ADAMTS13 recovery in acute thrombotic thrombocytopenic purpura after caplacizumab therapy.

ABSTRACT: Caplacizumab prevents the interaction between von Willebrand factor and platelets and is used to treat immune thrombotic thrombocytopenic purpura (iTTP). Its administration has been associated with a delay in ADAMTS13 activity restoration after plasma exchange (PEX) suspension. We analyzed the outcomes of 113 iTTP episodes, 75 of which were treated with caplacizumab, in 108 patients from the Spanish Registry of Thrombotic Thrombocytopenic Purpura. Caplacizumab shortened the time to platelet count normalization and reduced PEX requirement, exacerbations, and relapses. There was no difference in the time to achieve ADAMTS13 activity ≥20% after PEX end between caplacizumab-treated and nontreated episodes (median [interquartile range], 14.5 [7.7-27.2] vs 13.0 [8.0-29.0] days, P = .653). However, considering the 36 episodes in which caplacizumab was started ≤3 days after iTTP diagnosis, the time for ADAMTS13 restoration from PEX end was higher than in those episodes in which caplacizumab was started >3 days after iTTP diagnosis (20.0 [12.0-43.0] vs 11.0 [3.5-20.0] days, P = .003) or than in non-caplacizumab-treated episodes (P = .033). This finding could be related to a significantly shorter duration of PEX in early caplacizumab-treated episodes than in late caplacizumab-treated episodes (5.5 [4.0-9.0] vs 15.0 [11.0-21.5] days, P < .001) or non-caplacizumab-treated episodes (11.0 [6.0-26.0] days, P < .001). There were no differences in time to ADAMTS-13 restoration from PEX start (28.0 [17.2-47.5], 27.0 [19.0-37.5] and 29.5 [15.2-45.0] days in early caplacizumab-treated, late caplacizumab-treated and non-caplacizumab-treated episodes). Early administered caplacizumab does not prevent the requirement for immunosuppression but has beneficial effects by shortening PEX requirement without major safety concerns.

N-Acetylcistein for thrombotic thrombocytopenic purpura: an observational case series study.

Acquired thrombotic thrombocytopenic purpura (TTP) is a life-threatening disorder. N-Acetylcysteine (NAC) rapidly degrades ultra-large von Willebrand factor multimers by disrupting the disulfide bonds. We report a series of twelve consecutive patients diagnosed with acquired TTP successfully treated with high-dose NAC (150 mg/kg/day) in combination with plasma exchange and steroids. Eight patients also received rituximab. Two patients presented refractory TTP. All patients achieved a quick clinical response in a median time of 5.5 days after starting NAC and are alive after a median follow-up of 29 months. The treatment was feasible and well tolerated. These data provide further evidence of the potential benefit and safety of adding NAC to the standard of care.

Activated prothrombin complex concentrate to treat bleeding events in acquired hemophilia A: BAHAS study.

OBJECTIVE: Activated prothrombin complex concentrate (aPCC) is a bypassing agent indicated to treat bleeds in patients with acquired hemophilia A (AHA). Nevertheless, its efficacy and safety in the real-world setting have not often been addressed. METHODS: We report the experience of Spanish reference centers for coagulation disorders and from acquired hemophilia Spanish Registry (AHASR) from August 2012 to February 2021. Follow-up period of 30 days after aPCC withdrawal. RESULTS: Thirty patients with a median age of 70 years old, suffering from 51 bleeds treated with aPCC were finally evaluated. As first-line treatment, aPCC stopped bleeding in 13 of 14 (92.9%) cases. aPCC as the second line after recombinant factor VIIa failure, stopped bleeding in all cases. In 17 patients, aPCC was used far from initial bleed control as prophylaxis of rebleeding with 94% effectiveness. No thromboembolic episodes were communicated. One patient developed hypofibrinogenemia, which did not prevent aPCC from halting bleeding. No other serious adverse events possibly or probably associated with aPCC were reported. CONCLUSIONS: This data support aPCC as hemostatic treatment in AHA with high effectiveness and excellent safety profile in acute bleeds and as extended use to prevent rebleedings, even in aging people with high cardiovascular risk.

