Reasons for and consequences of oral anticoagulant underuse in atrial fibrillation with heart failure

Assessment of a systematic approach for implementing novel medications in clinical practice: an observational study with dapagliflozin

OBJECTIVE

To assess a systematic implementation approach for introducing dapagliflozin to individuals with heart failure and reduced ejection fraction in an outpatient clinical setting.

METHODS

Retrospective medical record data were analysed. All individuals diagnosed with heart failure who resided within the hospital catchment area and had visited cardiology or internal medicine department between 2010 and 2019 were screened by using the main inclusion criteria from the DAPA-HF trial. The effectiveness of the previously described seven-step systematic implementation approach was assessed by the proportion receiving information letter, dapagliflozin treatment, follow-ups at 2-12 weeks and 12 months post-dapagliflozin initiation, persistence on dapagliflozin, adverse events, and reasons for discontinuation.

RESULTS

Of the 2433 individuals, 352 met the main DAPA-HF trial criteria in step 2. After exclusions in steps 3 and 4, 191 individuals remained. Of these, 158 were invited for eligibility discussion in step 5, with 107 having received an information letter beforehand. In step 6, dapagliflozin was prescribed to 69 individuals, and in step 7, follow-ups were conducted with 56 individuals at 2-12 weeks and 62 individuals at 12 months. Sixty out of 69 persisted on dapagliflozin after 12 months. Adverse events were reported by nine individuals. Discontinuation was attributed to reasons such as urinary tract infections, genital or abdominal discomfort, and hypotension.

CONCLUSION

The systematic introduction of dapagliflozin to heart failure patients was effective. Despite this, challenges in uniformly implementing procedures across patients were evident, emphasizing the necessity for a systematic implementation approach.

Heart failure registries - Future directions

Heart failure (HF) is a growing, global public health issue. Despite advances in HF care, many challenges remain and HF outcomes are poor. Some of the major reasons for this are the lack of understanding and treatment for certain HF sub-types as well as the lack of implementation of treatment in areas where effective treatment exists. HF registries provide the opportunity to transform clinical research and patient care. Recently the registry-based randomized clinical trial has emerged as a pragmatic and inexpensive alternative to the gold standard in clinical trial design, the randomized controlled trial. Registries may also provide platforms for strategy trials, implementation trials, and screening. Using examples from the Swedish Heart Failure Registry and others, the present review provides insights into how registry-based research can address many of the unmet needs in HF.

Country and health expenditure are major predictors of withholding anticoagulation in atrial fibrillation patients at high risk of stroke

BACKGROUND

Guidelines for patients with atrial fibrillation (AF) at high thromboembolic risk recommend oral anticoagulants (OACs) for preventing stroke and systemic embolism (SE). The reasons for guideline non-adherence are still unclear.

AIM

The aim is to identify clinical, demographic and non-patient characteristics associated with withholding OAC in patients with AF at high stroke risk.

METHODS

Patients in the Global Anticoagulant Registry in the FIELD-AF, newly diagnosed with AF between March 2010 and August 2016, and with CHA2DS2-VASc Score≥2 (excluding sex), were grouped by OAC treatment at enrolment. Factors associated with OAC non-use were analysed by multivariable logistic regression.

RESULTS

Of 40 416 eligible patients, 12 126 (30.0%) did not receive OACs at baseline. Globally, OAC prescription increased over time, from 60.4% in 2010-2011 to 74.7% in 2015-2016. Country of enrolment was the major predictor for OAC withholding (χ2-df=2576). Clinical predictors of OAC non-use included type of AF (χ2-df=404), history of bleeding (χ2-df=263) and vascular disease (χ2-df=99). OACs were used most frequently around the age of 75 years and decreasingly with younger as well as older age beyond 75 years (χ2-df=148). Non-cardiologists (χ2-df=201) and emergency room physicians (χ2-df=14) were less likely to prescribe OACs. OAC prescription correlated positively with country health expenditure.

