Evidence-based management of anticoagulant therapy: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines

Primary Antiphospholipid Antibody Syndrome Complicated with Cerebellar Hemorrhage and Aortic Dissection: A Case Report

BACKGROUND Antiphospholipid antibody syndrome (APS) is a systemic autoimmune disease associated with arterial and venous thromboembolism and pregnancy complications. There have been several reports of APS with systemic lupus erythematosus (SLE) complicated with aortic dissection. However, none of them has been primary APS, which is APS without SLE. CASE REPORT A 42-year-old woman with primary APS and APS nephropathy on warfarin and aspirin therapy presented with coma due to cerebellar hemorrhage. The effect of warfarin was immediately reversed with prothrombin complex concentrate. We performed emergent evacuation of the hematoma, and her level of consciousness improved to normal on postoperative day (POD) 1. She had acute hypertension on arrival, which was resistant to multiple antihypertensives and was stabilized on POD 3. She also had exacerbation of chronic kidney disease after using contrast and prothrombin concentrate complex, and was on temporary renal replacement therapy from POD 3. Aortic dissection was found accidentally on echocardiography on POD 7, and she was subsequently treated medically. She was transferred to the rehabilitation hospital with mild dysarthria and truncal ataxia on POD 59. CONCLUSIONS We report the first case in the English literature of primary APS complicated with cerebellar hemorrhage and aortic dissection. Acute hypertension following hemorrhage and exacerbation of APS nephropathy likely triggered the dissection of the aortic wall, the integrity of which might have been compromised by longstanding antiphospholipid antibody and vasa vasorum thrombosis.

Development and validation of a web-based electronic application in managing antithrombotic agents in patients undergoing GI endoscopy

BACKGROUND AND AIMS

Antithrombotic therapy among patients undergoing GI procedures is frequently encountered and can impact the procedure and patient outcomes. The American Society for Gastrointestinal Endoscopy (ASGE) guidelines help to manage these medications before endoscopy depending on the patient's clinical status and the type of GI procedure. However, currently there is no readily available electronic tool that can assist in decision-making regarding preprocedural management of these agents. Our aim was to develop an electronic application, endoscopy + aid (ENDOAID), to help manage antithrombotic agents before endoscopy and to perform a validation study to test its accuracy.

METHODS

ENDOAID, a web-based application, was developed using JavaScript software (Oracle Corporation, Redwood Shores, Calif, USA) based on an algorithm to categorize patients and procedures into low and high risk as outlined in the updated ASGE guidelines published in 2016. Once pertinent information regarding a patient's clinical status and the procedure are entered, the application generates recommendations for the management of antithrombotic agents based on their cardiovascular risk and published ASGE guidelines. We performed a validation study with 52 patients who were referred to endoscopy and were taking antithrombotic agents. The patients were divided into groups of 5, and in the simulation each patient had 4 procedures. Different GI procedures were used in the simulation for each group of patients to ensure the entire spectrum of procedures were covered for analysis. Every simulation was then run through ENDOAID. The results from ENDOAID were compared with recommendations based on ASGE guidelines. The latter was derived by consensus between 2 endoscopists (the criterion standard). The personnel using the ENDOAID and those using the ASGE guidelines were different to avoid bias. Any clinical scenario that was unclear or not clearly outlined in ASGE guidelines was discussed with expert endoscopists for a final decision. We evaluated ASGE recommendations and calculated concordance rates between guidelines and ENDOAID results. The Pearson correlation coefficient (r) was calculated to assess the correlation between ENDOAID results to guidelines.

RESULTS

There was a total of 208 simulated encounters, including 26 procedures. Initial concordance between ENDOAID recommendations and the criterion standard was seen in 206 encounters (99.03%). The 2 encounters that needed further review occurred among patients with Factor V Leiden mutation and deep vein thrombosis from antiphospholipid antibody syndrome and who were undergoing high-risk procedures that had ambiguous guidelines. ENDOAID suggested consultations with an expert before the elective procedure. This suggestion was agreed on by expert endoscopist consensus. Thus, ENDOAID showed a 100% concordance with the ASGE guideline for managing antithrombotics. There was a high degree of correlation (r = .996, P < .01) between ENDOAID results with ASGE.

CONCLUSIONS

We have developed and validated an easy-to-use web-based application that can help in periprocedural management of antithrombotics. Such an application has the potential to simplify the management of these agents and potentially prevent procedural delays, cancellations, or unnecessary consults.

Patient Satisfaction With Extended International Normalized Ratio Follow-up Intervals in a Veteran Population

Background: For highly stable warfarin patients, limited data exists regarding patient satisfaction on extended international normalized ratio (INR) follow-up intervals and how this population compares with patients on a direct oral anticoagulant (DOAC). Objective: To assess the impact on patient satisfaction of extending INR follow-up intervals. Methods: Veterans on stable warfarin doses had extended INR follow-up intervals up to 12 weeks in a single-arm prospective cohort study for 2 years. This analysis included participants who completed at least 2 Duke Anticoagulation Satisfaction Scales (DASS). The primary outcome was the change in the DASS. A focus group described participant experiences. Participant satisfaction was compared to patients on a DOAC. Results: Of the 51 participants, 48 were included in the warfarin extended INR follow-up group. Compared with baseline, the mean DASS score (42.9 ± 12.08) was worse at 24 months (46.82 ± 15.2, P = 0.0266), with a small effect size (Cohen's d = 0.29). The 8 participants in the focus group were satisfied with the extended INR follow-up interval but would be uncomfortable extending follow-up past 2 to 3 months. The extended INR follow-up interval study had similar DASS scores as the 33 participants included on DOAC therapy (46.8 ± 15.1, P = 0.9970) but may be limited by differing populations using DOACs. Conclusion and Relevance: For patients currently stable on warfarin therapy, extending the INR follow-up interval up to 12 weeks or changing to a DOAC does not appear to improve patient satisfaction.

Transfusion strategies in patients with cirrhosis

Bleeding related to portal hypertension and coagulopathy is a common complication in patients with cirrhosis. Complications and management of bleeding is a significant source of healthcare cost and utilization, as well as morbidity and mortality. Due to the scarcity of evidence surrounding transfusion strategies and hemostatic interventions in patients with cirrhosis, there has been significant debate regarding the best practice. Emerging data suggest that evidence supporting transfusion of packed red blood cells to a hemoglobin threshold of 7-8 g/dL is strong. thrombopoietin (TPO) receptor agonists have shown promise in increasing platelet levels and reducing transfusions preprocedurally, although have not specifically been found to reduce bleeding risk. Data for viscoelastic testing (VET)-guided transfusions appear favorable for reducing blood transfusion requirements prior to minor procedures and during orthotopic liver transplantation. Hemostatic agents such as recombinant factor VIIa, prothrombin complex concentrates, and tranexamic acid have been examined but their role in cirrhotic patients is unclear. Other areas of growing interest include balanced ratio and whole blood transfusion. In the following manuscript, we summarize the most up to date evidence for threshold-guided, VET-guided, balanced-ratio, and whole blood transfusions as well as the use of hemostatic agents in cirrhotic patients to provide practice guidance to clinicians.

Acute Procedural Complications of Cryoballoon Ablation: A Comprehensive Review

Catheter ablation is increasingly performed for treatment of atrial fibrillation (AF). Balloon based procedures have been developed aiming at safer, easier and more effective treatment as compared to point to point ablation. In the present review article, we aimed to discuss acute procedural complications of cryoballoon ablation.

