P. A. Holme

Catheter‐directed thrombolysis vs. anticoagulant therapy alone in deep vein thrombosis: results of an open randomized, controlled trial reporting on short‐term patency

Summary.  Background: Approximately one in four patients with acute proximal deep vein thrombosis (DVT) given anticoagulation and compression therapy develop post‐thrombotic syndrome (PTS). Accelerated removal of thrombus by thrombolytic agents may increase patency and prevent PTS. Objectives: To assess short‐term efficacy of additional catheter‐directed thrombolysis (CDT) compared with standard treatment alone. Patients and methods: Open, multicenter, randomized, controlled trial. Patients (18–75 years) with iliofemoral DVT and symptoms < 21 days were randomized to receive additional CDT or standard treatment alone. After 6 months, iliofemoral patency was investigated using duplex ultrasound and air‐plethysmography assessed by an investigator blinded to previous treatment. Results: One hundred and three patients (64 men, mean age 52 years) were allocated additional CDT (n = 50) or standard treatment alone (n = 53). After CDT, grade III (complete) lysis was achieved in 24 and grade II (50%–90%) lysis in 20 patients. One patient suffered major bleeding and two had clinically relevant bleeding related to the CDT procedure. After 6 months, iliofemoral patency was found in 32 (64.0%) in the CDT group vs. 19 (35.8%) controls, corresponding to an absolute risk reduction (RR) of 28.2% (95% CI: 9.7%–46.7%; P = 0.004). Venous obstruction was found in 10 (20.0%) in the CDT group vs. 26 (49.1%) controls; absolute RR 29.1% (95% CI: 20.0%–38.0%; P = 0.004). Femoral venous insufficiency did not differ between the two groups. Conclusions: After 6 months, additional CDT increased iliofemoral patency from 36% to 64%. The ongoing long‐term follow‐up of this study will document whether patency is related to improved functional outcome.

Non-genetic risk factors and the development of inhibitors in haemophilia: a comprehensive review and consensus report.

Summary.  The development of inhibitors to the infused factor in patients with haemophilia is a serious clinical problem. Recent evidence suggests that alongside the strong genetic contribution to inhibitor formation, there are a number of non‐genetic factors – perceived by the immune system as danger signals – which promote formation of inhibitors. This study provides a comprehensive review of clinical studies relating to these factors and also presents a survey of opinion concerning their importance and clinical influence, conducted among the members of the European Haemophilia Treatment Standardisation Board (EHTSB). Taken together, this information highlights the lack of robust data concerning the influence of several non‐genetic risk factors on inhibitor development, and an urgent need for prospective, well‐conducted studies that adhere to recommendations made by the European Medicines Agency (EMEA) for studying inhibitors. Based on current literature, the EHTSB formulated consensus recommendations. It is desirable to minimize intensive treatment wherever possible, given the clinical situation. Prophylaxis should be offered to all children, although we still need to determine optimal dosing with respect to inhibitor development, and age for starting treatment. Vaccinations should be given subcutaneously and concomitant factor concentrate infusions avoided. According to the board, there is no evidence in the literature supporting suggestions that the type of concentrate influences inhibitor risk; but all patients should be monitored during their first exposures. Furthermore, there is no evidence to support an association between pregnancy‐related issues, breast feeding and treatment‐related factors (e.g. route of administration, or use of blood components) and inhibitor development.

Post-thrombotic syndrome after catheter-directed thrombolysis for deep vein thrombosis (CaVenT): 5-year follow-up results of an open-label, randomised controlled trial