Real-world effectiveness of caplacizumab vs the standard of care in immune thrombotic thrombocytopenic purpura.

Immune thrombotic thrombocytopenic purpura (iTTP) is a thrombotic microangiopathy caused by anti-ADAMTS13 antibodies. Caplacizumab is approved for adults with an acute episode of iTTP in conjunction with plasma exchange (PEX) and immunosuppression. The objective of this study was to analyze and compare the safety and efficacy of caplacizumab vs the standard of care and assess the effect of the concomitant use of rituximab. A retrospective study from the Spanish TTP Registry of patients treated with caplacizumab vs those who did not receive it was conducted. A total of 155 patients with iTTP (77 caplacizumab, 78 no caplacizumab) were included. Patients initially treated with caplacizumab had fewer exacerbations (4.5% vs 20.5%; P < .05) and less refractoriness (4.5% vs 14.1%; P < .05) than those who were not treated. Time to clinical response was shorter when caplacizumab was used as initial treatment vs caplacizumab used after refractoriness or exacerbation. The multivariate analysis showed that its use in the first 3 days after PEX was associated with a lower number of PEX (odds ratio, 7.5; CI, 2.3-12.7; P < .05) and days of hospitalization (odds ratio, 11.2; CI, 5.6-16.9; P < .001) compared with standard therapy. There was no difference in time to clinical remission in patients treated with caplacizumab compared with the use of rituximab. No severe adverse event was described in the caplacizumab group. In summary, caplacizumab reduced exacerbations and refractoriness compared with standard of care regimens. When administered within the first 3 days after PEX, it also provided a faster clinical response, reducing hospitalization time and the need for PEX.

Recomendaciones para el abordaje clínico de pacientes con púrpura trombocitopénica trombótica / Recommendations for the diagnosis and treatment of patients with thrombotic thrombocytopenic purpura

La púrpura trombocitopénica trombótica (PTT) es una microangiopatía trombótica (MAT) caracterizada por el desarrollo de anemia hemolítica microangiopática, trombocitopenia y disfunción orgánica isquémica asociada a niveles de ADAMTS13 inferiores al 10% en la mayoría de los casos.Recientemente se han producido numerosos avances en el campo de la PTT. Se han desarrollado nuevas técnicas rápidas y accesibles capaces de cuantificar los niveles de ADAMTS13 y los posibles inhibidores. Los sistemas de secuenciación masiva del gen ADAMTS13 facilitan la identificación de polimorfismos en este gen. Además, han aparecido nuevos fármacos como caplacizumab y se plantean estrategias de prevención de recaídas con el uso de rituximab.Los registros de pacientes con PTT permiten ahondar en el conocimiento de esta enfermedad, pero la gran variabilidad en el diagnóstico y tratamiento hace necesaria la elaboración de un documento que homogenice la terminología y la práctica clínica.Las recomendaciones recogidas en el presente documento se han elaborado siguiendo la metodología AGREE. Las preguntas de investigación se formularon de acuerdo con el formato PICO. Se realizó una búsqueda bibliográfica de la literatura publicada durante los últimos 10 años. Las recomendaciones se establecieron por consenso entre todo el grupo puntualizando las fortalezas y limitaciones existentes de acuerdo al nivel de evidencia obtenido.En conclusión, en el presente documento se recogen recomendaciones sobre el tratamiento, diagnóstico y tratamiento de la PTT con el objetivo final de elaborar pautas basadas en la evidencia publicada hasta la fecha que permitan a los profesionales sanitarios optimizar el tratamiento de la PTT. (AU)

