Reasons for nonadherence to the direct oral anticoagulant apixaban for atrial fibrillation

Eliminating Health Disparities in Atrial Fibrillation, Heart Failure, and Dyslipidemia: A Path Toward Achieving Pharmacoequity

PURPOSE OF REVIEW

Pharmacoequity refers to the goal of ensuring that all patients have access to high-quality medications, regardless of their race, ethnicity, gender, or other characteristics. The goal of this article is to review current evidence on disparities in access to cardiovascular drug therapies across sociodemographic subgroups, with a focus on heart failure, atrial fibrillation, and dyslipidemia.

RECENT FINDINGS

Considerable and consistent disparities to life-prolonging heart failure, atrial fibrillation, and dyslipidemia medications exist in clinical trial representation, access to specialist care, prescription of guideline-based therapy, drug affordability, and pharmacy accessibility across racial, ethnic, gender, and other sociodemographic subgroups. Researchers, health systems, and policy makers can take steps to improve pharmacoequity by diversifying clinical trial enrollment, increasing access to inpatient and outpatient cardiology care, nudging clinicians to increase prescription of guideline-directed medical therapy, and pursuing system-level reforms to improve drug access and affordability.

Ischemic Stroke and Systemic Embolism Among One-and-Done Direct Oral Anticoagulant Users with Non-valvular Atrial Fibrillation

INTRODUCTION

Direct oral anticoagulants (DOACs) are essential in ischemic stroke/systemic embolism (SE) prevention among patients with nonvalvular atrial fibrillation (NVAF). This study compared the risk of ischemic stroke/SE among patients with NVAF who discontinued DOACs following the first fill ("one-and-done") relative to patients who continued DOACs beyond the first fill ("continuers").

METHODS

De-identified data from Symphony Health, an ICON plc Company, PatientSource®, April 1, 2017 to October 31, 2020, were used to identify adults with NVAF initiated on DOACs (index date). Patients with only one DOAC claim during the 90-day landmark period starting on the index date were classified as one-and-done and the remaining as continuers. Inverse probability of treatment weighting was used to balance baseline characteristics in the cohorts. Time from the landmark period end to the first ischemic stroke/SE event or, among those without the event, to clinical activity or data end was compared between balanced cohorts using survival analysis.

RESULTS

Of patients initiating DOACs, 23.6% were classified as one-and-done users. After weighting was performed, 241,159 and 238,889 patients comprised the one-and-done and continuer cohorts, respectively. At 12 months of follow-up, the probability of ischemic stroke/SE was 1.44% in the one-and-done cohort and 1.00% in the continuer cohort [hazard ratio (95% confidence interval) 1.44 (1.34-1.54); p < 0.0001]. Results at earlier and later time points and in a sensitivity analysis with a 75-day landmark period were similar.

CONCLUSION

A substantial proportion of patients were one-and-done DOAC users, which was associated with significantly higher risk of ischemic stroke/SE events. There is an unmet need to improve access and encourage continuous use of DOACs among patients with NVAF so that severe and fatal complications may be mitigated.

Reasons for Nonadherence to the Direct Oral Anticoagulant Apixaban: A Cross-Sectional Survey of Atrial Fibrillation Patients

Background

Nonadherence to direct oral anticoagulants to prevent stroke occurs in up to 40% of atrial fibrillation patients. Underlying reasons are poorly understood.

Objectives

This study quantified patient-reported reasons for nonadherence and identified strategies to improve adherence.

Methods

This is a cross-sectional survey of atrial fibrillation patients in 2 academic health systems who reported apixaban nonadherence. We examined patient-reported reasons for nonadherence and level of nonadherence (assessed by a validated 3-item adherence measure) using a multivariable logistic regression model.

Results

Of 419 study patients, 41.5% were women. The mean age was 71.1 ± 10 years and mean CHA2DS2VASc score was 3.2 ± 1.6. About two-thirds had adherence scores ≥80 (mild nonadherence) and one-third scores <80 (poor adherence). In all groups, forgetfulness contributed to nonadherence. Attitudes/beliefs associated with adherence score <80 included: not believing apixaban was needed (odds ratio [OR]: 12.24 [95% CI: 2.25-66.47]); medication cost (OR: 3.97 [95% CI: 1.67-9.42]); and fear of severe bleeding (OR: 3.28 [95% CI: 1.20-8.96]). Strategies that patients with adherence scores <80 selected as helping "a great deal/a lot" to increase adherence included bloodwork to evaluate efficacy (56%), physician counseling about adherence (55%), and having a reversal agent (39%). Almost one-half of all patients did not disclose nonadherence to their providers.

Conclusions

Patients may not disclose their nonadherence to prescribers, and attitudes related to apixaban nonadherence differ among patients with mild nonadherence versus poor adherence. While all patients may benefit from strategies to address forgetfulness, concerns related to the purpose of apixaban, cost, and bleeding risk may require special attention in those with poor adherence.

Comparison of the DOAC Dipstick Test on Urine Samples With Chromogenic Substrate Methods on Plasma Samples in Outpatients Treated With Direct Oral Anticoagulants

Identifying adherence to direct oral anticoagulants (DOACs) plays a major role in treatment efficacy and safety. The DOAC Dipstick can detect DOACs in urine samples of acutely diseased patients at plasma thresholds of about 30 ng/mL. A prospective observational consecutive cohort study was performed on outpatients taking DOACs. The presence of direct oral factor Xa inhibitors (DXIs) in patient urine samples were independently evaluated by visual interpretation of the DOAC Dipstick pad colors. DOAC plasma concentration was assessed using STA®-Liquid Anti-Xa and STA®-Liquid Anti-IIa chromogenic substrate assays. Positive DOAC Dipstick results were compared with a threshold plasma of DOAC concentration ≥30 ng/mL. Of 120 patients (age 55.4  +  16.1 years, female n  =  63), 77 were on rivaroxaban and 43 on apixaban. Plasma concentrations were 129  ±  118 ng/mL for rivaroxaban, and 163  ±  130 ng/mL for apixaban, DOAC Dipstick test has a sensitivity of 97.2% and a positive predictive value of 89.5% at 30 ng/mL. No differences occurred between DXIs. Specificity and negative predictive value could not be determined due to the low number of true negative values. There were no differences in the interpretation of rivaroxaban and apixaban pad colors between observers (Kappa 1.0). Results show that DOAC Dipstick may be a useful tool for identifying DXIs in urine samples in an outpatient setting at a plasma threshold ≥ 30 ng/mL. Further studies should include patients treated with dabigatran, vitamin K antagonists, or other anticoagulants.