Intraoperative Administration of 4-Factor Prothrombin Complex Concentrate Reduces Blood Requirements in Cardiac Transplantation

An ISHLT consensus statement on strategies to prevent and manage hemocompatibility related adverse events in patients with a durable, continuous-flow ventricular assist device

Life expectancy of patients with a durable, continuous-flow left ventricular assist device (CF-LVAD) continues to increase. Despite significant improvements in the delivery of care for patients with these devices, hemocompatability-related adverse events (HRAEs) are still a concern and contribute to significant morbility and mortality when they occur. As such, dissemination of current best evidence and practices is of critical importance. This ISHLT Consensus Statement is a summative assessment of the current literature on prevention and management of HRAEs through optimal management of oral anticoagulant and antiplatelet medications, parenteral anticoagulant medications, management of patients at high risk for HRAEs and those experiencing thrombotic or bleeding events, and device management outside of antithrombotic medications. This document is intended to assist clinicians caring for patients with a CF-LVAD provide the best care possible with respect to prevention and management of these events.

A wide scope, pan-comparative, systematic meta-analysis of the efficacy of prophylactic strategies for cardiac surgery-associated acute kidney injury

Acute kidney injury (AKI) is the most common complication of cardiac surgery. Cardiac surgery-associated AKI (CSA-AKI) is caused by systemic and renal hemodynamic impairment and parenchymal injury. Prophylaxis of CSA-AKI remains an unmet priority, for which preventive strategies based on drug therapies, hydration procedures, and remote ischemic preconditioning (RIPC) have been tested in pre-clinical and clinical studies, with variable success. Contradicting reports and scarce or insufficiently pondered information have blurred conclusions. Therefore, with an aim to contribute to consolidating the available information, we carried out a wide scope, pan-comparative meta-analysis including the accessible information about the most relevant nephroprotective approaches assayed. After a thorough examination of 1892 documents retrieved from PubMed and Web of Science, 150 studies were used for the meta-analysis. Individual odds ratios of efficacy at reducing AKI incidence, need for dialysis, and plasma creatinine elevation were obtained for each alleged protectant. Also, the combined class effect of drug families and protective strategies was also meta-analyzed. Our results show that no drug family or procedure affords substantial protection against CSA-AKI. Only, a mild but significant reduction in the incidence of CSA-AKI by preemptive treatment with dopaminergic and adrenergic drugs, vasodilators, and the RIPC technique. The integrated analysis suggests that single-drug approaches are unlikely to cope with the variety of individual pathophysiological scenarios potentially underlying CSA-AKI. Accordingly, a theragnostic approach involving the etiopathological diagnosis of kidney frailty is necessary to guide research towards the development of pharmacological combinations concomitantly and effectively addressing the key mechanisms of CSA-AKI.

Trends in the Use of Recombinant Activated Factor VII and Prothrombin Complex Concentrate in Heart Transplant Patients in Virginia

OBJECTIVES

To explore trends in intraoperative procoagulant factor concentrate use in patients undergoing heart transplantation (HTx) in Virginia. Secondarily, to evaluate their association with postoperative thrombosis.

DESIGN

Patients who underwent HTx were identified using a statewide database. Trends in off-label recombinant activated factor VII (rFVIIa) use and on-label and off-label prothrombin complex concentrate (PCC) use were tested using the Mantel-Haenszel test. Multivariate logistic regression was used to test for an association between procoagulant factor concentrate administration and thrombosis.

SETTING

Virginia hospitals performing HTx.