CONCLUSIONS

Approximately one out of three AF patients did not receive OAC, while eligible according to the guidelines. Country of enrolment was the major determinant of anticoagulation strategy, while higher country health expenditure was associated with lower likelihood of withholding anticoagulation.

Contemporary trends and barriers to oral anticoagulation therapy in Non-valvular atrial fibrillation during DOAC predominant era

There is a need to reassess contemporary oral anticoagulation (OAC) trends and barriers against guideline directed therapy in the United States. Most previous studies were performed before major guideline changes recommended direct oral anticoagulant (DOAC) use over warfarin or have otherwise lacked patient level data. Data on overuse of OAC in low-risk group is also limited. To address these knowledge gaps, we performed a nationwide analysis to analyze current trends. This is a retrospective cohort study assessing non-valvular AF identified using a large United States de-identified administrative claims database, including commercial and Medicare Advantage enrollees. Prescription fills were assessed within a 90-day follow-up from the patient's index AF encounter between January 1, 2016, and December 31, 2020. Among the 339,197 AF patients, 4.4%, 8.0%, and 87.6% were in the low-, moderate-, and high-risk groups (according to CHA₂DS₂-VASc score). An over (29.6%) and under (52.2%) utilization of OAC was reported in low- and high-risk AF patients. A considerably high frequency for warfarin use was also noted among high-risk group patients taking OAC (33.1%). The results suggest that anticoagulation use for stroke prevention in the United States is still comparable to the pre-DOAC era studies. About half of newly diagnosed high-risk non-valvular AF patients remain unprotected against stroke risk. Several predictors of OAC and DOAC use were also identified. Our findings may identify a population at risk of complications due to under- or over-treatment and highlight the need for future quality improvement efforts.

Safety of the oral factor XIa inhibitor asundexian compared with apixaban in patients with atrial fibrillation (PACIFIC-AF): a multicentre, randomised, double-blind, double-dummy, dose-finding phase 2 study

BACKGROUND

Direct-acting oral anticoagulant use for stroke prevention in atrial fibrillation is limited by bleeding concerns. Asundexian, a novel, oral small molecule activated coagulation factor XIa (FXIa) inhibitor, might reduce thrombosis with minimal effect on haemostasis. We aimed to determine the optimal dose of asundexian and to compare the incidence of bleeding with that of apixaban in patients with atrial fibrillation.

METHODS

In this randomised, double-blind, phase 2 dose-finding study, we compared asundexian 20 mg or 50 mg once daily with apixaban 5 mg twice daily in patients aged 45 years or older with atrial fibrillation, a CHA₂DS₂-VASc score of at least 2 if male or at least 3 if female, and increased bleeding risk. The study was conducted at 93 sites in 14 countries, including 12 European countries, Canada, and Japan. Participants were randomly assigned (1:1:1) to a treatment group using an interactive web response system, with randomisation stratified by whether patients were receiving a direct-acting oral anticoagulant before the study start. Masking was achieved using a double-dummy design, with participants receiving both the assigned treatment and a placebo that resembled the non-assigned treatment. The primary endpoint was the composite of major or clinically relevant non-major bleeding according to International Society on Thrombosis and Haemostasis criteria, assessed in all patients who took at least one dose of study medication. This trial is registered with ClinicalTrials.gov, NCT04218266, and EudraCT, 2019-002365-35.