Thrombotic thrombocytopenic purpura (TTP) is a thrombotic microangiopathy (TMA) characterized by the development of microangiopathic haemolytic anaemia, thrombocytopenia, and ischaemic organ dysfunction associated with ADAMTS13 levels lower than 10% in most cases.Recently there have been numerous advances in the field of PTT, new, rapid and accessible techniques capable of quantifying ADAMTS13 activity and inhibitors. The massive sequencing systems facilitate the identification of polymorphisms in the ADAMTS13 gene. In addition, new drugs such as caplacizumab have appeared and relapse prevention strategies are being proposed with the use of rituximab.The existence of TTP patient registries allow a deeper understanding of this disease but the great variability in the diagnosis and treatment makes it necessary to elaborate guidelines that homogenize terminology and clinical practice.The recommendations set out in this document were prepared following the AGREE methodology. The research questions were formulated according to the PICO format. A search of the literature published during the last 10 years was carried out. The recommendations were established by consensus among the entire group, specifying the existing strengths and limitations according to the level of evidence obtained.In conclusion, this document contains recommendations on the management, diagnosis, and treatment of TTP with the ultimate objective of developing guidelines based on the evidence published to date that allow healthcare professionals to optimize TTP treatment. (AU)

Clinical Efficacy and Safety of Fanhdi®, a Plasma-Derived VWF/Factor VIII Concentrate, in von Willebrand Disease in Spain: A Retrospective Study.

OBJECTIVE: To evaluate the efficacy and safety of a plasma-derived factor VIII concentrate containing von Willebrand Factor (pdVWF/FVIII) in standard clinical practice in von Willebrand Disease (VWD) patients. METHODS: A retrospective, multicentric, observational study of VWD patients treated with Fanhdi®, a pdVWF/FVIII concentrate, from January 2011 to December 2017 was conducted at 14 centers in Spain. Efficacy and safety were evaluated for acute bleeding episodes, for prevention of bleeding in surgeries, and for secondary long-term prophylaxis. RESULTS: Seventy-two eligible patients, type 1, 2, 3 VWD (25%/38.9%/36.1%) were treated for spontaneous and traumatic bleeding (140 episodes, n = 41 patients), to prevent surgical bleeding (69 episodes, n = 43 patients); and for secondary long-term prophylaxis (18 programs, n = 13 patients). Replacement therapy with pdVWF/FVIII showed an excellent to good clinical efficacy in 96.7% of the bleeding episodes, 100% during surgical procedures and 100% during prophylaxis. No adverse events (AEs), nor serious AEs related to the product were observed. CONCLUSIONS: Fanhdi® was effective, safe and well tolerated in the management of bleeding episodes, the prevention of bleeding during surgeries, and for secondary long-term prophylaxis in VWD patients.

Mortality in acquired thrombotic thrombocytopenic purpura in the pre-caplacizumab era.

Despite the effectiveness of plasma exchange (PEX) and immunosuppressants in the treatment of acquired thrombotic thrombocytopenic purpura (aTTP), a number of patients still die as a result of the disease. Whether caplacizumab could rescue these patients remains still unsettled. The objective of this study was to characterise mortality patterns and prognostic factors in the first episode of aTTP.We queried the Spanish TTP Registry for patients with a diagnosis of aTTP in their presenting episode who fulfilled complete clinical and follow-up data (n = 102). The patients were diagnosed between 2004 and 2018, and all were treated with daily PEX and corticosteroids. Clinical and laboratory data were analysed at diagnosis and during the treatment course.Eight patients (7.7%) died between 12 h and 36 days after presentation, and could be classified into three patterns: death before treatment, early death driven by acute cardiac or neurologic events, and late death due to unremitted aTTP. Stupor or coma at diagnosis and platelet count < 20 × 109 /L by the 6th treatment day were independently associated with increased risk of death.Stupor or coma at diagnosis and lack of response to PEX by the 6th day in patients experiencing the first episode of aTTP are strong predictors of mortality. These patients could be rescued by novel agents aimed at halting the microvascular thrombosis until adequate immunosuppression is achieved.

Recommendations for the diagnosis and treatment of patients with thrombotic thrombocytopenic purpura. / Recomendaciones para el abordaje clínico de pacientes con púrpura trombocitopénica trombótica.

