Evaluation of Response to High-Dose Intravenous Vitamin K Administration.

BACKGROUND: Essential to the coagulation pathway, vitamin K (phytonadione) is used to correct clotting factor deficiencies and for reversal of warfarin-induced bleeding. In practice, high-dose intravenous (IV) vitamin K is often used, despite limited evidence supporting repeated dosing. OBJECTIVE: This study sought to characterize differences in responders and nonresponders to high-dose vitamin K to guide dosing strategies. METHODS: This was a case-control study of hospitalized adults who received vitamin K 10 mg IV daily for 3 days. Cases were represented by patients who responded to the first dose of IV vitamin K and controls were nonresponders. The primary outcome was change in international normalized ratio (INR) over time with subsequent vitamin K doses. Secondary outcomes included factors associated with response to vitamin K and incidence of safety events. The Cleveland Clinic Institutional Review Board approved this study. RESULTS: There were 497 patients included, and 182 were responders. Most patients had underlying cirrhosis (91.5%). In responders, the INR decreased from 1.89 at baseline (95% CI = [1.74-2.04]) to 1.40 on day 3 (95% CI = [1.30-1.50]). In nonresponders, the INR decreased from 1.97 (95% CI = [1.83-2.13]) to 1.85 ([1.72-1.99]). Factors associated with response included lower body weight, absence of cirrhosis, and lower bilirubin. There was a low incidence of safety events observed. CONCLUSIONS: In this study of mainly patients with cirrhosis, the overall adjusted decrease in INR over 3 days was 0.3, which may have minimal clinical impact. Additional studies are needed to identify populations who may benefit from repeated daily doses of high-dose IV vitamin K.

Thromboembolism after treatment with 4-factor prothrombin complex concentrate or plasma for warfarin-related bleeding.

Limited data exist in large, representative populations about whether the risk of thromboembolic events varies after receiving four-factor human prothrombin complex concentrate (4F-PCC) versus treatment with human plasma for urgent reversal of oral vitamin K antagonist therapy. We conducted a multicenter observational study to compare the 45-day risk of thromboembolic events in adults with warfarin-associated major bleeding after treatment with 4F-PCC (Kcentra®) or plasma. Hospitalized patients in two large integrated healthcare delivery systems who received 4F-PCC or plasma for reversal of warfarin due to major bleeding from January 1, 2008 to March 31, 2020 were identified and were matched 1:1 on potential confounders and a high-dimensional propensity score. Arterial and venous thromboembolic events were identified up to 45 days after receiving 4F-PCC or plasma from electronic health records and adjudicated by physician review. Among 1119 patients receiving 4F-PCC and a matched historical cohort of 1119 patients receiving plasma without a recent history of thromboembolism, mean (SD) age was 76.7 (10.5) years, 45.6% were women, and 9.4% Black, 14.6% Asian/Pacific Islander, and 15.7% Hispanic. The 45-day risk of thromboembolic events was 3.4% in those receiving 4F-PCC and 4.1% in those receiving plasma (P = 0.26; adjusted hazard ratio 0.76; 95% confidence interval 0.49-1.16). The adjusted risk of all-cause death at 45 days post-treatment was lower in those receiving 4F-PCC compared with plasma. Among a large, ethnically diverse cohort of adults treated for reversal of warfarin-associated bleeding, receipt of 4F-PCC was not associated with an excess risk of thromboembolic events at 45 days compared with plasma therapy.

Impact of Initial Warfarin Dosing on Time in Therapeutic Range for Postoperative Left Ventricular Assist Device Patients.