PARTICIPANTS

Adults undergoing HTx between 2012 and 2022.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Among 899 patients who required HTx, 100 (11.1%) received off-label rFVIIa, 69 (7.7%) received on-label PCC, and 80 (8.9%) received off-label PCC. There was a downward trend in the use of rFVIIa over the 10-year period (p = 0.04). There was no trend in on-label PCC use (p = 0.12); however, there was an increase in off-label PCC use (p < 0.001). Patients who received rFVIIa were transfused more and had longer cardiopulmonary bypass time (p < 0.001). Receipt of rFVIIa was associated with increased thrombotic risk (odds ratio [OR] 1.92; 95% CI 1.12-3.29; p = 0.02), whereas on-label and off-label PCC use had no association with thrombosis (OR 0.98, 95% CI 0.49-1.96, p = 0.96 for on-label use; and OR 0.61, 95% CI 0.29-1.30, p = 0.20 for off-label use).

CONCLUSIONS

Use of rFVIIa in HTx decreased over the past decade, whereas off-label PCC use increased. Receipt of rFVIIa was associated with thrombosis; however, patients who received rFVIIa were more severely ill, and risk adjustment may have been incomplete.

Dosing, Monitoring, Blood Product Utilization, and Thromboembolic Complications of Four-Factor Prothrombin Complex Concentrate as Part of an Institutional Protocol in Pediatric Cardiac Surgery: A Retrospective Cohort Study

Pediatric cardiac surgery patients are predisposed to blood loss. Blood product administration can lead to complications. Prothrombin complex concentrates (PCCs) offer potential advantages of factor composition, small volume, decreased immunogenicity/infectious risks, and accessibility. The objective of this study was to describe dosing, monitoring, blood product utilization, and thromboembolic complications of administering four-factor PCC (4F-PCC) in pediatric cardiac surgery. We performed a retrospective review of patients aged <18 years undergoing cardiac surgery from June 2020 to May 2022 (inclusive) who received 4F-PCC. Outcomes of interest included 4F-PCC dosing (units/kg) and number of doses administered, chest tube output, blood product administration, donor exposure, length of stay, and thromboembolic events. Eighty-six patients met eligibility criteria. The median (range) age and weight were 0.37 (0.01-16.3) years and 5.3 (1.6-98) kg, respectively. Median (range) total 4F-PCC dose per patient was 25 (9.2-50) units/kg, with 6 patients (7%) receiving a total of two doses. Median (range) 24-hour postoperative packed red blood cells, platelet, plasma, and cryoprecipitate administration volumes were 0 (0-2.57) mL/kg/24 h, 0 (0-1.09), 0 (0-2.64), and 0 (0-0.28 mL/kg/24 h), respectively. Median (range) length of stay and 24-hour postoperative chest tube output were 10 (6-26) days and 1.1 (0.1-4.2) mL/kg/h, respectively. Two (2%) patients experienced a thromboembolic event within 30 days of 4F-PCC administration. These retrospective findings suggest no worsening of hemostatic parameters, a mild median improvement in fibrinogen, low blood product utilization, and low thromboembolism rates following 4F-PCC use in pediatric cardiac surgery.

A Review of Direct-acting Oral Anticoagulants and Their Use in Solid Organ Transplantation

Direct-acting oral anticoagulant (DOAC) use has increased dramatically since their introduction because of the growing evidence of proven efficacy and enhanced safety compared with warfarin and the low-molecular-weight heparins in the general population. Unfortunately, there is a dearth of quality data regarding the safety and efficacy of the DOACs in patients awaiting organ transplant and those who received a solid organ transplant. This review aims to evaluate the available literature and considerations regarding anticoagulation use in transplant recipients, focusing on preoperative, perioperative, and postoperative DOAC use.

