Risk of major bleeding in patients with non-valvular atrial fibrillation treated with oral anticoagulants: a systematic review of real-world observational studies

OBJECTIVE

To conduct a systematic review of real-world (RWD) studies comparing the risk of major bleeding (MB) among patients with non-valvular atrial fibrillation (NVAF) on direct oral anticoagulants (DOACs) or warfarin.

METHODS

MEDLINE, Embase, NHS-EED, and EconLit were searched for RWD studies published between January 2003 and November 2016 comparing MB risk among DOACs and warfarin. Proceedings of clinical conferences from 2012 to 2016 were reviewed.

RESULTS

A total of 4218 citations were identified, 26 of which met eligibility criteria. Most studies were retrospective analyses of administrative claims databases and patient registries (n = 23 of 26); about half were based in the United States (n = 15). Apixaban showed a significantly lower risk of MB versus warfarin in all eight included studies. MB risk was either significantly lower (n = 9 of 16) or not significantly different (n = 7 of 16) between dabigatran and warfarin; there was no significant difference between rivaroxaban and warfarin in all seven included studies. The risk was significantly lower with apixaban versus rivaroxaban (n = 7 of 7) but not significantly different from dabigatran (n = 6 of 7). MB risk was significantly lower (n = 3 of 4) or not significantly different (n = 1 of 4) with dabigatran versus rivaroxaban. No evidence was identified for edoxaban.

CONCLUSION

DOACs were associated with similar or lower risks of MB versus warfarin. A lower MB risk was consistently observed for apixaban, but less consistently for dabigatran; MB risk was similar between rivaroxaban and warfarin. Among DOACs, the risk of MB with apixaban was consistently lower than with rivaroxaban, but similar to dabigatran.

Do Prior Driveline Infections Increase the Risk of Infection in Heart Transplant Patients Treated With Rabbit Antithymocyte Globulin Induction Therapy?

BACKGROUND

The use of mechanical circulatory support devices (MCSDs) has been increasing over the past several years. Driveline infections (DLIs) are one of the most common complications seen in these patients; reportedly, up to 50% of patients with MCSDs can develop this complication. It is believed that the removal of the driveline results in treatment of the localized infection area. MCSD patients are also known to develop circulating antibodies. These circulating antibodies have been associated with poor outcomes after heart transplantation. The use of rabbit antithymocyte globulin (ATG) as induction therapy reportedly decreases the development of circulating antibodies; it is now commonly used in sensitized patients undergoing heart transplantation. It is unknown whether ATG induction therapy immediate posttransplant will increase the risk of infection of those MCSD patients with DLIs.

METHODS

Between 2003 and 2013, we evaluated 57 MCSD patients who subsequently underwent heart transplantation and received ATG induction therapy. Patients were divided into those with previous MCSD DLI and those without, and they were assessed for 1-year freedom from infection (specifically, sternal wound infections). One-year survival and freedom from treated rejection, both cellular and antibody mediated, were also assessed.

RESULTS

MCSD patients with DLIs who received ATG induction did not have a lower freedom from any treated infection and from sternal wound infection posttransplant compared with those MCSD patients without DLIs and not treated with ATG induction. There were also no significant differences between the 2 groups in terms of 1-year posttransplant survival and freedom from treated rejection.

CONCLUSIONS

The use of ATG induction in patients with prior DLIs did not seem to increase the risk for posttransplant infection (eg, sternal wound infection). ATG induction can therefore be safely used in this population.

Impact of apixaban vs low molecular weight heparin/vitamin k antagonist on hospital resource use in patients with venous thromboembolism

BACKGROUND

The clinical and economic benefits associated with apixaban treatment have been established in clinical trials and published economic evaluations. The benefits associated with apixaban could extend to improving hospital efficiencies, potentially influencing hospital resource use, and bed days. The objective of this study is to estimate the impact of 6-month treatment with apixaban vs low molecular weight heparin/vitamin k antagonist (LMWH/VKA) on hospital resource use among patients with venous thromboembolism (VTE).

METHODS

A model was developed to assess the impact of apixaban vs LMWH/VKA for treatment of VTE and prevention of recurrences on hospital resource use and costs. Resource use items included total hospitalizations, length of stay (LOS), and emergency department (ED) visits, estimated for all incident VTE patients in the UK over a 5-year time horizon. Rates of hospitalizations, ED visits, and LOS associated with recurrent VTE, major, and clinically relevant non-major bleeding were obtained from the AMPLIFY trial; costs were obtained from UK published sources.

RESULTS

Over a 5-year time horizon, the model predicted that, compared to 6 months of LMWH/VKA, 6 months of apixaban led to 3,954 fewer hospitalizations (consisting of 2,341 fewer new admissions and 1,613 fewer re-admissions) and 32,214 fewer bed days, among 332,607 incident VTE patients. ED visits were reduced by 1,582. The reduction in hospital resource use led to a cost saving of ∼£4.5 million in a market of patients treated with apixaban as compared to a market treated with LMWH/VKA. Sensitivity analysis indicated these findings were robust over a wide range of inputs.