ABSTRACT: Initial warfarin dosing and time in therapeutic range (TTR) are poorly characterized for early post-operative left ventricular assist device (LVAD) patients. This study evaluated TTR after LVAD implantation compared between patients receiving low-dose (<3 mg) and high-dose (≥3 mg) warfarin. This single-center, retrospective analysis included 234 LVAD patients who received warfarin within 5 days of implantation. The primary outcome was TTR during the 5 days following first international normalized ratio (INR) ≥2 compared between low-dose and high-dose groups. Secondary outcomes were hospital and intensive care unit length of stay, time to first INR ≥2, TTR after first INR ≥2, and reinitiation of parenteral anticoagulation. No difference in TTR was detected between warfarin groups (57.2% vs. 62.7%, P = 0.13). Multivariable analysis did not detect any factors predictive of TTR during the primary outcome timeframe, but age and body mass index were associated with the warfarin dose. The low-dose group received a mean warfarin dose of 1.9 mg (±0.64 mg), and the high dose group received 4.34 mg (±1.38 mg). Cohort TTR during the primary outcome timeframe was 60.5% and 56.5% for hospitalization. The low-dose group had longer intensive care unit length of stay, shorter time to therapeutic INR, and more frequently reinitiated parenteral anticoagulation. Patients with recent LVAD implantation are complex and have diverse warfarin sensitivity factors, which did not allow for optimal warfarin dose detection, although half of all patients received doses between 2.04 mg and 4.33 mg. Individualized dosing should be used, adjusting for patient-specific factors such as age, body mass index, and drug interactions.

High versus low fixed-dose four factor-prothrombin complex concentrate for warfarin reversal in patients with intracranial hemorrhage.

BACKGROUND: Four-factor prothrombin complex concentrate 4F-PCC is the standard of care for warfarin reversal in patients with major bleed or requiring urgent surgery. Although the 4F-PCC dose is weight and international normalized ratio (INR) based, for practical purposes, a fixed-dose approach has been explored, especially for rapid reversal. We report our experience using two different fixed-dose 4F-PCC for warfarin reversal in patients presenting with intracranial hemorrhage (ICH). STUDY DESIGN AND METHODS: We completed a retrospective chart review comparing high (4000 units) versus low (2000 units) dose 4F-PCC by evaluating patient characteristics, laboratory data, and pre-and post-4F-PCC brain imaging. RESULTS: There was no significant difference between patient characteristics or INR correction (≤1.5) between the two groups. Eighty percent (12/15) of patients who received the low dose 4F-PCC had either improved or stable brain imaging as compared to 88% (14/16) of patients who received the high dose PCC. When the eight patients (4 from each arm of the study) who required neurosurgery were excluded, only two patients in each arm had worse imaging after 4F-PCC. CONCLUSION: There was no significant difference between the INR correction and the brain imaging changes in patients with an ICH who received either the high or the low fixed-dose 4F-PCC for warfarin reversal.

The effectiveness of split tablet dosing versus alternate-day dosing of warfarin: a randomized control trial.

Due to large dosage variation, a variety of warfarin prescription regimens are utilized for specific doses such as tablet splitting, or pill strength alternating. The clinical comparison between the two is lacking. We hypothesize that both approaches result in different times in therapeutic range. We randomized patients with specific warfarin dosage and stable INR for 6 months or longer to receive the whole tablet, alternate-day dosing or the split tablet, same daily-dosing regimen without initial dose change and followed them every 6 weeks for 6 months. The primary outcome was a time in therapeutic range of 2.0-3.0. The secondary outcomes included dosage, compliance, INR, anticoagulant-related events. A total of 66 patients were enrolled, 32 randomly assigned to the split tablet regimen (group S) and 34 to the alternate-day regimen (group A) with two withdrawers. The mean age was 58.6 ± 8.5 years. All baseline characteristics of both groups were similar. The average time in therapeutic range was 72.8 ± 25.4% in group S and 74.9 ± 22.0% in group A (p = 0.72). There were no significant differences in warfarin dosage, compliance, INR and, complications between the two groups. Both warfarin prescription methods, the split tablet and the alternate-day had comparable time in the therapeutic range.

New Internet-Based Warfarin Anticoagulation Management Approach After Mechanical Heart Valve Replacement: Prospective, Multicenter, Randomized Controlled Trial.