De Ritis ratio as a significant prognostic factor of international normalized ratio ≥4 in the initial 10 days of warfarin therapy

Aim: To assess the relationship between the De Ritis ratio on admission and warfarin sensitivity in the initial 10 days of anticoagulation therapy. Methods: We retrospectively reviewed data from 906 patients who underwent heart valve replacement surgery. Results: A De Ritis ratio of 1.19 was identified as the optimal cutoff according to the ROC curve. Patients with a high De Ritis ratio achieved an international normalized ratio (INR) ≥4 more easily and earlier than those with a low De Ritis ratio in the initial 10 days of warfarin therapy. Multivariate analysis showed that a high De Ritis ratio was an independent predictor of an INR ≥4 (HR: 2.567; p < 0.001). Conclusion: A De Ritis ratio ≥1.19 on admission was significantly associated with an INR ≥4 in the initial 10 days of warfarin therapy among patients underwent heart valve replacement surgery.

The Future Directions of Research in Cardiac Anesthesiology

This article provides an overview of knowledge gaps that need to be addressed in cardiac anesthesia, including mitigating the inflammatory effects of cardiopulmonary bypass, defining myocardial infarction after cardiac surgery, improving perioperative neurologic outcomes, and the optimal management of patients undergoing valve replacement. In addition, emerging approaches to research conduct are discussed, including the use of new analytical techniques like machine learning, pragmatic trials, and adaptive designs.

Periprocedural Major Bleeding Risk of Image-Guided Percutaneous Chest Tube Placement in Patients with an Elevated International Normalized Ratio

PURPOSE

To evaluate the incidence of major hemorrhage after image-guided percutaneous chest tube placement in patients with an abnormal international normalized ratio (INR) measured before the procedure.

MATERIALS AND METHODS

Between January 2013 and September 2017, 49 image-guided percutaneous chest tubes were placed in 45 adult patients who had an elevated INR of greater than 1.6. Data collected included routine serum pre-procedure coagulation studies, indication for chest tube placement, insertion technique, size of chest tube, and presence of complications after drain placement. Major bleeding complications were defined using the Society of Interventional Radiology classification system.

RESULTS

Mean patient age was 62 years (range, 22-94 years), with median American Society of Anesthesiologists score of 4. Mean INR was 2.1 (range, 1.7-3), with 21 (43%) procedures with an INR between 1.7 and 1.9, 20 (41%) procedures with an INR between 2.0 and 2.4, and 8 (16%) procedures with an INR between 2.5 and 3.0. Computed tomography guidance was used for 27 (55%) procedures; ultrasound guidance was used for 22 (45%) procedures. Median size of chest tube was 10 Fr (range, 8-14 Fr) used in 27 (55%) procedures. No major bleeding complications were observed. There was a small, significant decrease in mean hemoglobin after the procedure (mean = 0.9g/dL; P < .0001), which correlated to increasing chest tube size (P = .0269).

CONCLUSIONS

No major bleeding complications were observed after image-guided percutaneous chest tube placement in patients with an elevated INR. Major bleeding complications in these patients may be safer than initially considered, and this study encourages the conduct of larger trials for further evaluation.

Risk of rebleeding, vascular events and death after gastrointestinal bleeding in anticoagulant and/or antiplatelet users

BACKGROUND

Patients with gastrointestinal bleeding during anticoagulant and/or antiplatelet therapy represent a clinical challenge.

AIM

To determine the risk/rates of rebleeding, vascular events and death in patients treated with antiplatelet or anticoagulant agents who developed major gastrointestinal bleeding METHODS: This was an observational cohort study of patients who developed gastrointestinal bleeding while on antiplatelet and/or anticoagulant therapy. Drug use information was collected prospectively during bleeding events. Cox proportional hazards models were used to evaluate rebleeding, vascular events and death.

RESULTS

Among 871 patients (mean age 78.9 ± 8.6 years), 38.9% used an anticoagulant, 52.5% used an antiplatelet and 8.6% used both; 93.1% interrupted treatment after gastrointestinal bleeding and 80.5% restarted therapy within 7.6 ± 36.4 days; 38.7% had upper gastrointestinal bleeds, 46.7% lower gastrointestinal bleeds and 14.6% gastrointestinal bleeds of unknown origin. Median follow-up was 24.9 months (IQR: 7.0-38.0). Resumption of both therapies was associated with a higher risk of rebleeding, lower risk of ischaemic events or death and a similar risk for upper and lower gastrointestinal events. Resumption of therapy ≤ 7 days after bleeding showed a similar pattern with no differences in death. Rebleeding rates were higher in anticoagulant vs antiplatelet patients (138.0 vs 99.0 events per 1000 patient-years), and the bleeding location was identical in 61.8% of cases.

CONCLUSIONS

Resumption of anticoagulant or antiplatelet therapy after a gastrointestinal bleeding event was associated with a lower risk of vascular events and death and a higher rebleeding risk. The benefits of early reinstitution of anticoagulant/antiplatelet therapy outweigh the gastrointestinal-related risks.

Vena cava filters in patients presenting with major bleeding during anticoagulation for venous thromboembolism

The association between inferior vena cava filter (IVC) use and outcome in patients presenting with major bleeding during anticoagulation for venous thromboembolism (VTE) has not been thoroughly investigated. We used the RIETE registry to compare the 30-day outcomes (death, major re-bleeding or VTE recurrences) in VTE patients who bled during the first 3 months of therapy, regarding the insertion of an IVC filter. A propensity score matched (PSM) analysis was performed to adjust for potential confounders. From January 2001 to September 2016, 1065 VTE patients had major bleeding during the first 3 months of anticoagulation (gastrointestinal 370; intracranial 124). Of these, 122 patients (11%) received an IVC filter. Patients receiving a filter restarted anticoagulation later (median, 4 vs. 2 days) and at lower doses (95 ± 52 IU/kg/day vs. 104 ± 55 of low-molecular-weight heparin) than those not receiving a filter. During the first 30 days after bleeding (after excluding 246 patients who died within the first 24 h), 283 patients (27%) died, 63 (5.9%) had non-fatal re-bleeding and 19 (1.8%) had recurrent pulmonary embolism (PE). In PSM analysis, patients receiving an IVC filter (n = 122) had a lower risk for all-cause death (HR 0.49; 95% CI 0.31-0.77) or fatal bleeding (HR 0.16; 95% CI 0.07-0.49) and a similar risk for re-bleeding (HR 0.55; 95% CI 0.23-1.40) or PE recurrences (HR 1.57; 95% CI 0.38-6.36) than those not receiving a filter (n = 429). In VTE patients experiencing major bleeding during the first 3 months, use of an IVC filter was associated with reduced mortality rates.Clinical Trial Registration NCT02832245.

Three-Factor Versus Four-Factor Prothrombin Complex Concentrate for the Emergent Management of Warfarin-Associated Intracranial Hemorrhage

BACKGROUND

Four-factor prothrombin complex concentrates (PCC) produce a more rapid and complete INR correction compared with 3-factor PCC in patients receiving warfarin. It is unknown if this improves clinical outcomes in the setting of intracranial hemorrhage (ICH).

METHODS

This multicenter, retrospective cohort study included patients presenting with warfarin-associated ICH reversed with either 4- or 3-factor PCC. The primary outcome was in-hospital mortality. Secondary outcomes were 30-day mortality, discharge location, intensive care unit (ICU) and hospital-free days, INR reversal, and thromboembolic (TE) events at 90 days. Each was analyzed using regression analysis. Continuous and binary outcomes were analyzed using linear and logistic regression, respectively, while ordinal regression was used for discharge location.

