Factors influencing oral anticoagulant use in patients newly diagnosed with atrial fibrillation

Systematic Review and Meta-Analysis of Direct Oral Anticoagulants Versus Warfarin in Atrial Fibrillation With Low Stroke Risk

Pivotal trials comparing direct oral anticoagulants (DOACs) against warfarin in patients with atrial fibrillation (AF) predominantly involved patients with high stroke risk. This study aimed to evaluate the efficacy and safety of DOAC versus warfarin in patients with low stroke risk. An online literature search was conducted to retrieve studies comparing clinical outcomes between patients treated with DOAC versus warfarin for AF, reporting outcomes for patients at low or minimal risk of stroke (CHA2DS2-VASc scores ranging from 0 to 2 or CHADS2 scores ranging from 0 to 1). The primary outcome was the occurrence of stroke or systemic embolism. Secondary outcomes included major bleeding, intracranial hemorrhage, and all-cause mortality. Hazard ratios for all outcomes were pooled in random-effects meta-analyses. A network meta-analysis of individual DOACs versus warfarin was also conducted. In total, 11 studies (132,980 patients) were included. DOAC was associated with a significantly lower risk of stroke or systemic embolism (hazard ratio 0.85, 95% confidence interval 0.75 to 0.96, p = 0.008, I2 = 0%), major bleeding, intracranial hemorrhage, and mortality compared with warfarin. This benefit persisted even when study arms which had CHA2DS2-VASc scores of 2 were excluded. When restricted to 3 studies investigating only patients with a single nongender-related stroke risk factor, significant benefit was seen only for the outcome of major bleeding. In the network meta-analysis, only dabigatran was superior to warfarin for all 4 outcomes. In conclusion, DOACs should be the standard of care in low-risk patients with AF who require anticoagulation. In particular, dabigatran appears to have the best balance of stroke prevention and reduction in major bleeding.

Oral Anticoagulant Use in Patients with Atrial Fibrillation at Low Risk of Stroke and Associated Bleeding Complications

BACKGROUND

The use of oral anticoagulants (OACs) in patients with atrial fibrillation (AF) and low stroke risk might cause more harm than benefit. Little attention has been given to address its prevalence and associated consequences. This study aimed to investigate the prescription rate of OACs, identify associated factors, and describe incident bleeding events in low-risk patients.

METHODS

We included patients with a new diagnosis of AF between 1 January 2011 and 31 December 2018 having a low risk of stroke (CHA2DS2-VASc score of 0 for males and 1 for females) from Australian general practice data (MedicineInsight). Patients were classified as OAC users if there was a recorded prescription of an OAC within 60 days of AF diagnosis, and factors associated with the prescription of an OAC were assessed using logistic regression. Recorded incident bleeding events were identified within 6 months after AF diagnosis or after OAC initiation for OAC non-users and users, respectively. The risk of bleeding was compared between the two groups by adjusting their baseline differences using propensity score matching.

RESULTS

The study included 2810 low-risk patients (62.3% male) with a mean age of 49.3 ± 10.8 years. Of the total, 705 (25.1%) patients had a record of OAC prescription within 60 days of diagnosis of AF. Older age (odds ratio [OR] 1.03; 95% confidence interval [CI] 1.03-1.04) and diagnosis periods (2015-2016 [OR 1.46; 95% CI 1.10-1.94] and 2017-2018 [OR 1.65; 95% CI 1.17-2.23] vs. 2011-2012) were associated with higher odds of OAC initiation. Female sex (OR 0.71; 95% CI 0.59-0.85), higher bleeding risk (ORBIT score; OR 0.80; 95% CI 0.68-0.94), and higher socioeconomic index for areas (SEIFA) quintiles (SEIFA quintiles; 2 [OR 0.65; 95% CI 0.48-0.88], 3 [OR 0.74; 95% CI 0.56-0.98], 4 [OR 0.70; 95% CI 0.52-0.94], 5 [OR 0.69; 95% CI 0.52-0.91] compared with quintile 1) were associated with lower odds of OAC prescription. A total of 52 (in 1.8% of patients) incident bleeds were identified, with 18 (2.6%) among OAC users. The rate of bleeding was not significantly different between users and non-users after matching. However, within OAC users, commencement of OAC was associated with an increased risk of bleeding compared to the period before OAC initiation (p = 0.006).

