Prevalence of and risk factors for cerebral microbleeds among adult patients with haemophilia A or B.

INTRODUCTION: Cerebral microbleeds (CMBs) represent clinically silent haemorrhagic events. Cerebral microbleeds (CMBs) portend negative neurovascular and cognitive outcomes in the general population and are associated with cognitive impairment in persons with haemophilia (PWH). Prevalence, patterns, and risk factors for CMBs in PWH have not been directly compared to persons without coagulopathy. AIM: To examine prevalence, patterns, and risk factors for CMBs in PWH vs normal controls. METHODS: Adults with haemophilia A or B and haemostatically normal controls were recruited. Subjects were excluded if taking an antithrombotic agent other than low-dose aspirin (<100 mg). All subjects underwent T2*MRI of the brain; scans were reviewed independently by two neuroradiologists blinded to subject group to determine the presence of CMBs. RESULTS: We recruited 31 PWH and 32 controls. Human immunodeficiency virus (HIV) and history of hepatitis C virus (HCV) infection were more prevalent in PWH; smoking was more common among controls. Cardiovascular (CV) risk factors were similar between groups. Prevalence of CMBs was 35% in PWH and 25% in controls (P = .42). Among PWH, advanced age, history of HCV infection, and CV risk factors were associated with CMBs. Multiple and large (>5 mm) CMBs were seen only in PWH. CONCLUSIONS: Cerebral microbleeds (CMBs) are common in adults with haemophilia, but not clearly more prevalent than in haemostatically normal controls. In PWH, older age, HCV infection, CV risk factors, and the presence of an inhibitor were associated with CMBs. Large CMBs and multiple CMBs may be more prevalent in PWH than in the general population. The clinical impact of CMBs in PWH requires further study.

Recombinant factor VIIa addition to haemophilic blood perfused over collagen/tissue factor can sufficiently bypass the factor IXa/VIIIa defect to rescue fibrin generation.

INTRODUCTION: Factor VIII (FVIII) or factor IX (FIX)-deficient haemophilic patients display deficits in platelet and fibrin deposition under flow detectable in microfluidics. Compared to fibrin generation, decreased platelet deposition in haemophilic blood flow is more easily rescued with recombinant factor VIIa (rFVIIa), whereas rFVIIa requires FXIIa participation to generate fibrin when tissue factor (TF) is absent. AIMS: Perfusion of haemophilic whole blood (WB) over collagen/TF surfaces was used to determine whether rFVIIa/TF was sufficient to bypass poor FIXa/FVIIIa function in blood from patients with haemophilia A and B. METHODS: Whole blood treated with high-dose corn trypsin inhibitor (40 µg mL-1 ) from seven healthy donors and 10 patients was perfused over fibrillar collagen presenting low or high TF (TFlow or TFhigh ) at wall shear rate of 100 s-1 . RESULTS: With WB from healthy controls, platelet deposition and fibrin accumulation increased as TF increased. Factor-deficient WB (1-3% of normal) displayed striking deficits in platelet deposition and fibrin formation at either TFlow or TFhigh . In contrast, mildly factor-deficient WB (14-32%) supported fibrin formation under flow on TFhigh /collagen. With either TFlow or TFhigh , exogenously added rFVIIa (20 nm) increased platelet deposition and fibrin accumulation in WB from factor-deficient patients (1-3% of normal) to levels commensurate with untreated healthy WB. CONCLUSION: The absence of FIXa/FVIIIa in patients with severe haemophilia results in deficits in fibrin formation that cannot be rescued by wall-derived TF ex vivo. The effects of rFVIIa on platelet adhesion and rFVIIa/TF can act together to reinforce thrombin generation, platelet deposition and fibrin formation under flow.

Interventional therapies and in-hospital outcomes in acute coronary syndromes complicated by von Willebrand disease.

INTRODUCTION: von Willebrand disease (VWD) is one of the most common inherited bleeding disorders. AIM: Investigate the impact of the VWD bleeding tendency on in-hospital management of acute coronary syndromes (ACS). METHODS: Using discharge data from the National Inpatient Sample (NIS), the features of presentation and in-hospital treatment among ACS hospital discharges with and without a VWD diagnosis were investigated. A total of 264 case discharges and 705 860 control discharges were identified. RESULTS AND CONCLUSIONS: There was a significantly higher percentage of women among the case discharges compared to the control discharges (59.5% and 39.4%, respectively; P < 0.001). The rate of medical therapy alone [i.e. avoidance of percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG)] was significantly higher among unstable angina cases than controls (55.0% vs. 46.4%; P = 0.01), and among cases undergoing PCI, bare-metal stents (BMS) were utilized in preference to drug-eluting stents (DES) (adjusted OR = 3.5); P < 0.001). No difference in in-hospital death was identified, but reported bleeding among discharges that underwent CABG was higher in cases compared to controls (12.9% vs. 5.2%; P = 0.047). Although medical and interventional management of ACS appears to be well tolerated in the majority of hospitalized patients with VWD, the gender ratio is reversed, interventions and DES are utilized less frequently and procedure-related bleeding may be increased, calling for further study.

