Pulmonary embolism response teams. A description of the first 36-month Australian experience

BACKGROUND

High/intermediate-risk pulmonary embolism (PE) confers increased risk of cardiovascular morbidity and mortality. International guidelines recommend the formation of a PE response team (PERT) for PE management because of the complexity of risk stratification and emerging treatment options. However, there are currently no available Australian data regarding outcomes of PE managed through a PERT.

AIMS

To analyse the clinical and outcome data of patients from an Australian centre with high/intermediate-risk PE requiring PERT-guided management.

METHODS

We performed a retrospective observational study of 75 consecutive patients with high/intermediate-risk PE who had PERT involvement, between August 2018 and July 2021. We recorded clinical and interventional data at the time of PERT and assessed patient outcomes up to 30 days from PERT initiation. We used unpaired t tests to compare right to left ventricular (RV/LV) ratios by computed tomography criteria or transthoracic echocardiogram (TTE) at baseline and after interventions.

RESULTS

Data were available for 74 patients. Initial computed tomography pulmonary angiography RV/LV ratio was increased at 1.65 ± 0.5 and decreased to 1.30 ± 0.29 following PERT-guided interventions (P < 0.001). TTE RV/LV ratio also decreased following PERT-guided management (1.09 ± 0.19 vs 0.93 ± 0.17; P < 0.001). 20% of patients had any bleeding complication, but two-thirds were mild, not requiring intervention. All-cause mortality was 6.8%, and all occurred within the first 7 days of admission.

CONCLUSION

The PERT model is feasible in a large Australian centre in managing complex and time-critical PE. Our data demonstrate outcomes comparable with existing published international PERT data. However, successful implementation at other Australian institutions may require adequate centre-specific resource availability and the presence of multispeciality input.

Efficacy and safety of avatrombopag in combination with immunosuppressive therapy in treatment-naïve and relapsed/refractory severe aplastic anaemia: protocol for the DIAAMOND-Ava-FIRST and DIAAMOND-Ava-NEXT Bayesian Optimal Phase II trials

INTRODUCTION

Immunosuppressive therapy (IST) with antithymocyte globulin (ATG) and ciclosporin is standard of care for patients with severe aplastic anaemia (sAA) not eligible or suitable for allogeneic stem cell transplant. While patients respond to IST, few achieve complete responses and a significant proportion are refractory or relapse. The addition of eltrombopag, a thrombopoietin-receptor agonist (TPO-A), to IST has been shown to improve haematological responses in sAA. Avatrombopag is a second-generation TPO-A with potential advantages over eltrombopag. However, to date avatrombopag has not been studied in sAA.

METHODS AND ANALYSIS

Investigator-initiated, single-arm registry-based Bayesian Optimal Phase II trial of avatrombopag conducted in two cohorts, patients with untreated sAA (FIRST cohort) and in patients with sAA that has relapsed or is refractory to IST (NEXT cohort). In the FIRST cohort, participants receive IST (equine ATG and ciclosporin) plus avatrombopag from day 1 until day 180 at 60 mg oral daily, with dose adjusted according to platelet count. Participants in the NEXT cohort receive avatrombopag at 60 mg oral daily from day 1 until day 180, with or without additional IST at the discretion of the treating clinician.For each cohort, two primary endpoints (haematological response and acquired clonal evolution) are jointly monitored and the trial reviewed at each interim analysis where a 'go/no-go' decision is made by evaluating the posterior probability of the events of interests.

ETHICS AND DISSEMINATION

The trial has received ethics approval (Monash Health RES-18-0000707A). The trial conduct will comply with ICH-GCP and all applicable regulatory requirements. The results of the trial will be submitted to a peer-review journal for publication.

TRIAL REGISTRATION NUMBER

ACTRN12619001042134, ACTRN12619001043123.

Measurable Residual Disease (MRD) by Flow Cytometry in Adult B-Acute Lymphoblastic Leukaemia (B-ALL) and Acute Myeloid Leukaemia (AML): Correlation with Molecular MRD Testing and Clinical Outcome at One Year

Measurable residual disease (MRD) detected by flow cytometry (FC) is well established in paediatric B- lymphoblastic leukaemia (B-ALL) and adult chronic lymphocytic leukaemia (CLL), but its utility in adult B-ALL and adult acute myeloid leukaemia (AML) is less clear. In this prospective MRD study, one of the largest in Australia to date, we examined consecutive bone marrow aspirates from adult participants with B-ALL (n = 47) and AML (n = 87) sent for FC-MRD testing at a quaternary referral hospital in Sydney. FC-MRD results were correlated to corresponding Mol-MRD testing where available and clinical outcomes at three-month intervals over 1 year. B-ALL showed a moderate positive correlation (rs = 0.401, p < 0.001), while there was no correlation between FC-MRD and Mol-MRD for AML (rs = 0.13, p = 0.237). Five FC-MRD patterns were identified which had significant associations with relapse (X2(4) = 31.17(4), p > 0.001) and survival (X2(4) = 13.67, p = 0.008) in AML, but not in B-ALL. The three-month MRD results were also strongly associated with survival in AML, while the association in B-ALL was less evident. There was a moderate correlation between FC-MRD and Mol-MRD in B-ALL but not AML. The association of FC-MRD with relapse and survival was stronger in AML than in B-ALL. Overall, these findings suggest divergent utilities of FC-MRD in AML and B-ALL.

Direct oral anticoagulants or vitamin K antagonists in emergencies: comparison of management in an observational study

Background

Restoring hemostasis in patients on oral anticoagulants presenting with major hemorrhage (MH) or before surgical intervention has changed, with the replacement of vitamin K antagonist (VKA) with direct oral anticoagulants (DOACs).

Objectives

To observe the difference in urgent hemostatic management between patients on VKA and those on DOACs.

Methods

A multicenter observational study evaluated the variation in laboratory testing, hemostatic management, mortality, and hospital length of stay (LOS) in patients on VKA or DOACs presenting with MH or urgent hemostatic restoration.