FINDINGS

Between Jan 30, 2020, and June 21, 2021, 862 patients were enrolled. 755 patients were randomly assigned to treatment. Two patients (assigned to asundexian 20 mg) never took any study medication, resulting in 753 patients being included in the analysis (249 received asundexian 20 mg, 254 received asundexian 50 g, and 250 received apixaban). The mean age of participants was 73·7 years (SD 8·3), 309 (41%) were women, 216 (29%) had chronic kidney disease, and mean CHA₂DS₂-VASc score was 3·9 (1·3). Asundexian 20 mg resulted in 81% inhibition of FXIa activity at trough concentrations and 90% inhibition at peak concentrations; asundexian 50 mg resulted in 92% inhibition at trough concentrations and 94% inhibition at peak concentrations. Ratios of incidence proportions for the primary endpoint were 0·50 (90% CI 0·14-1·68) for asundexian 20 mg (three events), 0·16 (0·01-0·99) for asundexian 50 mg (one event), and 0·33 (0·09-0·97) for pooled asundexian (four events) versus apixaban (six events). The rate of any adverse event occurring was similar in the three treatment groups: 118 (47%) with asundexian 20 mg, 120 (47%) with asundexian 50 mg, and 122 (49%) with apixaban.

INTERPRETATION

The FXIa inhibitor asundexian at doses of 20 mg and 50 mg once daily resulted in lower rates of bleeding compared with standard dosing of apixaban, with near-complete in-vivo FXIa inhibition, in patients with atrial fibrillation.

FUNDING

Bayer.

'Real-world' observational studies in arrhythmia research: data sources, methodology, and interpretation. A position document from European Heart Rhythm Association (EHRA), endorsed by Heart Rhythm Society (HRS), Asia-Pacific HRS (APHRS), and Latin America HRS (LAHRS)

The field of observational studies or "real world studies" is in rapid development with many new techniques introduced and increased understanding of traditional methods. For this reason the current paper provides an overview of current methods with focus on new techniques. Some highlights can be emphasized: We provide an overview of sources of data for observational studies. There is an overview of sources of bias and confounding. Next There is an overview of causal inference techniques that are increasingly used. The most commonly used techniques for statistical modelling are reviewed with focus on the important distinction of risk versus prediction. The final section provides examples of common problems with reporting observational data.

The Risk of Falling and Consequences of Falling in Patients with Atrial Fibrillation Receiving Different Types of Anticoagulant

OBJECTIVE

Our objective was to investigate the predictors of falls requiring a visit to the emergency department in patients with nonvalvular atrial fibrillation (AF) receiving different types of anticoagulants and to investigate the clinical consequences of falling in the same population.

METHODS

A total of 1217 patients with nonvalvular AF from two institutions were retrospectively evaluated. Each patient underwent a physical examination, and clinical histories and medication profiles were taken from each patient at baseline.

RESULTS

The median age of our cohort was 71 years; 52.3% were males, and 86.1% of patients were receiving anticoagulation at study baseline. The 5-year freedom-from-falling rate was 81.6%. The use and type of anticoagulation was not significantly associated with the risk of falling (P = 0.222), whereas higher Morse Fall Scale (MFS), CHA₂DS₂-VAS_C (congestive heart failure, hypertension, age ≥ 75 years, diabetes mellitus, stroke or transient ischemic attack, vascular disease, age 65-74 years, sex category), and HAS-BLED (hypertension, abnormal renal/liver function, stroke, bleeding history or predisposition, labile international normalized ratio, elderly [> 65 years], drugs/alcohol concomitantly) scores were significantly associated with a higher hazard of the first fall in univariate analyses. In the multivariate Cox regression model, MFS, older age, osteoporosis, higher levels of high-density lipoprotein cholesterol, higher diastolic blood pressure, and use of amiodarone, diuretics, or short- and medium-acting benzodiazepines were mutually independent predictors of the first fall. Of 163 patients, 93 (57%) had a bone fracture during the fall. Type of anticoagulation significantly affected survival after the first fall (P < 0.001): patients inadequately anticoagulated with warfarin had worse survival rates, and patients receiving apixaban and dabigatran had the best survival rates after the first fall.

CONCLUSION

Older patients who had comorbidities and were taking amiodarone, diuretics, or short- or medium-acting benzodiazepines had the highest risk of falls. The type and quality of anticoagulation did not seem to affect the risk of falling but did significantly affect survival after the first fall.