RESULTS

Of the 103 patients, 63 received 4-factor PCC. Median age was 79 years [interquartile intervals(IQI 73-84)], median presenting INR was 2.7 (2.2-3.3), and presenting ICH was intraparenchymal in 51% of patients. In-hospital and 30-day mortality were 25 and 35%, respectively. In-hospital mortality was greater among those who received 4-factor PCC, yet was not statistically significant (OR 2.2, 95% CI 0.59-9.4, p = 0.26), as having Glasgow Coma Scale (GCS) ≤8 explained most of the difference (OR 48, 95% CI 14-219, p <0.001). The effect of 4-factor PCC was not statistically significant in any of the secondary analyses. Crude rates of TE events were higher in the 4-factor PCC group (19 vs. 10%), though not significantly.

CONCLUSIONS

In-hospital mortality was not improved with the use of 4- versus 3-factor PCC in the emergent reversal of warfarin-associated ICH. Secondary clinical outcomes were similarly nonsignificant.

Physicians' perceptions of shared decision-making for implantable cardioverter-defibrillators: Results of a physician survey

BACKGROUND

Centers for Medicare and Medicaid Services has mandated the use of shared decision-making (SDM) for implantable cardioverter-defibrillator (ICD) implantation. SDM tools help facilitate quality SDM by presenting patients with balanced evidence-based facts related to risk and benefits. Perceptions of ICD implantation may differ based on patients' sex and race.

OBJECTIVE

To determine if and how physicians are incorporating SDM in counseling patients about ICD and if they are aware of sex- and race-based differences in patients' perception of ICDs.

METHODS

This was a pilot study involving an online survey targeting attending physicians who implant ICDs. Physicians were randomly selected by a computer-based program; 350 surveys were sent.

RESULTS

Of the 124 (35%) respondents to the survey, 102 (84%) met the inclusion criteria, and of those, 99 (97%) were adult electrophysiologists. Most physicians (90, 88%) stated they engaged in SDM during the general consent process. Sixty-three (62%) physicians discuss end of life issues while obtaining general consent. Forty-four (43%) physicians said they use an existing SDM tool with the Colorado SDM tool being the most common (39, 89%). The majority of physicians were unaware of sex- and race-based differences in perceptions related to ICD implantation (sex 64, 63% and race 63, 62%).

CONCLUSION

A vast majority of physicians are engaging in SDM; however less than half are using a formal SDM tool, and a minority of physicians were aware of sex- and race-based differences in patients' perception of ICD implantation. Sex- and race-based tools might help address this gap.

Activated Prothrombin Complex Concentrate Versus 4-Factor Prothrombin Complex Concentrate for Vitamin K-Antagonist Reversal

OBJECTIVES

To compare the international normalized ratio normalization efficacy of activated prothrombin complex concentrates and 4-factor prothrombin complex concentrates and to evaluate the thrombotic complications in patients treated with these products for warfarin-associated hemorrhage.

DESIGN

Retrospective, Multicenter Cohort.

SETTING

Large, Community, Teaching Hospital.

PATIENTS

Patients greater than 18 years old and received either activated prothrombin complex concentrate or 4-factor prothrombin complex concentrate for the treatment of warfarin-associated hemorrhage. We excluded those patients who received either agent for an indication other than warfarin-associated hemorrhage, pregnant, had a baseline international normalized ratio of less than 2, received a massive transfusion as defined by hospital protocol, received plasma for treatment of warfarin-associated hemorrhage, or were treated for an acute warfarin ingestion.

INTERVENTIONS

Patients in the activated prothrombin complex concentrate group (enrolled from one hospital) with an international normalized ratio of less than 5 received 500 IU and those with an international normalized ratio greater than 5 received 1,000 IU. Patients in the 4-factor prothrombin complex concentrate (enrolled from a separate hospital) group received the Food and Drug Administration approved dosing algorithm.

MEASUREMENTS AND MAIN RESULTS

A total of 158 patients were included in the final analysis (activated prothrombin complex concentrate = 118; 4-factor prothrombin complex concentrate = 40). Those in the 4-factor prothrombin complex concentrate group had a higher pretreatment international normalized ratio (2.7 ± 1.8 vs 3.5 ± 2.9; p = 0.0164). However, the posttreatment international normalized ratio was similar between the groups. In addition, even when controlling for differences in the pretreatment international normalized ratio, there was no difference in the ability to achieve a posttreatment international normalized ratio of less than 1.4 (odds ratio, 0.753 [95% CI, 0.637-0.890]; p = 0.0009). Those in the activated prothrombin complex concentrate group did have higher odds of achieving a posttreatment international normalized ratio of less than 1.2 (odds ratio, 3.23 [95% CI, 1.34-7.81]; p = 0.0088). There was only one posttreatment thrombotic complication reported.

CONCLUSIONS

A low, fixed dose of activated prothrombin complex concentrate was as effective as standard dose 4-factor prothrombin complex concentrate for normalization of international normalized ratio. In addition, we did not see an increase in thrombotic events.

Prothrombin, alone or in complex concentrates or plasma, reduces bleeding in a mouse model of blood exchange-induced coagulopathy

Prothrombin complex concentrates (PCC) are fractionated plasma protein drugs that reverse warfarin anticoagulation. PCC may control more general bleeding. We sought to identify the dominant procoagulant factor in PCC in vivo. We tested PCC or coagulation factor (F) treatment in CD1 mice made coagulopathic by exchange of whole blood for washed red cells. Anesthetized mice were transfused with murine fresh-frozen plasma (mFFP), PCC, mixtures of human vitamin K-dependent proteins (VKDP) (prothrombin, FVII, FIX, or FX), or purified single human VKDP, immediately prior to tail transection (TT), liver laceration (LL), or intravascular laser injury (ILI). Plasma donor mice were treated with vehicle or control antisense oligonucleotide (ASO-CON) or ASO specific for prothrombin (FII) (ASO-FII) to yield mFFP or ASO-CON mFFP or ASO-FII mFFP. Blood losses were determined spectrophotometrically (TT) or gravimetrically (LL). Thrombus formation was quantified by intravital microscopy of laser-injured arterioles. PCC or four factor- (4F-) VKDP or prothrombin significantly reduced bleeding from TT or LL. Omission of prothrombin from 4F-VKDP significantly reduced its ability to limit bleeding. Mice transfused with ASO-FII mFFP demonstrated inferior haemostasis versus those transfused with ASO-FII following TT, LL, or ILI. Prothrombin is the dominant procoagulant component of PCC and could limit bleeding in trauma.

Endoscopy in the coagulopathic patient

PURPOSE OF REVIEW

The presence of coagulopathy in patients profoundly affects the performance of gastrointestinal endoscopy. However, the coagulopathy in chronic liver disease (CLD) and therapeutic anticoagulation to lower thromboembolic risk are different. In this review, we briefly discuss the hemostatic alterations in CLD leading to coagulopathy and the periprocedure management of antithrombotic medications in patients needing emergency or elective gastrointestinal endoscopy.

RECENT FINDINGS

Prothrombin time (PT) and international normalized ratio (INR) are unreliable measures of bleeding risk and hemostasis in CLD. Therefore, expert opinion advises no preprocedure fresh frozen plasma (FFP) infusion to correct the INR. There has been a proliferation of and increasing use of antithrombotic medications for therapeutic anticoagulation. Their management depends on the gastrointestinal endoscopy procedure bleeding risk, the acuity of the procedure, and the underlying thromboembolic risk of the patient.

SUMMARY

Cirrhotic coagulopathy features a rebalancing of procoagulant and anticoagulant factors. PT and INR do not accurately measure this rebalanced hemostasis. Thus, expert opinion does not recommend FFP infusion to correct the PT or INR before performing gastrointestinal endoscopy. Management of therapeutic anticoagulation in endoscopy depends on the acuity of the indication, the procedure bleeding risk, and the thromboembolic risk of stopping anticoagulation. At present, there are only expert opinion recommendations concerning periendoscopy coagulopathy management in CLD and in therapeutic anticoagulation. More controlled clinical studies will clarify bleeding risks when performing gastrointestinal procedures in these patients and better direct patient care. Until then, clinical management of antithrombotic medications are based an individual patient's medical conditions and available options for treatment.

