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

Propensity score adjusted comparison of three-factor versus four-factor prothrombin complex concentrate for emergent warfarin reversal: a retrospective cohort study

BACKGROUND

Prothrombin Complex Concentrates (PCC) are prescribed for emergent warfarin reversal (EWR). The comparative effectiveness and safety among PCC products are not fully understood.

METHODS

Patients in an academic level one trauma center who received PCC3 or PCC4 for EWR were identified. Patient characteristics, PCC dose and time of dose, pre- and post-INR and time of measurement, fresh frozen plasma and vitamin K doses, and patient outcomes were collected. Patients whose pre-PCC International Normalized Ratio (INR) was > 6 h before PCC dose or the pre-post PCC INR was > 12 h were excluded. The primary outcome was achieving an INR ≤ 1.5 post PCC. Secondary outcomes were the change in INR over time, post PCC INR, thromboembolic events (TE), and death during hospital stay. Logistic regression modelled the primary outcome with and without a propensity score adjustment accounting for age, sex, actual body weight, dose, initial INR value, and time between INR measurements. Data are reported as median (IQR) or n (%) with p < 0.05 considered significant.

RESULTS

Eighty patients were included (PCC3 = 57, PCC4 = 23). More PCC4 patients achieved goal INR (87.0% vs. 31.6%, odds ratio (OR) = 14.4, 95% CI: 3.80-54.93, p < 0.001). This result remained true after adjusting for possible confounders (AOR = 10.7, 95% CI: 2.17-51.24, p < 0.001). The post-PCC INR was lower in the PCC4 group (1.3 (1.3-1.5) vs. 1.7 (1.5-2.0)). The INR change was greater for PCC4 (2.3 (1.3-3.3) vs. 1.1 (0.6-2.0), p = 0.003). Death during hospital stay (p = 0.52) and TE (p = 1.00) were not significantly different.

CONCLUSIONS

PCC4 was associated with a higher achievement of goal INR than PCC3. This relationship was observed in the unadjusted and propensity score adjusted results.

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.

Subtherapeutic INR due to warfarin interaction with smokeless tobacco

We report an interesting case of warfarin resistance and subtherapeutic international normalized ratio (INR) in the setting of chronic smokeless tobacco use. A 33-year-old white male with a mechanical mitral valve failed to achieve therapeutic INR despite being on warfarin doses of up to 30 mg by mouth daily. The patient admits to chewing tobacco daily for the past 16 years. While evaluating potential causes of subtherapeutic INR, nonadherence, drug interactions, genetic polymorphisms, and dietary factors were considered. Subtherapeutic INR may be due to increased exposure to vitamin K from chewing tobacco. Tobacco is rich in vitamin K, and its chronic use may have caused the failure to attain a therapeutic INR. To our knowledge, there is only one other case of warfarin resistance resulting from smokeless tobacco described in published literature.

Definition of major bleeding: Prognostic classification

BACKGROUND

In patients on anticoagulant treatment, the major bleeding (MB) definition released by the International Society of Thrombosis and Haemostasis (ISTH) is widely accepted. However, this definition identifies MBs with highly variable short-term risk of death.

OBJECTIVES

The study aims were to derive and validate a classification of ISTH-defined MBs for the risk of short-term death.

METHODS

Consecutive patients admitted for ISTH-defined MB occurring while on treatment with oral anticoagulants were included in the study and divided into a derivation and a validation cohort. Death within 30 days was the primary study outcome.

RESULTS

Among 1077 patients with MB, 64/517 and 63/560 patients in the derivation and validation cohort died, respectively. In the derivation cohort, Glasgow coma scale (GCS) <14 and shock were predictors of death; critical site bleeding and hemoglobin decrease ≥2 g/dL, or transfusion ≥ 2 units were not. GCS <14 (hazard ratio [HR], 8.67; 95% confidence interval [CI], 3.93-19.13) was predictor of death in intracranial hemorrhage (ICH) and shock at admission (HR, 4.84; 95% CI, 2.01-11.70) and pericardial bleeding (HR, 11.37; 95% CI, 1.33-97.31) in non-ICH MBs. The predictive value of GCS <14 in ICH and shock and pericardial bleeding in non-ICH MBs was confirmed in the validation cohort. None of the patients with isolated ocular or articular bleeding died. A prognostic classification of ISTH-defined MBs for the risk of short-term death is proposed as "serious," "severe," and "life-threatening" (ICH with GCS <14 or non-ICH with shock) MBs.

CONCLUSION

According to our study, ISTH-defined MBs can be stratified for the risk of death within 30 days.

Current practice of antithrombotic prophylaxis in pediatric kidney transplantation-Results of an international survey on behalf of the European Society for Paediatric Nephrology

BACKGROUND

Renal graft thrombosis (RGT) is one of the main causes for early graft loss in pediatric kidney transplantation (KTx). Despite the lack of evidence-based recommendations, antithrombotic prophylaxis (aP) is used to prevent RGT.

METHODS

An online survey supported by the European Society for Pediatric Nephrology was developed to investigate the current practice of aP in pediatric KTx recipients <18 years.

RESULTS

A total of 80 pediatric KTx centers from 37 countries participated in the survey. Antithrombotic prophylaxis was performed in 96% of the pediatric renal transplant centers (all/selected patients: 54%/42%). The main overall used drugs were as follows: low-molecular-weight heparin (89%), unfractionated heparin (UFH) (69%), and acetylsalicylic acid (ASS) (55%). Ten different aP management strategies were identified as follows: 51% used a single drug and 48% combined two drugs sequentially. The corresponding centers started aP predominantly within 24 hours after pediatric KTx; 51% preferred UFH for starting aP. In centers switching to a second drug (51%), this change was performed after 10 ± 6 days; of these 57% preferred ASS for maintenance aP. Reported median aP duration was 51 days (range 1-360).

CONCLUSIONS

Despite the use of aP in almost all responding pediatric KTx centers, there is no uniform management strategy. Notwithstanding, UFH seems to be the preferred drug for the early post-operative period of pediatric KTx, and ASS for maintenance prophylaxis following pediatric KTx. Prospective studies are needed to further evaluate the benefits and risks of aP, preferably resulting in guidelines for the management in pediatric KTx.

Impact of Obesity on Warfarin Reversal With Fixed-Dose Factor VIII Inhibitor Bypassing Activity (aPCC)

BACKGROUND

Data are limited addressing anticoagulant reversal in obese patients using activated prothrombin complex concentrate (aPCC).

OBJECTIVE

Assess the impact of obesity on INR reversal with fixed aPCC dosing.

METHODS

Institutional review board-approved, retrospective cohort conducted in a large academic medical center. Patients 18 years or older who received fixed-dose aPCC for warfarin-associated hemorrhage were included. Patients who received aPCC for any other indications or who had no follow-up INR after aPCC administration were excluded. Patients with an INR of 5 or greater received 1000 units aPCC, whereas those with INR less than 5 received 500 units aPCC, per institutional protocol. Patients were stratified into obese and nonobese based on body mass index. Primary end point was INR reversal, defined as repeat INR of 1.4 or less within 4 hours following aPCC treatment, without a repeated dose. Secondary end points included percentage change in INR, proportion of patients requiring an additional dose of aPCC, bleeding complications, thrombotic complications, hospital length of stay, and in-hospital mortality.

