Budd-Chiari syndrome associated with congenital afibrinogenaemia reversed after orthotopic liver transplant.

A woman in her mid-20s, a known case of congenital afibrinogenaemia, presented with abdominal pain and distension. She was diagnosed with decompensated liver cirrhosis due to Budd-Chiari syndrome. She underwent deceased donor liver transplantation. Preoperatively, her serum fibrinogen level was undetectable and prothrombin time and international normalised ratio (INR) were unrecordable. Intraoperatively, she was given thromboelastography-guided human fibrinogen concentrate. Postoperatively, her fibrinogen, prothrombin time and INR normalised rapidly. This report summarises the rare occurrence of a complication of hypercoagulability (Budd-Chiari syndrome) in the setting of congenital hypocoagulability (congenital afibrinogenaemia). In this report, we discuss the simultaneous management of these two clinical problems and the curative role of liver transplantation.

Warfarin-related nephropathy: unveiling the hidden dangers of anticoagulation.

Warfarin-related nephropathy (WRN) is defined as acute kidney injury subsequent to excessive anticoagulation with warfarin. Patients with mechanical prosthetic valves require long-term anticoagulant therapy. Nonetheless, warfarin remains the sole available option for anticoagulant therapy. Consequently, patients with mechanical prosthetic valves constitute a special group among the entire anticoagulant population. The present study recorded two cases of patients who had undergone mechanical prosthetic valve surgery and were receiving warfarin therapy. They presented to the hospital with gross hematuria and progressive creatinine levels. Notably, their international normalized ratio (INR) did not exceed three. Subsequent renal biopsies confirmed WRN with IgA nephropathy. The two patients continued to receive warfarin as anticoagulation therapy and were prescribed oral corticosteroids and cyclophosphamide, which resulted in improved renal function during the follow-up. Based on a review of all relevant literature and the present study, we proposed a new challenge: must elevated INR levels be one of the criteria for clinical diagnosis of WRN? Perhaps some inspiration can be drawn from the present article.

Construction of warfarin population pharmacokinetics and pharmacodynamics model in Han population based on Bayesian method.

The purpose of this paper is to study the genetic polymorphisms of related gene loci (CYP2C9*3, VKORC1-1639G > A) based on demographic and clinical factors, and use the maximum a posterior Bayesian method to construct a warfarin individualized dose prediction model in line with the Chinese Han population. Finally, the built model is compared and analyzed with the widely used models at home and abroad. In this study, a total of 5467 INR measurements are collected from 646 eligible subjects in our hospital, and the maximum a posterior Bayesian method is used to construct a warfarin dose prediction that conforms to the Chinese Han population on the basis of the Hamberg model. The model is verified and compared with foreign models. This study finds that body weight and concomitant use of amiodarone have a significant effect on the anticoagulant effect of warfarin. The model can provide an effective basis for individualized and rational dosing of warfarin in Han population more accurately. In the performance of comparison with different warfarin dose prediction models, the new model has the highest prediction accuracy, and the prediction percentage is as high as 72.56%. The dose predicted by the Huang model is the closest to the actual dose of warfarin. The population pharmacokinetics and pharmacodynamics model established in this study can better reflect the distribution characteristics of INR values after warfarin administration in the Han population, and performs better than the models reported in the literature.

Time-in-therapeutic-range defined warfarin and direct oral anticoagulants in atrial fibrillation: a Nationwide Cohort Study.