Management of Severe Bleeding in Patients Treated With Oral Anticoagulants: Proceedings Monograph From the Emergency Medicine Cardiac Research and Education Group-International Multidisciplinary Severe Bleeding Consensus Panel October 20, 2018

In this Emergency Medicine Cardiac Research and Education Group (EMCREG)-International Proceedings Monograph from the October 20, 2018, EMCREG-International Multidisciplinary Consensus Panel on Management of Severe Bleeding in Patients Treated With Oral Anticoagulants held in Orlando, FL, you will find a detailed discussion regarding the treatment of patients requiring anticoagulation and the reversal of anticoagulation for patients with severe bleeding. For emergency physicians, critical care physicians, hospitalists, cardiologists, internists, surgeons, and family physicians, the current approach and disease indications for treatment with anticoagulants such as coumadin, factor IIa, and factor Xa inhibitors are particularly relevant. When a patient treated with anticoagulants presents to the emergency department, intensive care unit, or operating room with severe, uncontrollable bleeding, achieving rapid, controlled hemostasis is critically important to save the patient's life. This EMCREG-International Proceedings Monograph contains multiple sections reflecting critical input from experts in Emergency Cardiovascular Care, Prehospital Emergency Medical Services, Emergency Medicine Operations, Hematology, Hospital Medicine, Neurocritical Care, Cardiovascular Critical Care, Cardiac Electrophysiology, Cardiology, Trauma and Acute Care Surgery, and Pharmacy. The first section provides a description of the current indications for the treatment of patients using oral anticoagulants including coumadin, the factor IIa (thrombin) inhibitor dabigatran, and factor Xa inhibitors such as apixaban and rivaroxaban. In the remaining sections, the treatment of patients presenting to the hospital with major bleeding becomes the focus. The replacement of blood components including red blood cells, platelets, and clotting factors is the critically important initial treatment for these individuals. Reversing the anticoagulated state is also necessary. For patients treated with coumadin, infusion of vitamin K helps to initiate the process of protein synthesis for the vitamin K-dependent coagulation proteins II, VII, IX, and X and the antithrombotic protein C and protein S. Repletion of clotting factors for the patient with 4-factor prothrombin complex concentrate, which includes factors II (prothrombin), VII, IX, and X and therapeutically effective concentrations of the regulatory proteins (protein C and S), provides real-time ability to slow bleeding. For patients treated with the thrombin inhibitor dabigatran, treatment using the highly specific, antibody-derived idarucizumab has been demonstrated to reverse the hypocoagulable state of the patient to allow blood clotting. In May 2018, andexanet alfa was approved by the US Food and Drug Administration to reverse the factor Xa anticoagulants apixaban and rivaroxaban in patients with major bleeding. Before the availability of this highly specific agent, therapy for patients treated with factor Xa inhibitors presenting with severe bleeding usually included replacement of lost blood components including red blood cells, platelets, and clotting factors and 4-factor prothrombin complex concentrate, or if not available, fresh frozen plasma. The evaluation and treatment of the patient with severe bleeding as a complication of oral anticoagulant therapy are discussed from the viewpoint of the emergency physician, neurocritical and cardiovascular critical care intensivist, hematologist, trauma and acute care surgeon, hospitalist, cardiologist, electrophysiologist, and pharmacist in an approach we hope that the reader will find extremely practical and clinically useful. The clinician learner will also find the discussion of the resumption of oral anticoagulation for the patient with severe bleeding after effective treatment important because returning the patient to an anticoagulated state as soon as feasible and safe prevents thrombotic complications. Finally, an EMCREG-International Severe Bleeding Consensus Panel algorithm for the approach to management of patients with life-threatening oral anticoagulant-associated bleeding is provided for the clinician and can be expanded in size for use in a treatment area such as the emergency department or critical care unit.

Preoperative Vitamin K Reduces Blood Transfusions at Time of Left Ventricular Assist Device Implant

BACKGROUND

Congestive heart failure patients have hepatic congestion and abnormal coagulation profiles, increasing perioperative bleeding at time of ventricular assist device implantation. This study examined the impact of the preoperative administration of vitamin K on perioperative blood transfusion requirements.

METHODS

Retrospectively, 190 patients met inclusion criteria. Patients received no vitamin K (n = 62) or two 10-mg doses of intravenous vitamin K (n = 128) in the 24 hours before assist device implantation. Primary end points included transfusion requirements and reexploration rates for bleeding. Secondary outcomes were pump thrombosis and in-hospital mortality.

RESULTS

Baseline characteristics were similar between the 2 groups, with slight differences (not statistically significant) noted in the Interagency Registry for Mechanically Assisted Circulatory Support profile and total bilirubin levels. The only significant difference noted was the year of implantation (P < .001). Blood product usage was significantly lower in the vitamin K group compared to the no vitamin K group (P < .001). Higher rates of reexploration for bleeding (29.7% vs 13.6%, P = .023) and death at hospital discharge (16.2% vs 2.8%, P = .004) were noted for the no vitamin K group compared with the vitamin K group. After adjusting for age, sex, race, body mass index, Interagency Registry for Mechanically Assisted Circulatory Support profile, total bilirubin, surgeon, and year of operation, reexploration rates and death did not achieve statistical significance. No statistically significant difference was observed in stroke and pump thrombosis rates between the 2 groups.

CONCLUSIONS

Preoperative vitamin K administration may help reduce blood product use without any increased risk for strokes or pump thrombosis.

Bridging the Gaps in Personalized Medicine Value Assessment: A Review of the Need for Outcome Metrics across Stakeholders and Scientific Disciplines

Despite monumental advances in genomics, relatively few health care provider organizations in the United States offer personalized or precision medicine as part of the routine clinical workflow. The gaps between research and applied genomic medicine may be a result of a cultural gap across various stakeholders representing scientists, clinicians, patients, policy makers, and third party payers. Scientists are trained to assess the health care value of genomics by either quantifying population-scale effects, or through the narrow lens of clinical trials where the standard of care is compared with the predictive power of a single or handful of genetic variants. While these metrics are an essential first step in assessing and documenting the clinical utility of genomics, they are rarely followed up with other assessments of health care value that are critical to stakeholders who use different measures to define value. The limited value assessment in both the research and implementation science of precision medicine is likely due to necessary logistical constraints of these teams; engaging bioethicists, health care economists, and individual patient belief systems is incredibly daunting for geneticists and informaticians conducting research. In this narrative review, we concisely describe several definitions of value through various stakeholder viewpoints. We highlight the existing gaps that prevent clinical translation of scientific findings generally as well as more specifically using two present-day, extreme scenarios: (1) genetically guided warfarin dosing representing a handful of genetic markers and more than 10 years of basic and translational research, and (2) next-generation sequencing representing genome-dense data lacking substantial evidence for implementation. These contemporary scenarios highlight the need for various stakeholders to broadly adopt frameworks designed to define and collect multiple value measures across different disciplines to ultimately impact more universal acceptance of and reimbursement for genomic medicine.

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.

Pharmacist Presence Decreases Time to Prothrombin Complex Concentrate in Emergency Department Patients with Life-Threatening Bleeding and Urgent Procedures

BACKGROUND

Reversal of anticoagulation with four-factor prothrombin complex concentrate (4F-PCC) is critical, yet the optimal timing to 4F-PCC administration and whether quicker administration improves hemostasis remains unknown.

OBJECTIVE

The objective of this study was to determine if pharmacist presence is predictive of faster time to 4F-PCC.

