Utilization of Anticoagulants in Nonvalvular Atrial Fibrillation Before and After Catheter Ablation at Shanghai, China

Both vitamin K antagonists (VKAs) and novel oral anticoagulants (NOACs) are effective for stroke prevention in nonvalvular atrial fibrillation (NVAF) patients. This study evaluated the utilization of VKA and NOACs in NVAF patients before and after catheter ablation in China. Prescription data were retrospectively collected between January 1, 2016, and December 31, 2016, including indication of use, dose, renal function, and risk assessment (CHA₂DS₂-VASc score and HAS-BLED score) in Zhongshan Hospital of Fudan University. Trends and factors associated with anticoagulants use before and after ablation were evaluated. A total of 475 patients with NVAF who received ablation were included in the analysis. Of all, 53.26% of them received antithrombotic therapy preablation. Warfarin was prescribed in 35.26%, with NOACs in 11.37%. Four hundred seventy-three patients received antithrombotic therapy (99.58%) postablation, 236 patients with NOACs (49.68%). CHA₂DS₂-VASc score, HAS-BLED score, hypertension, diabetes mellitus, and alcohol were independently associated with anticoagulant utilization before catheter ablation. The higher CHA₂DS₂-VASc score was associated with less frequent prescription of NOACs postablation. The preablation anticoagulation use was still inadequate in China, and CHA₂DS₂-VASc score was a significant factor influencing the preablation anticoagulant utilization. The utilization rate of NOACs increased significantly postablation, especially for dabigatran, which implied that more physicians prefer to prescribe NOACs for NVAF patients after ablation in our country and may be attributed to the aspects such as ease of NOAC use but also possibly the greater safety and efficacy. Furthermore, the physicians may reluctant to use NOACs for high stroke risk atrial fibrillation patients after catheter ablation.

Exploring the Quality of Anticoagulant Prescribed for Patients With Atrial Fibrillation at the St John of God Hawkesbury District Health Centre, New South Wales, Australia

BACKGROUND

Limited data are available on the clinical management of atrial fibrillation (AF) and its outcomes from an Australian perspective.

OBJECTIVE

To describe the appropriateness of antithrombotic prescribing for patients who presented with a diagnosis of AF to the Hawkesbury St John of God Hospital, New South Wales, Australia.

METHODS

This retrospective observational study reviewed patients admitted to St John of God Hawkesbury Hospital with AF between June 2016 and June 2017. We calculated stroke risk using the CHA2DS2-VASc score based on medical records and reviewed the appropriateness of oral anticoagulant (OAC) prescribing compared to the 2016 European Society of Cardiology guidelines. Patients were excluded if they had only 1 episode of AF that reverted either spontaneously or upon cardioversion without any documented recurrences.

RESULTS

A total of 200 patients (18 years) were included, with 180 (90%) deemed eligible for anticoagulation. Of these 72.8% (n = 131) were prescribed an OAC. A total of 40.0% of patients at low risk of stroke and 68.4% at intermediate risk were prescribed an OAC, respectively. Apixaban was the direct OAC of choice with 36.6% of patients prescribed an OAC receiving apixaban. Warfarin was prescribed for 25.1% of the patients who were prescribed an OAC.

CONCLUSIONS

The underutilization of anticoagulant medication in high-risk groups and over utilization in low-risk groups remains an ongoing issue in contemporary AF management, and it highlights the need to improve AF-related stroke prevention in our jurisdiction.

Thromboembolism and Mortality in the Tasmanian Atrial Fibrillation Study

BACKGROUND

Although utilization of anticoagulation in patients with atrial fibrillation (AF) has increased in recent years, contemporary data regarding thromboembolism and mortality incidence rates are limited outside of clinical trials. This study aimed to investigate the impact of the direct oral anticoagulants (DOACs) on the clinical outcomes of patients with AF included in the Tasmanian Atrial Fibrillation Study.

METHODS

The medical records of all patients with a primary or secondary diagnosis of AF who presented to public hospitals in Tasmania, Australia, between 2011 and 2015, were retrospectively reviewed. We investigated overall thromboembolic events (TEs), ischemic stroke/transient ischemic attack (IS/TIA), and mortality incidence rates in patients admitted to the Royal Hobart Hospital, the main teaching hospital in the state. We compared outcomes in 2 time periods: prior to the availability of DOACs (pre-DOAC; 2011 to mid-2013) and following their general availability after government subsidization (post-DOAC; mid-2013 to 2015).

RESULTS

Of the 2390 patients with AF admitted during the overall study period, 942 patients newly prescribed an antithrombotic medication (465 and 477 from the pre-DOAC and post-DOAC time periods, respectively) were followed. We observed a significant decrease in the incidence rates of overall TE (3.2 vs 1.7 per 100 patient-years [PY]; P < .001) and IS/TIA (2.1 vs 1.3 per 100 PY; P = .022) in the post-DOAC compared to the pre-DOAC period. All-cause mortality was significantly lower in the post-DOAC period (2.9 vs 2.2 per 100 PY, P = .028). Increasing age, prior stroke, and admission in the pre-DOAC era were all risk factors for TE, IS/TIA, and mortality in this study population. The risk of IS/TIA was more than doubled (hazard ratio: 2.54; 95% confidence interval: 1.17-5.52) in current smokers compared to ex- and nonsmokers.

CONCLUSION

Thromboembolic event and all-cause mortality rates were lower following the widespread availability of DOACs in this population.

Bleeding-related admissions in patients with atrial fibrillation receiving antithrombotic therapy: results from the Tasmanian Atrial Fibrillation (TAF) study

PURPOSE

Limited data are available from the Australian setting regarding bleeding in patients with atrial fibrillation (AF) receiving antithrombotic therapy. We aimed to investigate the incidence of hospital admissions due to bleeding and factors associated with bleeding in patients with AF who received antithrombotic therapy.

METHODS

A retrospective cohort study was conducted involving all patients with AF admitted to the Royal Hobart Hospital, Tasmania, Australia, between January 2011 and July 2015. Bleeding rates were calculated per 100 patient-years (PY) of follow-up, and multivariable modelling was used to identify predictors of bleeding.

RESULTS

Of 2202 patients receiving antithrombotic therapy, 113 presented to the hospital with a major or minor bleeding event. These patients were older, had higher stroke and bleeding risk scores and were more often treated with warfarin and multiple antithrombotic therapies than patients who did not experience bleeding. The combined incidence of major and minor bleeding was significantly higher in warfarin- versus direct-acting oral anticoagulants (DOAC)- and antiplatelet-treated patients (4.1 vs 3.0 vs 1.2 per 100 PY, respectively; p = 0.002). Similarly, the rate of major bleeding was higher in patients who received warfarin than in the DOAC and antiplatelet cohorts (2.4 vs 0.4 vs 0.6 per 100 PY, respectively; p = 0.001). In multivariate analysis, increasing age, prior bleeding, warfarin and multiple antithrombotic therapies were independently associated with bleeding.

CONCLUSION

The overall rate of bleeding in this cohort was low relative to similar observational studies. The rate of major bleeding was higher in patients prescribed warfarin compared to DOACs, with a similar rate of major bleeding for DOACs and antiplatelet agents. Our findings suggest potential to strategies to reduce bleeding include using DOACs in preference to warfarin, and avoiding multiple antithrombotic therapies in patients with AF.