Results

Of the 1194 patients analyzed, 783 had MH (61% VKA) and 411 required urgent hemostatic restoration before surgery (56% VKA). Compared to the international normalized ratio (97.6%), plasma DOAC levels were measured less frequently (<45%), and the time taken from admission for the coagulation sample to reach the laboratory varied widely (median, 52.3 minutes; IQR, 24.8-206.7). No significant plasma DOAC level (<50 ng/mL) was found in up to 19% of patients. There was a poor relationship between plasma DOAC level and the usage of a hemostatic agent. When compared with patients receiving VKA (96.5%) or dabigatran (93.7%), fewer patients prescribed a factor Xa inhibitor (75.5%) received a prohemostatic reversal agent. The overall 30-day mortality for MH (mean: 17.8%) and length of stay (LOS) (median: 8.7 days) was similar between VKA and DOAC patients.

Conclusion

In DOAC patients, when compared to those receiving VKA, plasma DOAC levels were measured less frequently than the international normalized ratio and had a poor relationship with administering a hemostatic reversal agent. In addition, following MH, mortality and LOS were similar between VKA and DOAC patients.

Vaccine-induced immune thrombotic thrombocytopenia post dose 2 ChAdOx1 nCoV19 vaccination: Less severe but remains a problem

BACKGROUND

Vaccine-induced immune thrombotic thrombocytopenia (VITT) is a rare but established complication of 1st dose ChAdOx1 nCoV19 vaccination (AZD1222), however this complication after dose 2 remains controversial.

OBJECTIVES

To describe the clinicopathological features of confirmed cases of VITT post dose 2 AZD1222 vaccination in Australia, and to compare this cohort to confirmed cases of VITT post 1st dose.

METHODS

Sequential cases of clinically suspected VITT (thrombocytopenia, D-Dimer > 5x upper limit normal and thrombosis) within 4-42 days of dose 2 AZD1222 referred to Australia's centralised testing centre underwent platelet activation confirmatory testing in keeping with the national diagnostic algorithm. Final classification was assigned after adjudication by an expert advisory committee. Descriptive statistics were performed on this cohort and comparative analyses carried out on confirmed cases of VITT after 1st and 2nd dose AZD1222.

RESULTS

Of 62 patients referred, 15 demonstrated presence of antibody mediated platelet activation consistent with VITT after dose 2 AZD1222. Four were immunoassay positive. Median time to presentation was 13 days (range 1-53) platelet count 116x10^9/L (range 63-139) and D-dimer elevation 14.5xULN (IQR 11, 26). Two fatalities occurred. In each, the dosing interval was less than 30 days. In comparison to 1st dose, dose 2 cases were more likely to be male (OR 4.6, 95% CI 1.3-15.8, p = 0.03), present with higher platelet counts (p = 0.05), lower D-Dimer (p = 01) and less likely to have unusual site thromboses (OR 0.14, 95% CI 0.04-0.28, p = 0.02).

CONCLUSIONS

VITT is a complication of dose 2 AZD1222 vaccination. Whilst clinicopathological features are less severe, fatalities occurred in patients with concomitant factors.

Validating lactate dehydrogenase (LDH) as a component of the PLASMIC predictive tool (PLASMIC-LDH)

Background

The PLASMIC score is a convenient tool for predicting ADAMTS13 activity of <10%. Lactate dehydrogenase (LDH) is widely used as a marker of haemolysis in thrombotic thrombocytopenic purpura (TTP) monitoring, and could be used as a replacement marker for lysis. We aimed to validate the PLASMIC score in a multi-centre Asia Pacific region, and to explore whether LDH could be used as a replacement marker for lysis.

Methods

Records of patients with thrombotic microangiopathy (TMA) were reviewed. Patients' ADAMTS13 activity levels were obtained, along with clinical/laboratory findings relevant to the PLASMIC score. Both PLASMIC scores and PLASMIC-LDH scores, in which LDH replaced traditional lysis markers, were calculated. We generated a receiver operator characteristics (ROC) curve and compared the area under the curve values (AUC) to determine the predictive ability of each score.

Results

46 patients fulfilled the inclusion criteria, of which 34 had ADAMTS13 activity levels of <10%. When the patients were divided into intermediate-to-high risk (scores 5-7) and low risk (scores 0-4), the PLASMIC score showed a sensitivity of 97.1% and specificity of 58.3%, with a positive predictive value (PPV) of 86.8% and negative predictive value (NPV) of 87.5%. The PLASMIC-LDH score had a sensitivity of 97.1% and specificity of 33.3%, with a PPV of 80.5% and NPV of 80.0%.

Conclusion

Our study validated the utility of the PLASMIC score, and demonstrated PLASMIC-LDH as a reasonable alternative in the absence of traditional lysis markers, to help identify high-risk patients for treatment via plasma exchange.

Immune thrombocytopenia and COVID-19 vaccination: Outcomes and comparisons to prepandemic patients

Background

Immune thrombocytopenia (ITP) has been reported following COVID-19 vaccination. After index case fatalities, there was concern among patients both with and without a prior history of ITP in Australia.

Objectives

To describe treatment outcomes of ITP after COVID-19 vaccination and compare relapsed vs historical pre-COVID-19 ITP cohorts.

Methods

We collected ITP cases in Australia within 6 weeks of receiving any COVID-19 vaccination as part of primary vaccination (up to October 17, 2021). Second, we reviewed platelet charts in a historical ITP cohort to determine whether platelet variability was distinct from relapsed ITP after vaccination.

Results

We report on 50 patients (37 de novo, 13 relapsed ITP) vaccinated from March 22, 2021, to October 17, 2021. Although there was 1 fatality, bleeding was otherwise mostly minor: (70% WHO bleeding grade <2). De novo ITP was more likely after AstraZeneca ChAdOx1 nCoV-19 (89%) than Pfizer BNT162b2 (11%). Most patients responded quickly (median, 4 days; complete response, 40 of 45 [89%]). In the historical cohort, only 6 of 47 patients exhibited platelet variability (>50% decrease and platelets <100 × 10⁹/L), but median platelet nadir was significantly higher than vaccination relapse (27 vs 6 × 10⁹/L, P =.005).

Conclusion

ITP was more frequently reported after AstraZeneca ChAdOx1 nCoV-19 than Pfizer BNT162b2 vaccination. Standard ITP treatments remain highly effective for de novo and relapsed ITP (96%). Although thrombocytopenia can be severe after vaccination, bleeding is usually mild. Despite some sampling bias, our data do not support a change in treatment strategies for patients with ITP after vaccination.