Thrombotic thrombocytopenic purpura (TTP) is a thrombotic microangiopathy (TMA) characterized by the development of microangiopathic haemolytic anaemia, thrombocytopenia, and ischaemic organ dysfunction associated with ADAMTS13 levels lower than 10% in most cases. Recently there have been numerous advances in the field of PTT, new, rapid and accessible techniques capable of quantifying ADAMTS13 activity and inhibitors. The massive sequencing systems facilitate the identification of polymorphisms in the ADAMTS13 gene. In addition, new drugs such as caplacizumab have appeared and relapse prevention strategies are being proposed with the use of rituximab. The existence of TTP patient registries allow a deeper understanding of this disease but the great variability in the diagnosis and treatment makes it necessary to elaborate guidelines that homogenize terminology and clinical practice. The recommendations set out in this document were prepared following the AGREE methodology. The research questions were formulated according to the PICO format. A search of the literature published during the last 10 years was carried out. The recommendations were established by consensus among the entire group, specifying the existing strengths and limitations according to the level of evidence obtained. In conclusion, this document contains recommendations on the management, diagnosis, and treatment of TTP with the ultimate objective of developing guidelines based on the evidence published to date that allow healthcare professionals to optimize TTP treatment.

Real life behaviour of direct oral anticoagulants in patients with nonvalvular atrial fibrillation and morbid obesity.

Atrial fibrillation (AF) is the most prevalent arrhythmia worldwide and the main cause of anticoagulation, being direct oral anticoagulants (DOAC) increasingly used in this context. On the other hand, obesity is a known risk thromboembolic factor. In the clinical trials that led to the approval of DOAC for ischemic stroke prevention, patients with morbid obesity were underrepresented. The International Society of Thrombosis and Haemostasis suggests not using these drugs in morbid obese patients. Thus, the primary objectives of this study were to analyse the rates of mortality, thrombotic and haemorrhagic events in patients with morbid obesity. As secondary objectives, factors statistically associated with these events were analysed. Methods: multicentre retrospective study that included patients diagnosed with AF on treatment with DOAC from January 2013 to December 2016. The subgroup of patients with morbid obesity (BMI > 40 and / or weight > 120 kg) was analysed. Mean follow-up was 1.7 years. Results: Amongst 2,492 patients included in the study, 135 patients had morbid obesity (mean age was 71 ± 11 years). The mean scores of the CHA2DS2-VASc and HAS-BLED risk scales were 3.7 ± 1.6 and 2.2 ± 0.9, respectively. Neither differences were found regarding mortality (5.2 vs 6/100 patient-years, p = 0.662), ischemic stroke (0.8 vs 1.9/100 patient-years, p = 0.261) and major bleeding rates (3 vs 3.1/100 patient-years, p = 0.983) between morbidly obese population and general population. Nor was there an association found between the degree of obesity and any of the events studied. Conclusion: DOAC are safe and effective in morbidly obese patients.

Management of acquired hemophilia A: results from the Spanish registry.

The Spanish Acquired Hemophilia A (AHA) Registry is intended to update the status of AHA in Spain. One hundred and fifty-four patients were included and retrospectively followed for a median of 12 months. Patients were predominantly male (56.3%), with median age at diagnosis of 74 years. AHA was more frequently idiopathic (44.1%) and autoimmune disorder-associated (31.7%). Thirty-four percent of patients were on antithrombotic therapy at diagnosis. Hemostatic treatment was used in 70% of patients. Recombinant activated factor VII was more frequently infused (60.3% vs 20.6% activated prothrombin complex concentrate). Only 1 patient did not achieve control of hemorrhage. Complete remission (CR) was achieved by 84.2% of cases after immunosuppressive therapy. Steroids alone were less efficient than the other strategies (68.2% vs 87.2%, P = .049), whereas no differences existed among these (steroids/cyclophosphamide, 88.5%, vs steroids/calcineurin inhibitors, 81.2%, vs rituximab-based regimens, 87.5%). Female sex and high inhibitor levels influenced CR negatively. Thirty-six deaths (23.8%) were reported. Main causes of death were infection (15 patients, 9.9%) and hemorrhage (5 patients, 3.3%). All hemorrhage-related and half the infection-related deaths occurred within 2 months of diagnosis. Prior antithrombotic therapy was inversely associated with survival, irrespective of age. Median age of nonsurvivors was significantly higher (79 vs 73 years in survivors). Patients dying of infection were older than the other nonsurvivors (85 vs 78 years). In summary, fatal infection in the first months is common in our series. Antithrombotic therapy is associated with mortality. Particular care should be taken to avoid misdiagnosis.