BACKGROUND: Little is known how individual time-in-therapeutic-range (TTR) impacts the effectiveness and safety of warfarin therapy compared to direct oral anticoagulants (DOACs) in patients with atrial fibrillation (AF). OBJECTIVE: To compare the effectiveness and safety of standard dose DOACs to warfarin in patients with AF, while categorizing warfarin treated patients into quartiles based on their individual TTR. MATERIALS AND METHODS: We conducted a nationwide study including all patients with new-onset AF between 2011 and 2018 in Finland. Hazard ratios (HR) were calculated using Cox regression analysis with the inverse probability of treatment weighted method to assess the risks of ischaemic stroke (IS), intracranial haemorrhage (ICH) and mortality for users of apixaban (n = 12,426), dabigatran (n = 4545), rivaroxaban (n = 12,950) and warfarin (n = 43,548). RESULTS: The median TTR for warfarin users was 72%. Compared to the second best TTR quartile (reference), the risk of IS was higher in the two poorest TTR quartiles, and lower in the best TTR quartile and on rivaroxaban [2.35 (95% confidence interval, 1.85-2.85), 1.44 (1.18-1.75), 0.60 (0.47-0.77) and 0.72 (0.56-0.92)]. These differences were non-significant for apixaban and dabigatran. HR of ICH was 6.38 (4.88-8.35) and 1.87 (1.41-2.49) in the two poorest TTR groups, 1.44 (1.02-1.93) on rivaroxaban, and 0.58 (0.40-0.85) in the best TTR group compared to the reference group. Mortality was higher in the two poorest TTR groups and lowest in the best TTR group. CONCLUSIONS: The outcome was unsatisfactory in the two lowest TTR quartiles - in half of the patients treated with warfarin. The differences between the high TTR groups and standard dose DOACs were absent or modest.

Clinical versus fixed warfarin dosing and the impact on quality of anticoagulation (The ClinFix trial).

Different dosing strategies exist to initiate warfarin, most commonly fixed warfarin dosing (FWD), clinical warfarin dosing (CWD), and genetic-guided warfarin dosing (GWD). Landmark trials have shown GWD to be superior when compared to FWD in the EU-PACT trial or CWD in the GIFT trial. COAG trial did not show differences between GWD and CWD. We aim to compare the anticoagulation quality outcomes of CWD and FWD. This is a prospective cohort study with a retrospective comparator. Recruited subjects in the CWD (prospective) arm were initiated on warfarin according to the clinical dosing component of the algorithm published in www.warfarindosing.org. The primary efficacy outcome was the percentage time in the therapeutic range (PTTR) from day 3 to 6 till day 28 to 35. The study enrolled 122 and 123 patients in the CWD and FWD, respectively. The PTTR did not differ statistically between CWD and FWD (62.2 ± 26.2% vs. 58 ± 25.4%, p = 0.2). There was also no difference between both arms in the percentage of visits with extreme subtherapeutic international normalized ratio (INR) (<1.5; 15 ± 18.3% vs. 16.8 ± 19.1%, p = 0.44) or extreme supratherapeutic INR (>4; 7.7 ± 14.7% vs. 7.5 ± 12.4%, p = 0.92). We conclude that CWD did not improve the anticoagulation quality parameters compared to the FWD method.

Therapeutic plasma exchange provides native liver survival benefit in children with acute liver failure: A propensity score-matched analysis.

OBJECTIVES: This study aimed to evaluate the safety and efficacy of therapeutic plasma exchange (TPE) in pediatric acute liver failure (PALF). METHODS: All children aged 2-18 years with PALF were included. The intervention cohort included a subset of PALF patients undergoing complete three sessions of TPE, whereas the matching controls were derived by propensity score matching from the patient cohort who did not receive any TPE. Propensity matching was performed based on the international normalized ratio (INR), grade of hepatic encephalopathy (HE), age, bilirubin, and ammonia levels. The primary outcome measure was native liver survival (NLS) in the two arms on day 28. RESULTS: Of the total cohort of 403 patients with PALF, 65 patients who received TPE and 65 propensity-matched controls were included in analysis. The 2 groups were well balanced with comparable baseline parameters. On day 4, patients in the TPE group had significantly lower INR (P = 0.001), lower bilirubin (P = 0.008), and higher mean arterial pressure (MAP) (P = 0.033) than controls. The NLS was 46.15% in the TPE arm and 26.15% in the control arm. The overall survival (OS) was 50.8% in the TPE arm and 35.4% in the control arm. Kaplan-Meier survival analysis showed a significantly higher NLS in patients receiving TPE than controls (P = 0.001). On subgroup analysis, NLS benefit was predominantly seen in hepatitis A-related and indeterminate PALF. CONCLUSION: TPE improved NLS and OS in a propensity-matched cohort of patients with PALF. Patients receiving TPE had lower INR and bilirubin levels and higher MAP on day 4.