BACKGROUND Post-thrombotic syndrome is a common complication after acute proximal deep vein thrombosis (DVT) and is associated with reduced quality of life and a substantial cost burden. In the 2-year results of the CaVenT study, additional catheter-directed thrombolysis reduced the risk of post-thrombotic syndrome by 14% compared with conventional therapy, but did not affect quality of life. In this study we report results at the 5-year follow-up, aiming to assess whether findings for post-thrombotic syndrome and quality of life have persisted. METHODS Between Jan 3, 2006, and Dec 22, 2009, we recruited patients aged 18-75 years with a first-time high proximal leg DVT from 20 hospitals in the Norwegian southeastern health region. With sealed envelopes, participants were randomly assigned (1:1) to standard treatment with compression stockings and anticoagulants (control group) or to standard treatment plus catheter-directed thrombolysis with alteplase within 21 days from symptom onset. Pre-specified outcomes in this analysis were post-thrombotic syndrome at 5 years as assessed with the Villalta score and scores for quality of life at 5 years with EQ-5D and the disease-specific VEINES-QOL/Sym. Analyses were by intention to treat. The trial is registered with ClinicalTrials.gov, number NCT00251771. FINDINGS At 5 year follow-up (last date Oct 14, 2014), data were available for 176 patients (84% of the 209 patients originally randomised)--87 originally assigned to catheter-directed thrombolysis and 89 originally assigned to the control group. 37 patients (43%; 95% CI 33-53) allocated to catheter-directed thrombolysis developed post-thrombotic syndrome, compared with 63 (71%; 95% CI 61-79) allocated to the control group (p<0·0001), corresponding to an absolute risk reduction of 28% (95% CI 14-42) and a number needed to treat of 4 (95% CI 2-7). Four (5%) patients assigned to catheter-directed thrombolysis and one (1%) to standard treatment had severe post-thrombotic syndrome (Villalta score ≥ 15 or presence of an ulcer). Quality-of-life scores with either assessment scale did not differ between the treatment groups. INTERPRETATION Additional catheter-directed thrombolysis resulted in a persistent and increased clinical benefit during follow-up for up to 5 years, supporting the use of additional catheter-directed thrombolysis in patients with extensive proximal DVT. However, allocation to this therapy did not lead to better quality of life. The optimal endovascular thrombolytic approach needs further investigation. FUNDING Southeastern Norway Regional Health Authority, the Research Council of Norway, University of Oslo, Oslo University Hospital.

Acquired haemophilia: management of bleeds and immune therapy to eradicate autoantibodies

Summary.  Acquired haemophilia is a rare, but often severe bleeding disorder caused by autoantibodies against a coagulation factor, usually factor VIII (FVIII). Between 1997 and 2004 we observed 14 patients (mean age of 78 years) with acquired haemophilia. The aim of the present study was to investigate the effect of activated prothrombin complex concentrate (aPCC) for bleeds and the response to corticosteroids and cyclophosphamide to eradicate the offending autoantibodies. The most common clinical presentations were severe profuse bruising (12) and haematuria (5). Ten patients were classified as idiopathic. At the time of diagnosis all patients had a very low FVIII level, and one patient also showed factor IX < 1%. High levels of antibodies to FVIII varying from 10 to 1340 Bethesda units (BU) and prolonged activated partial thromboplastin time were disclosed in all patients. Eight severe bleeds were treated with aPCC (FEIBA®) at a dosage of 70 IU kg−1 every 8 h until haemostasis. Ten patients received corticosteroids and cyclophosphamide as immunomodulatory therapy. Effective haemostasis was achieved in all bleeds after aPCC. Ten of 11 patients responded either completely or partially to the immunomodulatory regime within 6 months. Five patients achieved complete response (CR) whereas partial responses were seen in five patients. The anti‐CD20 monoclonal antibody rituximab was given to two patients in conventional doses and a CR was seen in one patient. aPCC is effective in treating acute bleeds in patients with acquired haemophilia with high inhibitor levels. The combination of oral corticosteroids and cyclophosphamide seems to be effective to eradicate the inhibitor.

A dominant STIM1 mutation causes Stormorken syndrome.

Stormorken syndrome is a rare autosomal‐dominant disease with mild bleeding tendency, thrombocytopathy, thrombocytopenia, mild anemia, asplenia, tubular aggregate myopathy, miosis, headache, and ichthyosis. A heterozygous missense mutation in STIM1 exon 7 (c.910C>T; p.Arg304Trp) (NM_003156.3) was found to segregate with the disease in six Stormorken syndrome patients in four families. Upon sensing Ca2+ depletion in the endoplasmic reticulum lumen, STIM1 undergoes a conformational change enabling it to interact with and open ORAI1, a Ca2+ release‐activated Ca2+ channel located in the plasma membrane. The STIM1 mutation found in Stormorken syndrome patients is located in the coiled‐coil 1 domain, which might play a role in keeping STIM1 inactive. In agreement with a possible gain‐of‐function mutation in STIM1, blood platelets from patients were in a preactivated state with high exposure of aminophospholipids on the outer surface of the plasma membrane. Resting Ca2+ levels were elevated in platelets from the patients compared with controls, and store‐operated Ca2+ entry was markedly attenuated, further supporting constitutive activity of STIM1 and ORAI1. Thus, our data are compatible with a near‐maximal activation of STIM1 in Stormorken syndrome patients. We conclude that the heterozygous mutation c.910C>T causes the complex phenotype that defines this syndrome.

Rituximab as second-line treatment for adult immune thrombocytopenia (the RITP trial): a multicentre, randomised, double-blind, placebo-controlled trial.