Platelet function and microvesicle generation in patients with hemophilia A.

Our results do not support any effect of FVIII on platelet function in patients with severe HA treated under the regime of prophylaxis.

Incidence, diagnosis, and outcome of immune-mediated thrombotic thrombocytopenic purpura: A nationwide survey by the Spanish registry of thrombotic thrombocytopenic purpura.

BACKGROUND: Immune-mediated thrombotic thrombocytopenic purpura (iTTP) is a rare disease characterized by the presence of anti-ADAMTS13 autoantibodies. Achieving accurate information on incidence and customary disease management is important to provide appropriate diagnostic and therapeutic resources. The aim of this study was to determine the incidence and outcomes of iTTP in Spain. STUDY DESIGN AND METHODS: A cross-sectional survey was carried out among Spanish hospitals, focused on iTTP patients ≥16 years old attended between 2015 and 2017, and those at follow-up before that interval. Incidence, prevalence, mortality, refractoriness, exacerbations, treatment complications, relapses, and sequelae were estimated. RESULTS: Forty-two hospitals covering roughly 20 million inhabitants answered the survey and reported 203 episodes (138 newly-diagnosed and 65 relapses), of which 193 (95.1%) were treated. Incidence was 2.67 (95% CI 1.90-3.45) patients per million inhabitants per year and prevalence 21.44 (95% CI% 19.10-23.73) patients per million inhabitants. At diagnosis, ADAMTS13 activity and anti-ADAMTS13 autoantibody were measured in 97% and 84.3% of reported episodes, respectively. Fifteen patients (7.4%) died as a direct consequence of iTTP, 6 of them before receiving any iTTP-specific treatment. Thirty-one (16.1%) of the 193 treated episodes were refractory to plasma exchange and corticosteroids, and 51 (26.4%) suffered at least one exacerbation. CONCLUSION: iTTP incidence and prevalence were somewhat higher than those documented in neighboring countries. Together with data on treatments and outcomes, this information will allow us to better estimate what is needed to improve diagnosis and prognosis of iTTP patients in Spain.

Quality of electronic treatment records and adherence to prophylaxis in haemophilia and von Willebrand disease: Systematic assessments from an electronic diary.

INTRODUCTION: HaemoassistTM 2 is an electronic system designed for people with bleeding disorders and their physicians to record prophylactic infusions and treatment of bleeds. It aims to improve adherence by permitting reminders and accuracy of documentation by facilitating real-time reporting. AIM: To assess documentation quality and adherence to prophylactic regimens in patients with haemophilia A, haemophilia B or von Willebrand disease who are using HaemoassistTM 2. METHODS: Ten centres enrolled consecutive patients, who had been using HaemoassistTM 2 for ≥ 3 months (Cohort 1, 'quality of documentation'). Of these, patients who had a specified prophylactic regimen in HaemoassistTM 2 for ≥ 3 months were eligible for inclusion in Cohort 2 ('adherence to prophylaxis'). RESULTS: Cohort 1 comprised 796 patients (71% with severe haemophilia A; median 20.5 months of HaemoassistTM 2 use). The most common method of documentation for patients was using the mobile app; the median time between infusion and documentation was 4 hours using the app, compared with 85 hours using a web portal on a stationery device. The median total annualised number of infusions was consistent in the first and last 3 months of documentation (128; IQR: 70-184 and 120; IQR 64-176, respectively). Cohort 2 comprised 202 patients (79% severe haemophilia A; median of 13 months on prophylactic regimen in HaemoassistTM 2). The rate of adherence to prophylaxis was 83%; median deviation between planned and actual infusion time was ± 2 hours. CONCLUSION: HaemoassistTM 2 was used consistently over prolonged periods of time and allowed for precise analysis of adherence to prophylaxis.