Incidence of Coagulopathy After Resuscitation at a Role 1 Facility: The Prehospital Trauma Registry Experience.

BACKGROUND: The development of acute traumatic coagulopathy is associated with increased mortality and morbidity in patients with battlefield traumatic injuries. Currently, the incidence of acute traumatic coagulopathy in the Role 1 setting is unclear. METHODS: We queried the Prehospital Trauma Registry (PHTR) module of the Department of Defense Trauma Registry (DoDTR) for all encounters from inception through May 2019. The PHTR captures data on Role 1 prehospital care. Data from the PHTR was linked to the DoDTR to analyze laboratory data and patient outcomes using descriptive statistics. We defined coagulopathy as an international normalized ratio (INR) of ≥1.5 or platelet count ≤150×109/L. RESULTS: A total of 595 patients met the inclusion criteria; 36% (212) met our definition for coagulopathy, with 31% (185) carrying low platelet numbers, 11% (68) showing an elevated INR, and 7% (41) with both. The baseline (no coagulopathy) cohort had a mean INR of 1.10 (95% CI 1.09-1.12) versus 1.38 (95% CI 1.33-1.43) in the coagulopathic cohort. The mean platelet count was 218 (95% CI 213-223) ×109/L in the baseline cohort versus 117 (95% CI 110-125) ×109/L in the coagulopathic cohort. CONCLUSIONS: Our findings indicate a high incidence of coagulopathy in trauma patients. Approximately one-third of wounded patients had laboratory evidence of coagulopathy upon presentation to a forward medical care facility. Advanced diagnostic facilities are therefore needed to facilitate early diagnosis of acute traumatic coagulopathy. Blood products with a long shelf life can aid in early correction.

Abnormal coagulation after hepatectomy in patients with normal preoperative coagulation function.

BACKGROUND: To explore the risk factors for postoperative abnormal coagulation (PAC) and establish a predictive model for patients with normal preoperative coagulation function who underwent hepatectomy. MATERIALS AND METHODS: A total of 661 patients with normal preoperative coagulation function who underwent hepatectomy between January 2015 and December 2021 at the First Affiliated Hospital of Sun Yat-sen University were divided into two groups: the postoperative abnormal coagulation group (PAC group, n = 362) and the normal coagulation group (non-PAC group, n = 299). Univariate and multivariate logistic analyses were used to identify the risk factors for PAC. RESULTS: The incidence of PAC in 661 patients who underwent hepatectomy was 54.8% (362/661). The least absolute shrinkage and selection operator (LASSO) method was used for multivariate logistic regression analysis. The preoperative international normalized ratio (INR), intraoperative succinyl gelatin infusion and major hepatectomy were found to be independent risk factors for PAC. A nomogram for predicting the PAC after hepatectomy was constructed. The model presented a receiver operating characteristic (ROC) curve of 0.742 (95% confidence interval (CI): 0.697-0.786) in the training cohort. The validation set demonstrated a promising ROC of 0.711 (95% CI: 0.639-0.783), and the calibration curve closely approximated the true incidence. Decision curve analysis (DCA) was performed to assess the clinical usefulness of the predictive model. The risk of PAC increased when the preoperative international normalized ratio (INR) was greater than 1.025 and the volume of intraoperative succinyl gelatin infusion was greater than 1500 ml. CONCLUSION: The PAC is closely related to the preoperative INR, intraoperative succinyl gelatin infusion and major hepatectomy. A three-factor prediction model was successfully established for predicting the PAC after hepatectomy.

Efficacy of human prothrombin complex concentrate in the treatment of warfarin overdose in patients receiving warfarin for mechanical heart valve replacement.