CONCLUSIONS

One in four patients at low risk of stroke received an OAC within 60 days of AF diagnosis. Older age and the period following the widespread availability of direct-acting OACs were associated with an increased likelihood of OAC prescription. Positively, using OACs was not associated with an increased rate of bleeding compared to non-users.

Prescribing of anticoagulation for atrial fibrillation in primary care

Atrial fibrillation (AF) is common in primary care patients. Many patients who could benefit from anticoagulation do not receive it. The objective of this study was to describe anticoagulation prescribing by primary care physicians. We conducted an observational study in the Cleveland Clinic Health System among patients with AF and ≥ 1 primary care appointment between 2015 and 2018 and their physicians. We estimated differences in the odds of an eligible patient receiving anticoagulation versus not and a DOAC versus warfarin using two mixed effects logistic regression models, adjusted for patient sociodemographic factors, history of falls or dementia, and CHA2DS2-VASc and HAS-BLED scores. We categorized physicians into prescribing tertiles, based on their adjusted prescribing rate, which we included as predictors in the models. Among 5253 patients, 47% received anticoagulation. Of those, 56% received a DOAC. CHA2DS2-VASc and HAS-BLED scores were not associated with anticoagulation prescription. Black race was negatively associated with receiving anticoagulation overall (aOR:0.71; 95%CI:0.56-0.89) and with prescription for a DOAC (aOR:0.65; 95%CI:0.45-0.93). Among 195 physicians, the anticoagulation prescribing rate ranged from 27% to 57% and DOAC rates ranged from 34% to 69%. Physician prescribing tertile was associated with odds of a patient receiving anticoagulation overall (aOR:1.51; 95%CI: 1.13-2.01 for the highest versus lowest tertile), but not DOAC prescriptions. When prescribing anticoagulation, physicians appear not to consider risk of stroke or bleeding but patient race is an important determinant. Seeing a physician with a high anticoagulation prescribing rate was strongly associated with a patient receiving it, suggesting a lack of individualization.

Temporal Trends in Oral Anticoagulant Prescription in Atrial Fibrillation Patients between 2004 and 2019

BACKGROUND

In the recent years, antithrombotic prophylaxis in patients with atrial fibrillation (AF) has changed significantly. The main aim of this study is to assess the temporal trends of antithrombotic therapy and identify factors predisposing oral anticoagulant (OAC) use in stroke prevention in AF patients.

METHODS

The present study is a retrospective, observational, single-center study, which includes consecutively hospitalized patients in the reference cardiology center from January 2004 to December 2019.

RESULTS

A total of 9656 patients (43.7% female, mean age 71.2 years) with AF between 2004-2019 are included. Among the total study population, in most of the patients (81.1%), OAC therapy was used, antiplatelet (APT) therapy was prescribed for 13.5% patients, heparins for 2.1% patients and 3.3% of patients did not receive any stroke prevention. OAC prescription significantly increased from 61.6% in 2004 to 97.4% in 2019. The independent predictors of OAC prescription were: the period of hospitalization, non-paroxysmal AF, age, hypertension, diabetes mellitus, previous thromboembolism, hospitalization due to electrical cardioversion, ablation or AF without any procedures.

CONCLUSIONS

In hospitalized patients with AF, during sixteen years of the study period, a significant increase in OAC use and a decrease in APT use were noted. Factors other than these included in the CHA₂DS₂-VASc score were independent predictors of OAC use.

Comparing the renal outcomes in patients with atrial fibrillation receiving different oral anticoagulants

BACKGROUND

We aimed to compare renal function changes in patients with atrial fibrillation (AF) prescribed different oral anticoagulants (OACs).

RESEARCH DESIGN AND METHODS

We performed a retrospective analysis of Australian national primary care data. A total of 12,562 patients with AF and initiated OAC between 1 Jan 2013 and 31 Dec 2017 were included. Inverse probability of treatment weighting was used for balancing baseline characteristics and the risks of decline in estimated glomerular filtration rate (eGFR) in patients prescribed each OAC were compared using Cox proportional hazards regression model.

RESULTS

Compared with warfarin, prescribing of direct-acting oral anticoagulants (DOACs) was associated with a lower risk of renal function decline per 1000 person-years: hazard ratio (HR) 0.75, 95% confidence interval (CI) 0.68-0.81, p<0.001 for ≥30% decline in eGFR; HR 0.28, 95% CI 0.20-0.41, p<0.001 for eGFR decline to ≤30 mL/min/1.73m²; and HR 0.45, 95% CI 0.35-0.58, p<0.001 for serum creatinine doubling. Compared with dabigatran, rivaroxaban use had a significantly lowered risk of decline in eGFR to ≤30 mL/min/1.73m² (HR 0.29, 95% CI 0.13-0.66, p=0.003) and risk of doubling of serum creatinine (HR 0.62, 95% CI 0.40-0.95, p=0.030).