METHODS

This retrospective cohort study included patients receiving 4F-PCC for life-threatening bleeding or urgent procedure in the emergency department (ED) from 2014 to 2018. Patients with pharmacists at bedside (PharmD group) were compared with physician teams alone (control group). The primary outcome was time from ED presentation to 4F-PCC administration.

RESULTS

Of 252 patients evaluated, 116 patients (46%) were included (n = 50 PharmD group; n = 66 control group). Most patients presented on warfarin (68.1%), and of the life-threatening bleeds (94%), intracranial hemorrhage was most common (67.2%). The median time to 4F-PCC administration was significantly shorter in the PharmD group (66.5 vs. 206.5 min, p < 0.001). Pharmacist at bedside was the only factor independently associated with reduction in time to 4F-PCC (β coefficient -163.5 min, 95% confidence interval -249.4 to -77.7). Although there was no difference in hemostasis or mortality, patients in the PharmD group had a shorter intensive care unit length of stay (LOS) (2 vs. 5 days, p < 0.01) and hospital LOS (5.5 vs. 8 days, p = 0.02).

CONCLUSION

A pharmacist at the bedside of patients who present to the ED with life-threatening bleeding or need for emergent procedure decreased time to 4F-PCC administration by 140 min, even after accounting for confounders. Faster time to 4F-PCC was associated with significantly shorter intensive care unit and hospital LOS.

Reversal agents for oral anticoagulants

For more than half a century, warfarin, a vitamin K antagonist, has been the anticoagulant of choice. However, direct oral anticoagulants are rapidly gaining in popularity, which poses the need for efficacious reversal agents. This review article summarizes the strategies and agents used to reverse oral anticoagulants.

Bleeding Risk in Patients Using Oral Anticoagulants Undergoing Surgical Procedures in Dentistry: A Systematic Review and Meta-Analysis

The management of patients who undergo dental surgical procedures and receive oral anticoagulant therapy requires particular attention due to the risk of bleeding that may occur during the procedure. Bleeding rates in these trans- or post-operative patients tend to be unpredictable. The aim of this study was to conduct a systematic review in order to assess the risk of bleeding during and after performing oral surgery in patients administered oral anticoagulants compared with a group that discontinued anticoagulant therapy. For the purposes of this review, we searched the databases of the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (via Ovid), EMBASE (via Ovid), and the Virtual Health Library (VHL) from inception of the database to December 2018. The primary outcome was defined as the occurrence of local bleeding during and after oral surgical procedures. Four reviewers, independently and in pairs, screened titles and abstracts for full-text eligibility. Data regarding participant characteristics, interventions, and design and outcomes of the included studies were extracted. The data were pooled using random-effects meta-analyses and described as risk ratios (RRs) with a 95% confidence interval (95% CI). The confidence for the pooled estimates was ascertained through the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach, and the protocol of this review was recorded in PROSPERO (CRD42017056986). A total of 58 eligible studies were identified, of which three randomized controlled trials were included in the meta-analysis, covering a total of 323 adult participants, among whom 167 were taking anticoagulants at the time they underwent dental surgery. Of these patients, 14.2% had reported bleeding. The risk of bleeding was found to be one to almost three times greater in patients taking warfarin compared with patients who discontinued the use of anticoagulant during the trans-operative period (RR = 1.67, 95% CI = 0.97 to 2.89) and in the post-operative period (RR = 1.44, 95% CI = 0.71 to 2.92), although the quality of evidence was very low. The results indicate that there is no evidence that the use of anticoagulants eliminates the risk of bleeding during surgical dental procedures.

Reversal agents for direct oral anticoagulants: considerations for hospital physicians and intensivists

Direct oral anticoagulants (DOACs) include dabigatran etexilate, a direct thrombin inhibitor, and specific inhibitors of activated coagulation factor X (FXa; e.g. apixaban, betrixaban, edoxaban, rivaroxaban). DOACs are associated with lower rates of major and fatal bleeding events compared with warfarin. Clinicians may need to achieve rapid reversal of anticoagulation effects of the DOACs in an emergency setting. Idarucizumab and andexanet alfa, which reverse the anticoagulant effects of dabigatran and FXa inhibitors, respectively, are DOAC reversal agents available in the US. Other reversal agents (e.g. ciraparantag for heparins, DOACs) are in development. Alternative nonspecific agents (e.g. fresh frozen plasma, prothrombin complex concentrate) are available. Nonspecific prohemostatic agents can counteract the anticoagulant action of DOACs in emergency situations, when specific reversal agents are unavailable. However, specific reversal agents are efficacious and safe and should be preferred when available. In this review, we discuss practical issues in the initiation of DOAC therapy, situations where reversal may be needed, coagulation assays, reversal agents, and post-reversal complications in the context of published evidence and guidelines.

Safety and effectiveness of a prothrombin complex concentrate in approved and off-label indications

OBJECTIVE

To evaluate the effectiveness and safety of prothrombin complex concentrates (PCCs) in approved and off-label indications.

BACKGROUND

PCCs are approved for the urgent reversal of vitamin K antagonists (VKAs). Data concerning the efficacy, safety and dosing for off-label indications are limited, but they are included in massive bleeding protocols.

METHODS

This was a retrospective review of cases treated with four-factor PCCs (4F-PCCs) between January 2009 and 2016. Efficacy end-points include: (i) VKA reversal efficacy assessed by international normalised ratio (INR) normalisation (<1·5) and (ii) clinical efficacy as bleeding cessation and/or decreased number of transfused blood components and 24-h mortality in bleeding coagulopathy. The safety end-point is the incidence of thromboembolic events.

RESULTS

A total of 328 patients were included (51·8% male, median age 78 years old). Indications were as follows: VKA reversal (66·6%), bleeding coagulopathy (30·5%) and direct anticoagulant (DOAC) reversal due to bleeding (2·5%). VKA reversal was effective in 97·1% of patients, and 76·5% demonstrated complete reversal (INR < 1·5); only 34·3% patients needed hemoderivatives. Prior to emergency procedures, PCCs achieved global responses in 83% of patients, with no bleeding complication during intervention. DOAC reversal was effective in 88·9% of patients. Bleeding cessation was associated with the dose administered (P = 0·002). In coagulopathy bleeding, haemorrhage cessation, established by the International Society of Thrombosis and Haemostais (ISTH) definition, occurred in 56·7% of massive bleeding events and in 42·5% of other coagulopathies; 24-h mortality was 30%, mainly related to active bleeding. Ten thrombotic episodes were observed (3·1%).

CONCLUSION

4F-PCC was effective as adjuvant treatment with an acceptable safety profile, not only for the emergent reversal of VKAs but also for refractory coagulopathy associated with major bleeding.

How reliable is perioperative anticoagulant management? Determining guideline compliance and practice variation by a retrospective patient record review

OBJECTIVES

Surgery in patients on anticoagulants requires careful monitoring and risk assessment to prevent harm. Required interruptions of anticoagulants and deciding whether to use bridging anticoagulation add further complexity. This process, known as perioperative anticoagulant management (PAM), is optimised by using guidelines. Optimal PAM prevents thromboembolic and bleeding complications. The purpose of this study was to assess the reliability of PAM practice in Dutch hospitals. Additionally, the variations between hospitals and different bridging dosages were studied.

DESIGN

A multicentre retrospective patient record review.

SETTING AND PARTICIPANTS

Records from 268 patients using vitamin-K antagonist (VKA) anticoagulants who underwent surgery in a representative random sample of 13 Dutch hospitals were reviewed, 259 were analysed.

PRIMARY AND SECONDARY OUTCOME MEASURES

Our primary outcome measure was the reliability of PAM expressed as the percentage of patients receiving guideline compliant care. Seven PAM steps were included. Secondary outcome measures included different bridging dosages used and an analysis of practice variation on the hospital level.

