Control of Anticoagulation Therapy in Patients with Atrial Fibrillation Treated with Warfarin: A Study from the Chinese Atrial Fibrillation Registry

Effectiveness and Safety of the Coadministration of Rifampin and Warfarin versus Direct Oral Anticoagulants: A Cohort Study

Introduction

Pharmacokinetic studies have shown that rifampin reduces the levels of oral anticoagulants during the initiation of coadministration, raising concerns about an increased thrombotic risk, but there are limited comparative clinical outcomes between rifampin and warfarin compared with direct oral anticoagulants (DOACs). This study aimed to evaluate the effectiveness and safety of concurrent use of rifampin and warfarin versus DOACs, with assessments of outcome-associated factors and oral anticoagulant (OAC) management quality.

Methods

A total of 142 patients given rifampin plus warfarin (n = 56) or DOACs (n = 86) for over 7 days were included, and their clinical data and outcomes were compared.

Results

The median Charlson Comorbidity Index and HAS-BLED (hypertension, abnormal renal/liver function, stroke, bleeding history or predisposition, labile INR, elderly, drugs/alcohol concomitantly) score of the two groups were 2 and 3, respectively. The incidence rate of composite ischemic or thromboembolic events was 2.16 and 1.44 per 10,000 patient-days in the warfarin and DOAC groups, respectively, with an adjusted hazard ratio (HR) of 0.41 (95% confidence interval [CI] 0.02-7.34). The incidence rate of composite major bleeding or clinically relevant nonmajor bleeding events was 1.58 and 1.52 per 10,000 patient-days in the warfarin and DOAC groups, respectively, with an adjusted HR of 1.12 (95% CI 0.32-4.45). The risk of composite bleeding events increased with a higher HAS-BLED score (HR: 1.62, 95% CI: 1.02-2.63). Moreover, 34.3% of warfarin users maintained a percent time in therapeutic range of above 50%. Furthermore, 77.9% of DOAC users received appropriate dosing.

Conclusion

No significant differences were observed in terms of the incidence of thrombotic or bleeding events between the two groups during coadministration. In addition, a higher HAS-BLED score was associated with a greater risk of bleeding events regardless of the class of OACs used. Finally, close monitoring of bleeding events should be considered.

Integrating Real-World Evidence in Economic Evaluation of Oral Anticoagulants for Stroke Prevention in Non-valvular Atrial Fibrillation in a Developing Country

OBJECTIVE

This study aimed to estimate the cost effectiveness of non-vitamin K oral anticoagulants (NOACs) compared with warfarin for stroke prevention in patients with non-valvular atrial fibrillation (NVAF) in Thailand where suboptimal anticoagulation control is common.

MATERIALS AND METHODS

A hypothetical cohort of 65-year-old patients with NVAF and their disease progression was simulated in the Markov model. The following anticoagulant agents were used: warfarin, dabigatran, rivaroxaban, and apixaban. Warfarin with high, intermediate, and low time in therapeutic ranges (TTR) was used as the three different reference treatments. Baseline clinical events were obtained from a recently published real-world study in Thailand. A lifetime horizon was utilized in this model, and all analyses were performed from societal and healthcare perspectives. The results were reported as incremental cost-effectiveness ratios (ICERs) in 2021 US dollars per quality-adjusted life-year (QALY) gained. The sensitivity analyses were performed to assess the influence of parameter uncertainty.

RESULTS

Apixaban was a cost-effective intervention compared with warfarin with low and intermediate TTR groups. In the low TTR group, the ICERs were $779 and $816 per QALY gained from the societal and healthcare perspectives, respectively, and in the intermediate TTR group, the ICERs were $2038 and $3159 per QALY gained from the societal and healthcare perspectives, respectively. Both ICERs were below the accepted willingness-to-pay threshold ($4806) in the context of Thailand's healthcare.

CONCLUSIONS

In a developing country where suboptimal anticoagulation control is common, apixaban was the cost-effective alternative to warfarin for patients with both low and intermediate TTR control.