Implementation of sacubitril/valsartan in Sweden: clinical characteristics, titration patterns, and determinants

AIMS

The aim of this study is to study the introduction of sacubitril/valsartan (sac/val) in Sweden with regards to regional differences, clinical characteristics, titration patterns, and determinants of use and discontinuation.

METHODS AND RESULTS

A national cohort of heart failure was defined from the Swedish Prescribed Drug Register and National Patient Register. A subcohort with additional data from the Swedish Heart Failure Registry (SwedeHF) was also studied. Cohorts were subdivided as per sac/val prescription and registration in SwedeHF. Median sac/val prescription rate was 20 per 100 000 inhabitants. Between April 2016 and December 2017, we identified 2037 patients with ≥1 sac/val prescription, of which 1144 (56%) were registered in SwedeHF. Overall, patients prescribed with sac/val were younger, more frequently male, and had less prior cardiovascular disease than non-sac/val patients. In SwedeHF subcohort, patients prescribed with sac/val had lower ejection fraction. Overall, younger age [hazard ratio 2.81 (95% confidence interval 2.45-3.22)], registration in SwedeHF [1.97 (1.83-2.12)], male gender [1.50 (1.37-1.64)], ischaemic heart disease [1.50 (1.39-1.62)], lower left ventricular ejection fraction [3.06 (2.18-4.31)], and New York Heart Association IV [1.50 (1.22-1.84)] were predictors for sac/val use. As initiation dose in the sac/val cohort, 38% received 24/26 mg, 54% 49/51 mg, and 9% 97/103 mg. Up-titration to the target dose was achieved in 57% of the overall cohort over a median follow-up of 6 months. The estimated treatment persistence for any dose at 360 days was 82%.

CONCLUSIONS

Implementation of sac/val in Sweden was slow and varied five-fold across different regions; younger age, male, SwedeHF registration, and ischaemic heart disease were among the independent predictors of receiving sac/val. Overall, treatment persistence and tolerability was high.

Nurse-Led Heart Failure Clinics Are Associated With Reduced Mortality but Not Heart Failure Hospitalization

Background Follow-up in a nurse-led heart failure ( HF ) clinic is recommended in HF guidelines, but its association with outcomes remains controversial, with previous studies including few and highly selected patients. Thus, large analyses of "real-world" samples are needed. Aims were to assess: (1) independent predictors of and (2) prognosis associated with planned referral to nurse-led HF clinics. Methods and Results We analyzed data from the SwedeHF (Swedish HF Registry) using multivariable logistic regressions to identify independent predictors of planned referral to a nurse-led HF clinic and multivariable Cox regressions to test associations between planned referral and outcomes (all-cause death, HF hospitalization, and their composite). Of 40 992 patients, 39% were planned to be referred to a follow-up in a nurse-led HF clinic. Independent characteristics associated with planned referral were shorter duration of HF , clinical markers of more-severe HF, such as lower ejection fraction, higher New York Heart Association class and N-terminal pro-B-type natriuretic peptide, and lower blood pressure, as well as cohabitating versus living alone, male sex, fewer comorbidities, and more use of HF treatments. After adjustments, planned referral to a nurse-led HF clinic was associated with reduced mortality and mortality/ HF hospitalization, but not HF hospitalization alone. Conclusions In this nation-wide registry, 39% of our identified HF cohort was planned to be referred to a nurse-led HF clinic. Planned referral reflected more-severe HF , but also sex- and family-related factors, and it was independently associated with lower risk of death, but not of HF hospitalization.

Practical use of Direct Oral Anti Coagulants (DOACs) in the older persons with atrial fibrillation

Direct Oral Anticoagulants (DOACs) consistently demonstrated a greater net clinical benefit compared to Vitamin K Antagonists (VKAs) also in persons aged 75 years and over, who account for the largest proportion of AF patients; however, major uncertainties in DOACs prescription have to do with this age group. In this review, persistent uncertainties and implications of frailty and geriatric syndromes on DOACs prescription, and practical use of DOACs in real-world older persons, and will be discussed.