RESULTS

259 patients were included, of whom 83 were obese (32%). A significantly higher proportion of nonobese patients achieved an INR of 1.4 or less within 4 hours of treatment (169 [96.02%] vs 69 [83.13%]; P = 0.0004). There were no differences in any secondary end points.

CONCLUSION AND RELEVANCE

When fixed-dose aPCC is used for warfarin reversal, obesity is associated with a significantly lower rate of INR reversal, without increased bleeding. This study adds to the limited amount of literature on aPCC dosing in obesity.

Assessment of factors affecting mortality in geriatric patients with warfarin overdose

OBJECTIVES:

The aim of the present study was to perform a demographic analysis of complications and to determine the factors affecting in-hospital mortality in geriatric patients with warfarin overdose.

MATERIALS AND METHODS:

All patients aged 65 years or older using warfarin with an international normalized ratio (INR) level above 3.5 IU between 01.01.2014 and 01.01.2018 were included in the study. Characteristics of patients with in-hospital mortality and surviving patients were compared. Multivariate regression analysis was used to assess the predictors for in-hospital mortality.

RESULTS:

A total of 302 geriatric patients included in the study for statistical analyses. Bleeding rate was 14.2%. A comparison of patient characteristics for in-hospital mortality (survivor vs. nonsurvivor) revealed significant differences for age, gender, chronic renal failure history, creatinine, aspartate aminotransferase (AST), and alanine aminotransferase levels (P < 0.05). A multivariate logistic regression analysis was performed. It was found that elevated AST (P = 0.029, odds ratio [OR]: 1.004, 95% confidence intervals [CIs]; 1.001–1.007) and creatinine (P = 0.045, OR: 2.36, 95% CIs; 1.02–5.48) levels as well as advanced age (P = 0.031, OR: 1.11, 95% CIs; 1.01–1.22) and male gender (P = 0.017, OR: 5.48, 95% CIs; 1.35–22.1) had a negative impact on survival.

CONCLUSION:

Our study results revealed that male gender, advanced age, and hepatic and renal dysfunctions were the predictors of in-hospital mortality in the elderly with warfarin overdose. In order to avoid serious warfarin-related complications in the older age groups, particularly when there is renal or hepatic dysfunction, patients should be informed about minor warning side effects of warfarin, INR levels should be more frequently checked, and patients should have more strict follow-up schedules.

A Multicenter Prospective Observational Cohort Study to Investigate the Effectiveness and Safety of Rivaroxaban in Japanese Venous Thromboembolism Patients (The J'xactly Study)

BACKGROUND

There is insufficient real-world data on the current status of Japanese patients with venous thromboembolism (VTE) or its treatment and prevention with rivaroxaban.

METHODS AND RESULTS

In this multicenter, prospective, observational study conducted in Japan, 1,039 patients with acute symptomatic/asymptomatic deep vein thrombosis (DVT) and pulmonary embolism (PE) with or without DVT prescribed rivaroxaban were enrolled at 152 institutions and observed for a median of 21.3 months. Mean age was 68.0±14.7 years, mean body weight was 60.3±14.1 kg, 59.0% were females, and 19.0% had active cancer. Incidences of recurrence or aggravation of symptomatic VTE (primary effectiveness outcome) and major bleeding (principal safety outcome) were 2.6% and 2.9% per patient-year, respectively. These outcomes did not differ between patients with DVT and those with PE (primary effectiveness outcome: 2.6% vs. 2.5% per patient-year, P=0.810; principal safety outcome: 3.5% vs. 2.4% per patient-year, P=0.394). The incidence of composite clinically relevant events, including recurrence or aggravation of symptomatic VTE, acute coronary syndrome, ischemic stroke, all-cause death, or major bleeding events, was 9.2% per patient-year. Multivariate analysis revealed that male sex, being underweight, having active cancer, chronic heart and lung disease, and previous stroke were independent determinants for composite clinically relevant events.

CONCLUSIONS

In Japanese clinical practice, a single-drug approach with rivaroxaban was demonstrated to be a valuable treatment for a broad range of VTE patients.

Optimal Dosage and Administration Practices for Vitamin K Antagonist Reversal With 4-Factor Prothrombin Complex Concentrate

Expert consensus and international guidelines recommend urgent co-administration of vitamin K and 4-factor prothrombin complex concentrates (4F-PCCs) to rapidly reverse VKA-related bleeding. This narrative review examined real-world evidence and strategies to optimize international normalized ratio (INR) reversal, hemostasis, and outcomes in patients receiving 4F-PCC in this setting. Key determinants for success include the appropriate use of alternative dosing and administration strategies, such as fixed dosing and increased infusion speed, adherence to institutional guidelines, and removing significant institutional barriers to reduce time to treatment. In the opinion of authors, minimizing the time to treatment with 4F-PCCs is of paramount importance when treating patients with VKA-related bleeding. Practices that safely and feasibly shorten the time to administration should be included in guidelines for institutions responsible for anticoagulant care, and adhered to in centers that perform invasive procedures on patients receiving VKA therapy. Further studies are required to optimize use of 4F-PCC, particularly in relation to the ideal dosing strategy and the role of INR.

Direct oral anticoagulants in patients with severe inherited thrombophilia: a single-center cohort study

We investigated the safety and efficacy of direct oral anticoagulants (DOACs) in patients with venous thromboembolism (VTE) associated with severe inherited thrombophilia. In this single-center cohort study, we enrolled 56 consecutive VTE patients with severe inherited thrombophilia, defined as the presence of antithrombin (n = 18), protein C (n = 12) and protein S (n = 12) deficiencies, homozygous Factor V Leiden (n = 3) and prothrombin G20210AA (n = 4) mutations, or combined defects (n = 7). During a median follow-up of 44.5 (IQR 30-52.5) months, rivaroxaban was used in 30 (53.6%), apixabanin 14 (25%), and dabigatran in 12 (21.4%) subjects. Recurrent nonfatal VTE was observed in 5 (8.9%) patients (2.4 per 100 patient-years), treated with rivaroxaban (n = 4) and apixaban (n = 1). Major bleeding and clinically relevant non-major bleeding (CRNMB) occurred in 2 (3.5%) and 4 (7%) subjects, respectively (0.96 per 100 patient-years and 1.92 per 100 patient-years, respectively), including 4 patients on rivaroxaban. The event-free survival analysis showed that the use of rivaroxaban was associated with increased risk of recurrent VTE or bleeding, compared with apixaban or dabigatran (HR 2.76, 95% CI 1.26-3.92, p = 0.039). In conclusion, the results of our cohort study indicate that full-dose dabigatran or apixaban are effective and safe in patients with severe inherited thrombophilia.

