Citations

AbstractIn hemophilia B (HB), factor IX gene (F9) genotyping is used for molecular confirmation of affected individuals, for carrier testing, to facilitate the identification of those at risk for anaphylaxis/inhibitors (associated with large deletions), and to assist in assigning disease severity. Owing to test costs, optimal test utilization involves pre/post-test counseling and appropriate patient and test selection (e.g., mutation screening [F9MS] vs. known mutation [F9KM] testing). This article aims to review the trends and outcomes of F9-genotyping orders and describe the spectrum of variants identified in a sample of individuals in our reference laboratory. We performed a retrospective review of consecutive orders submitted to the Special Coagulation DNA Diagnostic Laboratory, Mayo Clinic, between 2012 and 2015. A total of 133 orders (38%) were identified for men: 118 (88%) were F9MS and 15 (12%) were F9KM. Thirteen orders (10%) were cancelled. A total of 209 orders were identified for women: 178 (85%) were F9MS and 31 (15%) were F9KM. Thirty-seven orders (18%) were cancelled and 30% of the tests performed yielded negative results. A total of 164 samples (47%) were received without clinical information. Seventeen previously unreported variants were identified. F9 genotyping provides useful information for HB management; however, 18% of our orders were cancelled and almost half were received without relevant clinical information, thus reaffirming the need for ongoing scrutiny of submitted orders. Optimal patient and test selection is important as is the accurate interpretation of variants identified. Most of the pathogenic variants identified were point mutations, with very few large deletions, consistent with the literature.

AbstractThe global incidence of venous thromboembolism is high so laboratory testing for hereditary thrombophilia and selected acquired thrombophilia is common. Given the costs associated with testing and multiple pre‐analytic and analytic variables affecting the assays, careful patient selection and timing of testing and diligent application to patient management are critical to providing high‐value clinical care. Collaboration between the ordering providers and performing laboratories has the potential to achieve these goals. Herein, utility of thrombophilia testing, variables that affect the assays, and impact on patient management are reviewed. Where available, information on cost‐effectiveness is discussed.

Venous thromboembolism (VTE) contributes to significant morbidity, mortality, and socioeconomic burden. There is a paucity of literature regarding sex-based sociodemographic differences in VTE presentation and short-term outcomes. We aimed to compare clinical outcomes between men and women hospitalized for VTE management. We performed a retrospective analysis using data from the National Inpatient Sample (NIS) database from 2012 to 2013. Inclusion criteria were age 18 years and older and a primary discharge diagnosis of VTE. Sociodemographic features and medical comorbidities were analyzed, as were hospital length of stay and in-hospital mortality rates. A total of 107,896 patients met the inclusion criteria; 53% were female. Median age was 65 years (interquartile range 51–77) and women were older than men (65 vs 62 years, p<0.001). There were significant differences between men and women with respect to race, primary insurance payer and medical comorbidities, and small differences with respect to VTE location. Female sex was associated with a small but significantly longer hospital length of stay (mean ratio 1.04, 95% CI 1.03–1.05, p<0.001) but no significant difference in in-hospital mortality (2.2% vs 2.1%, p=0.15). In a multivariate model, there was no significant difference between women and men with respect to hospital length of stay or in-hospital mortality. In conclusion, we used data from the NIS to study over 100,000 patients hospitalized for VTE, and identified several sex-based disparities in sociodemographic factors and location of VTE. However, in a multivariable analysis correcting for these factors, sex was not associated with significant differences in clinical outcomes.