CONCLUSIONS

6-month treatment with apixaban for treatment of VTE and prevention of recurrences on hospital resource use led to a reduction in hospitalizations and LOS in comparison to LMWH/VKA. These findings can help the efforts in reducing the growing burden of preventable re-admissions to hospitals.

Comparison of the Non-VKA Oral Anticoagulants Apixaban, Dabigatran, and Rivaroxaban in the Extended Treatment and Prevention of Venous Thromboembolism: Systematic Review and Network Meta-Analysis

Background

Historically, warfarin or aspirin have been the recommended therapeutic options for the extended treatment (>3 months) of VTE. Data from Phase III randomised controlled trials (RCTs) are now available for non-VKA oral anticoagulants (NOACs) in this indication. The current systematic review and network meta-analysis (NMA) were conducted to compare the efficacy and safety of anticoagulants for the extended treatment of VTE.

Methods

Electronic databases (accessed July 2014 and updated April 2016) were systematically searched to identify RCTs evaluating apixaban, aspirin, dabigatran, edoxaban, rivaroxaban, and warfarin for the extended treatment of VTE. Eligible studies included adults with an objectively confirmed deep vein thrombosis, pulmonary embolism or both. A fixed-effect Bayesian NMA was conducted, and results were presented as relative risks (RRs). Sensitivity analyses examining (i) the dataset employed according to the time frame for outcome assessment (ii) the model used for the NMA were conducted.

Results

Eleven Phase III RCTs (examining apixaban, aspirin, dabigatran, rivaroxaban, warfarin and placebo) were included. The risk of the composite efficacy outcome (VTE and VTE-related death) was statistically significantly lower with the NOACs and warfarin INR 2.0–3.0 compared with aspirin, with no significant differences between the NOACs. Treatment with apixaban (RR 0.23, 95% CrI 0.10, 0.55) or dabigatran (RR 0.55, 95% Crl 0.43, 0.71) was associated with a statistically significantly reduced risk of ‘major or clinically relevant non-major bleed’ compared with warfarin INR 2.0–3.0. Apixaban also showed a significantly reduced risk compared with dabigatran (RR 0.42, 95% Crl 0.18, 0.97) and rivaroxaban (RR 0.23, 95% Crl 0.09, 0.59). Sensitivity analyses indicate that results were dependent on the dataset, but not on the type of NMA model employed.

Conclusions

Results from the NMA indicate that NOACs are an effective treatment for prevention of VTE or VTE-related death) in the extended treatment setting. However, bleeding risk differs between potential treatments, with apixaban reporting the most favourable profile compared with other NOACs, warfarin INR 2.0–3.0, and aspirin.

Predictors of physical activity levels of individuals following traumatic brain injury remain unclear: A systematic review

OBJECTIVE

To identify factors which influence physical activity levels (PALs) of people with traumatic brain injury (TBI).

DATA SOURCES

Eight electronic databases.

STUDY SELECTION

A systematic search was performed to identify articles that reported the measurement (quantity) of PALs of individuals with TBI.

DATA EXTRACTION/SYNTHESIS

Two authors reviewed andextracted the data independently. Article quality was evaluated using the Law critical review tool.

RESULTS

Six studies were identified that met the inclusion criteria. All studies found that PALs of participants with TBI were below those recommended for health benefits. Although a number of environmental and personal barriers restricted PA participation, motivation and exercise self-efficacy were the most frequently identified facilitators of PA in the TBI population. Despite apparent links, the relationship between mobility capacity and PALs was unclear from the results of this systematic review.

CONCLUSION

The results of this systematic review demonstrated that little is known about PALs of individuals with TBI. PALs of participants with TBI were less than required for health maintenance. Self-efficacy to exercise and motivation were the most frequently identified facilitators of PA in the TBI population.

Perceptions in the U.S. building industry of the benefits and costs of improving indoor air quality

How building stakeholders (e.g. owners, tenants, operators, and designers) understand impacts of Indoor Air Quality (IAQ) and associated energy costs is unknown. We surveyed 112 stakeholders across the United States to ascertain their perceptions of their current IAQ and estimates of benefits and costs of, as well as willingness to pay for, IAQ improvements. Respondents' perceived IAQ scores correlated with the use of high-efficiency filters but not with any other IAQ-improving technologies. We elicited their estimates of the impacts of a ventilation-filtration upgrade (VFU), that is, doubling the ventilation rate from 20 to 40 cfm/person (9.5 to 19 l/s/person) and upgrading from a minimum efficiency reporting value 6 to 11 filter, and compared responses to estimates derived from IAQ literature and energy modeling. Minorities of respondents thought the VFU would positively impact productivity (45%), absenteeism (23%), or health (39%). Respondents' annual VFU cost estimates (mean = $257, s.d. = $496, median = $75 per person) were much higher than ours (always <$32 per person), and the only yearly cost a plurality of respondents said they would pay for the VFU was $15 per person. Respondents holding green building credentials were not more likely to affirm the IAQ benefits of the VFU and were less likely to be willing to pay for it.