Evaluation of the utility of the ISTH-BAT in haemophilia carriers: a multinational study.

INTRODUCTION: There has been increasing recognition in recent years that female carriers of haemophilia manifest abnormal bleeding; however, data on the use of bleeding assessment tools in this population are lacking. AIM: Our objective was to validate the ISTH-BAT in haemophilia carriers to describe bleeding symptoms and allow for comparisons with factor levels and other patient groups. METHODS: This was a prospective, observational, cross-sectional study performed by members of Global Emerging HEmostasis Panel (GEHEP). Unselected consecutive haemophilia carriers were recruited and a CRF and the ISTH-BAT were completed by study personnel. RESULTS: A total of 168 haemophilia carriers were enrolled: 155 haemophilia A and 13 haemophilia B. The mean age was 40 years (range: 20-82). Carriers had higher mean bleeding scores (BS) compared with age-matched controls (n = 46; 5.7 vs. 1.43; P < 0.0001) and Type 3 VWD OC (n = 32; 3.0; P = 0.009), but lower BS compared with women with Type 1 VWD (n = 83; 8.7; P < 0.0001). Fifteen carriers reported haemarthrosis, and of those six had normal FVIII/FIX levels. There was a significant but weak negative correlation between BS and factor level (Spearman's r2  = -0.36, P < 0.001). CONCLUSION: Our results show that haemophilia carriers experience abnormal bleeding, including haemarthrosis. Overall, BS in women with Type 1 VWD > haemophilia carriers > Type 3 VWD OC > controls. Understanding the performance of the ISTH-BAT in this population is a critical step in future research aimed at investigating the underlying pathophysiology of abnormal bleeding, with the ultimate goal of optimizing treatment.

Presentation and management of acute coronary syndromes among adult persons with haemophilia: results of an international, retrospective, 10-year survey.

Sparse data are available on presentation and management of acute coronary syndromes (ACS), including unstable angina and non-ST- and ST-elevation myocardial infarction, among persons with haemophilia (PWH). The aim of this study was to determine demographics, bleeding disorder characteristics, cardiovascular risk factors (CRFs), interventions, haemostatic protocol, revascularization outcomes and complications among PWH with ACS. Members of an international consortium comprising >2000 adult PWH retrospectively completed case report forms for episodes of ACS in a >10-year follow-up period (2003-2013). Twenty ACS episodes occurred among 19 patients [rate, 0.8% (95% CI 0.4, 1.2)]. Seven patients (37%) were aged <50 years; 10 (53%) had ≥3 CRFs. In 5/20 episodes (25%), the initial ACS management protocol was altered because of the bleeding disorder. None of the eight patients with severe haemophilia underwent coronary artery bypass grafting (CABG), compared with 54.5% of patients with non-severe disease (P = 0.02). Revascularization with percutaneous coronary intervention (PCI) or CABG was rated successful in 13/13 cases, with no excessive bleeding during initial management. During chronic exposure to antiplatelet agents, secondary haemophilia prophylaxis was more prevalent in patients with severe haemophilia compared with non-severe haemophilia (85.7% vs. 30%, P = 0.05). No ACS-related deaths occurred during initial management, but one patient with severe haemophilia A died of undetermined cause 36 months after the ACS event while on aspirin therapy. ACS occurs even among relatively younger PWH, typically in association with multiple CRFs. Revascularization with PCI/CABG is feasible, and antiplatelet agents plus secondary prophylaxis appears to be well tolerated in selected PWH with ACS.

Recombinant factor VIIa enhances platelet deposition from flowing haemophilic blood but requires the contact pathway to promote fibrin deposition.