Barriers and facilitators to optimal oral anticoagulant management: a scoping review

Oral anticoagulants (OACs) are high alert medications and require high-quality management to optimize health outcomes. The objective of this scoping review was to identify barriers and facilitators (B&Fs) associated with the quality of OAC management. We searched MEDLINE, EMBASE, and CINAHL databases until July 12, 2018, and cross-referenced the bibliographies of the retrieved studies. We included quantitative and qualitative studies that assessed B&Fs to OAC management. The study selection and data extraction processes were performed in duplicate. Analyses included measuring the prevalence of reported B&Fs from studies reporting quantitative data, identifying B&Fs in narrative analyses, and identifying their impact on important outcomes of OAC management. B&Fs were coded and aggregated to higher-level themes using a consensus approach. Factors were described as "key" if they were statistically associated with important outcomes in a randomized trial or observational study. We included 62 studies-three randomized clinical trials (RCTs), 46 observational studies (cross-sectional studies, cohort studies, and case-control studies), 11 qualitative studies, and two mixed-methods studies. Factors identified could be grouped into four themes-therapy-related, patient-related, healthcare provider-related, and health system-related. Key barriers to optimal OAC management were mostly patient-related, whereas interventions focused on education or implementing protocols were shown through RCTs to be effective at improving knowledge scores of OAC patients. While multiple barriers and some facilitators were identified in this review, none was proven to be associated with clinical outcomes. With this in mind, individual physicians may wish to address the key barriers in their practice as a quality improvement initiative but system-wide or policy changes should await high-quality evidence. Future trials should address these factors.Systematic review registration: PROSPERO CRD42017069043.

Standardization of Prothrombin Time/International Normalized Ratio (PT/INR)

The prothrombin time (PT) represents the most commonly used coagulation test in clinical laboratories. The PT is mathematically converted to the international normalized ratio (INR) for use in monitoring anticoagulant therapy with vitamin K antagonists such as warfarin in order to provide test results that are adjusted for thromboplastin and instrument used. The INR is created using two major PT 'correction factors', namely the mean normal PT (MNPT) and the international sensitivity index (ISI). Manufacturers of reagents and coagulometers have made some efforts to harmonizing INRs, for example, by tailoring reagents to specific coagulometers and provide associated ISI values. Thus, two types of ISIs may be generated, with one being a 'general' or 'generic' ISI and others being reagent/coagulometer-specific ISI values. Although these play a crucial role in improving INR results between laboratories, these laboratories reported INR values are known to still differ, even when laboratories use the same thromboplastin reagent and coagulometer. Moreover, ISI values for a specific thromboplastin can vary among different models of coagulometers from a manufacturer using the same method for clot identification. All these factors can be sources of error for INR reporting, which in turn can significantly affect patient management. In this narrative review, we provide some guidance to appropriate ISI verification/validation, which may help decrease the variability in cross laboratory reporting of INRs.

Pharmacists views on participating in New Zealand's community pharmacy anticoagulation management service: a mixed-methods study

Background Optimal anticoagulation management is key for improving outcomes. The Community Pharmacy Anticoagulation Management Service (CPAMS) has beneficial effects on anticoagulant management. However, limited research exists on pharmacists' views of CPAMS provision, particularly the perspectives of pharmacists who do not provide CPAMS. Objectives To explore the experience and attitudes of pharmacists who do and do not provide CPAMS, and to identify factors that may influence further uptake of CPAMS. Setting CPAMS providing and non-providing pharmacies throughout New Zealand. Methods A mixed-methods study design was employed. Separate online surveys were conducted with CPAMS providers (N = 35) and non-providers (N = 73) to explore their views on the service. Twelve interviews were conducted with purposively selected participants, equally distributed between CPAMS providers and non-providers, to gain further insight into the issues surrounding CPAMS provision. Quantitative data were analysed using student's t-test and Mann Whitney U-test, and thematic analysis was used for qualitative data. Main outcome measure Experiences of and attitudes towards CPAMS. Results Our survey findings demonstrated that community pharmacists have high self-efficacy and motivation to providing CPAMS, and CPAMS had increased job satisfaction amongst providers. The overwhelming majority of CPAMS providers' survey participants believed that CPAMS improves the pharmacist-patient relationship, allowing them to assist patients with other aspects of their healthcare. Most non-provider survey participants also believed that their patients would benefit from CPAMS. The two most frequently reported barriers by non-providers survey participants were remuneration and staffing of pharmacists. The interview findings fell within five overarching themes: self-efficacy, CPAMS benefits to patients, barriers to providing CPAMS, the impact of CPAMS on pharmacist-patient and pharmacist-general practitioner relationships. Overall, the current funding model, the capping on the number of enrolled patients, and staffing were the main factors perceived by interview participants preventing the further uptake and implementation of CPAMS. CPAMS non-providers are willing to provide CPAMS; the main factor preventing this is availability of contracts. Conclusions Overall, pharmacists have favourable experiences of and attitudes towards CPAMS and strongly supported its wider implementation. Promoting the benefits and addressing the barriers highlighted in this study may lead to wider implementation of CPAMS.

Use of direct oral anticoagulants in patients with thrombotic antiphospholipid syndrome: Guidance from the Scientific and Standardization Committee of the International Society on Thrombosis and Haemostasis

Clarity and guidance is required with regard to the use of direct oral anticoagulants in antiphospholipid syndrome (APS) patients, within the confines of the recent European Medicines Agency recommendations, discrepant recommendations in other international guidelines and the limited evidence base. To address this, the Lupus Anticoagulant/Antiphospholipid Antibodies Scientific and Standardization Committee (SSC) chair and co-chairs together with SSC Control of Anticoagulation members propose guidance for healthcare professionals to help them manage APS patients. Uncertainty in this field will be addressed. This guidance will also serve as a call and focus for research.

Ambulatory care practice in the COVID-19 era: Redesigning clinical services and experiential learning

The coronavirus disease (COVID-19) has created a variety of challenges for health care professionals, including ambulatory care clinical pharmacists. High-quality remote and minimal-contact care has become a necessity. Ambulatory care clinical pharmacists around the nation have adjusted their practice. In many cases, this included implementation of telehealth programs for comprehensive medication management. The redesign of ambulatory care Advanced Pharmacy Practice Experiences (APPE) also required quick adaptation. In this paper, we describe the clinical practice and experiential education challenges encountered by an ambulatory care clinical pharmacist workgroup in a COVID-19 "hotspot," with an emphasis on solutions and guidance. We discuss how to adapt ambulatory care clinical pharmacy practices including methods of minimal-contact care, reimbursement opportunities, tracking outcomes, and restructuring ambulatory care APPE. As ambulatory care clinical pharmacists continue to expand the services they provide in response to COVID-19, we also describe opportunities to promote pharmacists as providers during times of pandemic and into the future.