TIME Impact - a new user-friendly tuberculosis (TB) model to inform TB policy decisions

Tuberculosis (TB) is the leading cause of death from infectious disease worldwide, predominantly affecting low- and middle-income countries (LMICs), where resources are limited. As such, countries need to be able to choose the most efficient interventions for their respective setting. Mathematical models can be valuable tools to inform rational policy decisions and improve resource allocation, but are often unavailable or inaccessible for LMICs, particularly in TB. We developed TIME Impact, a user-friendly TB model that enables local capacity building and strengthens country-specific policy discussions to inform support funding applications at the (sub-)national level (e.g. Ministry of Finance) or to international donors (e.g. the Global Fund to Fight AIDS, Tuberculosis and Malaria).TIME Impact is an epidemiological transmission model nested in TIME, a set of TB modelling tools available for free download within the widely-used Spectrum software. The TIME Impact model reflects key aspects of the natural history of TB, with additional structure for HIV/ART, drug resistance, treatment history and age. TIME Impact enables national TB programmes (NTPs) and other TB policymakers to better understand their own TB epidemic, plan their response, apply for funding and evaluate the implementation of the response.The explicit aim of TIME Impact's user-friendly interface is to enable training of local and international TB experts towards independent use. During application of TIME Impact, close involvement of the NTPs and other local partners also builds critical understanding of the modelling methods, assumptions and limitations inherent to modelling. This is essential to generate broad country-level ownership of the modelling data inputs and results. In turn, it stimulates discussions and a review of the current evidence and assumptions, strengthening the decision-making process in general.TIME Impact has been effectively applied in a variety of settings. In South Africa, it informed the first South African HIV and TB Investment Cases and successfully leveraged additional resources from the National Treasury at a time of austerity. In Ghana, a long-term TIME model-centred interaction with the NTP provided new insights into the local epidemiology and guided resource allocation decisions to improve impact.

Comparison of the Novel Oral Anticoagulants Apixaban, Dabigatran, Edoxaban, and Rivaroxaban in the Initial and Long-Term Treatment and Prevention of Venous Thromboembolism: Systematic Review and Network Meta-Analysis

Background

Anticoagulation with low molecular weight heparin and vitamin K antagonists is the current standard of care (SOC) for venous thromboembolism (VTE) treatment and prevention. Although novel oral anti-coagulants (NOACs) have been compared with SOC in this indication, no head-to-head randomised controlled trials (RCTs) have directly compared NOACs. A systematic review and network meta-analysis (NMA) were conducted to compare the efficacy and safety of NOACs for the initial and long-term treatment of VTE.

Methods

Electronic databases (accessed July 2014) were systematically searched to identify RCTs evaluating apixaban, dabigatran, edoxaban, and rivaroxaban versus SOC. Eligible patients included adults with an objectively confirmed deep vein thrombosis (DVT), pulmonary embolism (PE) or both. A fixed-effect Bayesian NMA was conducted for outcomes of interest, and results were presented as relative risks (RR) and 95% credible intervals (Crl).

Results

Six Phase III RCTs met criteria for inclusion: apixaban (one RCT; n = 5,395); rivaroxaban (two RCTs; n = 3,423/4,832); dabigatran (two RCTs; n = 2,539/2,568); edoxaban (one RCT; n = 8,240). There were no statistically significant differences between the NOACs with regard to the risk of ‘VTE and VTE-related death. Apixaban treatment was associated with the most favourable safety profile of the NOACs, showing a statistically significantly reduced risk of ‘major or clinically relevant non-major (CRNM) bleed’ compared with rivaroxaban (0.47 [0.36, 0.61]), dabigatran (0.69 [0.51, 0.94]), and edoxaban (0.54 [0.41, 0.69]). Dabigatran was also associated with a significantly lower risk of ‘major or CRNM bleed’ compared with rivaroxaban (0.68 [0.53, 0.87]) and edoxaban (0.77 [0.60, 0.99]).

Conclusions

Indirect comparisons showed statistically similar reductions in the risk of ‘VTE or VTE-related death for all NOACs. In contrast, reductions in ‘major or CRNM bleed’ for initial/long-term treatment were significantly better with apixaban compared with all other NOACs, and with dabigatran compared with rivaroxaban and edoxaban. Results from the current analysis indicate that the NOACs offer clinical benefit over conventional therapy while highlighting relative differences in their bleeding profile.