In prior microfluidic studies with haemophilic blood perfused over collagen, we found that a severe deficiency (<1% factor level) reduced platelet and fibrin deposition, while a moderate deficiency (1-5%) only reduced fibrin deposition. We investigated: (i) the differential effect of rFVIIa (0.04-20 nm) on platelet and fibrin deposition, and (ii) the contribution of the contact pathway to rFVIIa-induced haemophilic blood clotting. Haemophilic or healthy blood with low and high corn trypsin inhibitor (CTI, 4 or 40 µg mL(-1) ) was perfused over collagen at an initial venous wall shear rate of 100 s(-1) . At 100 s(-1) wall shear rate, where FXIIa leads to thrombin production without added tissue factor, FXI-deficient blood (3%) or severely FVIII-deficient blood (<1%) produced no fibrin at either CTI level. Whereas rFVIIa potently enhanced platelet deposition, fibrin generation was not rescued. Distinct from the high CTI condition, engagement of the contact pathway (low CTI) in moderately FVIII-deficient (3%) or moderately FIX-deficient blood (5%) resulted in enhanced platelet and fibrin deposition following 4 nm rFVIIa supplementation. In mildly FVIII-deficient blood (15%) at <24 h since haemostatic therapy, rFVIIa enhanced both platelet and fibrin generation in either CTI condition although fibrin was produced more quickly and abundantly in low CTI. For tissue factor-free conditions of severe haemophilic blood clotting, we conclude that rFVIIa reliably generates low levels of 'signaling' thrombin sufficient to enhance platelet deposition on collagen, but is insufficient to drive fibrin polymerization unless potentiated by the contact pathway.

Recombinant factor VIII Fc fusion protein: extended-interval dosing maintains low bleeding rates and correlates with von Willebrand factor levels.

BACKGROUND: Routine prophylaxis with replacement factor VIII (FVIII) - the standard of care for severe hemophilia A - often requires frequent intravenous infusions (three or four times weekly). An FVIII molecule with an extended half-life could reduce infusion frequency. The A-LONG study established the safety, efficacy and prolonged pharmacokinetics of recombinant FVIII Fc fusion protein (rFVIIIFc) in previously treated adolescents and adults with severe hemophilia A. OBJECTIVE: In this post hoc analysis, we investigated the relationship between subjects' prestudy (FVIII) and on-study (rFVIIIFc) regimens. METHODS: We analyzed two subgroups of subjects: prior prophylaxis and on-study individualized prophylaxis (n = 80), and prior episodic treatment and on-study weekly prophylaxis (n = 16). Subjects' prestudy dosing regimens and bleeding rates were compared with their final rFVIIIFc regimens and annualized bleeding rates (ABRs) in the last 3 months on-study. Dosing regimen simulations based on population pharmacokinetics models for rFVIII and rFVIIIFc were performed. RESULTS: As compared with their prestudy regimen, 79 of 80 (98.8%) subjects on individualized rFVIIIFc prophylaxis decreased their infusion frequency. Overall ABRs were low, with comparable factor consumption. Longer dosing intervals, including 5-day dosing, were associated with higher baseline von Willebrand factor antigen levels. Simulated dosing regimens predicted a greater proportion of subjects with steady-state FVIII activity trough levels of ≥ 1 IU dL(-1) (1%) with rFVIIIFc than with equivalent rFVIII regimens. CONCLUSION: These results suggest that patients on rFVIIIFc prophylaxis can reduce their infusion frequency as compared with their prior FVIII regimen while maintaining low bleeding rates, affording more patients trough levels of ≥ 1 IU dL(-1) than with rFVIII products requiring more frequent dosing regimens.

Microfluidic assay of hemophilic blood clotting: distinct deficits in platelet and fibrin deposition at low factor levels.

BACKGROUND: Coagulation factor deficiencies create a range of bleeding phenotypes. Microfluidic devices offer controlled hemodynamics and defined procoagulant triggers for measurement of clotting under flow. OBJECTIVES: We tested a flow assay of contact pathway-triggered clotting to quantify platelet and fibrin deposition distal of dysfunctional thrombin production. Microfluidic metrics were then compared with PTT or % factor activity assays. METHODS: Whole blood (WB) treated with low level corn trypsin inhibitor (4 µg mL⁻¹) from nine healthy donors and 27 patients (deficient in factor [F] VIII, 19 patients; FIX, one patient; FXI, one patient; VWF, six patients) was perfused over fibrillar collagen at wall shear rate = 100 s⁻¹. RESULTS: Using healthy WB, platelets deposited within 30 s, while fibrin appeared within 6 min. Compared with healthy controls, WB from patients displayed a 50% reduction in platelet deposition only at < 1% factor activity. In contrast, striking defects in fibrin deposition occurred for patients with < 13% factor activity (or PTT > 40 s). Full occlusion of the 60-µm high channel was completely absent over the 15-min test in patients with < 1% factor activity, while an intermediate defect was present in patients with > 1% factor. CONCLUSION: Spontaneous bleeding in patients with < 1% factor activity may be linked to deficits in both platelet and fibrin deposition, a risk known to be mitigated when factor levels are raised to > 1% activity (PTT of ~40-60 s), a level that does not necessarily rescue fibrin formation under flow.