Treatment of immune thrombocytopenia in Australian adults: A multicenter retrospective observational study

Background

In Australia, prescribing restrictions limit access to internationally recommended second‐line therapies such as rituximab and thrombopoietin agonists (TPO‐A) (eltrombopag and romiplostim). Subsequent lines of therapy include an array of immunosuppressive and immune‐modulating agents directed by drug availability and physician and patient preference.

Objectives

The objective of the study was to describe the use of first and subsequent lines of treatment for adult immune thrombocytopenia (ITP) in Australia and to assess their effectiveness and tolerability.

Patients/Methods

A retrospective review of medical records was conducted of 322 patients treated for ITP at eight participating centers in Australia between 2013 and 2020. Data were analyzed by descriptive statistics and frequency distribution using pivot tables, and comparisons between centers were assessed using paired t tests.

Results

Mean age at diagnosis of ITP was 48.8 years (standard deviation [SD], 22.6) and 58.3% were women. Primary ITP was observed in 72% and secondary ITP in 28% of the patients; 95% of patients received first‐line treatment with prednisolone (76%), dexamethasone (15%), or intravenous immunoglobulin (48%) alone or in combination. Individuals with secondary ITP were less steroid dependent (72% vs. 76%) and required less treatment with a second‐line agent (47% vs. 58%) in the study sample. Over half (56%) of the cohort received treatment with one or more second‐line agents. The mean number of second‐line agents used for each patient was 1.9 (SD, 1.2). The most used second‐line therapy was rituximab, followed by etrombopag and splenectomy. These also generated the highest rates of complete response (60.3%, 72.1%, and 71.8% respectively). The most unfavorable side effect profiles were seen in long‐term corticosteroids and splenectomy.

Conclusion

A wide range of “second‐line” agents were used across centers with variable response rates and side effect profiles. Findings suggest greater effectiveness of rituximab and TPO‐A, supporting their use earlier in the treatment course of patients with ITP across Australia.

Pregnancy, childbirth and neonatal outcomes in women with inherited bleeding disorders: A retrospective analysis

Women with inherited bleeding disorders can deliver without complication when best practices are maintained.

Two Weeks of Low Molecular Weight Heparin for Isolated Symptomatic Distal Vein Thrombosis (TWISTER study)

BACKGROUND

Treatment of low-risk patients with isolated symptomatic distal deep vein thrombi (IDDVT) is uncertain.

OBJECTIVE

assess whether two weeks of therapeutic anticoagulation is efficacious/safe for IDDVT.

PRIMARY OUTCOME

symptomatic three-month venous thromboembolism (VTE) incidence in the two-week anticoagulation group. Secondary outcomes included post-thrombotic syndrome (PTS) and bleeding.

METHODS

Prospective multicentre cohort study. Consecutive low-risk IDDVT patients enrolled within 72 h of diagnosis and treated with therapeutic dose enoxaparin or rivaroxaban. At two weeks, patients had repeat complete whole leg compression ultrasound (CUS)/clinical review. If resolution of leg symptoms AND no radiological evidence of thrombus extension, anticoagulation was stopped. If ongoing symptoms and/or radiographic extension within distal veins, anticoagulation was continued for four more weeks. Patients with extension into the popliteal vein on two-week ultrasound were treated off-study. Patients were reviewed at three and six months.

FINDINGS/INTERPRETATION

241 eligible patients received ≥2 weeks anticoagulation. 167/241 (69%) were assigned to the 2-week anticoagulation group; 71/241 (30%) to the six-week anticoagulation group; 3/241 patients (1%) had extension into the popliteal vein on two-week CUS. Two patients in the two-week anticoagulation group had symptomatic IDDVT recurrence in ≤3 months; VTE recurrence 2/156; 1.3%(95% CI 0.05-4.85%). 69% of patients had complete resolution of symptoms within two weeks. Six-month PTS rates were 8/184, 4.4%(95% CI 2.1-8.5%). No major bleeding was reported. Our findings suggest it's safe/efficacious to stop therapeutic anticoagulation at two weeks in low-risk IDDVT patients with resolution of symptoms/no extension on ultrasound. This could replace 6-12 weeks of anticoagulation for ambulatory, low-risk IDDVT patients.

TRIAL REGISTRATION

ClinicalTrials.govNCT01252420.

Immune thrombocytopenia following vaccination during the COVID-19 pandemic

Not available.

Why is Misdiagnosis of von Willebrand Disease Still Prevalent and How Can We Overcome It? A Focus on Clinical Considerations and Recommendations

Despite von Willebrand disease (VWD) being the most common inherited bleeding disorder, its accurate diagnosis is frequently shrouded by diagnostic pitfalls. VWD is frequently under-diagnosed, over-diagnosed and misdiagnosed, leading to significant avoidable patient morbidity and health care system burden. At the heart of this dilemma lies the heterogeneity and complexity of von Willebrand factor (VWF) and associated defects, and the necessity of coalescing clinical and laboratory features to obtain an accurate diagnosis. Common pitfalls include poor clinical and scientific understanding and familiarity with VWD, incomplete clinical history and lack of routine use of standardised bleeding assessment tools (BAT), difficulty in accessing a comprehensive repertoire of laboratory tests, significant pre-analytical, analytical and post-analytical issues, and lack of expertise in laboratory testing and interpretation. Errors, resulting in under-diagnosis, over-diagnosis, and misdiagnosis of VWD, are presented and discussed. Strategies to minimise errors include better education of clinicians and laboratory staff on VWD, routine use of validated BAT, utilising a comprehensive gamut of laboratory investigations according to a standardised algorithm, and repeating testing to minimise pre-analytical errors. Recommendations on appropriate patient selection for VWD testing, how VWD should be investigated in the laboratory, and how to ensure test results are accurately interpreted in the correct clinical context are detailed.

Elective surgery in patients with inherited bleeding disorders: A retrospective analysis

INTRODUCTION

Published guidelines are available to assist in the management of patients with inherited bleeding disorders in the elective surgical setting however good quality outcome data is lacking.