RESULTS

Preoperative compliance was lowest for timely VKA interruptions: 58.8% (95% CI 50.0% to 67.7%) and highest for timely preoperative assessments: 81% (95% CI 75.0% to 86.5%). Postoperative compliance was lowest for timely VKA restarts: 39.9% (95% CI 33.1% to 46.7%) and highest for the decision to apply bridging: 68.5% (95% CI 62.3% to 74.8%). Variation in compliance between hospitals was present for the timely preoperative assessment (range 41%-100%), international normalised ratio testing (range 21%-94%) and postoperative bridging (range 20%-88%). Subtherapeutic bridging was used in 50.5% of patients and increased with patients' weight.

CONCLUSIONS

Unsatisfying compliance for most PAM steps, reflect suboptimal reliability of PAM. Furthermore, the hospital performance varied. This increases the risk for adverse events, warranting quality improvement. The development of process measures can help but will be complicated by the availability of a strong supporting evidence base and integrated care delivery regarding PAM.

Warfarin-Induced Rapid Rise in INR Post-Cardiac Surgery Is Not Associated With Increased Bleeding Risk

Background: Post-cardiac surgery bleeding can have devastating consequences, and it is unknown if warfarin-induced rapid international normalized ratio (INR) rise during the immediate postoperative period increases bleed risk. Objective: To determine the impact of warfarin-induced rapid-rise INR on post-cardiac surgery bleeding. Methods: This was a single-center, retrospective chart review of post-cardiac surgery patients initiated on warfarin at Mayo Clinic Hospital, Rochester. Patients were grouped based on occurrence or absence of rapid-rise INR (increase ≥1.0 within 24 hours). The primary outcome compared bleed events between groups. Secondary outcomes assessed hospital length of stay (LOS) and identified risk factors associated with bleed events and rapid rise in INR. Results: During the study period, 2342 patients were included, and 56 bleed events were evaluated. Bleed events were similar between rapid-rise (n = 752) and non-rapid-rise (n = 1590) groups in both univariate (hazard ratio [HR] = 1.22; P = 0.594) and multivariable models (HR = 1.24; P = 0.561). Those with rapid-rise INR had longer LOS after warfarin administration (discharge HR = 0.84; P = 0.0002). The most common warfarin dose immediately prior to rapid rise was 5 mg. Risk factors for rapid-rise INR were low body mass index, female gender, and cross-clamp time. Conclusion and Relevance: This represents the first report to assess warfarin-related rapid-rise INR in post-cardiac surgery patients and found correlation to hospital LOS but not bleed events. Conservative warfarin dosing may be warranted until further research can be conducted.

Adherence and Concomitant Medication Use among Patients on Warfarin Therapy: Insight from a Large Pharmacy Dispensing Database in Japan

Warfarin is a drug used for anticoagulation management, with a narrow therapeutic range and multiple drug-drug interactions. Adherence and proper use of concomitant medication are thus fundamental to the efficacy and safety of warfarin therapy. In 2012, we retrospectively analyzed data from three large-scale pharmacy chains in Japan. We included all adults (≥ 20 years old) with at least one record of warfarin dispensation. We examined patient demographic data, adherence as measured by medication possession ratio (MPR), and co-dispensation focusing on the number of concomitant dispensations and concurrent use of medications that increase bleeding risk. Thresholds of underadherence and overadherence were set at <0.9 and >1.1, considering the narrow therapeutic window. We reviewed 443007 warfarin dispensation records of 71340 individuals (median age, 73 years; 62% male). The MPR was 1.0 (interquartile range: 0.96-1.0), and underadherence and overadherence was found in 16.3 and 1.9% of individuals, respectively. The median number of co-dispensed drugs was eight at each pharmacy encounter, which did not differ by age group. Drugs associated with a high bleeding risk were dispensed in 40.0% of encounters and accounted for 16.4% of all co-dispensed drugs. In summary, we found optimal overall adherence, as assessed by MPR, among our Japanese study population, even when defining a strict cut-off value. However, polypharmacy was common in all age groups and medications with a high bleeding risk profile were often co-dispensed with warfarin. Future research addressing how these dispensation patterns affect patient outcome is warranted.

Chinese Patients With Heart Valve Replacement Do Not Benefit From Warfarin Pharmacogenetic Testing on Anticoagulation Outcomes

BACKGROUND

Genotype-guided warfarin dosing has been shown in some randomized trials to improve anticoagulation outcomes in individuals of European ancestry; yet, its utility in Chinese patients with heart valve replacement remains unresolved.

METHODS

A total of 2264 patients who underwent heart valve replacement at Wuhan Asia Heart Hospital were enrolled in this study. Patients were randomly divided into 2 groups, namely, a genotype-guided and a traditional clinically guided warfarin dosing group. In the genotype-guided group (n = 1134), genotyping for CYP2C9 and VKORC1 (-1639 G→A) was performed using TaqMan genotyping assay. Warfarin doses were predicted with the International Warfarin Pharmacogenetics Consortium algorithm. Patients in the control group (n = 1130) were clinically guided. The primary outcome was to compare the incidence of adverse events (major bleeding and thrombotic) during a 90-day follow-up period between 2 groups. Secondary objectives were to describe effects of the pharmacogenetic intervention on the first therapeutic-target-achieving time, the stable maintenance dose, and the hospitalization days.

RESULTS

A total of 2245 patients were included in the analysis. Forty-nine events occurred during follow-up. Genotype-guided dosing strategy did not result in a reduction in major bleeding (0.26% versus 0.63%; hazard ratio, 0.44; 95% confidence interval, 0.13-1.53; P = 0.20) and thrombotic events (0.89% versus 1.61%; hazard ratio, 0.56; 95% confidence interval, 0.27-1.17; P = 0.12) compared with clinical dosing group. Compared with traditional dosing, patients in the genotype-guided group reached their therapeutic international normalized ratio in a shorter time (3.8 ± 2.0 versus 4.4 ± 2.0 days, P < 0.001). There was no difference in hospitalization days (P = 0.28).

CONCLUSIONS

Warfarin pharmacogenetic testing according to the International Warfarin Pharmacogenetics Consortium algorithm cannot improve anticoagulation outcomes in Chinese patients with heart valve replacement.

Prothrombin complex concentrate for vitamin K antagonist reversal in acute bleeding settings: efficacy and safety

Introduction: Current guidelines recommend the administration of prothrombin complex concentrate in combination with vitamin K for normalization of coagulation in patients presenting with vitamin K antagonist-associated major bleeding, but until recently no adequately powered comparative trials had been conducted to support these recommendations. In this article, the authors review the evidence from studies assessing prothrombin complex concentrate treatment in these patients. Areas covered: A PubMed search (spanning January 1900 to September 2018) was conducted using the following search terms: prothrombin complex concentrate* AND (warfarin or (vitamin K antagonist*)), and papers relevant to major hemorrhagic events were identified; results from studies that used a randomized controlled trial (RCT) or a prospective design are presented here. Overall, the identified studies support the current guideline recommendations and indicate that prothrombin complex concentrates have at least similar safety profiles to other treatment options, such as fresh frozen plasma and recombinant activated factor VII. Expert opinion: It is hoped that the results from studies discussed here will inform future guideline updates; however, local clinical practice may also occasionally act as a barrier to adoption of guideline recommendations. There is an urgent need for further RCTs/prospective trials directly comparing PCC and plasma administration in acute bleeding settings.