BACKGROUND: Mechanical heart valve replacement (MHVR) is an effective method for the treatment of severe heart valve disease; however, it subjects patient to lifelong warfarin therapy after MHVR with the attendant risk of bleeding and thrombosis. Whether internet-based warfarin management reduces complications and improves patient quality of life remains unknown. OBJECTIVE: This study aimed to compare the effects of internet-based warfarin management and the conventional approach in patients who received MHVR in order to provide evidence regarding alternative strategies for long-term anticoagulation. METHODS: This was a prospective, multicenter, randomized, open-label, controlled clinical trial with a 1-year follow-up. Patients who needed long-term warfarin anticoagulation after MHVR were enrolled and then randomly divided into conventional and internet-based management groups. The percentage of time in the therapeutic range (TTR) was used as the primary outcome, while bleeding, thrombosis, and other events were the secondary outcomes. RESULTS: A total of 721 patients were enrolled. The baseline characteristics did not reach statistical differences between the 2 groups, suggesting the random assignment was successful. As a result, the internet-based group showed a significantly higher TTR (mean 0.53, SD 0.24 vs mean 0.46, SD 0.21; P<.001) and fraction of time in the therapeutic range (mean 0.48, SD 0.22 vs mean 0.42, SD 0.19; P<.001) than did those in the conventional group. Furthermore, as expected, the anticoagulation complications, including the bleeding and embolic events had a lower frequency in the internet-based group than in the conventional group (6.94% vs 12.74%; P=.01). Logistic regression showed that internet-based management increased the TTR by 7% (odds ratio [OR] 1.07, 95% CI 1.05-1.09; P<.001) and reduced the bleeding and embolic risk by 6% (OR 0.94, 95% CI 0.92-0.96; P=.01). Moreover, low TTR was found to be a risk factor for bleeding and embolic events (OR 0.87, 95% CI 0.83-0.91; P=.005). CONCLUSIONS: The internet-based warfarin management is superior to the conventional method, as it can reduce the anticoagulation complications in patients who receive long-term warfarin anticoagulation after MHVR. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR1800016204; http://www.chictr.org.cn/showproj.aspx?proj=27518. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): RR2-10.1136/bmjopen-2019-032949.

Outpatient management of chronic warfarin therapy at a pharmacist-run anticoagulation clinic during the COVID-19 pandemic.

As a result of infection control regulations during the coronavirus disease 2019 (COVID-19) pandemic, anticoagulation clinics have been required to adjust their practices in order to continue providing safe and effective services for their patients. In accordance with a guidance document issued by the Anticoagulation Forum, The Brooklyn Hospital Center (TBHC) anticoagulation clinic in Brooklyn, New York implemented measures including telemedicine follow-ups instead of in-person clinic visits, extending the interval of INR testing, and reviewing eligible candidates for transition from warfarin to direct oral anticoagulants. This study describes the outcomes of one hospital-based clinic location in the 3 months before and after COVID-19 became a significant concern in the New York City area. The primary outcome of time-in-therapeutic range (TTR) for patients receiving warfarin was 60.6 % and 65.8 % in the pre-COVID and post-COVID groups, respectively (p = 0.21). For secondary outcomes, there was no difference in percent of therapeutic INRs (51.5 % pre-COVID v. 44.8 % post-COVID, p = 0.75) or percent of INRs ≥ 4.5 (2.3 % pre-COVID v. 4 % post-COVID, p = 0.27). Based on the data reported in this study, the short-term changes implemented at TBHC's anticoagulation clinic did not appear to cause reductions in safety and efficacy of chronic warfarin therapy management.

Safety and Efficacy of Vitamin K Antagonists versus Rivaroxaban in Hemodialysis Patients with Atrial Fibrillation: A Multicenter Randomized Controlled Trial.

