Clinical Studies with Anticoagulants that Have Changed Clinical Practice

Usual On-therapy Ranges of Drug Concentrations in Patients with Atrial Fibrillation Treated with Direct Oral Anticoagulants: A Systematic Review and Meta-analysis

BACKGROUND

 Although most patients with atrial fibrillation (AF) receiving a direct oral anticoagulant (DOAC) do not require drug concentration measurements, there are situations where such information could be useful. Existing guidance documents provide usual on-therapy ranges for drug concentrations, but these have important limitations.

METHODS

 This is a systematic review and meta-analysis of studies reporting trough and peak levels of DOAC regimens approved for stroke prevention in AF. We used random effects models and the quantile estimation method to estimate the median and a usual on-therapy range (10th and 90th percentiles).

RESULTS

 Of 4,822 unique publications, 53 studies met eligibility (29,266 trough and 12,103 peak levels). Usual on-therapy ranges for trough levels were 38 to 155 and 58 to 206 ng/mL for apixaban 2.5 and 5 mg twice daily; 35 to 138 and 33 to 151 ng/mL for dabigatran 110 and 150 mg twice daily; 8 to 54 and 13 to 66 ng/mL for edoxaban 30 and 60 mg daily; and 16 to 74 and 19 to 72 ng/mL for rivaroxaban 15 and 20 mg daily. The corresponding range for peak levels were 96 to 251 and 132 to 343; 65 to 223 and 76 to 285; 57 to 219 and 127 to 407; 131 to 384, and 169 to 313 ng/mL, respectively.

CONCLUSION

 This systematic review and meta-analysis provides updated and more representative usual on-therapy ranges of DOAC levels in patients with AF.

Innovative Diagnostic Solutions in Hemostasis

Hemostasis describes the process of blood clotting homeostasis. Hemostasis reflects a balance of procoagulant and anticoagulant mechanisms that aim to prevent both bleeding and thrombosis. If hemostasis is disrupted, and bleeding or thrombosis occur, then laboratory testing may ensue to either diagnose the reason for bleeding or thrombosis, or to manage patients under therapy or treatment for bleeding or thrombosis. A wide range of tests of hemostasis are available to laboratories and to clinicians, from routine coagulation assays to specialized hemostasis assays and platelet function. In the current narrative review, we highlight some of the history of innovative diagnostic solutions, such as the integration of chemiluminescence and flow cytometry in the hemostasis diagnostic armamentarium, as well as providing a glimpse to the possible future of diagnostic hemostasis testing. Future directions include the potential for artificial intelligence in diagnostics, the development of more global test systems that can assess both primary and secondary hemostasis, and several innovations to enable the ongoing evolution of therapies to rebalance hemostasis and requiring precise monitoring. This review underscores the ongoing need for innovation to enhance the diagnostic landscape of hemostasis, ensuring better patient outcomes through more accurate and efficient diagnostic methods.

Prescription and switching patterns of direct oral anticoagulants in patients with atrial fibrillation

Background

The patterns of direct oral anticoagulant (DOAC) selection and switching to a different oral anticoagulant (OAC) in patients with atrial fibrillation (AF) are unknown.

Objectives

To describe temporal patterns in first DOAC prescriptions, estimate the incidence, and identify predictors of switching to a different OAC within 1 year in OAC-naive AF patients.

Methods

In this retrospective cohort study, using a near-nationwide prescription registry (IQVIA, the Netherlands), we determined the number of patients per month initiated on each DOAC and identified predictors of switching within 1 year with robust Poisson regression.

Results

We included 94,874 patients. From November 2015 to November 2019, the monthly use of apixaban (n = 366 to n = 1066, +191%), rivaroxaban (n = 379 to n = 868, +129%), and edoxaban (n = 2 to n = 305, +15,150%) increased, whereas that of dabigatran decreased (n = 317 to n = 179, -44%). In the 66,090 patients with ≥1 year of available calendar time, 7% switched to a different OAC within 1 year. Strong predictors of switching to a different DOAC were using dabigatran (adjusted risk ratio [aRR], 3.33; 95% CI, 3.02-3.66) or edoxaban (aRR, 1.56; 95% CI, 1.34-1.82) rather than apixaban and using a standard DOAC dose (aRR, 2.54; 95% CI, 2.23-2.88). Strong predictors of switching to a vitamin K antagonist were using rivaroxaban (aRR, 1.36; 95% CI, 1.19-1.54 vs apixaban) and using a standard DOAC dose (aRR, 1.49; 95% CI, 1.26-1.77).

Conclusion

In the Netherlands, factor Xa inhibitors are increasingly being selected for OAC-naive AF patients. Seven percent of patients switch to a different OAC within 1 year, and the initial DOAC type and dose are strong predictors of switching.

Approaches to Precision-based Anticoagulation management in the critically Ill

Anticoagulant therapy is commonly associated with a high incidence of avoidable adverse events, especially in the acute care setting. This has led to several initiatives by key national health care stakeholders, including specific attention to The Joint Commission's National Patient Safety Goals, to improve anticoagulation management. The subject of special populations has long been identified as challenging by clinicians with the use of anticoagulants. This is driven in part by numerous variables that can contribute to hard outcomes such as bleeding, thrombosis, length of stay, hospital re-admission, morbidity, and mortality. Despite the notable effort to improve the use of anticoagulants with numerous clinical trials, guidelines, guidance statements, and other sources of published evidence, notable difficulties continue to challenge practitioners in managing this class of medications. This is especially the case with very diverse critically ill populations where countless variables exist, many of which were never explored in trials or have historically been frequently excluded. Trials evaluating anticoagulation therapy often can only account for small portions of variables that may affect thrombosis and hemostasis, and study methods often do not reflect the constantly changing dynamic conditions seen in unique critically ill patients. Clinicians providing care to the numerous critically ill populations are faced with conditions that lead to relatively small therapeutic windows, which makes designing safe optimal anticoagulation management plans difficult when dealing with complex patients and mechanical support devices. The approach to crafting a successful management plan for anticoagulant therapy must incorporate the numerous variables that are continuously assessed and revised during the patient's time in the intensive care unit. We explore considerations and approaches when developing, assessing, and implementing an individualized or precision-based management plan that involves the use of anticoagulants in the critically ill. The skills and thought process provided will assist clinicians in managing this unique, variable, and challenging population.