AbstractBackgroundFactor XI (FXI) deficiency (hemophilia C [HEM‐C]) is a bleeding disorder with unpredictable severity that correlates poorly with FXI coagulation activity (FXI:C). It poses a perioperative hemostatic management challenge. For US patients with severe disease, fresh frozen plasma (FFP) or, in current use, thawed plasma is the most readily available option but comes with risk of volume overload. We report our experience of using therapeutic plasma exchange (TPE) as an alternative perioperative management strategy.MethodsA retrospective review of all HEM‐C patients who underwent surgical procedures. Data were collected, including demographics, bleeding history, surgical site, perioperative hemostatic intervention, and outcome.ResultsBetween July 1997 and September 2014, 28 HEM‐C patients (12 men) were identified, 4 with severe disease (FXI:C <2% or excessive bleeding). Nineteen patients underwent 91 invasive procedures. For nearly 60% of the procedures, no periprocedural hemostatic intervention was provided; before 4 procedures (3 patients), 1 plasma volume TPE preoperatively with FFP was administered. Patient 1, a 28‐year‐old woman (FXI:C, 35%) with a history of excessive surgical bleeding, underwent 2 TPE procedures before laparoscopic pelvic biopsy and subsequent abdominal hysterectomy with salpingo‐oophorectomy that increased her FXI:C to 48%. Patient 2, a 79‐year‐old man (FXI:C, <2%), had TPE before total hip arthroplasty, increasing his FXI:C to 24%. Patient 3, a 59‐year‐old man (FXI:C, <2%), had TPE before prostate laser enucleation, increasing his FXI:C to 46%. Patients 1 and 3 had mild reactions during TPE; no patient had evidence of volume overload. All patients had adequate intraoperative surgical hemostatic outcomes.ConclusionTPE is an effective alternative presurgical hemostatic intervention in HEM‐C with potentially lower risk of circulatory volume overload.

AbstractObjectivesTo analyze the economic impact of testing for activated protein C resistance (APC-R) due to factor V Leiden (FVL) mutation with APC-R with reflexive FVL genotyping (algorithmic approach) or genotyping alone.MethodsOptumLabs Data Warehouse (OLDW) data were used to assess testing approaches. Insurance claims for APC-R and FVL in 2013 were compared with the Mayo Clinic database. Centers for Medicare & Medicaid Services diagnostic fee schedules were used to assign costs.ResultsOf 19.3 million OLDW-covered individuals, 74,242 (0.385%) received 75,608 tests: APC-R, 2,265 (2.9%); FVL genotyping, 70,619 (90.1%); and both APC-R and FVL, 2,724 (7.0%). In total, 1,317 tests were performed at Mayo Clinic: APC-R with reflex FVL (1,256; 95.4%) and FVL alone (61; 4.6%). Costs per evaluated individual and per total population (person/year) in OLDW and algorithmic approach were $83.77 vs $36.38 and $0.32 vs $0.14, respectively.ConclusionsThe cost-optimized algorithmic approach reduces health care costs.

Abstract Rationale There is sparse published literature on the causes and outcomes of hospitalization of patients with hereditary hemorrhagic telangiectasia (HHT). Objectives To evaluate rates of various complications, comorbidities, and in-hospital outcomes of patients with HHT using a large, multihospital inpatient database. Methods We identified patients with HHT in the U.S. Nationwide Inpatient Sample between 2000 and 2012. Rates of hemorrhagic, neurological, hepatic, and cardiopulmonary complications among hospitalized patients with HHT were evaluated. We also studied procedure use rates for blood transfusion, endoscopy, and epistaxis treatment. Hospitalization outcomes, including in-hospital mortality, discharge status, charges, and length of stay, were evaluated. Measurements and Main Results: We identified 10,293 patients with HHT. The mean age of the HHT population was 60.7 years. Sixty percent of patients were female. More than 75% of HHT hospitalizations occurred in those older than 50 years of age. Patients with HHT had high rates of bleeding-related complications, including anemia (53.3%), epistaxis (16.2%), and gastrointestinal bleeding (10.8%). Overall, bleeding complications accounted for 62.7% of HHT-related complications. Thirty-eight percent of hospitalized patients with HHT received one or more transfusions of a blood product. Cardiopulmonary complications were present in 41.0% of the cases. Congestive heart failure was the second most common individual complication among patients with HHT, affecting 19.9% of patients. The in-hospital mortality rate was 1.9%. Conclusions In this large, nationwide study, we found that nearly two-thirds of patients hospitalized with HHT experienced a bleeding-related complication. Nearly 40% of hospitalized patients with HHT required transfusion of blood products. Cardiopulmonary complications, including congestive heart failure, were the second most common complication. The high burden of bleeding-related complications points to a significant unmet clinical need for these patients.