AIM

- Evaluate the outcomes of adult patients with inherited bleeding disorders, who received factor replacement for elective surgery in NSW/ACT, Australia. - Assess adherence to relevant guidelines including Haemophilia Treatment Centre (HTC) utilisation and appropriate factor replacement.

METHOD

A retrospective analysis was performed between 2000 and 2018 to describe patient characteristics, surgical details, factor provision and outcomes. Univariate analysis was used to determine variables associated with guideline adherence. Covariates with p < 0.1 were included in the multivariate analysis.

RESULTS

A total of 1065 surgeries were performed on 571 patients. Diagnoses included Haemophilia A (43.5%), Haemophilia B (9.7%), von Willebrand disease (VWD) (45.3%) and rare bleeding disorders (RBDs) (1.6%). Bleeding complications were reported in 14 surgeries and 19 patients received factor replacement beyond standard duration of prophylaxis. Approximately 50% of all surgeries were performed in a HTC. Multivariate analysis demonstrated that diagnosis, surgical specialty, sex and year (p < 0.001) were associated with non-compliance with variable pattern within each category. Factor replacement was as expected except for plasma-derived Factor VIII/VWF usage in patients with VWD undergoing major bleeding risk surgery. VWD classification (p < 0.001) was associated with this deviation.

CONCLUSION

Low complication rates demonstrate that elective surgery in Australia is being safely performed in patients with inherited bleeding disorders however non-compliance with published guidelines exists highlighting areas of practice and policy discrepancies that warrant further exploration.

COVID-19 vaccination in haematology patients: an Australian and New Zealand consensus position statement

Australia and New Zealand have achieved excellent community control of COVID-19 infection. In light of the imminent COVID-19 vaccination roll out in both countries, representatives from the Haematology Society of Australia and New Zealand and infectious diseases specialists have collaborated on this consensus position statement regarding COVID-19 vaccination in patients with haematological disorders. It is our recommendation that patients with haematological malignancies, and some benign haematological disorders, should have expedited access to high-efficacy COVID-19 vaccines, given that these patients are at high risk of morbidity and mortality from COVID-19 infection. Vaccination should not replace other public health measures in these patients, given that the effectiveness of COVID-19 vaccination, specifically in patients with haematological malignancies, is not known. Given the limited available data, prospective collection of safety and efficacy data of COVID-19 vaccination in this patient group is a priority.

HOW Collaborative position paper on the management of thrombocytopenia in pregnancy

Thrombocytopenia in pregnancy is a common occurrence, affecting up to 10% of women by the time of birth. These recommendations aim to provide pragmatic guidance on the investigation, diagnosis and management of thrombocytopenia in pregnancy; including safety of neuraxial anaesthesia and precautions required for birth. Management of neonatal thrombocytopenia is also addressed. The authors are clinicians representing haematology, obstetric medicine, maternal-fetal medicine, and anaesthesia. Each author conducted a detailed literature review then worked collaboratively to produce a series of unanimous recommendations. The recommendation strength is limited by the lack of high-quality clinical trial data, and represents level C evidence.

Clinical consequences of the extremely rare anti-PP1Pk isoantibodies in pregnancy: a case series and review of the literature

BACKGROUND

The absence of the red cell antigens P, P1 and P^k , known as 'p', represents an extremely rare red cell phenotype. Individuals with this phenotype spontaneously form anti-PP1P^k isoantibodies, associated with severe haemolytic transfusion reactions, recurrent spontaneous abortion and haemolytic disease of the fetus and newborn (HDFN).

METHODS

We report a series of four successful pregnancies in three women with anti-PP1P^k isoantibodies, one complicated by HDFN, another by intrauterine growth restriction, all managed supportively. We also review the literature regarding the management of pregnancy involving anti-PP1P^k isoimmunization.

RESULTS

The literature surrounding anti-PP1P^k in pregnancy is limited to a very small number of case reports. The majority report management with therapeutic plasma exchange (TPE) with or without intravenous immunoglobulin. The relationship between titre and risk of pregnancy loss remains unclear, though a history of recurrent pregnancy loss appears important. Although a positive cord blood direct antiglobulin test is frequently noted, clinically significant HDFN appears uncommon, though possible.

CONCLUSION

Early initiation of TPE in high risk patients should be strongly considered. If possible, pregnancies should be managed in a high-risk obstetric or maternal fetal medicine service. The fetus should be monitored closely with interval fetal ultrasound and middle cerebral artery peak systolic volume Doppler to screen for fetal anaemia. Timely sourcing of compatible blood products is likely to be highly challenging, and both directed and autologous donation should be contemplated where appropriate. The International Red Cell Donor Panel may also provide access to compatible products.

How we diagnose 2M von Willebrand disease (VWD): Use of a strategic algorithmic approach to distinguish 2M VWD from other VWD types

INTRODUCTION

von Willebrand disease (VWD) is the most common inherited bleeding disorder and caused by an absence, deficiency or defect in von Willebrand factor (VWF). VWD is currently classified into six different types: 1, 2A, 2B, 2N, 2M, 3. Notably, 2M VWD is more often misdiagnosed as 2A or type 1 VWD than properly identified as 2M VWD.

AIM

To describe an algorithmic approach to better ensure appropriate identification of 2M VWD, and reduce its misdiagnosis, as supported by sequential laboratory testing.

METHODS

Comparative assessment of types 1, 2A, 2B and 2M VWD using various laboratory tests, including VWF antigen and several VWF activity assays, plus DDAVP challenge data, ristocetin-induced platelet agglutination (RIPA) data, multimer analysis and genetic testing.

RESULTS

Types 1, 2A, 2B and 2M VWD give characteristic test patterns that can provisionally classify patients into particular VWD types. Notably, type 1 VWD shows low levels of VWF, but VWF functional concordance (VWF activity/Ag ratios >0.6), with both baseline assessment and post-DDAVP. Types 2A, 2B and 2M VWD show VWF functional discordance (low VWF activity/Ag ratio(s)) dependent on the defect, but type 2M separates from 2A/2B VWD based on specific test patterns, especially with collagen binding vs glycoprotein Ib binding assays. RIPA identifies 2B VWD. Multimers separate 2M from 2A/2B.