How we manage prostate biopsy and prostate cancer therapy in men with haemophilia.

A 56-year-old African American male with severe haemophilia A [baseline factor VIII (FVIII) activity <1%] and chronic hepatitis C virus infection started annual serial monitoring of prostate-specific antigen (PSA) at age 40 because of a family history of prostate cancer (his father died from the disease at age 63). His most recent PSA level was 4.4 ng L (-1); previous values were <3 ng L(-1 . Digital rectal examination was unrevealing.

Survey of current prophylaxis practices and bleeding characteristics of children with severe haemophilia A in US haemophilia treatment centres.

Every other day (qod) factor VIII prophylaxis prevents joint bleeds in children with severe haemophilia A. Although three times weekly or qod prophylaxis is recommended by the National Hemophilia Foundation (NHF), how widely these practices have been adopted is not known. We sought to define current prophylaxis practices at US haemophilia treatment centres (HTCs). An email survey was distributed to US HTCs, utilizing web-based membership rosters of the Centers for Disease Control (CDC) and the Hemostasis Thrombosis Research Society (HTRS). Of 62 HTCs responding, prophylaxis is initiated on a three times weekly schedule in 29 (46.8%), twice weekly in 13 HTCs (21.0%) and once weekly in 20 HTCs (32.2%). Central venous catheters are used to infuse factor prophylactically at 55 HTCs (88.7%), including in 100% of children initiating prophylaxis at 19 HTCs (30.6%) and in 50% of those at 41 HTCs (66.1%), but avoided altogether at seven HTCs (11.3%). Prophylaxis is initiated after one or more bleeds in 56 HTCs (90.3%), but after the first bleed in only 28 HTCs (25.2%). Among 226 newborns with severe haemophilia A in 62 HTCs, 1.82 births/HTC/year, the median age at first bleed, excluding circumcision, is 7 months. Of the 113 (53.5%) newborns who underwent circumcision, 62 (54.9%) bled. Despite a recommended standard of three times weekly prophylaxis, over half of surveyed HTCs do not follow these guidelines, and nearly one-third begin prophylaxis on a once weekly schedule to delay or avoid the need for central venous access.

Outcomes in total elbow arthroplasty in patients with haemophilia at the University of California, San Francisco: a retrospective review.

Severe haemophilic arthropathy of the elbow is a significant cause of morbidity among adults with haemophilia. However, previous reports of total elbow arthroplasty (TEA) in the haemophilic population have been based on small numbers of patients with relatively short-term follow-up. The records of seven total elbow arthroplasties in six adult men with haemophilia at the University of California, San Francisco who underwent TEA over a period of 25 years were retrospectively reviewed. Type of haemophilia, age at time of TEA, HIV infection status, pre- and postoperative range-of-motion (ROM) scores, complications (including infections), need for subsequent surgical revision and functional outcomes were recorded. Four patients had severe factor VIII deficiency and two patients had severe factor IX deficiency. None of the patients had an inhibitor. The mean age at the time of surgery was 34 years (range, 22-46 years) and the mean follow-up period was 118 months (range, 37-176 months). One of the six patients had TEA in both elbows. Five of the six patients were infected with HIV. There were no immediate perioperative complications. At a mean of 19.2 months postoperatively, ROM had improved in five of seven TEAs: mean flexion had increased from 110.7° (SD = 15.0) to 120.1° (SD = 14.5), whereas mean preoperative extension increased from -44.3° (SD = 21.5) to -36.9° (SD = 27.0). One patient required a revision at 30 months because of ulnar component loosening. This same patient sustained a staph epidermidis infection and ultimate removal of the prosthesis 15 years postoperatively. At a mean of 118 months postoperatively, five of six patients continued to report reduced pain and preserved functionality, with ability to perform normal daily activities. TEA resulted in favourable results in six of seven procedures. Our findings support the viability of TEA for individuals with severe haemophilic arthropathy of the elbow, especially to reduce pain and preserve or restore functionality.

Emerging clinical concerns in the ageing haemophilia patient.