Deep Vein Thrombosis in Patients with Intertrochanteric Fracture: A Retrospective Study

BACKGROUND

This study aimed to investigate the incidences of pre- and post-operative lower extremity deep venous thrombosis (DVT) in hospitalized patients with intertrochanteric fractures and to analyze the relevant risk factors.

METHODS

A retrospective study was conducted between July 2014 and October 2016 in 218 intertrochanteric fracture patients who presented at Xi'an Honghui Hospital and underwent Doppler ultrasonography for DVT diagnosis. We divided DVT into distal, proximal, and mixed thrombosis. Patients were divided into either the thrombosis or no thrombosis group according to preoperative and postoperative ultrasonography results. All patients were evaluated for the risk factors associated with thrombosis.

RESULTS

A total of 37.61% of preoperative patients had DVT, and the postoperative incidence increased to 58.72%. The days between fracture and hospitalization and the days between fracture and surgery were independent risk factors for preoperative DVT. The days between fracture and hospitalization and d-dimer levels at postoperative 1 day were independent risk factors of postoperative DVT. In total 23.4% of the patients progressed from having no thrombosis preoperatively to having distal, proximal, or mixed DVT postoperatively (22.02%, 0.46%, and 0.92%, respectively). Distal DVT constituted 86.59% and 90.63% of all preoperative and postoperative DVTs, respectively.

CONCLUSION

Intertrochanteric fracture is a common type of hip fracture in the elderly, and the incidence of DVT after intertrochanteric fracture may be underestimated. Early intervention (early admission and early surgery) might reduce the incidence of DVT.

Management of Outpatient Warfarin Therapy amid COVID-19 Pandemic: A Practical Guide

Many healthcare resources have been and continue to be allocated to the management of patients with COVID-19. Therefore, the ongoing care of patients receiving oral anticoagulation with warfarin is likely to be compromised amid this unprecedented crisis. This article discusses a stepwise algorithm for the management of outpatient warfarin therapy. Alternative management strategies are presented and discussed, including alternative pharmacological therapy options and self-monitoring. Our algorithm aims to help clinicians safely optimize the treatment of patients requiring anticoagulation therapy in the context of the global response to the current pandemic.

Management of Outpatient Warfarin Therapy amid COVID-19 Pandemic: A Practical Guide

Many healthcare resources have been and continue to be allocated to the management of patients with COVID-19. Therefore, the ongoing care of patients receiving oral anticoagulation with warfarin is likely to be compromised amid this unprecedented crisis. This article discusses a stepwise algorithm for the management of outpatient warfarin therapy. Alternative management strategies are presented and discussed, including alternative pharmacological therapy options and self-monitoring. Our algorithm aims to help clinicians safely optimize the treatment of patients requiring anticoagulation therapy in the context of the global response to the current pandemic.

Switch from oral anticoagulants to parenteral heparin in SARS-CoV-2 hospitalized patients

The development of COVID-19 syndrome in anticoagulated patients, and especially their admission to intensive-care units with acute severe respiratory syndrome (SARS-CoV-2), expose them to specific problems related to their therapy, in addition to those associated with the acute viral infection. Patients on VKA hospitalized with SARS-CoV-2 show high instability of PT INR due to the variability of vitamin K metabolism, diet, fasting, co-medications, liver impairment, and heart failure. Patients on DOAC are exposed to under/over treatment caused by significant pharmacological interferences. In consideration of the pharmacological characteristics of oral anticoagulant drugs, the multiple pharmacological interactions due to the treatment of acute disease and the possible necessity of mechanical ventilation with hospitalization in intensive-care units, we suggest replacing oral anticoagulant therapies (VKA and DOAC) with parenteral heparin to avoid the risk of over/under treatment.

Thrombin generation and thromboelastometry in monitoring the in-vitro reversal of warfarin: a comparison between 3-factor and 4-factor prothrombin complex concentrates

: The efficacy of three-factor prothrombin complex concentrates (PCCs) in the reversal of vitamin K antagonists is still a matter of debate. We compared the 'in-vitro' effect of three PCCs (one three-factor and two four-factor) on international normalized ratio (INR), thrombin generation and thromboelastometry of patients at different degrees of anticoagulation with vitamin K antagonist. We tested three concentrations of PCC (0.5, 1 and 1.5 U/ml) in six patients: three (INR 2.0-2.9) and three (INR 3.0-4.0). In this preliminary phase, we determined the lowest effective dose for a target INR less than 1.5 and to normalize endogenous thrombin potential and clotting time in EXTEM assay. In the validation phase, we tested the effect of the newly determined lowest effective PCC dose on samples of 40 (INR 2.0-2.9) and 20 (INR 3.0-4.0) patients. The minimum efficacious dosage to achieve the target INR with three-factor PCC (3-PCC) was 0.5 (INR 2.0-2.9) and 1.5 U/ml (INR 3.0-4.0). Four-factor PCCs (4-PCCs) achieved target INR with the lowest dose (0.5 U/ml) independently of baseline INR. Thrombin generation endogenous thrombin potential and EXTEM clotting time achieved normal values with the lowest dose (0.5 U/ml) of either 3-PCC or 4-PCC independently of baseline INR. Data observed in the preliminary phase were confirmed in the validation phase. 3-PCC appears to be as effective as 4-PCC in reversing oral anticoagulant treatment based on thrombin generation and EXTEM data, but not INR data, at least in the range of INR considered in our study. Further studies are needed to address the clinical implications of our results.

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.

A systematic review and meta-analysis of supplemental education in patients treated with oral anticoagulation

Oral anticoagulants (OACs) are indicated for treatment and prevention of thromboembolic diseases. Supplemental patient education (education) has been proposed to improve outcomes, and this systematic review assesses the effect of education on mortality, thromboembolic events (TEEs) including venous thromboembolism (VTE), and bleeding in patients taking OACs. Randomized controlled trials were included, and 2 authors independently screened articles and assessed risk of bias. In 9 trials (controls, n = 720; intervention group patients, n = 646), 4 assessed critical outcomes of mortality, TEEs (VTE, stroke, and systemic embolism), and bleeding to estimate absolute risk ratios. When comparing education with usual care, in 1000 patients, there may be 12 fewer deaths (95% confidence interval [CI], 19 fewer to 154 more) and 16 fewer bleeding events (95% CI, 34 fewer to 135 more), but this evidence is uncertain; the evidence also suggests 6 fewer VTEs (95% CI, 10 fewer to 16 more) and 8 fewer TEEs (95% CI, 16 fewer to 18 more). The mean difference in time in therapeutic range may be 2.4% higher in the education group compared with usual care (95% CI, 2.79% lower to 7.58% higher). We also found very low certainty of evidence for a large increase in knowledge scores (standardized mean difference, 0.84 standard deviation units higher; 95% CI, 0.51-1.16). Overall, the certainty of evidence was low to very low because of serious risk of bias and serious imprecision. Additional sufficiently powered trials or different approaches to education are required to better assess supplemental education effects on outcomes in patients taking OACs.