CONCLUSION

We provide strategies to improve correct diagnosis of VWD, especially focussed on 2M VWD, and which can be used by most diagnostic haemostasis laboratories, reserving genetic analysis (if required) for confirmation.

Pregnancy complicated by refractory severe hypercholanaemia from sodium taurocholate co-transporting polypeptide deficiency

Sodium taurocholate co-transporting polypeptide deficiency is a rare metabolic autosomal recessive condition resulting in critically elevated plasma bile acid levels. Hypercholanaemia in similar conditions such as intrahepatic cholestasis of pregnancy has been associated with an increased risk of adverse obstetric outcomes including stillbirth. We present the first case of Sodium taurocholate co-transporting polypeptide deficiency in a current pregnancy in a patient with one previous stillbirth in the context of severe hypercholanaemia, where conventional treatments for cholestasis including ursodeoxycholic acid, rifampicin and cholestyramine were ineffective. Therapeutic plasma exchange and novel treatment with elobixibat were trialed with mixed results. The pregnancy resulted in an iatrogenic preterm delivery of a live infant at 32 weeks gestation.

Immune-Mediated Thrombotic Thrombocytopenic Purpura: A Narrative Review of Diagnosis and Treatment in Adults

Immune-mediated thrombotic thrombocytopenic purpura (iTTP) is a rare and potentially lethal disease characterized by fragmentary hemolysis, moderate-to-severe thrombocytopenia, end-organ dysfunction, and severely reduced ADAMTS13 levels (< 10%). Survival in iTTP has improved significantly since the introduction of plasma exchange as standard therapy combined with immune suppression to address the underlying pathophysiology. A host of challenges remain including prompt recognition of the disease, treatment of the end-organ effects of the disease, improving the early mortality rate, significantly reducing the relapse rate as well as addressing refractory disease. Discussed in this narrative review of iTTP are the recent measures aimed at addressing these issues, including improvements in clinical prediction models, postremission maintenance approaches with early retreatment as well as the development of novel therapies.

Dental extractions on direct oral anticoagulants vs. warfarin: The DENTST study

BACKGROUND

Conflicting recommendations exist addressing the management of direct oral anticoagulants (DOACs) for invasive dental procedures.

OBJECTIVES

To determine the safety of DOAC continuation compared to warfarin continuation for dental extractions with regards to bleeding outcomes.

METHODS

A single-center, prospective, cohort study was performed to compare 7-day bleeding outcomes between patients who continued their DOAC, and patients on warfarin with an International Normalized Ratio (INR) between 2.0 and 4.0. Blood tests including oral anticoagulant drug levels were measured immediately prior to extraction. The gauze used to apply pressure to the socket was weighed before and after extraction to estimate blood loss. Patients were contacted by phone 2 and 7 days after extraction.

RESULTS

Eighty-six patients on a DOAC had a total of 145 teeth extracted, and 21 patients on warfarin had 50 teeth extracted. There were no major bleeding events. The rate of minor plus clinically relevant nonmajor bleeding was comparable between the DOAC and warfarin cohorts (36% and 43%, respectively; odds ratio, 0.75; 95% confidence interval, 0.29-1.98). Preextraction apixaban and dabigatran levels were comparable between bleeders and nonbleeders, while rivaroxaban levels were higher in those who bled. The weight change of gauze used to tamponade the socket was similar between the 2 cohorts.

CONCLUSION

Dental extractions on patients continuing DOACs led to bleeding rates similar to patients on warfarin with an INR between 2.0 and 4.0. There is no need to adjust DOAC dosing prior to dental extractions.

Lessons learnt from local real-life experience with idarucizumab for the reversal of dabigatran

BACKGROUND

Idarucizumab is a specific antidote for the direct thrombin inhibitor oral anticoagulant dabigatran etexilate. It has been used with increasing frequency in Australia since it was granted Therapeutic Goods Administration approval in October 2016.

AIMS

To assess idarucizumab usage, effect on coagulation parameters and clinical outcomes in patients who received idarucizumab in Western Sydney Local Health District (WSLHD).

METHODS

A retrospective audit was conducted of all patients who received idarucizumab in WSLHD between September 2015 and December 2017.

RESULTS

Of the 23 patients who received idarucizumab, 17 (74%) had bleeding, and 6 (26%) required urgent surgery/procedure. Thrombin time (TT) or activated partial thromboplastin time (APTT, when TT not available) remained prolonged at 24 h post-idarucizumab infusion in 10 of 20 (50%) patients. Renal impairment at admission was associated with prolonged TT/APTT at 24 h (P = 0.02). Of the six (26%) patients who died during hospital admission, five had raised TT/APTT at 24 h (P = 0.05). Two deaths were due to continued bleeding despite idarucizumab. Only 17% of patients received prohaemostatic treatments, and none received plasma derivatives. Despite assay availability, dabigatran drug level was only measured in eight patients.

CONCLUSION

Idarucizumab helped achieve haemostasis in 15 bleeding patients and allowed 6 patients to undergo urgent surgery. Half the patients had prolonged TT/APTT at 24 h post-idarucizumab, which was more likely to occur in patients with impaired renal function.

To Maintain or Cease Non–Vitamin K Antagonist Oral Anticoagulants Prior to Minimal Bleeding Risk Procedures: A Review of Evidence and Recommendations

For procedures associated with minimal bleeding risk, there are data and experience to support the practice of continuing vitamin K antagonists rather than interrupting therapy, to prevent exposing patients to the undue risk of developing thromboembolism during anticoagulation cessation. Despite the increasing use of non–vitamin K oral anticoagulants (NOACs), there is little evidence to guide the management of these drugs around minimal bleeding risk procedures. This review examines and discusses the major society guidelines and recommendations addressing the management of NOACs around minimal bleeding risk procedures. Additionally, it summarizes the existing evidence, and highlights the gaps in knowledge where evidence is not yet available. Finally, recommendations are made to assist the proceduralist deal with this area of limited evidence.