Current status of venous thromboembolism development during the perioperative period for colorectal cancer, its prevention with enoxaparin, and monitoring methods

Background: There is a high incidence of venous thromboembolism (VTE) during the perioperative period for cancer. Therefore, there is an urgent need to elucidate the perioperative onset and appropriate prophylaxis for VTE. Purpose: VTE during the perioperative period for colorectal cancer was evaluated by lower limb venous ultrasonic examinations (lower limb echo) under enoxaparin prophylaxis. We also examined the relationship between hemorrhagic adverse events and anti-Xa factor activity. Patients and methods: Eighty-three subjects who underwent lower limb echo during the perioperative period for colorectal cancer were prospectively included. Enoxaparin was administered for 5 days, from day 1 to day 5 after surgery. Lower limb echo was performed before surgery and on day 5 after surgery. The activated partial thromboplastin time, D-dimer levels, and anti-Xa factor activity were measured before surgery and on days 1, 3, 5, 7, and 9 after surgery. Results: VTEs before surgery were observed on lower limb echo for 16 patients (19.2%). Three patients (3.6%) had a new thrombus during the perioperative period. The preoperative D-dimer level was an independent prognostic factor for newly formed postoperative VTEs (p=0.0036; odds ratio, 19.37). Three patients (3.6%) had hemorrhagic events; however, there was no significant trend for anti-Xa factor activity. Conclusion: VTE prevention using enoxaparin was relatively safe, and D-dimer measurements before surgery were useful for predicting perioperative VTE.

Low-dose compared to manufacturer-recommended dose four-factor prothrombin complex concentrate for acute warfarin reversal

BACKGROUND

Four-factor PCC is the recommended standard of care for acute warfarin reversal but optimal dosing is unknown. We aim to show that a low-dose strategy is often adequate and may reduce the risk of thromboembolic events when compared to manufacturer-recommended dosing.

METHODS

A weight-based dosing strategy of 15-25 units/kg was established as the institutional standard of care in May 2015. This retrospective, before-and-after cohort analysis included patients receiving 4F-PCC according to a manufacturer-recommended (n = 122) or a low-dose (n = 83) strategy. The primary efficacy outcome was a combination of INR reversal on first check and hemostatic efficacy at 24 h.

RESULTS

Demographics, indications for warfarin, and presenting INR values were similar between the two groups. Patients in the manufacturer-recommended dose group received significantly more 4F-PCC than the low dose group (2110 units vs. 1530 units). More patients in the manufacturer-recommended dose group achieved the primary endpoint (75.4% vs. 61.4%), with more patients achieving the target INR on recheck in the manufacturer-recommended dose group (95.9% vs. 84.3%) and no difference in hemostatic efficacy between groups (79.5% vs. 74.7%). There was no difference in thromboembolic events at 72 h (4.1% vs. 1.2%) or at 30 days (8.2% vs. 4.8%). Significantly more patients in the manufacturer-recommended dose group died or were transferred to hospice care during hospitalization (21.3% vs. 9.6%).

CONCLUSION

Utilization of a low-dose 4F-PCC strategy resulted in fewer patients achieving target INR reversal, but no difference in hemostatic efficacy, thromboembolic events, or survival.

Feasibility and safety of a 12-week INR follow-up protocol over 2 years in an anticoagulation clinic: a single-arm prospective cohort study

The 2012 American College of Chest Physicians' guidelines recommended a 12-week INR follow-up interval may be appropriate for patients on stable warfarin doses. Limited evidence supports this recommendation. A single-arm, prospective cohort study over 24 months was completed in a Veterans Affairs anticoagulation clinic to determine the long-term feasibility and safety of implementing an extended INR follow-up interval in Veterans on stable doses of warfarin. Participants were required to have a stable warfarin dose for 6 months prior to enrollment. A prespecified protocol was used to titrate, extend, and manage the INR interval up to 12 weeks. Scheduling of extended INR intervals was a primary outcome. Safety outcomes included major and serious bleeding and thromboembolic events. A post-hoc comparison of baseline characteristics between individuals who were scheduled for at least 4 consecutive 12-week INR follow-up intervals and those who were not was completed. Of the 50 participants, 36 (72%) were scheduled for at least one 12-week interval and 15 (30%) were scheduled for 4 consecutive intervals. There were 2 thromboembolic events that occurred in 1 participant. There were 28 major and serious bleeding events in 19 participants; 8 occurred while on the extended INR interval. In the post-hoc analysis, no participants scheduled for 4 consecutive 12-week intervals had heart failure. Based on 2 years of monitoring, a 12-week INR follow-up interval using a detailed protocol with titration of INR interval extension appears feasible for a subset of patients. Patients with heart failure may not be suitable for this intervention.

Occurrence of Antithrombotic Related Adverse Events in Hospitalized Patients: Incidence and Clinical Context between 2008 and 2016

Antithrombotic drugs are consistently involved in medication-related adverse events (MRAEs) in hospitalized patients. We aimed to estimate the antithrombotic-related adverse event (ARAE) incidence between 2008 and 2016 and analyse their clinical context in hospitalized patients in The Netherlands. A post-hoc analysis of three national studies, aimed at adverse event (AE) identification, was performed. Previously identified AEs were screened for antithrombotic involvement. Crude and multi-level, case-mix adjusted ARAE and MRAE incidences were calculated. Various contextual ARAE characteristics were analysed. ARAE incidence between 2008 and 2016 decreased significantly in in-hospital deceased patients from 1.20% (95% confidence interval (CI): 0.63-2.27%) in 2008 to 0.54% (95% CI: 0.27-1.11%) in 2015/2016 (p = 0.02). In discharged patients ARAE incidence remained stable. By comparison, overall MRAE incidence remained stable for both deceased and discharged patients. Most ARAEs involved Vitamin-K antagonists (VKAs). Preventable ARAEs occurred more during weekends and with increasing multidisciplinary involvement. Antiplatelet and combined antithrombotic use seemed to be increasingly involved in ARAEs over time. ARAE incidence declined by 55% in deceased patients between 2008 and 2016. Opportunities for improving antithrombotic safety should target INR monitoring and care delivery aspects such as multidisciplinary involvement and weekend care. Future ARAE monitoring for the involvement of antiplatelet, combined antithrombotic and direct oral anticoagulant (DOAC) use is recommended.

Comparative Stability of Oral Vitamin K Liquids Stored in Refrigerated Amber Plastic Syringes

Background: Compounded vitamin K oral liquids may be useful in some patient populations, or when an appropriate solid dosage form is not available. While vitamin K oral liquid is typically prepared with sterile water for injection (SWFI), other compounding agents may be more palatable. Objective: To evaluate stability of compounded vitamin K liquids in SWFI, Ora-Sweet, simple syrup, cherry syrup, and SyrPalta stored in amber plastic oral syringes. Methods: Five types of compounded vitamin K liquids were prepared in triplicate-Ora-Sweet, simple syrup, cherry syrup, SyrPalta, and SWFI without flavoring; aliquoted into amber plastic oral syringes; and stored in a laboratory refrigerator (4.9°C to 5.4°C). On study days, 3 syringes from each batch were removed, diluted to assay concentration, and compared with a freshly prepared US Pharmacopeia reference solution. The samples and reference were analyzed using a previously validated high-performance liquid chromatography-ultraviolet method. Product stability was defined as 90% to 110% labeled amount. Results were further compared using a 2-way ANOVA (analysis of variance; P = .05) with post hoc Tukey's correction for multiple comparisons. Results: Vitamin K in SWFI, SyrPalta, and cherry syrup was stable for 21 days, 7 days, and 24 hours, respectively, under refrigeration in amber plastic oral syringes. Vitamin K in Ora-Sweet and simple syrup demonstrated high within-day variability and low potency. Statistically significant differences were detected between the SWFI formulation and all other vehicles. Conclusion: Vitamin K in SWFI is appropriate for longer-term storage of unit-dosed vitamin K; however, SyrPalta and cherry syrup may be used for short-term storage or immediate administration of vitamin K.