Effects of vitamin K1 treatment on plasma concentrations of long-acting anticoagulant rodenticide enantiomers following inhalation of contaminated synthetic cannabinoids

Background: An outbreak of synthetic cannabinoid (SC)-associated coagulopathy and bleeding in Illinois, USA was determined to be due to inhalation of SC contaminated with brodifacoum (BDF), difenacoum (DiF), and bromadiolone (BDL), highly potent long-acting anticoagulant rodenticides (LAARs). Treatment with high-dose vitamin K1 (VK1) prevented mortality; however, plasma LAAR levels were not measured risking recurrence of coagulopathy and bleeding due to premature discontinuation. The goal of this study was to determine if plasma LAAR levels were reduced following standard of care treatment to normalize coagulopathy.Methods: Blood samples were collected from a cohort of 32 patients, and ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) analysis used to quantify plasma LAAR levels including enantiomers.Results: BDF was detected in 31 samples; 30 also contained DiF and 18 contained BDL. Initial plasma levels were 581 ± 87, 11.0 ± 1.9, and 14.9 ± 5.9 ng/mL for BDF, DiF, and BDL, respectively (mean ± SE). At discharge plasma, BDF levels remained elevated at 453 ± 68 ng/mL. Plasma half-lives for BDF, DiF, and BDL were 7.5 ± 1.3, 7.2 ± 1.9, and 1.8 ± 0.3 days, respectively. The half-life for trans-BDF enantiomers (5.7 ± 0.8 days) was shorter than for cis-enantiomers (7.6 ± 1.9 days). BDF half-lives were shorter, and coagulopathy normalized faster in patients receiving intravenous VK1 as compared to oral VK1. Patients prescribed VK1 at discharge had fewer re-admittances.Conclusions: These results demonstrate that plasma LAAR levels at discharge were elevated in poisoned patients despite normal coagulation, and that the route of VK1 administration affected LAAR pharmacokinetics and INR normalization. We propose plasma LAAR levels and coagulation be monitored concomitantly during follow-up of patients with LAAR poisoning. KEY POINTSIn patients treated with high-dose vitamin K1 for LAAR poisoning, plasma levels remained 40-fold above safe levels upon discharge from hospital.LAAR half-lives, normalization of coagulopathy, and readmittances were reduced by treatment with intravenous vitamin K1.

Management of antiplatelet or anticoagulant therapy in endoscopy: A review of literature

Endoscopic procedures hold a basal risk of bleeding that depends on the type of procedure and patients’ comorbidities. Moreover, they are often performed in patients taking antiplatelet and anticoagulants agents, increasing the potential risk of intraprocedural and delayed bleeding. Even if the interruption of antithrombotic therapies is undoubtful effective in reducing the risk of bleeding, the thromboembolic risk that follows their suspension should not be underestimated. Therefore, it is fundamental for each endoscopist to be aware of the bleeding risk for every procedure, in order to measure the risk-benefit ratio for each patient. Moreover, knowledge of the proper management of antithrombotic agents before endoscopy, as well as the adequate timing for their resumption is essential.

This review aims to analyze current evidence from literature assessing, for each procedure, the basal risk of bleeding and the risk of bleeding in patients taking antithrombotic therapy, as well as to review the recommendation of American society for gastrointestinal endoscopy, European society of gastrointestinal endoscopy, British society of gastroenterology, Asian pacific association of gastroenterology and Asian pacific society for digestive endoscopy guidelines for the management of antithrombotic agents in urgent and elective endoscopic procedures.

Comparison of Hemostatic Outcomes in Patients Receiving Fixed-Dose vs. Weight-Based 4-Factor Prothrombin Complex Concentrate

BACKGROUND

Four-factor prothrombin complex concentrate (4F-PCC) is a blood coagulation product indicated for urgent reversal of warfarin. Currently there are no studies using 4F-PCC as a fixed dose to achieve hemostasis with warfarin as well as direct factor Xa inhibitors.

OBJECTIVES

The objective of this study was to evaluate the efficacy and safety of 4F-PCC administration using a fixed dose of approximately 2000 factor IX units to achieve hemostasis in anticoagulated patients, compared with weight-based therapy.

METHODS

This single-center, retrospective cohort study was performed at a 433-bed tertiary care hospital in central Kentucky. Patients from January 1, 2014 to December 31, 2018 were included if they were 18 years or older and received 4F-PCC for hemostasis of oral anticoagulation. Efficacy was assessed by determining if clinically effective hemostasis was achieved after receiving a fixed-dose vs. a weight-based dose of 4F-PCC.

RESULTS

Seventy-two patients were included in the study. Thirty-eight received weight-based dosing, compared with 34 receiving a fixed dose. Results yielded no statistical difference in clinically effective hemostasis using a fixed-dose vs. weight-based dosing, 91.2% and 78.9%, respectively (p = 0.150). There was no significant difference in adverse events, length of stay, or in-hospital mortality between groups; however, significant acquisition cost savings was realized.

CONCLUSIONS

A fixed-dose regimen of approximately 2000 factor IX units of 4F-PCC may be a reasonable approach to achieve hemostasis in patients receiving warfarin or factor Xa inhibitors. Additionally, utilization of a fixed-dose regimen may lead to significant acquisition cost savings for facilities.

Direct oral anticoagulant plasma levels' striking increase in severe COVID-19 respiratory syndrome patients treated with antiviral agents: The Cremona experience

BACKGROUND

Antiviral drugs are administered in patients with severe COVID-19 respiratory syndrome, including those treated with direct oral anticoagulants (DOACs). Concomitant administration of antiviral agents has the potential to increase their plasma concentration. A series of patients managed in the Cremona Thrombosis Center were admitted at Cremona Hospital for SARS-CoV-2 and started antiviral drugs without stopping DOAC therapy. DOAC plasma levels were measured in hospital and results compared with those recorded before hospitalization.

METHODS

All consecutive patients on DOACs were candidates for administration of antiviral agents (lopinavir, ritonavir, or darunavir). Plasma samples for DOAC measurement were collected 2to 4 days after starting antiviral treatment, at 12 hours from the last dose intake in patients on dabigatran and apixaban, and at 24 hours in those on rivaroxaban and edoxaban. For each patient, C-trough DOAC level, expressed as ng/mL, was compared with the one measured before hospitalization.

RESULTS

Of the 1039 patients hospitalized between February 22 and March 15, 2020 with COVID-19 pneumonia and candidates for antiviral therapy, 32 were on treatment with a DOAC. DOAC was stopped in 20 and continued in the remaining 12. On average, C-trough levels were 6.14 times higher during hospitalization than in the pre-hospitalization period.

CONCLUSION

DOAC patients treated with antiviral drugs show an alarming increase in DOAC plasma levels. In order to prevent bleeding complications, we believe that physicians should consider withholding DOACs from patients with SARS-CoV-2 and replacing them with alternative parenteral antithrombotic strategies for as long as antiviral agents are deemed necessary and until discharge.