Anticoagulation at the extremes of body weight: choices and dosing

INTRODUCTION

The landscape of therapeutic anticoagulation has changed dramatically over the past decade, with availability of direct oral anticoagulants (DOACs), which inhibit factor Xa or thrombin. However, the optimal anticoagulant agent and dosing strategy for patients at both extremes of body weight has not been established for any anticoagulant, including DOACs, vitamin K antagonists (VKA), and the various heparin options. Areas covered: This paper reviews available evidence to assist clinicians in prescribing of anticoagulation therapy at the extremes of body weight. Expert commentary: There are limited data to guide prescribing of all available anticoagulants at the extremes of weight and further research regarding efficacy and safety outcomes in these groups is required. Laboratory monitoring to guide dosing of traditional anticoagulants provides reassurance of 'predictable' efficacy. In contrast agents that are not routinely monitored by laboratory testing provide greater challenges. For example, underweight patients are at risk of receiving higher drug exposures of DOACs, whereas the use of fixed dose DOACs in obese patients may be associated with lower drug exposures.

Incidence of in-hospital and post-discharge diagnosed hospital-associated venous thromboembolism using linked administrative data

BACKGROUND

Hospital-associated venous thromboembolism (HA-VTE) is a serious adverse event, preventable with appropriate care during and post-admission. Accurate measurement of in-hospital and post-discharge incidences is essential for implementation and evaluation of prevention strategies and monitoring.

AIMS

To estimate in-hospital and post-discharge diagnosed VTE, trends and risk factors.

METHODS

This was a population-based study in New South Wales, Australia, using linked hospital admission and emergency department data for 2010-2013 of adult patients with a minimum stay of 48 h. HA-VTE were diagnosed in-hospital or post-discharge (within 90 days). Multi-level modelling schemes produced adjusted rates and ratios for patient, admission and hospital-related characteristics.

RESULTS

From 1 865 059 admissions, the HA-VTE incidence rate was 9.7 per 1000 admissions; 71% were diagnosed post-discharge, and 4.3% died with a greater risk for VTE diagnosed in hospital compared to post-discharge (8.4% vs 2.6%, P < 0.001). Compared with surgical patients, medical patients developed fewer HA-VTE (IRR = 0.60, 95% CI: 0.58-0.63) but were more likely to be diagnosed post-discharge (OR = 2.19; 95% CI: 2.00-2.40). HA-VTE increased 6.5% over the period, driven by the 44% increase in in-hospital diagnoses and not by the 9% decrease in post-discharge diagnoses.

CONCLUSIONS

HA-VTE is a continuing burden, and diagnosis after recent hospital discharge is notably high. Incidence varies across patients and facilities, highlighting the need for individual VTE risk assessment. Inclusive measures and routine monitoring of HA-VTE incidence and mortality are essential for implementing best practice and assessing effectiveness of prevention strategies.

Variation in the incidence and timing of diagnosis of hospital-associated venous thromboembolism using linked administrative data

Venous thromboembolism (VTE) is a potentially preventable adverse effect of hospitalisation. Inter-hospital variation in the incidence of hospital-associated VTE (HA-VTE) and timing of diagnosis (in-hospital or post-discharge) in New South Wales public hospitals were examined. Large variations in incidence (22% risk difference) and post-discharge diagnosis (115% odds difference) were evident after adjustment for case mix, which only explained 59% and 32% of inter-hospital variation respectively. The need for improved compliance with best practice guidelines is reinforced.

Intravenous iron vs blood for acute post-partum anaemia (IIBAPPA): a prospective randomised trial

BACKGROUND

Acute post-partum anaemia can be associated with significant morbidity including a predisposition for postnatal depression. Lack of clear practice guidelines means a number of women are treated with multiple blood transfusions. Intravenous iron has the potential to limit the need for multiple blood transfusions but its role in the post-partum setting is unclear.

METHODS/DESIGN

IIBAPPA is a multi-centre randomised non-inferiority trial. Women with a primary post-partum haemorrhage (PPH) >1000 mL and resultant haemoglobin (Hb) 5.5-8.0 g/dL after resuscitation with ongoing symptomatic anaemia who are otherwise stable (no active bleeding) are eligible to participate. Patients with sepsis or conditions necessitating rapid Hb restoration are excluded. Eligible participants are randomised to receive a blood transfusion or a single dose of intravenous iron polymaltose calculated using the Ganzoni formula. Primary outcome measures include Hb, Ferritin and C-Reactive Protein levels on Day 7. Secondary outcomes evaluate (i) Hb, Ferritin and CRP levels on Day 14, 28, (ii) anaemia symptoms on Day 0, 7, 14 and 28 using structured health related quality of life questionnaires, (iii) treatment safety by assessing adverse reactions and infection endpoints and (iv) the quantitative impact of anaemia on breast feeding quality using a hospital designed questionnaire.

DISCUSSION

If equivalence in Hb and ferritin levels, symptom scores and safety endpoints is demonstrated, intravenous iron may become the preferred treatment for women with acute post-partum anaemia to minimise transfusion reactions and costs.

TRIAL REGISTRATION

Australian and New Zealand Clinical Trials Registry: ACTRN12615001370594 on 16th December, 2015 (prospective approval).

Acquired haemophilia A complicating alemtuzumab therapy for multiple sclerosis

Alemtuzumab is a highly efficacious therapy used in the treatment of multiple sclerosis (MS), but uncoupling of T and B cell repopulation during immune reconstitution associates with an increasing range of secondary B cell-mediated autoimmune complications. A 34-year-old woman developed Graves' disease 11 months following an initial course of alemtuzumab treatment for MS. Nine months following the second treatment with alemtuzumab, the patient presented with spontaneous intramuscular and subcutaneous haemorrhage due to development of an inhibitory autoantibody to coagulation factor VIII. Acquired haemophilia A (AHA) is an extremely rare complication in patients treated with alemtuzumab. Treatment with rituximab may induce a rapid remission of AHA; however, the patient's high John Cunningham virus (JCV) antibody index and alemtuzumab-induced T cell lymphopenia may lead to an increased risk of progressive multifocal leucoencephalopathy, a potential complication which was unacceptable to the patient.