Outcomes in Newly Diagnosed Atrial Fibrillation and History of Acute Coronary Syndromes: Insights from GARFIELD-AF

BACKGROUND

Many patients with atrial fibrillation have concomitant coronary artery disease with or without acute coronary syndromes and are in need of additional antithrombotic therapy. There are few data on the long-term clinical outcome of atrial fibrillation patients with a history of acute coronary syndrome. This is a 2-year study of atrial fibrillation patients with or without a history of acute coronary syndromes.

METHODS

Adults with newly diagnosed atrial fibrillation and ≥1 investigator-defined stroke risk factor were enrolled in GARFIELD-AF between March 2010 and September 2015. The association between prior acute coronary syndromes and long-term outcomes was determined using a Cox proportional hazards model, adjusting for baseline risk factors, oral anticoagulation (OAC) ± antiplatelet (AP) therapy, and usual care.

RESULTS

Of 39,679 patients, 10.5% had a history of acute coronary syndromes. At 2-year follow-up, patients with prior acute coronary syndromes had higher adjusted risks of stroke/systemic embolism (hazard ratio [HR] 1.39; 95% confidence interval [CI], 1.08-1.78), major bleeding (HR 1.30; 95% CI, 0.95 -1.79), all-cause mortality (HR 1.34; 95% CI, 1.21 -1.49), cardiovascular mortality (HR 1.85; 95% CI, 1.51-2.26), and new acute coronary syndromes (HR 3.42; 95% CI, 2.62-4.45). Comparing antithrombotic therapy in the acute coronary syndromes vs no acute coronary syndromes groups, most patients received OAC ± AP: 60.8% vs 66.1%, but AP therapy was more likely in the acute coronary syndromes group (68.1% vs 32.9%), either alone (34.9% vs 20.8%) or with OAC (33.2% vs 12.1%). Overall, 17.8% in the acute coronary syndromes group received dual AP therapy with (5.3%) or without OAC (12.5%). Among patients with moderate/high risk for stroke/systemic embolism, fewer in the acute coronary syndromes group received OAC with or without AP therapy (Congestive heart failure, Hypertension, Age 75 years, Diabetes mellitus, prior Stroke, TIA, or thromboembolism, Vascular disease, Age 65-74 years, Sex category [CHA₂DS₂-VASc] 2: 52.1% vs 64.6%; CHA₂DS₂-VASc ≥3: 62.0% vs 70.7%), and the majority with a Hypertension (uncontrolled systolic blood pressure >160 mm Hg), Abnormal renal or liver function, previous Stroke, Bleeding history or predisposition, Labile international normalized ratios, Elderly, and concomitant Drugs or alcohol excess (HAS-BLED) score ≥3 were on AP therapy (83.8% vs 65.5%).

CONCLUSIONS

In GARFIELD-AF, previous acute coronary syndromes are associated with worse 2-year outcomes and a greater likelihood of under-treatment with OAC, while two-thirds of patients receive AP therapy. Major bleeding was more common with previous acute coronary syndromes, even after adjusting for all risk factors.

Efficacy and Safety of Direct Oral Anticoagulants in Patients With Atrial Fibrillation and High Thromboembolic Risk. A Systematic Review

Background: The aim of the study was to evaluate the efficacy and safety of direct oral anticoagulants (DOACs) in a subgroup of patients with atrial fibrillation (AF), CHADS₂ score ≥3, advanced age, and heart failure (HF) coming from the main DOACs randomized clinical trials.

Methods: We searched MEDLINE, MEDLINE In-Process, and Other Non-Indexed Citations, EMBASE, PubMed, and the Cochrane Central Register of Controlled Trials. English-language articles published from 2002 to March 2019 dealing with DOACs for preventing thrombotic events in AF were considered. We did not conduct any statistical analyses, as indirect comparison between DOACs represents hypothesis generators.