Warfarin, a widely utilized anticoagulant, is paramount for preventing thromboembolic events in patients with mechanical heart valve replacements. However, its narrow therapeutic index can lead to over-anticoagulation and overdose, resulting in serious health risks. This study examines the efficacy of human prothrombin complex concentrate (PCC) in managing warfarin overdose, in comparison with traditional treatments. A retrospective analysis was conducted on 162 adults who presented with warfarin overdose (INR > 5.0) at a tertiary care hospital between 2016 and 2020. Participants were divided into 2 groups-those treated with PCC (n = 57) and those treated with conventional methods (n = 105), including vitamin K and fresh frozen plasma. The primary outcome was the rate of reaching the target (International Normalized Ratio) INR within 24 hours. Secondary outcomes included transfusion requirements, thromboembolic events, adverse reactions, 30-day mortality, and length of hospital stay. PCC demonstrated significant efficacy, with 89.5% of patients achieving the target INR within 24 hours, compared to 64.8% in the control group (P < .05). The PCC group also had reduced transfusion requirements and a shorter average hospital stay. There was no significant difference in thromboembolic events or adverse reactions between the 2 groups, and the reduced 30-day mortality in the PCC group was not statistically significant. Human prothrombin complex concentrate is associated with rapid reaching the target INR, decreased transfusion needs, and shortened hospitalization, making it a promising option for warfarin overdose management. While the results are encouraging, larger, multicenter, randomized controlled trials are necessary to further validate these findings and optimize PCC administration protocols.

Utility of TTR-INR guided warfarin adjustment protocol to improve time in therapeutic range in patients with atrial fibrillation receiving warfarin.

Warfarin remains the most prescribed oral anticoagulant of choice in atrial fibrillation (AF) patient in resource-limited settings. Despite evidence linking Time in Therapeutic Range (TTR) to patient outcomes, its use in clinical practice is not widespread. This prospective study explores the impact of a TTR-INR guided Warfarin adjustment protocol on TTR in AF patients. Conducted at the Warfarin clinic of King Chulalongkorn Memorial Hospital. TTR was calculated using the Rosendaal linear interpolation method at baseline, and then at 6 and 12 months post-protocol implementation. The primary outcome was the improvement in TTR following the protocol's implementation. The study analyzed 57 patients, with a mean age of 72 years and an even gender distribution. At baseline, 53% of patients had a TTR of less than 65%. However, TTR significantly improved from 65% at baseline to 80% after 12 months of protocol implementation (p < 0.001). Furthermore, there was a significant increase in the proportion of patients with a TTR of 65% or more, from 47 to 88% (p < 0.001). During the follow-up period in the first 12 months, three patients died, but no ischemic or major bleeding events occurred. The significant improvement in TTR after 12 months of protocol implementation suggests that this strategy could provide additional value in improving TTR and outcomes in AF patients receiving Warfarin.

The effect of administering preprocedural VITamin K on the international normalized ratio in patients anticoagulated with ACEnocoumarol (VITKACE-study): a prospective cohort study.

BACKGROUND: The effect of the vitamin K antagonist acenocoumarol on coagulation needs to be reversed when patients undergo an invasive procedure with considerable bleeding risk. A strategy to achieve this is by administering oral vitamin K before a procedure while continuing acenocoumarol. OBJECTIVES: To assess the effect on periprocedural international normalized ratio (INR) values and safety using oral vitamin K as anticoagulant reversal method. METHODS: In this prospective cohort study, consecutive patients using acenocoumarol undergoing elective procedures between 2019 and 2022 were included. According to standard of care in our hospital, patients took 10 mg oral vitamin K 36 to 48 hours before the procedure while continuing their normal use of acenocoumarol. Effectiveness to lower INR to <1.8 preprocedural was assessed. Bleeding and thrombotic complications within 30 days after the procedure were assessed. Periprocedural course of INR was monitored by collecting additional blood samples. RESULTS: Seventy-four patients were included for analysis. On the day of the procedure, an adequate INR of <1.8 was achieved in 99% of patients. One clinically relevant nonmajor bleeding complication and no thrombotic complications were observed during the first 30 days after the procedure. INR gradually restored to therapeutic level during the days after the procedure. CONCLUSION: Using oral vitamin K while patients continue acenocoumarol intake is an effective way to adequately lower INR before an invasive procedure. Low amount of bleeding complications and absence of thromboembolic complications suggest that this is a safe strategy. The INR values returned gradually to therapeutic range after the procedure, probably contributing to the observed low bleeding rate.