Intraoperative prothrombin complex concentrate administration and outcomes in patients undergoing left ventricular assist device implantation

Prothrombin complex concentrate (PCC) administration has increased among cardiac surgery patients in recent years; however, use in LVAD implantation/exchange is not widespread due to the fear of thrombotic complications. The purpose of this study was to compare the clinical outcomes of patients undergoing LVAD implantation/exchange with intraoperative PCC administration versus traditional transfusion practices alone. Adult LVAD implants/exchanges at our institution between 2015 and 2018 were included. Patients were categorized as receiving intraoperative PCC or no-PCC (traditional). The primary outcome was the need for allogenic transfusion and transfusion volume at 48 hours after initial intensive care unit (ICU) admission. Secondary outcomes included metrics of morbidity and mortality. A total of 160 patients (39 PCC, 121 traditional) were analyzed. In unadjusted analysis, patients in the PCC group received lower intraoperative transfusion volumes compared to the traditional group although not statistically significant (1464 mL [IQR 796, 4876] vs. 2568 mL [IQR 1292, 3606]; P value .37). In the fully adjusted analysis, patients in the PCC group had increased odds of transfusion within 48 hours of ICU admission (OR 4.06, 95% CI: 1.35-12.20; P < .01); however, there was no significant difference in transfusion volumes (P = .09). Patients receiving PCCs had higher incidence of deep vein thrombosis (10.3% vs. 0%; P  < .01) and 30-day mortality (17.9% vs. 4.1%; P < .01). LVAD pump thrombosis occurred in 2.6% versus 0.8% in the PCC and traditional groups, respectively; P = .98. Patients undergoing LVAD implantation and exchange represent a complex surgical cohort. The results of this study suggest that the intraoperative PCC use during LVAD implant/exchange was associated with reduced intraoperative transfusions. Intraoperative PCC use was, however, associated with higher odds of postoperative transfusion, although transfusion volumes were not significantly different. While the deep vein thrombosis and 30-day mortality rates were higher in the PCC group, these results are likely related to the degree of surgical and patient complexity rather than PCC use itself. Further studies are needed to assess PCC use in this surgical cohort.

Prothrombin Complex Concentrate for Warfarin Reversal in Patients with Continuous-Flow Left Ventricular Assist Devices: A Narrative Review

Durable left ventricular assist device (LVAD) recipients require long-term anticoagulation to prevent thromboembolic complications. Their management is complicated by the risk of bleeding, which may require rapid anticoagulation reversal. We conducted a narrative review of data published from January 2007 to September 2018, analyzing anticoagulation reversal strategies in patients with durable, continuous-flow LVADs. The aim of this review is to provide guidance for reversal strategies in patients with LVADs experiencing bleeding complications or needing urgent surgical procedures, incorporating four-factor prothrombin complex concentrate (4F-PCC). Most data were from small, retrospective studies. Data for 4F-PCC use were more robust for heart transplant than for other surgical procedures or bleeding management. In patients undergoing heart transplant, 4F-PCC reversed warfarin more rapidly and reduced total blood product use versus other reversal strategies. Most surgical procedures were conducted without excess bleeding when utilizing 4F-PCCs. Time to warfarin reversal was shorter when managing intracranial hemorrhage with 4F-PCC. No differences in thromboembolic rates between 4F-PCC and control groups were observed. Overall, the use of 4F-PCC resulted in more rapid and predictable warfarin reversal in LVAD patients with no apparent risk of thromboembolism. Well-designed, larger prospective trials are required to better define 4F-PCC use in patients with LVADs.

A European consensus statement on the use of four-factor prothrombin complex concentrate for cardiac and non-cardiac surgical patients