Trenonacog alfa for prophylaxis, on-demand and perioperative management of hemophilia B

INTRODUCTION

Current treatment for hemophilia B involves replacing the missing coagulation factor IX (FIX) with either plasma-derived or recombinant (r) FIX. Trenonacog alfa is the third normal half-life rFIX that has been granted FDA approval. Area covered: In this review, the authors examine trenonacog alfa for the treatment of hemophilia B including prophylaxis, on-demand and perioperative hemostasis. They compare the PK profile to nonacog alfa and evaluate the drug's efficacy and safety from published studies. Expert opinion: Trenonacog alfa appears to be an effective and safe treatment option for patients with hemophilia B with a PK profile similar to that of nonacog alfa. Despite the advent of extended half-life rFIX and other novel therapeutic approaches, normal half-life rFIX products, including trenonacog alfa, are likely to continue to have a place in hemophilia B treatment for at least the immediate future while the new landscape takes shape, particularly in countries that cannot afford the newer treatments.

Acute pulmonary embolism during warfarin therapy and long-term risk of recurrent fatal pulmonary embolism

The clinical characteristics and long-term outcomes of patients presenting with acute pulmonary embolism (PE) during treatment with warfarin have not been described. Clinical details of all patients admitted to a tertiary institution from 2000-2007 with acute PE were retrieved retrospectively, baseline warfarin status and the international normalised ratio (INR) were recorded, and their outcomes tracked using a statewide death registry. Of 923 patients with clearly documented warfarin status included in this study, 83 (9%) were taking warfarin. Mean (± standard deviation) day-1 INR of those taking warfarin was 2.3 ± 0.9, with 67% of patients therapeutically anti-coagulated (INR ≥2.0) at presentation (49 patients with INR <2.5 and 34 with INR ≥2.5). Patients taking warfarin on admission were more likely to have heart failure, atrial fibrillation and valvular heart disease, with similar prevalence of malignancy and ischaemic heart disease, compared to patients not on warfarin. Total mortality of the cohort (mean follow-up 4.0 ± 2.5 years) was 31.6% (in-hospital mortality 1.5%), and was similar between warfarin and no warfarin groups. There was however a greater than four-fold increased risk of post-discharge death due to recurrent PE for the patients taking warfarin on admission (hazard ratio [HR] 4.43, 95% confidence interval [CI] 1.36-14.42, p=0.01). Among patients taking warfarin on admission, day-1 INR <2.5 significantly increased long-term all-cause mortality compared to INR ≥2.5 (adjusted HR 2.51, 95% CI 1.08-5.86, p=0.03). In conclusion, patients presenting with PE during treatment with warfarin have an increased risk of death from recurrent PE. Admission INR appears to have independent long-term prognostic importance in these patients.

Managing and Supporting Surgery in Patients with Bleeding Disorders

Patients with inherited bleeding disorders are likely to require surgery at various times throughout life. In some cases, this may be major orthopaedic surgery required due to their underlying condition, for example, hemophilic arthropathy. For inherited disorders with significant bleeding risk, surgery should take place in a hemophilia treatment center with the availability of hematologic, anesthetic, surgical, nursing, scientific laboratory, and allied health expertise. Preoperative assessment, planning, and communication between team members are crucial. Specific replacement therapy is usually required, as may other adjunctive therapies. Venous thromboembolism (VTE) risk assessment is individualized, taking account of other underlying risks in the patient and risks associated with the procedure, including the replacement agent itself, and use of mechanical prophylaxis may be the safest approach in many cases. Pain management is also modified to take account of risks associated with the bleeding disorder, and spinal or epidural analgesia is restricted compared with patients who do not have hemostatic defects. In patients with acquired bleeding disorders, the preoperative assessment includes decisions regarding how best to optimize management of the underlying condition prior to proceeding with surgery. If this is achieved, specific replacement therapy may not be required. If complete remission of the acquired bleeding disorder is achieved preoperatively, then VTE prophylaxis and pain management options will not be limited by the bleeding disorder. The perioperative management of both hereditary and acquired bleeding disorders is discussed and contrasted.

Integrative Genomics Identifies the Molecular Basis of Resistance to Azacitidine Therapy in Myelodysplastic Syndromes

Myelodysplastic syndromes and chronic myelomonocytic leukemia are blood disorders characterized by ineffective hematopoiesis and progressive marrow failure that can transform into acute leukemia. The DNA methyltransferase inhibitor 5-azacytidine (AZA) is the most effective pharmacological option, but only ∼50% of patients respond. A response only manifests after many months of treatment and is transient. The reasons underlying AZA resistance are unknown, and few alternatives exist for non-responders. Here, we show that AZA responders have more hematopoietic progenitor cells (HPCs) in the cell cycle. Non-responder HPC quiescence is mediated by integrin α5 (ITGA5) signaling and their hematopoietic potential improved by combining AZA with an ITGA5 inhibitor. AZA response is associated with the induction of an inflammatory response in HPCs in vivo. By molecular bar coding and tracking individual clones, we found that, although AZA alters the sub-clonal contribution to different lineages, founder clones are not eliminated and continue to drive hematopoiesis even in complete responders.

The Overall Hemostatic Potential (OHP) Assay

The principle of the overall hemostatic potential (OHP) assay is the generation of a fibrin time curve by optical density readings, which represent the balance between fibrin generation, triggered by thrombin or tissue factor, and fibrinolysis, triggered by tissue plasminogen activator (tPA). OHP measures the integrated effect of procoagulant, anticoagulant, and fibrinolytic factors, and OHP assay parameters provide a means of quantifying both the coagulation and fibrinolytic potential of platelet poor plasma. In particular, the OHP assay can be used to evaluate hypercoagulable states and abnormalities of fibrinolysis which are not well defined by assays which are routinely available in the coagulation laboratory. OHP is a technically simple assay, with potential for application in the routine laboratory at minimal cost.

Formalising multidisciplinary peer review: developing a haematological malignancy-specific electronic proforma and standard operating procedure to facilitate procedural efficiency and evidence-based clinical practice

BACKGROUND

Multidisciplinary team (MDT) meetings aimed at facilitating peer review have become standard practice in oncology. However, there is scant literature on the optimal structure and conduct of such meetings.

AIMS

To develop a process for formal peer review of patients with haematological malignancies and to audit any resulting changes made to the management recommendations of the treating physician.