Acute coronary syndrome in patients treated by vitamin K antagonists or non-vitamin K antagonist oral anticoagulants: Proposed management algorithm for the first 48hours.

Around 10% of patients with acute coronary syndrome are treated by vitamin K antagonists or non-vitamin K antagonist oral anticoagulants for various indications. The initial management of these patients is highly complex, and new guidelines specify that, only during percutaneous coronary intervention, a bolus of unfractionated heparin is recommended in one of the following circumstances: (1) if the patient is receiving a non-vitamin K antagonist oral anticoagulant; or (2) if the international normalized ratio is<2.5 in a patient being treated with a vitamin K antagonist. In this review, we report on five key messages essential for the management of these patients. There are no randomized studies to date, and we propose two diagnostic and/or therapeutic decision algorithms. However, randomized studies are needed to validate these strategies.

CoaguChek and Coag-Sense PT2 Meter Point of Care INR Device Validation.

OBJECTIVE: To standardize international normalized ratio (INR) measurements and improve data integrity by enabling electronic result transmission for warfarin monitoring, two point-of-care (POC) devices were evaluated against an internal plasma INR reference method. METHODS: A multicenter study was pursued (January 24, 2022, through October 19, 2022) to compare concordance of two commercially available POC devices, Coag-Sense PT2 Meter (Coag-Sense) and CoaguChek XS Pro and Plus devices (CoaguChek), against an internal plasma INR method among patients treated with warfarin. Bias and linear regression analysis were assessed for these devices including dosing decision accuracy compared with plasma INR reference. RESULTS: Two hundred ninety-nine patients treated with warfarin across three Mayo Clinic sites agreed to participate. Atrial fibrillation (n=191, 63.9%), venous thromboembolism (n=65; 21.7%), and heart valve prosthesis (n=46; 15.4%) were common anticoagulant indications with a 2.5 INR target for 280 (93.6%) of patients. For the CoaguChek devices, 243 (81.3%) of values fell within 0.2 INR units with plasma INR referent and 285 (95.3%) within 0.4 units (R2=0.93). For the Coag-Sense device, 102 (34.1%) of values fell within 0.2 INR units and 180 (60.2%) within 0.4 INR units of plasma INR values, (R2=0.83; P<.0001). Using the plasma INR as the gold standard, appropriate dosing recommendations would have occurred for 292 (97.7%) of the CoaguChek and 244 (81.6%) of the Coag-Sense results. CONCLUSION: Compared with a plasma referent, INR values obtained from the CoaguChek devices exhibited less systematic bias compared with Coag-Sense measures. This translates to a greater percentage of concordant management decisions between POC and laboratory INR methods.

International Normalized Ratio Predicts Recurrence and Bleeding in Patients With Acute Venous Thromboembolism Who Undergo Direct Oral Anticoagulants.

Prothrombin time/international normalized ratio (PT/INR) is related to both antithrombotic effect and risk of bleeding. Its role in the prediction of venous thromboembolism (VTE) recurrence and bleeding for patients with acute VTE who undergo direct oral anticoagulants (DOACs) treatment is unclear, despite previous studies revealed some association between them. The predictive efficiency of INR for VTE recurrence and bleeding were analyzed in a retrospective cohort with VTE patients who underwent DOACs treatment. Then its predictive efficiency for VTE recurrence and bleeding were validated in a prospective cohort with the acquired cutoffs range, and compared with anti-Xa level, DASH and VTE-BLEED scores. In the retrospective cohort (n = 1083), the sensitivity and specificity of INR for the prediction of VTE recurrence were 79.4% and 92.8%, respectively. The area under the curve (AUC) was 0.881 (0.803-0.960)(P = .025). The cutoff value of INR was 0.9. The sensitivity and specificity of INR for the prediction of bleeding were 85.7% and 77.9%, respectively. The AUC was 0.876 (0.786-0.967)(P < .001). The cutoff value of INR was 2.1. In the prospective cohort (n = 202), the calibration showed that there were 4 (50%) patients with VTE recurrence, 156 (97.5%) patients with non-recurrence and bleeding (non-R&B), and 20 (58.8%) patients with bleeding in the low (INR < 0.9)(n = 8), intermediate (0.9 ≤ INR ≤ 2.1)(n = 160), and high (INR > 2.1)(n = 34) groups, respectively. The baseline PT/INR value at the initiation of DOACs treatment is an independent predictor for VTE recurrence and bleeding in patients with acute VTE who undergo DOACs treatment.