Modern four-factor prothrombin complex concentrate was designed originally for rapid targeted replacement of the coagulation factors II, VII, IX and X. Dosing strategies for the approved indication of vitamin K antagonist-related bleeding vary greatly. They include INR and bodyweight-related protocols as well as fixed dose regimens. Particularly in the massively bleeding trauma and cardiac surgery patient, four-factor prothrombin complex concentrate is used increasingly for haemostatic resuscitation. Members of the Transfusion and Haemostasis Subcommittee of the European Association of Cardiothoracic Anaesthesiology performed a systematic literature review on four-factor prothrombin complex concentrate. The available evidence has been summarised for dosing, efficacy, drug safety and monitoring strategies in different scenarios. Whereas there is evidence for the efficacy of four-factor prothrombin concentrate for a variety of bleeding scenarios, convincing safety data are clearly missing. In the massively bleeding patient with coagulopathy, our group recommends the administration of an initial bolus of 25 IU.kg^-1 . This applies for: the acute reversal of vitamin K antagonist therapy; haemostatic resuscitation, particularly in trauma; and the reversal of direct oral anticoagulants when no specific antidote is available. In patients with a high risk for thromboembolic complications, e.g. cardiac surgery, the administration of an initial half-dose bolus (12.5 IU.kg^-1 ) should be considered. A second bolus may be indicated if coagulopathy and microvascular bleeding persists and other reasons for bleeding are largely ruled out. Tissue-factor-activated, factor VII-dependent and heparin insensitive point-of-care tests may be used for peri-operative monitoring and guiding of prothrombin complex concentrate therapy.

The use of prothrombin complex concentrate as a warfarin reversal agent in pediatric patients undergoing orthotopic heart transplantation

BACKGROUND

Patients supported with a ventricular assist device are predisposed to severe bleeding at the time of orthotopic heart transplant due to several risk factors including anticoagulation with vitamin K antagonists. Kcentra, a four-factor prothrombin complex concentrate, has been approved by the FDA for warfarin reversal in adults prior to urgent surgery. There is a lack of published data on the preoperative use of four-factor prothrombin complex concentrates in pediatric patients undergoing cardiacsurgery.

METHODS

This is a single-center retrospective analysis of pediatric patients with a continuous-flow ventricular assist device who underwent heart transplant, comparing patients who received Kcentra for anticoagulation reversal with a historical patient cohort who did not. Consecutive patients from January 2013 to December 2017 were analyzed. The primary outcome was volume of blood product transfusion prior to cardiopulmonary bypass initiation. Secondary outcomes include blood product transfusion after cardiopulmonary bypass intraoperatively and up to 24 hours postoperatively, chest tube output within 24 hours of surgery, time to extubation, incidence of thromboembolism, and post-transplant length ofstay.

RESULTS

From 2013 to 2017, 31 patients with continuous-flow ventricular assist devices underwent heart transplant, with 27 patients included in the analysis. Fifteen patients received Kcentra compared with 12 patients who received fresh-frozen plasma for anticoagulation reversal. Compared with the control group, patients who received Kcentra had less packed red blood cells, fresh-frozen plasma, and platelets transfused prior to cardiopulmonary bypass initiation. The Kcentra group also received less packed red blood cells on bypass and less packed red blood cells after cardiopulmonary bypass termination. There were no differences in chest tube output, time to extubation, intensive care unit length of stay, or overall hospital length of stay. Neither group had thromboembolic complications detected during the first seven postoperative days.

CONCLUSION

This small retrospective study indicates that preoperative warfarin reversal with Kcentra reduces blood product exposure in pediatric patients with ventricular assist devices undergoing heart transplant.

Acute Kidney Injury in Patients Undergoing Cardiac Transplantation: A Meta-Analysis

Background: Acute kidney injury (AKI) is a common complication following solid-organ transplantation. However, the epidemiology of AKI and mortality risk of AKI among patients undergoing cardiac transplantation is not uniformly described. We conducted this study to assess the incidence of AKI and mortality risk of AKI in adult patients after cardiac transplantation. Methods: A systematic review of EMBASE, MEDLINE, and Cochrane Databases was performed until June 2019 to identify studies evaluating the incidence of AKI (by standard AKI definitions), AKI requiring renal replacement therapy (RRT), and mortality risk of AKI in patients undergoing cardiac transplantation. Pooled AKI incidence and mortality risk from the included studies were consolidated by random-effects model. The protocol for this study is registered with PROSPERO (no. CRD42019134577). Results: 27 cohort studies with 137,201 patients undergoing cardiac transplantation were identified. Pooled estimated incidence of AKI and AKI requiring RRT was 47.1% (95% CI: 37.6-56.7%) and 11.8% (95% CI: 7.2-18.8%), respectively. The pooled ORs of hospital mortality and/or 90-day mortality among patients undergoing cardiac transplantation with AKI and AKI requiring RRT were 3.46 (95% CI, 2.40-4.97) and 13.05 (95% CI, 6.89-24.70), respectively. The pooled ORs of 1-year mortality among patients with AKI and AKI requiring RRT were 2.26 (95% CI, 1.56-3.26) and 3.89 (95% CI, 2.49-6.08), respectively. Conclusion: Among patients undergoing cardiac transplantation, the incidence of AKI and severe AKI requiring RRT are 47.1% and 11.8%, respectively. AKI post cardiac transplantation is associated with reduced short term and 1-year patient survival.