On-label compared to off-label four-factor prothrombin complex concentrate use: a retrospective, observational study

BACKGROUND

Four-factor prothrombin complex concentrate (4F-PCC) is US Food and Drug Administration approved for the urgent reversal of coagulation factor deficiency induced by a vitamin K antagonist complicated by acute major bleeding or in situations in which invasive procedures are urgently needed. Although recent evidence suggests the superiority of 4F-PCC over plasma for on-label indications, the off-label use of 4F-PCC has not been rigorously studied.

STUDY DESIGN AND METHODS

Eighty-nine patients receiving 4F-PCC at a single institution from July 2016 to December 2017 were retrospectively analyzed. Two cohorts, "On-Label" and "Off-Label" uses of 4F-PCC, were evaluated, comparing patient characteristics, blood utilization, and clinical outcomes including in-hospital mortality.

RESULTS

Patients receiving 4F-PCC for off-label reasons (n = 46) were younger and sicker compared to those receiving 4F-PCC for on-label reasons (n = 43). Notably, the mortality rate for off-label use was approximately twofold greater than the mortality rate for on-label use (26 of 46 [56.5%] vs. 12 of 43 [27.9%]; p = 0.006). Patients receiving 4F-PCC for off-label reasons received more units per patient of each blood component than their on-label counterparts. The average cost estimate per patient for 4F-PCC was similar (approx. $4300) in each cohort.

CONCLUSION

4F-PCC is an effective but expensive treatment option for those requiring urgent reversal of vitamin K antagonist-induced coagulopathy. However, providers should be conscious of the high costs and questionable efficacy when using 4F-PCC off-label.

Venous Thromboembolism Incidence After Craniofacial Surgery

INTRODUCTION

Current protocols for venous thromboembolism (VTE) prophylaxis after craniofacial surgery (CFS) vary widely with substantial disagreements in both indications and managements. An evidence-based approach to this issue requires the following: the incidence of postoperative VTE, comorbidities associated with coagulopathy, risk reduction after VTE prophylaxis, and complications attributable to prophylaxis. This study addresses the first two.

DESIGN

Retrospective cross-sectional study.

METHODS

Discharge data from 64,170 patients undergoing CFS between 2008 and 2013 extracted from the Healthcare Cost and Utilization Project Nationwide Inpatient Sample were analyzed. The outcome measures extracted were: deep venous thrombosis, pulmonary embolism, demographic data, common comorbidities, length of stay, total cost, and discharge outcome.

RESULTS

Diagnoses of deep venous thrombosis or pulmonary embolism, collectively classified as VTE, were observed in 355 (0.55%) of 64,170 patients discharged after CFS. Other surgeries exhibited a VTE rate of 1.17%. Men exhibited nearly double the incidence of VTE relative to women (0.69% compared with 0.37% respectively, P < 0.001), and the risk factors of adulthood, advanced age, cardiovascular disease, obesity, and malignancy were associated with increased VTE incidence with odds ratios of 9.93, 3.66, 1.80, 2.02, and 2.02, respectively (P < 0.005). Tobacco use did not exhibit any significant association (odds ratio, 0.94; P = 0.679). Afflicted patients experienced 4.60 times longer hospital stays averaging 23.8 days (95% confidence interval, 21.4-26.2; P < 0.001) compared the average of 5.2 days experienced by CFS patients without VTE. They incurred an average cost of US $298,228 (95% confidence interval, 262,726 to 333,731; P < 0.001) which was 4.17 times the US $72,376 expense of treating other CFS patients. The likelihood for a CFS patient to experience a poor outcome at the time of discharge was 54.6% higher after VTE.

CONCLUSIONS

The risk of postoperative VTE after CFS is significantly increased in adults, patients with advanced age, cardiovascular disease, obesity, and malignancy. However even in those high-risk cases, postoperative VTE incidence remains relatively low after CFS. These findings in conjunction with further study regarding the risk associated with the addition of VTE chemoprophylaxis compared against mechanical VTE prophylaxis, such as sequential pneumatic compression stockings, may determine whether routine use of VTE chemoprophylaxis is appropriate.

Management of anticoagulation in patients with metastatic castration-resistant prostate cancer receiving abiraterone + prednisone

PURPOSE

Abiraterone has been proven to be an effective agent used in the management of metastatic castration-resistant prostate cancer, significantly improving overall and progression-free survival. Due to the pharmacodynamic and pharmacokinetic properties of abiraterone, concurrent use with anticoagulation may pose a challenge for clinicians. Thrombosis within the cancer setting continues to increase patient mortality; therefore, appropriate anticoagulation through the use of a management algorithm can reduce adverse events and increase quality of life.

METHODS

A review of the literature was preformed by a medical oncologist, haematologist and pharmacists to identify relevant randomized controlled trials, meta-analyses and retrospective studies. Major society guidelines were reviewed to further aid in developing the anticoagulation protocol for non-valvular atrial fibrillation and venous thromboembolism within this patient population. After reviewing the literature, a clinical framework was designed to aid clinicians in the management of those patients receiving abiraterone concurrently with an anticoagulant.

RESULTS

In this review, we describe the potential interactions between abiraterone and various anticoagulants and provide management strategies based on the most recent literature for atrial fibrillation, venous thromboembolism and mechanical heart valves to avoid potential drug-drug interactions.

CONCLUSION

Abiraterone therapy has become a mainstay of the management of advanced prostate cancer and is often used over prolonged years. In this review, we have summarized a framework of how to use abiraterone in men with prostate cancer on anticoagulants. Evidence available to date suggests that patients with an indication for anticoagulation such as atrial fibrillation, venous thromboembolism and mechanical heart valves can be treated safely with abiraterone in the appropriate setting, with appropriate monitoring.

Management of Rodenticide Poisoning Associated with Synthetic Cannabinoids

Synthetic cannabinoids may be adulterated with potent vitamin K antagonists, which should be considered if a patient presents with unexplained coagulopathy, widespread bleeding, and a history of synthetic cannabinoid use.

Venous thromboembolism in the critically ill: A prospective observational study of occurrence, risk factors and outcome

BACKGROUND

The aim of the study was to explore occurrence, risk factors and outcome of venous thromboembolism (VTE) in intensive care unit (ICU) patients.

METHODS

Prospective observational study of ICU patients receiving thromboprophylaxis at Oslo University Hospital in Norway. Adult medical and surgical patients with ICU length of stay (LOS) longer than 48 hours were included. For detection of VTE, Doppler ultrasound screening of neck, upper and lower extremity veins was used, and computed tomography angiography when clinically indicated for any medical reason.

RESULTS

Among 70 included patients, 79% were males and mean age was 62 (±12.1) years. All received thromboprophylaxis with dalteparin, and 44 (63%) used graduated compression stockings. VTE was found in 19 (27%) patients; deep vein thrombosis in 15 (21%) and pulmonary embolism in 4 (6%). Among the VTEs, 11 (58%) presented within the first 48 hours after admission, two (11%) were located in the lower limbs and five (26%) were symptomatic. Risk factors for VTE in multivariable analyses were malignancy, abdominal surgery and SAPS II score <41 with an AuROC (95% CI) of 0.72 (0.58-0.85, P = 0.01). Patients with and without VTE had comparable ICU LOS (13 vs 11 days, P = 0.27) and mortality (16% vs 20%, P = 0.72).

CONCLUSION

Venous thromboembolism was observed in 27% of ICU patients receiving thromboprophylaxis. Factors associated with increased risk of VTE were malignancy, abdominal surgery and SAPS II score <41. Presence of VTE did not impact on patient outcome.