BACKGROUND: In patients with normal renal function or early stage CKD, the risk-benefit profile of direct oral anticoagulants (DOACs) is superior to that of vitamin K antagonists (VKAs). In patients on hemodialysis, the comparative efficacy and safety of DOACs versus VKAs are unknown. METHODS: In the Valkyrie study, 132 patients on hemodialysis with atrial fibrillation were randomized to a VKA with a target INR of 2-3, 10 mg rivaroxaban daily, or rivaroxaban and vitamin K2 for 18 months. Patients continued the originally assigned treatment and follow-up was extended for at least an additional 18 months. The primary efficacy end point was a composite of fatal and nonfatal cardiovascular events. Secondary efficacy end points were individual components of the composite outcome and all-cause death. Safety end points were life-threatening, major, and minor bleeding. RESULTS: Median (IQR) follow-up was 1.88 (1.01-3.38) years. Premature, permanent discontinuation of anticoagulation occurred in 25% of patients. The primary end point occurred at a rate of 63.8 per 100 person-years in the VKA group, 26.2 per 100 person-years in the rivaroxaban group, and 21.4 per 100 person-years in the rivaroxaban and vitamin K2 group. The estimated competing risk-adjusted hazard ratio for the primary end point was 0.41 (95% CI, 0.25 to 0.68; P=0.0006) in the rivaroxaban group and 0.34 (95% CI, 0.19 to 0.61; P=0.0003) in the rivaroxaban and vitamin K2 group, compared with the VKA group. Death from any cause, cardiac death, and risk of stroke were not different between the treatment arms, but symptomatic limb ischemia occurred significantly less frequently with rivaroxaban than with VKA. After adjustment for competing risk of death, the hazard ratio for life-threatening and major bleeding compared with the VKA group was 0.39 (95% CI, 0.17 to 0.90; P=0.03) in the rivaroxaban group, 0.48 (95% CI, 0.22 to 1.08; P=0.08) in the rivaroxaban and vitamin K2 group and 0.44 (95% CI, 0.23 to 0.85; P=0.02) in the pooled rivaroxaban groups. CONCLUSIONS: In patients on hemodialysis with atrial fibrillation, a reduced dose of rivaroxaban significantly decreased the composite outcome of fatal and nonfatal cardiovascular events and major bleeding complications compared with VKA. CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER: Oral Anticoagulation in Hemodialysis, NCT03799822.

Drug-drug interaction between warfarin and statins: A Danish cohort study.

Initiation of statin treatment is suggested to increase the international normalised ratio (INR) among warfarin users. However, available data is limited and conflicting. We conducted a register-based cohort study to evaluate the drug-drug interaction between warfarin and statins. By linking data on INR measurements and filled prescriptions, we identified warfarin users 2000-2015 initiating simvastatin (n = 1363), atorvastatin (n = 165) or rosuvastatin (n = 23). Simvastatin initiation led to an increase in mean INR from 2.40 to 2.71, with INRs peaking after 4 weeks, corresponding to a mean change of 0.32 (95%CI 0.25-0.38). High-dose and low-dose simvastatin led to comparable changes (mean change 0.33 vs 0.29). Initiation of atorvastatin and rosuvastatin lead to INR increases of 0.27 (95%CI 0.12-0.42) and 0.30 (95%CI -0.09-0.69). In conclusion, initiation of simvastatin, atorvastatin or rosuvastatin among warfarin users led to a minor increase in INR. The magnitude of this change is for most patients likely of limited clinical relevance.

Effects of Herba Erigerontis injection on pharmacodynamics and pharmacokinetics of warfarin in rats in vivo.

Herba Erigerontis injection (HEI) is an aqueous solution derived from whole plants of Erigeron breviscapus, which may be co-administered with warfarin to treat cardiovascular and cerebrovascular disorders. This research was conducted to make sure whether HEI would affect anticoagulation of warfarin to guarantee reasonable medication. The pharmacodynamic study was designed to measure prothrombin time (PT) and activated partial thromboplastin time (APTT) values, and international normalized ratio (INR) values were calculated. For pharmacokinetic study, ultra performance liquid chromatography-tandem mass spectrometer (UPLC-MS/MS) technology was applied to measure plasma concentrations of warfarin enantiomers. The influence of HEI on plasma protein binding rate of warfarin was assessed by ultrafiltration. Pharmacodynamic study demonstrated that both HEI alone and co-administered with warfarin could increase PT and INR values significantly (P < .01), whereas the APTT values were unaffected (P > .05). Pharmacokinetic study manifested that Cmax , AUC and t1/2 prolonged significantly (P < .01) for R/S-warfarin in presence of HEI. Low (3.6 mL/kg), medium (7.2 mL/kg) and high (10.8 mL/kg) doses of HEI could decrease plasma protein binding rate of warfarin significantly (P < .01). The results mean that HEI can potentiate the anticoagulant response of warfarin through both pharmacodynamics and pharmacokinetics.

Drive-thru anticoagulation clinic: Can we supersize your care today?