Prothrombin Complex Concentrates for Perioperative Vitamin K Antagonist and Non-vitamin K Anticoagulant Reversal

Vitamin K antagonist therapy is associated with an increased bleeding risk, and clinicians often reverse anticoagulation in patients who require emergency surgical procedures. Current guidelines for rapid anticoagulation reversal for emergency surgery recommend four-factor prothrombin complex concentrate and vitamin K coadministration. The authors reviewed the current evidence on prothrombin complex concentrate treatment for vitamin K antagonist reversal in the perioperative setting, focusing on comparative studies and in the context of intracranial hemorrhage and cardiac surgery. The authors searched Cochrane Library and PubMed between January 2008 and December 2017 and retrieved 423 English-language papers, which they then screened for relevance to the perioperative setting; they identified 36 papers to include in this review. Prothrombin complex concentrate therapy was consistently shown to reduce international normalized ratio rapidly and control bleeding effectively. In comparative studies with plasma, prothrombin complex concentrate use was associated with a greater proportion of patients achieving target international normalized ratios rapidly, with improved hemostasis. No differences in thromboembolic event rates were seen between prothrombin complex concentrate and plasma, with prothrombin complex concentrate also demonstrating a lower risk of fluid overload events. Overall, the studies the authors reviewed support current recommendations favoring prothrombin complex concentrate therapy in patients requiring vitamin K antagonist reversal before emergency surgery.

Noteworthy Literature Published in 2018 for Thoracic Organ Transplantation

Publications of note from 2018 are reviewed for the cardiothoracic transplant anesthesiologist. Strategies to expand the availability of donor organs were highlighted, including improved donor management, accumulating experience with increased-risk donors, ex vivo perfusion techniques, and donation after cardiac death. A number of reports examined posttransplant outcomes, including outcomes other than mortality, with new data-driven risk models. Use of extracorporeal support in cardiothoracic transplantation was a prominent theme. Major changes in adult heart allocation criteria were implemented, aiming to improve objectivity and transparency in the listing process. Frailty and prehabilitation emerged as targets of comprehensive perioperative risk mitigation programs.

Blood, blood components, plasma, and plasma products

This review of 2018 publications identifies side effects of blood, blood components, and plasma products. In addition, albumin, blood transfusion (erythrocytes, granulocytes, and platelets), blood substitutes (hemoglobin-based oxygen carriers), plasma products (alpha1-antitrypsin, C1 esterase inhibitor concentrate, cryoprecipitate, and fresh frozen plasma), plasma substitutes (etherified starches, and gelatin), globulins (intravenous immunoglobulin, subcutaneous immunoglobulin, and anti-D immunoglobulin), coagulation proteins (factor I, factor II, factor VIIa, factor VIII, factor IX, prothrombin complex concentrate, antithrombin III, and von Willebrand factor/factor VIII concentrates), erythropoietin and derivatives, thrombopoietin and receptor agonists, transmission of infectious agents through blood donation, and stem cells are reviewed. This chapter informs the reader about newly recognized and published data in the blood product domain.