Unraveling the Influence of Common von Willebrand factor variants on von Willebrand Disease Phenotype: An Exploratory Study on the Molecular and Clinical Profile of von Willebrand Disease in Spain Cohort.

The clinical diagnosis of von Willebrand disease (VWD), particularly type 1, can be complex because several genetic and environmental factors affect von Willebrand factor (VWF) plasma levels. An estimated 60% of the phenotypic variation is attributable to hereditary factors, with the ABO blood group locus being the most influential. However, recent studies provide strong evidence that nonsynonymous single nucleotide variants (SNVs) contribute to VWF and factor VIII phenotypic variability in healthy individuals. This study aims to investigate the role of common VWF SNVs on VWD phenotype by analyzing data from 219 unrelated patients included in the "Molecular and Clinical Profile of von Willebrand Disease in Spain project." To that end, generalized linear mixed-effects regression models were fitted, and additive and epistatic analyses, and haplotype studies were performed, considering five VWD-related measures (bleeding score, VWF:Ag, VWF:RCo, factor VIII:C, and VWF:CB). According to these analyses, homozygotes: for p.Thr789Ala(C) would be expected to show 39% higher VWF:Ag levels; p.Thr1381Ala(C), 27% lower VWF:Ag levels; and p.Gln852Arg(C), 52% lower VWF:RCo levels. Homozygotes for both p.Thr789Ala(C) and p.Gln852Arg(T) were predicted to show 185% higher VWF:CB activity, and carriers of two copies of the p.Thr1381Ala(T)/p.Gln852Arg(T) haplotype would present a 100% increase in VWF:RCo activity. These results indicate a substantial effect of common VWF variation on VWD phenotype. Although additional studies are needed to determine the true magnitude of the effects of SNVs on VWF, these findings provide new evidence regarding the contribution of common variants to VWD, which should be taken into account to enhance the accuracy of the diagnosis and classification of this condition. ClinicalTrials.gov identifier: NCT02869074.

Real-life behaviour of direct oral anticoagulants in a Spanish cohort with non-valvular atrial fibrillation: Refase Registry.

Aim: To analyse the effectiveness and safety of DOAC (direct oral anticoagulants) in non-valvular atrial fibrillation (NVAF) patients attending clinical practice.Methods: Retrospective study of AF patients who started treatment with DOAC from January 1, 2013 to December 31, 2016 in three Spanish hospitals. Mean follow-up was 1.6 years. The primary outcomes were rates of all-cause death, ischaemic stroke, and bleeding. These outcomes were also studied depending on correct dosage adjustment and standard/adjusted dose.Results: The study included 2494 patients (age = 76.0 ± 9.5 years, CHA2DS2-VASc = 4.0 ± 1.6). The most prescribed DOAC was rivaroxaban (41.1%). Patients taking dabigatran were the youngest (mean age = 73.1 ± 10.3 years), with better kidney function (mean CrCl = 80.6 ± 35.8 ml/min) and lower CHA2DS2-VASc (3.7 ± 1.4) and HAS-BLED (2.1 ± 0.9) scores. Patients taking apixaban were the oldest, and had the highest CHA2DS2-VASc and HAS-BLED scores (4.3 ± 1.6 and 2.6 ± 0.9, respectively). Rates of stroke/major bleeding/intracranial bleeding were 1.8/3.0/0.3 events per 100 patient-years, respectively, with no differences among DOAC. Based on dose adjustment according to technical data, it was observed that 517 patients (23.5%) received DOAC doses inconsistent with labelling (p < .001) and, within this group, under-dosed patients had a higher death rate although it did not reach a significant result after multivariate adjustment.Conclusions: The results of safety and efficacy are very similar to those of other previously published national registries. There were no differences among the different types of DOAC regarding outcomes. However, it was found that people taking the adjusted dose of the drug seemed to have a higher risk of death. A non-negligible proportion of patients received DOAC doses inconsistent with labelling (mostly underdose).