Warfarin therapy requires maintenance of a therapeutic international normalized ratio (INR) and thus requires routine monitoring to ensure benefits of anticoagulation, while avoiding complications. As the pharmacist's role evolves from traditional medication dispensing towards direct patient care, many anticoagulation management services are pharmacist-managed. Due to the coronavirus disease 2019 (COVID-19) pandemic, healthcare providers were faced with re-evaluating anticoagulation management practices to minimize person-to-person exposure risk. Although being anticoagulated is not considered high risk for illness from the coronavirus, these patients are often of advanced age and frequently have multiple comorbidities, putting them at increased risk. Consequently, two hospital-based, pharmacist-managed outpatient anticoagulation management services developed drive-thru curbside clinics to continue providing care to warfarin patients. The services utilized universal COVID-19 precautions to conduct curbside appointments where pharmacists determined patient's warfarin therapy plan, scheduled timely follow-up, and provided dosing instructions. With the unexpected coronavirus outbreak, this immediate change to traditional anticoagulation management was essential for safe and effective anticoagulation therapy. Implementing a curbside clinic allowed for safe distancing while managing warfarin appropriately.

Khat Chewing Effect on the International Normalized Ratio in Patients with Mechanical Heart Valves under Warfarin Therapy.

BACKGROUND AND OBJECTIVE: Khat is a plant that contains the alkaloids cathine and cathinone which have some amphetamine-like properties. It is cultivated and it's leaves chewed for their euphoric effect. This study intended to elucidate the effect of khat chewing on blood coagulation by using the International Normalized Ratio (INR) value as a calculable benchmark. MATERIALS AND METHODS: In this cohort study, 146 patients with Mechanical Heart Valves (MHV) were assessed for two consecutive visits at one-month intervals. For each visit, the date of surgery, the patient's compliance, the dose of warfarin and the INR reading were assessed by the researcher. RESULTS: Out of 146 patients with MHV, the mean age was 33.72±12.43 years (range, 14-65 years); 82 (56.2%) were female and 64 (43.8%) were male. The results revealed that the mean of absolute INR readings was lower in khat-chewers than non-chewers by average 0.2 on the first and second visits (p = 0.038 and 0.002, respectively). CONCLUSION: Khat chewing has a significant coagulant effect. There was a significant decrease in the value of INR for khat chewers patients with MHV when compared to non-khat chewers.

Time in Therapeutic Range for Dialysis Patients on Warfarin: Determination and the Effect of Dietary Intervention.

This study aimed to identify the time in therapeutic range (TTR) for dialysis patients on warfarin, and improve TTR with dietary review and intervention of interacting foods. We identified 151 patients undergoing hemodialysis in two units who were being treated with warfarin from January 1, 2010, through February 1, 2018, who were included in the overall TTR study. Of these, 15 patients were available to undergo the dietary intervention. International normalized ratio values were collected retrospectively for all eligible hemodialysis patients, and TTR was calculated for each period in which the patient was on hemodialysis. Patients who were available and agreed to the intervention underwent targeted dietician review of interacting foods, and their TTR post-treatment was calculated. The median (interquartile range [IQR]) TTR was 44 (IQR, 29 to 53) % among the 151 patients. Among the 15 patients who underwent the intervention, median (IQR) TTR was 52 (IQR, 32 to 56) pre-intervention and 51 (IQR, 38 to 69) post-intervention (P=0.53). TTR for dialysis patients is low in this overall cohort despite patients being seen at an integrated health care system. Focused improvement projects such as dietary review of interacting foods may help increase a patient's TTR.

Warfarin drug interaction with vitamin K and other foodstuffs / Interacción de la droga warfarina con la vitamina K y otros productos alimenticios

Vitamin K is found in higher concentrations in dark green plant and in vegetable oils. The adequate intake of vitamin K is 90 and 120ug/day for adult elderly men and women, respectively. The main function of vitamin K is to act as an enzymatic cofactor for hepatic prothrombin synthesis, blood coagulation factors, and anticoagulant proteins. Prominent among the many available anticoagulants is warfarin, an antagonist of vitamin K, which exerts its anticoagulant effects by inhibiting the synthesis of vitamin K1 and vitamin KH2. From the beginning of the therapy it is necessary that the patients carry out the monitoring through the prothrombin time and the international normalized ratio. However, it is known that very low intake and/or fluctuations in vitamin K intake are as harmful as high consumption. In addition, other foods can interact with warfarin, despite their content of vitamin K. The aim of this study was to gather information on the drug interaction of warfarin with vitamin K and with dietary supplements and other foods.