Results: This systematic review was restricted to the subgroup of patients with CHADS₂ score ≥3 (n = 31,203), elderly (n = 24,788), and with HF (n = 29,297) derived from the pivotal trials. Risk index (RI) was calculated. The RI for stroke/systemic embolism was similar in all of the patients treated with DOACs or warfarin. The lowest RI was in rivaroxaban patients (CHADS₂ score ≥3: RI = 0.04; elderly: RI = 0.09; HF: RI = 0.05). The RIs for bleeding were higher in patients treated with dabigatran (CHADS₂ score ≥3: RI₁₁₀ = 0.23; elderly: RI₁₁₀ = 0.22; HF: RI₁₁₀ = 0.16; CHADS₂score ≥3: RI₁₅₀ = 0.30; elderly: RI₁₅₀ = 0.24; HF: RI₁₅₀ = 0.16). The bleeding RIs were higher with apixaban (CHADS₂ score ≥3: RI = 0.23; elderly: RI = 0.25; HF: RI = 0.14) and dabigatran (CHADS₂ score ≥3: RI = 0.28; elderly: RI = 0.21; HF: RI = 0.19).

Conclusions: The use of DOACs is a reasonable alternative to vitamin K antagonists in AF patients with CHADS₂ score ≥3, advanced age, and HF. The RI constitutes a useful, additional tool to facilitate clinicians in choosing DOACs or warfarin in particular category of AF patients.

Utilization of oral anticoagulants in Korean nonvalvular atrial fibrillation patients

Background Although the majority of clinical guidelines indicate the use of NOAC (nonvitamin K antagonist oral anticoagulant) over vitamin K antagonist in nonvalvular atrial fibrillation patients, there is no information on real-world prescription factors that lead to a specific type of oral anticoagulant selection. Objective To evaluate the prescription factors for choosing a specific oral anticoagulant for nonvalvular atrial fibrillation patients in Korea. Setting Nationwide sampled database in South Korea. Methods In this study, we defined nonvalvular atrial fibrillation patients as having one or more hospitalizations or two or more out-patient visits with a stroke risk score (CHA2DS2-VASc scores) ≥ 2 eligible for oral anticoagulant therapy from Jan 1st, 2016 to Dec 31st, 2016. Baseline characteristics were analyzed, including sex, age, comorbidities, CHA2DS2-VASc, bleeding risk score (mHAS-BLED), prescribing specialty, insurance type, medical institution type and location. Univariate and multivariate logistic regression analyses were conducted for being prescribed NOAC compared with vitamin K antagonist. Main outcome measure Adjusted odds ratio of the NOAC group and vitamin K antagonist group. Results Of 9,226 patients eligible for oral anticoagulant therapy, 4999 patients (54.2%) received oral anticoagulant therapy, and 4517 patients took NOAC or vitamin K antagonist only during the study period. Prior stroke, transient ischemic attack, thromboembolism, thyroid disease, dyslipidemia, cancer, mHAS-BLED ≥ 5, in-patient care, and specialty in internal medicine and neurology were positive predictors of NOAC use over vitamin K antagonist, whereas young age (≤64), renal dysfunction, and secondary care institution were negative predictors of NOAC use over vitamin K antagonist. Conclusions The presence of comorbidities was linked to NOAC use over vitamin K antagonist, which is different from prescription factor studies in other countries and requires further study.

The Swedish Heart Failure Registry: a living, ongoing quality assurance and research in heart failure

Heart failure (HF) represents a global pandemic. Although in HF with reduced ejection fraction (HFrEF) randomized controlled trials have provided effective treatments, prognosis still remains poor, with signals of undertreatment. HF with mid-range EF (HFmrEF) has no evidence-based therapy, and its characterization is ongoing. Trials in HF with preserved EF (HFpEF) have failed to provide any effective treatment, but there are several concerns about their design. Thus, current challenges in the HF field are: 1) optimizing the use of existing treatments in HFrEF; 2) developing and proving efficacy of new treatments, and of new use of existing treatments in HFpEF and HFmrEF. Here we describe how registry-based research can improve knowledge addressing the unmet needs in HF, and in particular we focus on the contribution of the Swedish Heart Failure Registry to this field.