Involvement of antifactor VIII autoantibodies specificity in the outcome of inhibitor eradication therapies in acquired hemophilia a patients.

: We hypothesized that inhibitor specificity may predict the outcome of antifactor VIII autoantibodies eradication treatment in acquired hemophilia A. Our objective was to analyze the association between factor VIII domains recognized by inhibitors and outcome of the immunosuppressive therapies (ISTs) in a prospective, observational study. 16 patients were recruited. Inhibitor specificities were assessed at diagnosis and throughout the study. Their association with IST outcome was addressed. First-line IST succeeded in 56% of patients. Inhibitors reacted mainly with light chain domains (69%) and/or the A2 domain (44%). 31% inhibitors recognized more than one domain. Significantly, the number of patients whose inhibitors recognized the light chain was significantly higher in the group of those who did not reach complete remission after first line IST when compared with those who did [6/7 (85.7%) vs. 4/9 (44.4%), P < 0.05]. Therefore, inhibitor specificity could predict the success of IST in acquired hemophilia A.

Effectiveness and safety of rivaroxaban in nonvalvular atrial fibrillation: data from a contemporary Spanish registry.

Objective: To ascertain the clinical profile, management and rates of thromboembolic and bleeding complications in a contemporary cohort of patients with nonvalvular atrial fibrillation (NVAF) on rivaroxaban treatment, with a particular focus on some subgroups of patients. Methods: Retrospective study that included all NVAF patients who started treatment with rivaroxaban for the prevention of stroke or systemic embolism between December 2012 and December 2015. Rates of outcomes (stroke, nonfatal myocardial infarction, major bleeding, intracranial bleeding and death) during follow-up were calculated. Results: A total of 732 patients (mean age 76.4 ± 9.2 years; 54.5% women) were included. Comorbidities were common (hypertension 87.5%; diabetes 26.5%; renal insufficiency 24.6%; prior stroke/transient ischemic attack 16.8%). Mean CHA2DS2-VASc was 3.9 ± 1.5 and HAS-BLED 2.3 ± 0.9; 61.9% of patients were rivaroxaban naïve users. After a mean treatment period of 22.7 ± 7.4 months, rates of stroke, nonfatal myocardial infarction, major bleeding, intracranial bleeding and death were 1.8, 1.0, 3.2, 0.4 and 5.5 events per 100 patient-years, respectively. Rates of stroke and death were higher in patients >75 years (vs. ≤75 years) and in patients with prior stroke/transient ischemic attack or renal insufficiency. Rates of major bleeding were higher among patients >75 years and in patients with prior stroke/transient ischemic attack. Conclusions: In this contemporary Spanish cohort of NVAF patients on rivaroxaban, patients had many comorbidities, a high thromboembolic risk and a moderate bleeding risk. Overall, rates of stroke and bleeding complications were low and similar to other previous studies. These data suggest that rivaroxaban is effective and safe in routine practice.

Joint status in Spanish haemophilia B patients assessed using the Haemophilia Early Arthropathy Detection with Ultrasound (HEAD-US) score.

AIM: The use of musculoskeletal ultrasound (MSK-US) following protocols for haemophilic arthropathy and the Haemophilia Early Arthropathy Detection with Ultrasound (HEAD-US) score can help standardize monitoring in haemophilia. This study evaluated the joint status (elbows, knees and ankles) of patients with haemophilia B (HB) in Spain using MSK-US and the HEAD-US score. METHODS: Haemophilia B patients ≥14 years old were included in this observational, multicentre, cross-sectional study, regardless of their clinical condition, HB severity and treatment received. Two blinded observers were involved in image acquisition and scoring in each centre. RESULTS: Eighty-two patients from 12 centres were enrolled: 27% mild HB, 23% moderate, 50% severe HB. Mean age was 38.9 ± 16.4 years, 60% were treated on demand (OD) and 40% were on prophylaxis. HEAD-US was zero in all joints in 28.6% OD patients and 36.4% on prophylaxis. Mean scores significantly worsened with HB severity, except for the left knee. Patients on primary and secondary prophylaxis had significantly better joint health vs OD patients in all joints, except the right ankle. Among OD patients, those with severe disease presented significantly worse scores in all HEAD-US items related to permanent damage. CONCLUSION: Joint status of HB patients in Spain is influenced by severity and treatment modality, related to the development of arthropathy, which appears prevalent in OD patients with severe HB. Routine assessment with an imaging tool such as ultrasound and HEAD-US system may help to improve joint health by personalizing and adjusting treatment in this population.