Treatment of gastrointestinal bleeding in left ventricular assist devices: A comprehensive review

Left ventricular assist devices (LVAD) are increasingly become common as life prolonging therapy in patients with advanced heart failure. Current devices are now used as definitive treatment in some patients given the improved durability of continuous flow pumps. Unfortunately, continuous flow LVADs are fraught with complications such as gastrointestinal (GI) bleeding that are primarily attributed to the formation of arteriovenous malformations. With frequent GI bleeding, antiplatelet and anticoagulation therapies are usually discontinued increasing the risk of life-threatening events. Small bowel bleeds account for 15% as the source and patients often undergo multiple endoscopic procedures. Treatment strategies include resuscitative measures and endoscopic therapies. Medical treatment is with octreotide. Novel treatment options include thalidomide, angiotensin converting enzyme inhibitors/angiotensin II receptor blockers, estrogen-based hormonal therapies, doxycycline, desmopressin and bevacizumab. Current research has explored the mechanism of frequent GI bleeds in this population, including destruction of von Willebrand factor, upregulation of tissue factor, vascular endothelial growth factor, tumor necrosis factor-α, tumor growth factor-β, and angiopoetin-2, and downregulation of angiopoetin-1. In addition, healthcare resource utilization is only increasing in this patient population with higher admissions, readmissions, blood product utilization, and endoscopy. While some of the novel endoscopic and medical therapies for LVAD bleeds are still in their development stages, these tools will yet be crucial as the number of LVAD placements will likely only increase in the coming years.

Management of oral anticoagulants prior to emergency surgery or with major bleeding: A survey of perioperative practices in North America: Communication from the Scientific and Standardization Committees on Perioperative and Critical Care Haemostasis and Thrombosis of the International Society on Thrombosis and Haemostasis

BACKGROUND

There is limited information on real-world practice versus current clinical practice guidelines for oral anticoagulant reversal before emergency surgery.

OBJECTIVE

To identify current practice/knowledge gaps for oral anticoagulant reversal emergency surgery among anesthesiologists.

METHODS

A 22-question survey covering aspects of clinical practice relating to oral anticoagulant reversal was sent to American Society of Anesthesiology members with weekly reminders during data collection from October to December 2018.

RESULTS

Responses were received from 2315 anesthesiologists of which 86% of respondents were United States based. Emergency surgery was defined as occurring within 4 hours of the decision to operate by 60% of respondents. Fresh frozen plasma (FFP) was used by 75% of respondents for vitamin K antagonist (VKA) reversal and by 54% for direct oral anticoagulant (DOAC) reversal in emergency surgery and 67% in major operative bleeding. Only 32% of institutions had emergency anticoagulant reversal protocols, and 54% of respondents selected an international normalized ration (INR) ratio goal for VKA reversal of ≤1.5. Only 13% initially consulted or coordinated management with hematologists, and the final decision regarding coagulation management was made by the respondent in 26% of cases. A coordinated approach with hematologists and cardiologists was reported by 64%, and over half (51%) required approval for prothrombin complex concentrate administration for emergency procedures.

CONCLUSIONS

Despite recommendations to the contrary, FFP is extensively used for emergency VKA and DOAC reversal. There is a clear need for institutions to develop guideline-informed recommendations/management algorithms based on input from medical professionals routinely involved in management of these patients.

Vitamin K versus warfarin interruption alone in patients without bleeding and an international normalized ratio > 10

BACKGROUND

Reversal of an international normalized ratio (INR) > 10 with vitamin K is recommended in patients experiencing bleeding; however, information on outcomes with reversal using vitamin K in non-bleeding patients is lacking.

OBJECTIVE

To compare clinical and safety outcomes between non-bleeding patients receiving warfarin with an INR > 10 who did and did not receive a prescription for vitamin K.

PATIENTS/METHODS

This was a retrospective cohort study conducted in an integrated health-care delivery system. Adult patients receiving warfarin therapy who experienced an INR > 10 without bleeding between 01/01/2006 and 06/30/2018 were included. Patients were assessed for an outpatient dispensing or in-office administration of vitamin K on the day of or the day after an INR > 10 and then clinically relevant bleeding, thromboembolism, all-cause mortality, and time to INR < 4 within the next 30 days.

RESULTS

A total of 809 patients was included with 332 and 477 who were and were not dispensed vitamin K, respectively. Overall, mean patient age was 71.7 years, 60.1% were female and the mean INR was 10.4 at presentation. There were no differences between groups in 30-day rates of bleeding or thromboembolism (both P > .05). Patients dispensed vitamin K had a higher likelihood of mortality (15.1% versus 10.1%, P = .032, adjusted odds ratio = 1.63, 95% confidence interval 1.03 to 2.57). Overall, time to an INR < 4 was similar between groups.

CONCLUSION

Vitamin K administration was not associated with improved clinical outcomes in asymptomatic patients with an INR > 10.

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.

Precision Dosing Priority Criteria: Drug, Disease, and Patient Population Variables

The administered dose of a drug modulates whether patients will experience optimal effectiveness, toxicity including death, or no effect at all. Dosing is particularly important for diseases and/or drugs where the drug can decrease severe morbidity or prolong life. Likewise, dosing is important where the drug can cause death or severe morbidity. Since we believe there are many examples where more precise dosing could benefit patients, it is worthwhile to consider how to prioritize drug-disease targets. One key consideration is the quality of information available from which more precise dosing recommendations can be constructed. When a new more precise dosing scheme is created and differs significantly from the approved label, it is important to consider the level of proof necessary to either change the label and/or change clinical practice. The cost and effort needed to provide this proof should also be considered in prioritizing drug-disease precision dosing targets. Although precision dosing is being promoted and has great promise, it is underutilized in many drugs and disease states. Therefore, we believe it is important to consider how more precise dosing is going to be delivered to high priority patients in a timely manner. If better dosing schemes do not change clinical practice resulting in better patient outcomes, then what is the use? This review paper discusses variables to consider when prioritizing precision dosing candidates while highlighting key examples of precision dosing that have been successfully used to improve patient care.

Quantitative analysis of direct oral anticoagulant rivaroxaban by terahertz spectroscopy

Rivaroxaban, as a direct oral anticoagulant, has been widely used in the treatment and prevention of thrombosis disease (TD). However, even if the same dose of rivaroxaban is taken, different pathophysiological characteristics of TD patients determine the differences in plasma concentrations between individuals, leading to the difficulties of dosage selection and plasma concentration control. Conventional rivaroxaban detection methods, including prothrombin time method, anti-Xa assay and liquid chromatography-tandem mass spectrometry (LC-MS/MS), are not widely used in clinical practice due to the limitations of accuracy, speed and cost. Here, we present a simple quantitative detection method for rivaroxaban by terahertz (THz) spectroscopy. Combining density functional theory (DFT) method and THz spectroscopy, the THz absorption peaks of rivaroxaban and the corresponding low-frequency vibrational modes are studied theoretically and experimentally. We find linear relationships between the amplitudes of these characteristic peaks and the concentrations of rivaroxaban. Based on these linear functions, we can analyse the rivaroxaban concentration with a detection time of 1 minute per test and the lowest detection limit of 2 μmol mL^-1. As compared to Raman spectroscopy method (its detection limit is about 80 μmol mL^-1), our method has more potential and is practical for the clinical quantitative detection of rivaroxaban as well as other direct oral anticoagulants.