The availability of safe replacement clotting factor concentrates together with effective antiviral drugs to treat human immunodeficiency and hepatitis C viruses and the provision of care at designated haemophilia treatment centres have resulted in a new phenomenon in haemophilia management - the ageing patient. Today, increasing numbers of persons with haemophilia (PWH) are middle-aged and older, and they face the same age-related health issues as the general population. The impact of these risks on PWH is unclear, however, and there is a paucity of information about how to manage comorbidities in this patient population. This review focuses on five comorbidities that uniquely affect older PWH: cardiovascular disease, liver disease, cancer, renal disease and joint disease. Available research is summarized and potential management approaches are suggested.

What did the doctor say?

It is well known that 40 - 80% of information provided by clinicians is forgotten immediately by patients. Furthermore, 50% of the information remembered is incorrect. Research has shown that receiving written communication meets with high satisfaction from patients. According to the NHS plan to improve healthcare delivery, it has been recommended that patients should receive copies of letters written by doctors and that the policy would be implemented in full by April 2004. A total of 100 consecutive patients undergoing day-case gynaecological surgery under a single consultant were sent a postal questionnaire. Questions included were whether the letter was helpful, informative, reassuring, confusing or alarming. Patients were further asked whether they would prefer a similar communication in the future. A total of 78 patients replied. Of these, 67 patients found the letter helpful and preferred to have similar communication in future. Only two patients found the letter confusing and one of these was alarmed as well. Overall, 62 patients found the letter reassuring. The majority of the patients found the copy of GP discharge letter helpful, informative, non-alarming and reassuring and wanted a similar communication in the future. The extra workload involved was minimal and the extra expense involved only an extra page, envelope and postage.

Epidemiology of the most frequent diseases in the European a-symptomatic post-menopausal women. Is there any difference between Ireland and the rest of Europe?

Osteoporosis, cardiovascular disease, breast cancer and genitourinary diseases are some of the most frequently diagnosed diseases in a-symptomatic post-menopausal women. There is a marked European geographic distribution of osteoporosis. Rates are higher in Scandinavia than in the Southern European countries. The possible reasons for this higher incidence of osteoporotic fractures in the Northern European countries is associated with the climate, which limits physical activity and exposure to sunlight and increases the risk of falls. During the next two decades, the number of hip fractures for European women over 65 years is expected to nearly double. Despite these figures, osteoporosis prevention has not yet been adopted in many European countries. There is a devastating impact and a huge financial burden on the European economy and health care system. Breast cancer is the most common cancer in females in Europe. The regions of highest incidence are Western and Northern Europe, while Southern and Eastern Europe have lower incidence rates. The causes of differences in breast cancer incidences between Northern and Southern Europe are not known, but the average 5-year survival of women with breast cancer has increased in Europe in the last three decades. Studies have revealed marked differences in cardiovascular diseases across Europe, showing cardiovascular death rates as highest among the Eastern and Central European countries and lowest in the Mediterranean countries. Cardiovascular disease is the major cause of mortality in European women. However, in North European countries, there are more ischaemic heart diseases in women than in Mediterranean countries. In Mediterranean countries, on the other hand, there are more strokes than in Northern Europe. These strokes events occur 10 years later than the ischaemic heart attacks.

T cell receptor VB repertoire diversity in patients with immune thrombocytopenia following splenectomy.

In recent years, a pathophysiological role for T cells in immune thrombocytopenia (ITP) has been established. We applied cDNA size distribution analysis of the T cell receptor (TCR) beta-variable (VB) complementarity-determining region 3 (CDR3) in order to investigate T cell repertoire diversity among immune thrombocytopenia patients who had either responded or not responded to splenectomy, and compared them to normal controls. ITP patients who had had a durable platelet response to splenectomy showed a mean 2.8 +/- 2.1 abnormal CDR3 size patterns per patient, similar to healthy volunteers (2.9 +/- 2.0 abnormal CDR3 size patterns). In contrast, patients unresponsive to splenectomy demonstrated evidence of significantly more clonal T cell expansions than patients who had responded to splenectomy or controls (11.3 +/- 3.3 abnormal CDR3 size patterns per patient; P < 0.001). Of the VB subfamilies analysed, VB3 and VB15 correlated with response or non-response to splenectomy, each demonstrating oligoclonality in non-responding patients (P < 0.05). These findings suggest that removal of the spleen may lead directly or indirectly to reductions in T cell clonal expansions in responders, or that the extent of T cell clonality impacts responsiveness to splenectomy in patients with ITP.