BACKGROUND Immune thrombocytopenia is characterised by immune-mediated destruction and suboptimum production of platelets. Despite the absence of supporting evidence, rituximab is frequently used off-label in patients with immune thrombocytopenia. We aimed to assess the efficacy of rituximab as compared with placebo as a splenectomy-sparing treatment in patients who were previously treated with corticosteroids. METHODS In this multicentre, randomised, double-masked, placebo-controlled trial, we enrolled corticosteroid unresponsive adult patients (aged ≥18 years) with primary immune thrombocytopenia and a platelet count of less than 30 × 10(9) platelets per L. Patients were randomly assigned (1:1) to four weekly infusions of 375 mg/m(2) rituximab or placebo. Concurrent treatment with corticosteroids only was allowed during the study. The primary endpoint was rate of treatment failure within 78 weeks--a composite of splenectomy or meeting criteria for splenectomy after week 12 if splenectomy was not done, assessed in all patients who received at least one dose of study treatment. Secondary endpoints were response rates, relapse rates, and duration of response. Efficacy endpoints were assessed with the Kaplan-Meier method. Safety endpoints were assessed in all patients who received at least one dose. This trial is registered with ClinicalTrials.gov, number NCT00344149. FINDINGS Between Aug 17, 2006, and June 30, 2011, we enrolled 112 patients. 32 (58%) of 55 patients in the rituximab group and 37 (69%) of 54 patients in the placebo group had treatment failure within 78 weeks (Kaplan-Meier cumulative incidence 46% for rituximab vs 52% for placebo (hazard ratio [HR] 0·89, 95% CI 0·55-1·45; p=0·65). The cumulative incidence of overall response was 81% in the rituximab group versus 73% in the placebo group (p=0·15) and complete response was 58% in the rituximab group versus 50% in the placebo group (p=0·12). Of those achieving an overall response, 68% relapsed in the rituximab group and 78% relapsed in the placebo group, and of those achieving complete response, 50% relapsed in the rituximab group and 62% relapsed in the placebo group. Time to relapse in the rituximab group was longer in patients who achieved overall response (36 vs 7 weeks; p=0·01) but not complete response (76 vs 49 weeks; p=0·19). Rates of bleeding were similar in the two groups (21 [38%] in the rituximab group vs 27 [50%] in the placebo group; p=0·08) as were rates of infection (22 [40%] vs 13 [24%]; p=0·09). INTERPRETATION Despite no reduction in the rate of long-term treatment failure with rituximab, a small benefit cannot be ruled out, as suggested by an apparently longer duration of response and numerically higher response rates with rituximab. FUNDING South-East Regional Health Authority and Østfold Hospital, Norway; Roche, France; and Roche, Norway.

Combined treatment with APCC (FEIBA®) and tranexamic acid in patients with haemophilia A with inhibitors and in patients with acquired haemophilia A – a two‐centre experience

Summary.  The management of bleeding in haemophilia patients with inhibitors can be challenging when using monotherapy with either activated prothrombin complex concentrate (APCC) or recombinant activated FVII (rFVIIa) fail. The antifibrinolytic agent tranexamic acid (TXA) increases clot stability and is used concomitantly with coagulation factor replacement to improve haemostasis in haemophilia patients without inhibitors in many countries in Europe. Combined treatment with TXA and rFVIIa is not contraindicated in haemophlia patients with inhibitors. However, the combined approach of TXA and APCC has not been investigated due to safety concerns of increased risk of thrombosis or disseminated intravasal coagulation (DIC). The aim of this study is to report our experience of concomitant use of APCC and TXA in haemophilia A patients with inhibitor and in patients with acquired haemophilia A with respect to safety and efficacy. Seven (n = 6) haemophilia A patients with inhibitors and one (n = 1) with acquired haemophilia A from Oslo (Norway) and Stockholm (Sweden) were included in the study. The APCC was given at doses consistent to the manufacturers’ recommendation. TXA was administered concomitantly either 10 mg kg−1 every 6–8 h intravenously or 20 mg kg−1 every 6–8 h orally. Haemostatic response was assessed by thromboelastography (TEG) and thrombin generation assay (TGA) in three of the patients. A total number of three bleeding episodes and two minor and six major surgical procedures were performed under the coverage with APCC and TXA. Haemostatic outcome was rated excellent or good in 10 of 11 (91%) treatment episodes. One episode was rated with poor effect. No episodes of arterial, venous thrombosis or DIC occurred during or after the treatment. Data from TEG and TGA analysis showed no signs of hypercoagulability following the combined treatment. This report demonstrates that, in a limited number of patients, combined treatment with APCC and TXA seemed to be safe, tolerated and relatively effective in management of bleeding episodes and in preventing haemorrhage during surgery in haemophilia patients with inhibitors and in a patient with acquired haemophilia A. Further studies should be performed to confirm these data.