METHODS

A standard operating procedure (SOP) for MDT meetings was developed essentially to integrate clinical peer review with weekly pathology and radiology meetings. The centrepiece is the electronic submission of a patient-specific proforma (Microsoft InfoPath) prior to the meeting. It serves as the template for presentation, discussion and recording of recommendations and conclusions. The final verified document is stored in the electronic patient record, and a copy is sent to the general practitioner. The proposed management plans were compared to the consensus recommendations of the meeting for the first 4 years since inception.

RESULTS

Both SOP and proforma underwent continual improvements. These provided the framework for the conduct of a robust weekly MDT meeting for peer review of the management of patients with haematological malignancies. On 20% of occasions, patient management plans were altered to optimise patient care as a direct consequence on peer review at the MDT.

CONCLUSION

Our streamlined process, in its ultimate format, has provided a mature and efficient forum for formal peer review in a genuine multidisciplinary environment. Both initial data and informal feedback support its ongoing activity as an integral component of delivering quality patient care.

Monitoring Therapy during Treatment of von Willebrand Disease

von Willebrand factor (VWF) is an adhesive plasma protein that primarily acts to bridge platelets to sites of vascular injury and thus prevent bleeding. von Willebrand disease (VWD) is the most common inherited bleeding disorder and is caused by deficiency and/or defects of VWF, leading to low levels of plasma VWF or dysfunctional VWF. Factor VIII (FVIII) is also reduced in many patients with VWD, since VWF stabilizes and protects FVIII from degradation. Treatment of VWD primarily entails replacement of VWF, and sometimes FVIII, to protect against bleeding. This may entail use of VWF/FVIII concentrates, and/or desmopressin (1-deamino-8-d-arginine vasopressin) to release endogenous VWF in some patients. Adjunct therapies include antifibrinolytics and hormonal therapies in women. Optimal treatment of VWD entails measuring the effects of treatment, either as a trial before surgery or during therapeutic management. This is usually accomplished by performance of the same tests that are used to help diagnose VWD, although additional monitoring (clinically and/or by laboratory testing) may also be performed. The current review provides an overview of the treatment of VWD but is primarily focused on the monitoring of such therapy.

Type 2M and Type 2A von Willebrand Disease: Similar but Different

Analogous to the differentiation between hemophilia A and B, respectively, reflecting deficiency in factor VIII (FVIII) and FIX, and increasing being recognized as reflecting clinically different disorders, types 2A and 2M von Willebrand disease (VWD) can also be shown to express both similarities and differences in their prevalence, genetic defects, laboratory test results, clinical features, and treatment responses. In this narrative review, we explore these two “subtypes” of type 2 VWD, identifying parallels and dissimilarities in various aspects of their presentation to clinicians and to scientists/laboratories. This differential will become increasingly important as we strive to provide personalized approaches to future management of patients with VWD, particularly in the emerging landscape of recombinant von Willebrand factor.

Why Do Patients Bleed?

Patients undergoing surgical procedures can bleed for a variety of reasons. Assuming that the surgical procedure has progressed well and that the surgeon can exclude surgical reasons for the unexpected bleeding, then the bleeding may be due to structural (anatomical) anomalies or disorders, recent drug intake, or disorders of hemostasis, which may be acquired or congenital. The current review aims to provide an overview of reasons that patients bleed in the perioperative setting, and it also provides guidance on how to screen for these conditions, through consideration of appropriate patient history and examination prior to surgical intervention, as well as guidance on investigating and managing the cause of unexpected bleeding.

Global hypercoagulability in patients with schizophrenia receiving long-term antipsychotic therapy

BACKGROUND

Patients with schizophrenia are at increased risk of venous thromboembolism. The mechanisms underlying this association are poorly understood.

AIMS

We investigated whether there is a global hypercoagulable state in patients with schizophrenia utilising the overall haemostatic potential (OHP) assay which assesses overall coagulation potential (OCP), haemostatic potential (OHP) and fibrinolytic potential (OFP).

METHOD

Citrated plasma was collected for OHP assays from patients with schizophrenia on long-term antipsychotic treatment and compared with healthy age- and sex-matched controls. Time courses of fibrin formation and degradation were measured by spectrophotometry (absorption of 405nm) after the addition of tissue factor and tissue plasminogen activator to plasma.

RESULTS

Ninety patients with schizophrenia (antipsychotic treatment-15.9±9.7years) and 30 controls were recruited. Patients with schizophrenia had higher rates of smoking and levels of inflammatory markers (high-sensitivity C-reactive protein and neutrophil-to-lymphocyte ratio) than controls. Whilst D-dimer, fibrinogen and platelet count did not differ between patients with schizophrenia and controls, the OCP (54.0±12.6 vs 45.9±9.1, p=0.002) and OHP (12.6±5.8 vs 7.2±3.7, p<0.001) were higher, and OFP was lower (76.6±9.8% vs 84.9±6.4%, p<0.001) in patients with schizophrenia, implying both a hypercoagulable and hypofibrinolytic state in these patients. Importantly, abnormalities in overall coagulation were independently predicted by levels of plasminogen-activator-inhibitor-1, fibrinogen, platelet count, inflammatory markers and plasma triglycerides, suggesting a multifactorial aetiology.

CONCLUSION

Patients with schizophrenia have evidence of a global hypercoagulable and hypofibrinolytic state which may contribute to their increased risk of venous thromboembolism.

New oral anticoagulants: a practical guide on prescription, laboratory testing and peri-procedural/bleeding management. Australasian Society of Thrombosis and Haemostasis

New oral anticoagulants (NOAC) are becoming available as alternatives to warfarin to prevent systemic embolism in patients with non-valvular atrial fibrillation and for the treatment and prevention of venous thromboembolism. An in-depth understanding of their pharmacology is invaluable for appropriate prescription and optimal management of patients receiving these drugs should unexpected complications (such as bleeding) occur, or the patient requires urgent surgery. The Australasian Society of Thrombosis and Haemostasis has set out to inform physicians on the use of the different NOAC based on current available evidence focusing on: (i) selection of the most suitable patient groups to receive NOAC, (ii) laboratory measurements of NOAC in appropriate circumstances and (iii) management of patients taking NOAC in the perioperative period, and strategies to manage bleeding complications or 'reverse' the anticoagulant effects for urgent invasive procedures.