The Relationship Between Preoperative International Normalized Ratio and Postoperative Major Bleeding in Total Shoulder Arthroplasty.

INTRODUCTION: This study aimed to assess the relationship between preoperative international normalized ratio (INR) levels and major postoperative bleeding events after total shoulder arthroplasty (TSA). METHODS: The American College of Surgeons National Surgical Quality Improvement Program database was queried for TSA from 2011 to 2020. A final cohort of 2405 patients with INR within 2 days of surgery were included. Patients were stratified into four groups: INR ≤ 1.0, 1.0 < INR ≤ 1.25, 1.25< INR ≤ 1.5, and INR > 1.5. The primary outcome was bleeding requiring transfusion within 72 hours, and secondary outcome variables included complication, revision surgery, readmission, and hospital stay duration. Multivariable logistic and linear regression analyses adjusted for relevant comorbidities were done. RESULTS: Of the 2,405 patients, 48% had INR ≤ 1.0, 44% had INR > 1.0 to 1.25, 7% had INR > 1.25 to 1.5, and 1% had INR > 1.5. In the adjusted model, 1.0 < INR ≤ 1.25 (OR 1.7, 95% CI 1.176 to 2.459), 1.25 < INR ≤ 1.5 (OR 2.508, 95% CI 1.454 to 4.325), and INR > 1.5 (OR 3.200, 95% CI 1.233 to 8.302) were associated with higher risks of bleeding compared with INR ≤ 1.0. DISCUSSION: The risks of thromboembolism and bleeding lie along a continuum, with higher preoperative INR levels conferring higher postoperative bleeding risks after TSA. Clinicians should use a patient-centered, multidisciplinary approach to balance competing risks.

Pharmacogenetic guided versus standard warfarin dosing for routine clinical care with its pharmacoeconomic impact: a randomized controlled clinical trial.

BACKGROUND: Empirical use of pharmacogenetic test(PGT) is advocated for many drugs, and resource-rich setting hospitals are using the same commonly. The clinical translation of pharmacogenetic tests in terms of cost and clinical utility is yet to be examined in hospitals of low middle income countries (LMICs). AIM: The present study assessed the clinical utility of PGT by comparing the pharmacogenetically(PGT) guided- versus standard of care(SOC)- warfarin therapy, including the health economics of the two warfarin therapies. METHODS: An open-label, randomized, controlled clinical trial recruited warfarin-receiving patients in pharmacogenetically(PGT) guided- versus standard of care(SOC)- study arms. Pharmacogenetic analysis of CYP2C9*2(rs1799853), CYP2C9*3(rs1057910) and VKORC1(rs9923231) was performed for patients recruited to the PGT-guided arm. PT(Prothrombin Time)-INR(international normalized ratio) testing and dose titrations were allowed as per routine clinical practice. The primary endpoint was the percent time spent in the therapeutic INR range(TTR) during the 90-day observation period. Secondary endpoints were time to reach therapeutic INR(TRT), the proportion of adverse events, and economic comparison between two modes of therapy in a Markov model built for the commonest warfarin indication- atrial fibrillation. RESULTS: The study enrolled 168 patients, 84 in each arm. Per-protocol analysis showed a significantly high median time spent in therapeutic INR in the genotype-guided arm(42.85%; CI 21.4-66.75) as compared to the SOC arm(8.8%; CI 0-27.2)(p < 0.00001). The TRT was less in the PG-guided warfarin dosing group than the standard-of-care dosing warfarin group (17.85 vs. 33.92 days) (p = 0.002). Bleeding and thromboembolic events were similar in the two study groups. Lifetime expenditure was ₹1,26,830 in the PGT arm compared to ₹1,17,907 in the SOC arm. The QALY gain did not differ in the two groups(3.9 vs. 3.65). Compared to SOC, the incremental cost-utility ratio was ₹35,962 per QALY gain with PGT test opting. In deterministic and probabilistic sensitivity analysis, the base case results were found to be insensitive to the variation in model parameters. In the cost-effectiveness-acceptability curve analysis, a 90% probability of cost-effectiveness was reached at a willingness-to-pay(WTP) of ₹ 71,630 well below one time GDP threshold of WTP used. CONCLUSION: Clinical efficacy and the cost-effectiveness of the warfarin pharmacogenetic test suggest its routine use as a point of care investigation for patient care in LMICs.