CONCLUSIONS

The risk of renal function decline appeared to be lower in patients prescribed DOACs versus warfarin.

Worldwide trends in oral anticoagulant use in patients with atrial fibrillation from 2010 to 2018: a systematic review and meta-analysis

AIMS

Non-vitamin K antagonist oral anticoagulants (NOACs) are effective and safe alternatives compared with vitamin K antagonists (VKAs) for thromboembolic prevention in atrial fibrillation (AF), while antiplatelets are no longer recommended. However, to which extent NOAC introduction and guideline updates have increased OAC use in AF, is unclear. Therefore, worldwide trends in real-life prescribing of OACs, NOACs, VKAs, and antiplatelet monotherapy in AF patients were investigated.

METHODS AND RESULTS

Using PubMed and Embase, observational nationwide cohort studies on annual prevalent and/or incident OAC use in non-selected AF patients since 2010 were included. A meta-analysis of single proportions was performed. Twenty-one studies were included assessing prevalent and incident use among 9 758 637 and 197 483 OAC-eligible AF patients, respectively. Worldwide prevalence and incidence of OAC users increased from 0.42 [95% confidence interval (CI) 0.22-0.65] and 0.43 (95% CI 0.37-0.49) in 2010 to 0.78 (95% CI 0.77-0.78) and 0.75 (95% CI 0.74-0.76) in 2018, respectively. Prevalent and incident NOAC users increased globally from 0 in 2010 to 0.45 (95% CI 0.45-0.46) and 0.68 (95% CI 0.67-0.69) in 2018, respectively, whereas prevalent and incident VKA use decreased from 0.42 (95% CI 0.22-0.65) and 0.42 (95% CI 0.36-0.49) in 2010 to 0.32 (95% CI 0.32-0.32) and 0.06 (95% CI 0.06-0.07) in 2018, respectively. Prevalent antiplatelet monotherapy use decreased from 0.37 (95% CI 0.32-0.42) in 2010 to 0.09 (95% CI 0.09-0.10) in 2018.

CONCLUSION

The proportion of OAC users worldwide almost doubled following NOAC introduction. As one-quarter of OAC-eligible AF subjects were not anticoagulated and 9% were only treated with antiplatelets in 2018, there is still room for improvement.

Risk of dementia in patients with atrial fibrillation: Short versus long follow-up. A systematic review and meta-analysis

BACKGROUND

No previous meta-analyses have compared the risk of dementia, due to an underlying atrial fibrillation (AF), in the short-term versus the long-term period.

AIM

To perform an update meta-analysis of studies examining the association between AF and dementia and the relative impact of follow-up period.

METHODS

Data were obtained searching MEDLINE and Scopus for all investigations published between 1 January 2000 and March 1, 2021 reporting the risk of dementia in AF patients. The following MeSH terms were used for the search: "Atrial Fibrillation" AND "Dementia" OR "Alzheimer's disease". From each study, the adjusted hazard ratio (aHR) with the related 95% confidence interval (CI) was pooled using a random effect model.

RESULTS

The analysis was carried out on 18 studies involving 3.559.349 subjects, of which 902.741 (25.3%) developed dementia during follow-up. A random effect model revealed an aHR of 1.40 (95% CI: 1.27-1.54, p < 0.0001; I2  = 93.5%) for dementia in subjects with AF. Stratifying the studies according to follow-up duration, those having a follow-up ≥10 years showed an aHR for dementia of 1.37 (95% CI: 1.21-1.55, p < 0.0001, I2  = 96.6%), while those with a follow-up duration <10 years has a slightly higher aHR for dementia (HR: 1.59, 95%CI: 1.51-1.67, p < 0.0001, I2  = 49%). Nine studies showed that the aHR for Alzheimer's disease (AD) in AF patients was 1.30 (95%CI: 1.12-1.51, p < 0.0001, I2  = 87.6%).

CONCLUSIONS

Evidence suggests that patients with AF have an increased risk of developing dementia and AD. The risk of dementia was slightly higher when the follow-up was shorter than 10 years.