La vitamina K se encuentra en concentraciones más altas en plantas de color verde oscuro y en aceites vegetales. La ingesta adecuada de vitamina K es de 90 y 120 ug/día para hombres y mujeres adultos mayores, respectivamente. La función principal de la vitamina K es actuar como un cofactor enzimático para la síntesis de protrombina hepática, factores de coagulación de la sangre y proteínas anticoagulantes. Entre los muchos anticoagulantes disponibles destaca la warfarina, un antagonista de la vitamina K, que ejerce sus efectos anticoagulantes al inhibir la síntesis de la vitamina K1 y la vitamina KH2. Desde el inicio de la terapia, es necesario que los pacientes realicen el monitoreo a través del tiempo de protrombina y la proporción normalizada internacional. Sin embargo, se sabe que una ingesta muy baja y/o fluctuaciones en la ingesta de vitamina K son tan dañinas como un consumo alto. Además, otros alimentos pueden interactuar con la warfarina, a pesar de su contenido de vitamina K. El objetivo de este estudio fue recopilar información sobre la interacción de los medicamentos de la warfarina con la vitamina K y con los suplementos dietéticos y otros alimentos.

Regular Bleeding Risk Assessment Associated with Reduction in Bleeding Outcomes: The mAFA-II Randomized Trial.

BACKGROUND: The mobile atrial fibrillation application (mAFA-II) randomized trial reported that a holistic management strategy supported by mobile health reduced atrial fibrillation-related adverse outcomes. The present study aimed to assess whether regular reassessment of bleeding risk using the Hypertension, Abnormal renal and liver function, Stroke, Bleeding, Labile international normalized ratio, Elderly, Drugs or alcohol (HAS-BLED) score would improve bleeding outcomes and oral anticoagulant (OAC) uptake. METHODS: Bleeding risk (HAS-BLED score) was monitored prospectively using mAFA, and calculated as 30 days, days 31-60, days 61-180, and days 181-365. Clinical events and OAC changes in relation to the dynamic monitoring were analyzed. RESULTS: We studied 1793 patients with atrial fibrillation (mean, standard deviation, age 64 years, 24 years, 32.5% female). Comparing baseline and 12 months, the proportion of atrial fibrillation patients with HAS-BLED ≥3 decreased (11.8% vs 8.5%, P = .008), with changes in use of concomitant nonsteroidal antiinflammatory drugs/antiplatelets, renal dysfunction, and labile international normalized ratio contributing to the decreased proportions of patients with HAS-BLED ≥3 (P < .05). Among 1077 (60%) patients who had 4 bleeding risk assessments, incident bleeding events decreased significantly from days 1-30 to days 181-365 (1.2% to 0.2%, respectively, P < .001). Total OAC usage increased from 63.4% to 70.2% (Ptrend < .001). Compared with atrial fibrillation patients receiving usual care (n = 1136), bleeding events were significantly lower in atrial fibrillation patients with dynamic monitoring of their bleeding risk (mAFA vs usual care, 2.1%, 4.3%, P = .004). OAC use decreased significantly by 25% among AF patients receiving usual care, when comparing baseline to 12 months (P < .001). CONCLUSION: Dynamic risk monitoring using the HAS-BLED score, together with holistic App-based management using mAFA-II reduced bleeding events, addressed modifiable bleeding risks, and increased uptake of OACs.

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 Effect of Warfarin Administration Time on Anticoagulation Stability (INRange): A Pragmatic Randomized Controlled Trial.