On-X aortic valve replacement patients treated with low-dose warfarin and low-dose aspirin.

OBJECTIVES: To assess if warfarin targeted to international normalized ratio (INR) 1.8 (range 1.5-2.0) is safe for all patients with an On-X aortic mechanical valve. METHODS: This prospective, observational registry follows patients receiving warfarin targeted at an INR of 1.8 (range 1.5-2.0) plus daily aspirin (75-100 mg) after On-X aortic valve replacement. The primary end point is a composite of thromboembolism, valve thrombosis and major bleeding. Secondary end points include the individual rates of thromboembolism, valve thrombosis and major bleeding, as well as the composite in subgroups of home or clinic-monitored INR and risk categorization for thromboembolism. The control was the patient group randomized to standard-dose warfarin (INR 2.0-3.0) plus daily aspirin 81 mg from the PROACT trial. RESULTS: A total of 510 patients were enroled at 23 centres in the UK, USA and Canada. Currently, the median follow-up duration is 3.4 years, and median achieved INR is 1.9. The primary composite end point rate in the low INR patients is 2.31% vs 5.39% (95% confidence interval 4.12-6.93%) per patient-year in the PROACT control group, constituting a 57% reduction. Results are consistent in subgroups of home or clinic-monitored, and high-risk patients, with reductions of 56%, 57% and 57%, respectively. Major and total bleeding are decreased by 85% and 73%, respectively, with similar rates of thromboembolic events. No valve thrombosis occurred. CONCLUSIONS: Interim results suggest that warfarin targeted at an INR of 1.8 (range 1.5-2.0) plus aspirin is safe and effective in patients with an On-X aortic mechanical valve with or without home INR monitoring.

Prognostic markers in hepatitis A-related pediatric acute liver failure and validation of the Peds-hepatitis A virus prognostic model.

OBJECTIVES: Hepatitis A virus (HAV) is the commonest cause for pediatric acute liver failure (PALF) in India. The objective of the study was to identify the predictors of mortality and to evaluate the utility of Peds-HAV model in a cohort of non-LT HAV-PALF. METHODS: The study included HAV-related PALF from two non-transplant centers. The predictors of outcome were identified by univariate analysis followed by Cox regression analysis. The prognostic accuracy of Peds-HAV model, King's College Hospital (KCH) criteria and pediatric end-stage liver disease score (PELD) were evaluated. RESULTS: As many as 140 children with PALF were included, of whom 96 (68.6%) children had HAV-PALF. On Cox regression analysis, international normalized ratio (INR) (p < 0.001), jaundice to encephalopathy (JE) interval (p < 0.001) and hepatic encephalopathy (HE) grade 3/4 (p = 0.01) were independent predictors of mortality. The mortality rates were 0% (0/42), 14.3% (3/21), 60% (9/15) and 94.4% (17/18) when none, 1, 2 or 3 criteria of the Peds-HAV were met, respectively. Peds-HAV model at a listing cut-off of  ≥ 2 criteria predicted death with 89.7% sensitivity and 89.6% specificity. In contrast, KCH criteria had a lower sensitivity of 62.1%. PELD score had a sensitivity of 89.7% and specificity of 85.1% at a cut-off of 30. The overall prognostic accuracy of Peds-HAV model (89.6%) was higher than those of KCH (83.3%) and PELD (86.5%). CONCLUSION: INR, HE grade and JE interval were independent predictors of mortality. The study provides an external validation of Peds-HAV model as a prognostic score in HAV-PALF. CLINICAL TRIAL REGISTRY NUMBER: Not applicable as this is a retrospective study.