CYP2C9-mediated warfarin and milk thistle interaction

WHAT IS KNOWN AND OBJECTIVE

In vitro studies suggest a CYP2C9-mediated interaction between milk thistle and warfarin, but there has been no in vivo case report on this interaction.

CASE DESCRIPTION

A White Hispanic man in his 30s was well controlled on warfarin therapy for mitral valve replacement. His INR increased from 2.64 to 4.12, and he denied changes to his medications and diet but noted starting a 'liver cleanse' supplement which contained milk thistle (200 mg). After stopping the supplement his INR normalized, and he remains on the same warfarin dose.

WHAT IS NEW AND CONCLUSION

This is the first in vivo report of an interaction between milk thistle and warfarin.

Impact of Anticoagulation on Mortality and Resource Utilization Among Critically Ill Patients With Major Bleeding

OBJECTIVES

Patients with major bleeding are commonly admitted to the ICU. A growing number are on either oral or parenteral anticoagulation, but the impact of anticoagulation on patient outcomes is unknown. We sought to examine this association between anticoagulation therapy and mortality, as well as the independent effects of warfarin compared to direct oral anticoagulants.

DESIGN

Analysis of a prospectively collected registry (2011-2017) of consecutive ICU patients admitted with major bleeding (as defined by International Society on Thrombosis and Haemostasis clinical criteria).

SETTING

Two hospitals within a single tertiary care level hospital system.

PATIENTS

We analyzed 1,598 patients identified with major bleeding, of which 245 (15.3%) had been using anticoagulation at the time of ICU admission. Of patients on anticoagulation, 149 were using warfarin, and 60 were using a direct oral anticoagulant.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The primary outcome, in-hospital mortality, was analyzed using a multivariable logistic regression model. Patients with anticoagulation-associated major bleeding had higher in-hospital mortality (adjusted odds ratio, 1.49; 95% CI, 1.16-1.92). Among survivors, anticoagulation use was associated with longer median hospital length of stay, and higher mean costs. No differences in hospital mortality were seen between warfarin- and direct oral anticoagulant-associated major bleeding. Patients with warfarin-associated major bleeding had longer median length of stay (11 vs 6 d; p = 0.02), and higher total costs than patients with direct oral anticoagulant-associated major bleeding.

CONCLUSIONS

Among ICU patients admitted with major bleeding, pre-admission anticoagulation use was associated with increased hospital mortality, prolonged length of stay, and higher costs among survivors. As compared to direct oral anticoagulants, patients with warfarin-associated major bleeding had increased length of stay and costs. These findings have important implications in the care of ICU patients with major bleeding.

Intravenous vitamin K1 normalises prothrombin time in 1 hour in dogs with anticoagulant rodenticide toxicosis

Four dogs with anticoagulant rodenticide toxicosis were treated with intravenous vitamin K₁ in lieu of plasma transfusion due to client cost constraints. Two dogs experienced a suspected anaphylactoid reaction, necessitating cessation of the treatment in one dog. Prothrombin time was rechecked 1 h after treatment in the remaining three dogs and all results were within the normal reference range. All four dogs were discharged from hospital within 48 h of presentation. Intravenous vitamin K₁ rapidly reverses the coagulopathic state in dogs with anticoagulant rodenticide toxicosis. It is a viable alternative therapy to plasma transfusion if circumstances preclude its use; however, patients must be monitored for anaphylactoid reactions.

Feasibility of Venovenous Extracorporeal Membrane Oxygenation Without Systemic Anticoagulation

BACKGROUND

Venovenous extracorporeal membrane oxygenation (ECMO) is increasingly being used for acute respiratory distress syndrome and as a bridge to lung transplantation. After initiation of venovenous ECMO, systemic anticoagulation therapy is traditionally administered and can cause bleeding diathesis. Here, we investigated whether venovenous ECMO can be administered without continuous systemic anticoagulation administration for patients with acute respiratory distress syndrome.

METHODS

This is a retrospective review of an institutional ECMO database. We included consecutive patients from January 2015 through February 2019. Overall, 38 patients received low levels of continuous systemic anticoagulation (AC+) whereas the subsequent 36 patients received standard venous thromboprophylaxis (AC-). Published Extracorporeal Life Support Organization guidelines were used for the definition of outcomes and complications.

RESULTS

Overall, survival was not different between the two groups (P = .58). However, patients in the AC+ group had higher rates of gastrointestinal bleeding (28.9%, vs AC- group 5.6%; P < .001). The events per patient-day of gastrointestinal bleeding was 0.00025 in the AC- group and 0.00064 in the AC+ group (P < .001). In addition, oxygenator dysfunction was increased in the AC+ group (28.9% and 0.00067 events per patient-day, vs AC- 11.1% and 0.00062 events per patient-day; P = .02). Furthermore, the AC+ group received more transfusions: packed red blood cells, AC+ group 94.7% vs AC- group 55.5% (P < .001); fresh frozen plasma, AC+ 60.5% vs AC- 16.6% (P = .001); and platelets, AC+ 84.2% vs AC- 27.7% (P < .001). There was no circuit thrombosis in either groups throughout the duration of ECMO support.

CONCLUSIONS

Our results suggest that venovenous ECMO can be safely administered without continuous systemic anticoagulation therapy. This approach may be associated with reduced bleeding diathesis and need for blood transfusions.

Assessment of warfarin algorithms for hospitalized adults: searching for a safe dosing strategy

This study evaluates three warfarin dosing algorithms (Kimmel, Dawson, High Dose ≥ 2.5 mg) for hospitalized older adults. A random selection of 250 patients with overshoots (INR ≥ 5 after 48 h of hospitalization) and 250 patients without overshoots were accessed from a database of 12,107 inpatients ≥ 65 years treated with chronic warfarin during hospitalization between January 1, 2014 and June 30, 2016. Algorithms were retrospectively applied to patients 2 days prior to overshoots in the overshoot group, and 2 days prior to the maximum INR reached after 48 h of hospitalization in the non-overshoot group. Patients were categorized as overdosed or not overdosed and compared using descriptive statistics. Logistic regression modeling determined predictors for overshoots. There was no significant difference between overdose and non-overdose groups for progressing to overshoots by the Kimmel (51.0% vs. 48.7%, p = 0.67) or Dawson (48.5 vs. 57.9%, p = 0.19) algorithms. The Low Dose Group (≤ 2.5 mg) was significantly more likely to experience an overshoot than the High Dose Group (56.6% vs. 45.5%, p = 0.04). The Low Dose Group was more likely to be older (81.4% vs. 71.1%, p = 0.02), female (63.5% vs. 49.8%, p = 0.02), weigh less (71.3 ± 21.9 vs. 79 ± 23.1, p = 0.002), and be prescribed amiodarone (16.6% vs. 8.1%, p = 0.01). While none of the algorithms predicted overshoots in logistic regression modeling, weight over 70 kg and black race remained protective. The High Dose Algorithm revealed that providers appropriately gave lower doses to patients at highest risk for warfarin sensitivity. Future studies are needed to investigate tools for inpatient warfarin dosing in older adults.

