also was lower (18 [39%]) in the levosimendan group versus that in the placebo group (29 [66%]) (absolute difference -26.8 [-46.7 to -6.90]; p = 0.011). A trend toward lower serum creatinine at intensive care unit discharge was observed in the levosimendan group (1.18 [0.99-1.49] mg/dL) versus that in the placebo group (1.39 [1.05-1.76] mg/dL) (95% confidence interval -0.23 [-0.49 to 0.01]; p = 0.07). CONCLUSIONS: Levosimendan may improve renal outcome in cardiac surgery patients with chronic kidney disease undergoing mitral valve surgery who develop perioperative myocardial dysfunction. Results of this exploratory analysis should be investigated in future properly designed randomized controlled trials.

Nonsurgical Strategies to Reduce Mortality in Patients Undergoing Cardiac Surgery: An Updated Consensus Process

OBJECTIVE:A careful choice of perioperative care strategies is pivotal to improve survival in cardiac surgery. However, there is no general agreement or particular attention to which nonsurgical interventions can reduce mortality in this setting. The authors sought to address this issue with a consensus-based approach.DESIGN:A systematic review of the literature followed by a consensus-based voting process.SETTING:A web-based international consensus conference.PARTICIPANTS:More than 400 physicians from 52 countries participated in this web-based consensus conference.INTERVENTIONS:The authors identified all studies published in peer-reviewed journals that reported on interventions with a statistically significant effect on mortality in the setting of cardiac surgery through a systematic Medline/PubMed search and contacts with experts. These studies were discussed during a consensus meeting and those considered eligible for inclusion in this study were voted on by clinicians worldwide.MEASUREMENTS AND MAIN RESULTS:Eleven interventions finally were selected: 10 were shown to reduce mortality (aspirin, glycemic control, high-volume surgeons, prophylactic intra-aortic balloon pump, levosimendan, leuko-depleted red blood cells transfusion, noninvasive ventilation, tranexamic acid, vacuum-assisted closure, and volatile agents), whereas 1 (aprotinin) increased mortality. A significant difference in the percentages of agreement among different countries and a variable gap between agreement and clinical practice were found for most of the interventions.CONCLUSIONS:This updated consensus process identified 11 nonsurgical interventions with possible survival implications for patients undergoing cardiac surgery. This list of interventions may help cardiac anesthesiologists and intensivists worldwide in their daily clinical practice and can contribute to direct future research in the field.

Acute Normovolemic Hemodilution Reduces Allogeneic Red Blood Cell Transfusion in Cardiac Surgery: A Systematic Review and Meta-analysis of Randomized Trials.

BACKGROUND: To better understand the role of acute normovolemic hemodilution (ANH) in a surgical setting with high risk of bleeding, we analyzed all randomized controlled trials (RCTs) in the setting of cardiac surgery that compared ANH with standard intraoperative care. The aim was to assess the incidence of ANH-related number of allogeneic red blood cell units (RBCu) transfused. Secondary outcomes included the rate of allogeneic blood transfusion and estimated total blood loss. METHODS: Twenty-nine RCTs for a total of 2439 patients (1252 patients in the ANH group and 1187 in the control group) were included in our meta-analysis using PubMed/MEDLINE, Cochrane Controlled Trials Register, and EMBASE. RESULTS: Patients in the ANH group received fewer allogeneic RBCu transfusions (mean difference = -0.79; 95% confidence interval [CI], -1.25 to -0.34; P = .001; I = 95.1%). Patients in the ANH group were overall transfused less with allogeneic blood when compared with controls (356/845 [42.1%] in the ANH group versus 491/876 [56.1%] in controls; risk ratio = 0.74; 95% CI, 0.62 to 0.87; P < .0001; I = 72.5%), and they experienced less postoperative blood loss (388 mL in ANH versus 450 mL in control; mean difference = -0.64; 95% CI, -0.97 to -0.31; P < .0001; I = 91.8%). CONCLUSIONS: ANH reduces the number of allogeneic RBCu transfused in the cardiac surgery setting together with a reduction in the rate of patients transfused with allogeneic blood and with a reduction of bleeding.

MortalitY in caRdIAc surgery (MYRIAD): A randomizeD controlled trial of volatile anesthetics. Rationale and design

Objective: There is initial evidence that the use of volatile anesthetics can reduce the postoperative release of cardiac troponin I, the need for inotropic support, and the number of patients requiring prolonged hospitalization following coronary artery bypass graft (CABG) surgery. Nevertheless,small Randomized Controlled Trials have failed to demonstrate a survival advantage. Thus, whethervolatile anesthetics improve the postoperative outcome of cardiac surgical patients remains uncertain. An adequately powered randomized controlled trial appears desirable.Design: Single blinded, international, multicenter randomized controlled trial with 1:1 allocation ratio.Setting: Tertiary and University hospitals.

Randomized evidence for reduction of perioperative mortality: an updated consensus process

Objective: Out of the 230 million patients undergoing major surgical procedure every year, morethan 1 million will die within 30 days. Thus, any nonsurgical interventions that help reduce perioperative mortality might save thousands of lives. We decided to update a previous consensus process to identify all the nonsurgical interventions, supported by randomized evidence, that may help reduce perioperative mortality. Design and Setting: A web-based international consensus conference. Participants: 500 hundred clinicians from 61 countries. Interventions: A systematic literature search was performed to identify published literature aboutnonsurgical interventions, supported by randomized evidence showing a statistically significant impact on mortality. Eligible papers were discussed by a Consensus Conference of experts. The interventions identified by the conference were then submitted to colleagues worldwide through aweb-based survey...