Unraveling the effect of silent, intronic and missense mutations on VWF splicing: contribution of next generation sequencing in the study of mRNA.

Large studies in von Willebrand disease patients, including Spanish and Portuguese registries, led to the identification of >250 different mutations. It is a challenge to determine the pathogenic effect of potential splice site mutations on VWF mRNA. This study aimed to elucidate the true effects of 18 mutations on VWF mRNA processing, investigate the contribution of next-generation sequencing to in vivo mRNA study in von Willebrand disease, and compare the findings with in silico prediction. RNA extracted from patient platelets and leukocytes was amplified by RT-PCR and sequenced using Sanger and next generation sequencing techniques. Eight mutations affected VWF splicing: c.1533+1G>A, c.5664+2T>C and c.546G>A (p.=) prompted exon skipping; c.3223-7_3236dup and c.7082-2A>G resulted in activation of cryptic sites; c.3379+1G>A and c.7437G>A) demonstrated both molecular pathogenic mechanisms simultaneously; and the p.Cys370Tyr missense mutation generated two aberrant transcripts. Of note, the complete effect of three mutations was provided by next generation sequencing alone because of low expression of the aberrant transcripts. In the remaining 10 mutations, no effect was elucidated in the experiments. However, the differential findings obtained in platelets and leukocytes provided substantial evidence that four of these would have an effect on VWF levels. In this first report using next generation sequencing technology to unravel the effects of VWF mutations on splicing, the technique yielded valuable information. Our data bring to light the importance of studying the effect of synonymous and missense mutations on VWF splicing to improve the current knowledge of the molecular mechanisms behind von Willebrand disease. clinicaltrials.gov identifier:02869074.

Role of multimeric analysis of von Willebrand factor (VWF) in von Willebrand disease (VWD) diagnosis: Lessons from the PCM-EVW-ES Spanish project.

The multimeric analysis (MA) of plasma von Willebrand factor (VWF) evaluates structural integrity and helps in the diagnosis of von Willebrand disease (VWD). This assay is a matter of controversy, being considered by some investigators cumbersome and only slightly informative. The centralised study 'Molecular and Clinical Profile of von Willebrand Disease in Spain (PCM-EVW-ES)' has been carried out by including the phenotypic assessment and the genetic analysis by next generation sequencing (NGS) of the VWF gene (VWF). The aim of the present study was to evaluate the role of MA to the diagnosis of these patients and their potential discrepancies. Two hundred and seventy out of 480 patients centrally diagnosed with VWD had normal multimers, 168 had abnormal multimers and 42 a total absence of multimers. VWF MA was of great significance in the diagnosis of 83 patients (17.3%), it was also of help in the diagnosis achieved in 365 additional patients (76%) and was not informative in 32 cases (6.7%). With regard to discrepancies, 110 out of 480 (23%) patients centrally diagnosed with VWD presented some kind of discordance between VWF:RCo/VWF:Ag and/or VWF:CB/VWF:Ag ratios, multimeric study and/or genetic results. The VWF MA was key in the presence of novel mutations as well as in cases with phenotypic discrepancies. A comparison between the contribution of MA and VWF:CB showed a clearly higher contribution of the former in the diagnostic process. These data seem to reinforce the relevance of the VWF MA in VWD diagnosis, despite all its limitations.