Comparison of the Therapeutic Effects of Rivaroxaban Versus Warfarin in Antiphospholipid Syndrome: A Systematic Review

OBJECTIVES

This study aims to review the studies evaluating the therapeutic effects of rivaroxaban versus those of warfarin in patients with antiphospholipid syndrome (APS).

MATERIALS AND METHODS

The study included randomized clinical trials, comparative studies, cross-sectional investigations, and case series that focused on the effects of warfarin and rivaroxaban and compared the effects of these anticoagulants in patients with APS. The relevant articles published until 2018 were searched in several databases, including PubMed, Scopus, ScienceDirect, Google Scholar, Embase, and Web of Science.

RESULTS

The findings of the reviewed studies showed that rivaroxaban can be used as an effective and safe alternative to warfarin in APS patients. However, the effectiveness of rivaroxaban in the prevention of thrombosis in high-risk APS patients is suspected.

CONCLUSION

Given the high risk of using rivaroxaban in thrombotic APS patients with labile international normalized ratio (INR) or poor adherence to INR monitoring, it is not suggested to use this agent for these patients.

Prognosis and risk factors in older patients with lung cancer and pulmonary embolism: a propensity score matching analysis

Older patients, especially those with malignancy, may have an increased risk of pulmonary embolism (PE). However, few studies have evaluated the clinical characteristics and prognosis of older patients. We evaluated the clinical characteristics, prognosis, and risk factors in older patients with lung cancer complicated with PE. This was a single-center, prospective cohort study. Older patients (≥65 years) with lung cancer admitted in Beijing Hospital from January 2006 to December 2016 were enrolled. The patients were divided into two groups according to the presence of PE using propensity score matching (PSM). After PSM, one hundred and six patients (53 per group) with an average age of (77.3 ± 10.9) years were enrolled. Adenocarcinoma was the most common histology in patients with PE (52.8%, n = 28), and most lung cancer patients were in stages III and IV (59.4%, n = 63). Patients with PE were stratified to low risk (52.8%, n = 28), intermediate-low risk (24.5%, n = 13), intermediate-high risk (15.1%, n = 8), high-risk (7.5%, n = 4) subgroups. Most PE patients presented with dyspnea (75.5%), and the majority of patients (86.8%, n = 46) developed PE within 3 months after the diagnosis of cancer. The median follow-up time was 23.7 months (12.0-62.0 months), and 7 patients (6.6%) were lost to follow-up. During the follow-up period, 92 patients (86.8%) died, including 8 cases (8.7%) of PE-related death, 73 (79.3%) of tumor death, and 11 (11.9%) of unknown cause. There were significant differences in all-cause mortality (94.3% vs. 83.0%) and PE-related mortality (15.1% vs. 0) between the PE and control groups, but the rate of tumor-related mortality (75.5% vs. 66.0%) was comparable between the groups. Among the 92 patients who died, the mortality rates at 3, 6, 12, and > 12 months after tumor diagnosis were 33.0% (33/106), 57.5% (61/106), 78.3% (83/106), and 89.6% (95/106), respectively. Kaplan-Meier survival analysis showed that the median overall survival time was significantly different between the PE and the control groups (4.3 vs. 9.2 months, P = 0.0015). Multivariate stepwise logistic regression analysis showed that age ≥ 77 years (OR = 2.58, 95%CI: 1.66-4.01), clinical stage III-IV (OR = 2.21, 95%CI: 1.03-4.74), adenocarcinoma (OR = 3.24, 95%CI: 1.75-6.00), high D-dimer (≥600 mg/L) (OR = 2.73, 95%CI: 1.25-5.96), and low partial pressure of oxygen (PaO₂; <75 mmHg) (OR = 2.85, 95%CI: 1.74-4.67) were independent risk factors for PE in older patients with lung cancer. Older patients with lung cancer and PE often have poor prognosis. Advanced age, clinical stage III-IV, adenocarcinoma, high D-dimer level, and low PaO₂ are independent risk factors for PE.

The Role of CYP450 Drug Metabolism in Precision Cardio-Oncology

As many novel cancer therapies continue to emerge, the field of Cardio-Oncology (or onco-cardiology) has become crucial to prevent, monitor and treat cancer therapy-related cardiovascular toxicity. Furthermore, given the narrow therapeutic window of most cancer therapies, drug-drug interactions are prevalent in the cancer population. Consequently, there is an increased risk of affecting drug efficacy or predisposing individual patients to adverse side effects. Here we review the role of cytochrome P450 (CYP450) enzymes in the field of Cardio-Oncology. We highlight the importance of cardiac medications in preventive Cardio-Oncology for high-risk patients or in the management of cardiotoxicities during or following cancer treatment. Common interactions between Oncology and Cardiology drugs are catalogued, emphasizing the impact of differential metabolism of each substrate drug on unpredictable drug bioavailability and consequent inter-individual variability in treatment response or development of cardiovascular toxicity. This inter-individual variability in bioavailability and subsequent response can be further enhanced by genomic variants in CYP450, or by modifications of CYP450 gene, RNA or protein expression or function in various 'omics' related to precision medicine. Thus, we advocate for an individualized approach to each patient by a multidisciplinary team with clinical pharmacists evaluating a treatment plan tailored to a practice of precision Cardio-Oncology. This review may increase awareness of these key concepts in the rapidly evolving field of Cardio-Oncology.

Patient compliance with an anticoagulation management system based on a smartphone application

We developed a novel anticoagulation management system (Anticlot Assistant) based on a smartphone application (App). This study was performed to evaluate patient compliance with Anticlot Assistant. This prospective case series study involved patients receiving warfarin therapy. The eligible patients were managed via Anticlot Assistant, and outcome data were analyzed. Thirty patients were recruited. The mean time within the therapeutic range (TTR) was 56.5% ± 26.2% and the mean patient compliance with Anticlot Assistant was 52.7% ± 40.4%. The patients in good compliance group had higher TTR (65.6 ± 25.0% vs. 40.0 ± 21.0%, P = 0.009), lower time in the extremely low range (9.4 ± 10.6% vs. 27.4 ± 13.2%, P = 0.000) and in the extremely high range (1.3 ± 2.8% vs. 14.1 ± 22.3%, P = 0.004) than those in poor compliance group. Logistic regression analysis revealed that receiving an education of > 6 years was the only independent predictor of good compliance (odds ratio 8.400, 95% confidence interval 1.274-55.394, P = 0.027). Patient compliance is critical important for good outcomes and it might increase with improvements in education and more widespread use of information technology. Although further improvement is needed, Anticlot Assistant is promising and this study offered valuable experiences for further research.