PURPOSE: Without supporting evidence, clinicians commonly recommend that warfarin be taken in the evening. We conducted a randomized controlled trial to evaluate the effect of administration time (morning vs evening) on the stability of warfarin's anticoagulant effect. METHODS: A total of 236 primary care physicians serving 54 western Canadian communities mailed letters of invitation to all their warfarin-using patients. Eligible patients were community-dwelling warfarin users (any indication) with at least 3 months of evening warfarin use and no plans for discontinuation. Participants were randomized (by web-based allocation) to morning vs continued evening warfarin ingestion. We used the Rosendaal method to determine the proportion of time within therapeutic range (TTR) of the international normalized ratio (INR) blood test month 2 to 7 postrandomization vs the 6 months prerandomization. The primary outcome was the percent change in proportion of time outside target INR range (with an a priori minimum clinically important difference of ±20%). All analyses were intention to treat. RESULTS: Between March 8, 2015 and September 30, 2016, we randomized 109 participants to morning and 108 to evening warfarin use. TTR rose from 71.8% to 74.7% in the morning group, and from 72.6% to 75.6% in the evening group, for a change in TTR of 2.9% in the former vs 3.0% in the latter (difference, -0.1%; P = .97; 95% CI for the difference, -6.1% to 5.9%). The difference in percent change in proportion of time outside the therapeutic INR range (obtained via Hodges-Lehmann estimation of the difference in medians) was 4.4% (P = .62; 95% CI for the difference, -17.6% to 27.3%). CONCLUSIONS: Administration time has no statistically significant nor clinically important impact on the stability of warfarin's anticoagulant effect. Patients should take warfarin whenever regular compliance would be easiest.

Role of therapeutic plasma exchange in acute liver failure due to yellow phosphorus poisoning.

BACKGROUND: Therapeutic plasma exchange (TPE) has been utilized in various liver disorders. There is limited data on the efficacy of TPE in patients with acute liver failure (ALF). METHODS: Study group consisted of patients who underwent TPE for ALF due to yellow phosphorous poisoning (YPP) between 2015 and 2019. Demographic data and biochemical parameters were recorded before and after TPE. Overall survival and transplant-free survival (based on King's College Hospital Criteria [KCHC]) were analyzed. RESULTS: Forty-three patients underwent TPE for ALF due to YPP. Most of them were young males. Overall survival was 34 (79.06%). In our study population, 20 patients fulfilled KCHC (Group A) and 23 did not fulfill KCHC (Group B). Both the groups showed significant improvement in alanine aminotransferase, aspartate aminotransferase, and international normalized ratio (INR) after TPE (p < 0.05). In Group B, there was significant improvement in ammonia after TPE (p < 0.05) and all 23 patients (100%) survived after TPE. In Group A, 4 underwent liver transplantation (LT), 7 survived without LT, and the remaining 9 died without LT. Mean survival after completing TPE was 41.2 ± 44.5 days in Group A and 90 days in Group B. This difference was statistically significant (p = 0.001). There was statistically significant difference in post-TPE values of INR (p = 0.012) and ammonia (p = 0.011) between non-survivors and survivors. Adverse events such as hypotension (11.62%) and minor allergic reaction (4.65%) were managed conservatively. CONCLUSION: TPE is an effective procedure in ALF due to YPP, not fulfilling KCHC for LT. In KCHC fulfilled group, though it shows LT-free survival benefit, there is requirement of prospective, large volume, multi-center study to assess its efficacy.

Acute Hepatic Failure and Nutrition.

Malnutrition is prevalent in patients with hepatic failure and remains an independent risk factor for morbidity and mortality in these patients. Factors that contribute to malnutrition in this patient population include altered metabolic rate, fat malabsorption, and impaired gastric emptying, all in the setting of an acute and potentially prolonged hospitalization. Acute liver failure (ALF), different from cirrhosis or chronic liver disease, is an uncommon but dramatic clinical syndrome that demonstrates severe and rapid decline in hepatic metabolic function. ALF has a significant risk of mortality. There are >10 cases per million persons per year in developed countries, but ALF presents with unique challenges in clinical management related to heterogeneity in severity and etiology. Patients with ALF by definition should not have a prior history of liver disease, and liver disease is subsequently defined by the onset of liver injury, the presence of hepatic encephalopathy (HE), and coagulopathy as defined by an international normalized ratio > 1.5. HE usually develops within 1-4 weeks of the onset of liver injury but may occur within 26 weeks of the initial presentation. Rates of survival from ALF have improved over recent years, but the rarity and severity of presentation have resulted in traditionally limited evidence to guide basic supportive care. Over time, advances in critical care management and the use of emergency liver transplantation have improved. In this article, we will review current nutrition considerations for patients with ALF.