Hypercoagulability in patients with haematological neoplasia : No apparent initiation by tissue factor

Patients with haematological malignancies carry increased risk of venous thrombosis (VT). However, the mechanisms that link these malignancies to activated coagulation have not been fully identified. Since anti-haemostatic agents are studied in clinical trials for their potential to prolong survival in cancer patients, a detailed characterisation of haemostatic markers in cancer subtypes is needed. Hence, in this study, we measured the plasma concentrations and mRNA expression in blood mononuclear cells of haemostatic parameters in 93 patients with haematological neoplasias (acute myeloid leukaemia, chronic lymphatic leukaemia, multiple myeloma, and non-Hodgkins lymphoma) before start and after completion of cancer therapy. At diagnosis we found activation of coagulation and fibrinolysis, especially in patients with acute myeloid leukaemia. This hypercoagulation was not associated with increased levels of tissue factor (TF) or factor VII (fVII) antigen or mRNA, or levels of activated fVII. In conclusion we found a hypercoagulable state in patients with haematological malignancy that did not seem to be initiated by TF.

Haemophilic arthropathy: long-term outcomes in 107 primary total knee arthroplasties.

BACKGROUND Arthropathy of the knee is a frequent complication in patients with severe bleeding disorders leading to considerable pain and disability. Total knee arthroplasty (TKA) provides marked pain relief. However, a modest functional outcome and a high number of complications due to prosthetic infection and loosening are reported. Data on long-term outcomes are scarce, and most case series include few patients. We have studied clinical outcomes and complications of TKAs with special emphasis on prosthetic survival and periprosthetic infection. METHODS A consecutive series of 107 TKAs in 74 patients with haemophilic arthropathy were retrospectively reviewed. Follow-up was mean 11.2 years (range 0.8-33.1 years). RESULTS Five- and 10-year survival rates, with component removal for any reason as the end point, were 92% and 88%, respectively. Twenty-eight TKAs were removed after median 10 years (range 0.8-28 years). The most common cause of failure was aseptic loosening (14 knees) and periprosthetic infection (seven knees). The overall infection rate was 6.5%. The mean postoperative drop in haemoglobin levels was 4.3 g/dL (range 0.5-9.4) with a significant difference between haemophilia A patients with and without inhibitor (6.3 g/dL (range 3.6-9.4) versus 3.7 g/dL (range 0.5-8.1) (p<0.001). A painless knee was reported in 93% of the TKAs at the latest follow-up. CONCLUSIONS The medium and long-term results of primary TKA in a large haemophilic population show good prosthetic survival at five and 10 years with an excellent relief of pain. Periprosthetic infection is still a major concern compared to the non-haemophilic population. LEVEL OF EVIDENCE Level IV.

Continuous infusion in haemophilia: current practice in Europe

Summary. Continuous infusion (CI) of factor VIII (FVIII) is an effective method for replacement therapy in haemophilia. Recently, concerns have been raised regarding association of CI with the development of inhibitors. The aim of this study was to gain information on the current practices in Europe regarding CI and the true inhibitor incidence after this mode of therapy. In a cross sectional study performed in 22 Comprehensive Care Centres (CCCs), we evaluated CI techniques, treatment protocols, efficacy, safety and complications of CI including inhibitors. Thirteen (59%) CCCs reported a total of 1079 CI treatments, given peri‐operatively or for major bleeds, in 742 patients. Most centres used ‘adjusted dose’ CI aimed at median target FVIII level of 0.8 IU mL‐1. CI was haemostatically very effective with a low incidence of complications: median incidence of postoperative bleeding was 1.8%, six centres observed phlebitis in 2–11% of CI treatments. Only nine (1.2%) patients developed inhibitors (0.45% of 659 severe and 7.2% of 83 mild haemophilia patients). Additional analysis of inhibitor patients revealed several confounding factors (low number of prior FVIII exposure days, high steady‐state factor levels during CI, high‐risk genotype). In this unprecedentedly large cohort, CI treatment appears to be an effective and safe treatment that does not increase the risk of inhibitor development in patients with severe haemophilia. Thus, previous small case series reports suggesting that CI may increase inhibitorsb cannot be confirmed. Inhibitor risk in mild haemophilia could not be evaluated as the influence of other, potentially confounding, risk factors could not be excluded.