New score for assessing bleeding risk in patients with atrial fibrillation treated with NOACs

Background

Information is needed on bleeding risk factors specific for patients with atrial fibrillation (AF) treated with non-vitamin K oral anticoagulants (NOACs). We aimed to identify risk factors in a large real-world cohort and to derive a bleeding risk score for patients with AF treated with NOACs.

Methods

From nationwide registries (the Norwegian Patient Registry and the Norwegian Prescription Database), we identified patients with AF with a first prescription of a NOAC between January 2013 and June 2015. Cox proportional-hazards analysis was used to identify the strongest risk factors for major or clinically relevant non-major (CRNM) bleeding. Based on these, a risk prediction score was derived. Discrimination was assessed with Harrel’s C-index. C-indexes for the modified Hypertension, Age, Stroke, Bleeding tendency/predisposition, Labile international normalised ratios, Elderly age, Drugs or alcohol excess (HAS-BLED), the Anticoagulation and Risk Factors in Atrial Fibrillation (ATRIA) and the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation (ORBIT) scores were also calculated from the same cohort.

Results

Among 21 248 NOAC-treated patients with a median follow-up time of 183 days, 1257 (5.9%) patients experienced a major or CRNM bleeding. Ten independent risk factors for bleeding were identified, which when included in a risk prediction model achieved a C-index of 0.68 (95% CI 0.66 to 0.70). A simplified score comprising three variables; age, history of bleeding and non-bleeding related hospitalisation within the last 12 months, yielded a c-index of 0.66 (95% CI 0.65 to 0.68). In the same cohort, the modified HAS-BLED, ATRIA and ORBIT scores achieved c-indexes of 0.62 (95% CI 0.60 to 0.63), 0.66 (95% CI 0.64 to 0.67) and 0.66 (95% CI 0.64 to 0.67), respectively.

Conclusions

Our proposed simplified bleeding score could be a useful clinical tool for quick estimation of risk of bleeding in patients with AF treated with NOACs.

Characteristics of Apixaban-Treated Patients, Evaluation of the Dose Prescribed, and the Persistence of Treatment: A Cohort Study in Catalonia

BACKGROUND

Apixaban is a direct oral anticoagulant, which inhibits factor Xa. It has demonstrated clinical efficacy in prevention of stroke and systemic embolism in adult patients with nonvalvular atrial fibrillation and a better safety profile compared to warfarin.

OBJECTIVES

(1) To describe the characteristics of patients with nonvalvular atrial fibrillation beginning treatment with apixaban, (2) to analyze concomitant prescriptions of medications that could potentially interact with apixaban, (3) to evaluate the level of appropriate usage according to the recommended dosage, and (4) to estimate the level of apixaban persistence among naive and non-naive patients.

METHODS

Cohort study using data from primary care (System for Research in Primary Care database, users of the Institut Català de la Salut; Catalonia, Spain) from August 2013 to December 2015.

RESULTS

Mean age for apixaban-treated patients was 71.8 years (standard deviation = 11.1) and 55.6% were male. In all, 3.2% of patients receiving apixaban were taking drugs described as potentially related to either pharmacokinetic or pharmacodynamic interactions. According to the summary of product characteristics, 81.1% of patients with a recommended dose of 2.5 mg twice daily and 51.8% with a recommended dose of 5 mg twice daily actually took this dose. After 1 year of follow-up, 62.6% of the apixaban users showed good adherence.

CONCLUSION

The prescribed dose of apixaban did not fully follow the recommended dose, particularly in patients who were treatment naive. Patients with a prior history of anticoagulant treatment were more likely to remain persistent to treatment with apixaban.