Social App to Improve Warfarin Therapy in Post-MHVR Chinese Patients: A Randomized Controlled Trial

Background

Poor anticoagulation quality was a major problem among warfarin-treated patients, which called for innovative and effective methods to improve it.

Objective

To investigate whether social app could be used to reduce warfarin-associated adverse events among post-MHVR Chinese patients.

Method

735 warfarin-treated patients (aged 50.8 ± 9.6 years, 59.9% female) were enrolled and randomized to a social app care group (warfarin therapy was guided by experienced clinicians via a social app) or a routine care group (warfarin therapy was managed through traditional in-office visits) at a 1 : 1 ratio. Ending points (bleeding and thrombotic events) were recorded during an 18-month follow-up period.

Results

A total of 718 patients were included in analysis. 57 of them suffered warfarin-associated adverse events, including 30 major bleedings and 27 thrombotic events. The time in the therapeutic range (TTR, Rosendaal method) in the social app group was 71.5%, which was significantly better than 52.6% in the routine care group (difference: 18.8%, 95% CI: 16.8-20.8). Compared with the patients from the social app group, patients under routine care experienced more bleeding (hazard ratio (HR): 2.31, 95% CI: 1.13-4.72). The social app care group had lower variation (0.55 vs. 0.70) in the international normalized ratio (INR) values and fewer incidents of extremely high INR (e.g., INR > 5.0, 0.87% vs. 3.42%) than the routine care group.

Conclusions

Social app management could significantly improve warfarin control and was associated with a reduction in bleeding risk. This trial was registered with NCT03264937.

Efficacy and Safety of Direct Oral Anticoagulants in Stable Coronary Artery Disease and Atrial Fibrillation: A Systematic Review and Network Meta-Analysis

Direct Oral Anticoagulants (DOACs) , which partially replace warfarin, have been developed as a safe and effective therapy for patients with stable coronary artery disease (SCAD) and atrial fibrillation (AF). However, the choice of DOACs and warfarin remains controversial. We conducted a network meta-analysis (NMA) using randomized controlled trials (RCTs) through a systematic literature review to evaluate the the efficacy and safety of DOACs in SCAD and AF patients. Five RCTs with 6524 patients were included. The results showed that patients taking DOACs had a lower risk of stroke/systemic embolism (OR, 0.64; 95% CI, 0.54-0.76, P < .00001, I2 = 89%), intracranial bleeding (OR, 0.41; 95% CI, 0.26-0.64, P = .0001, I2 = 0%), major bleeding (OR, 0.98; 95% CI, 0.81-1.148, P = .80, I2 = 88%), and all-cause mortality (OR, 1.04; 95% CI, 0.88-1.22, P = .66, I2 = 51%) than those taking warfarin. Compared to warfarin, rivaroxaban (20 mg, once/day) was more advantageous in preventing stroke/systemic embolism, as was apixaban (5 mg or 2.5 mg, twice/day) in reducing major bleeding (OR, 0.79; 95% CI, 0.48-1.3) and all-cause mortality (OR, 0.97; 95% CI, 0.69-1.4). Different doses of DOACs showed obvious advantages against intracranial hemorrhage, without significant differences. Thus, DOACs have more effective than warfarin in clinical efficacy and safety.

Variables affecting the quality of anticoagulation in atrial fibrillation patients newly initiating vitamin K antagonists: insights from the national and multicentre SULTAN registry

AIMS

Vitamin K antagonists (VKAs) are effective drugs reducing the risk for stroke in atrial fibrillation (AF), but the benefits derived from such therapy depend on the international normalized ratio (INR) maintenance in a narrow therapeutic range. Here, we aimed to determine independent variables driving poor anticoagulation control [defined as a time in therapeutic range (TTR) <65%] in a 'real world' national cohort of AF patients.

METHODS AND RESULTS

The SULTAN registry is a multicentre, prospective study, involving patients with non-valvular AF from 72 cardiology units expert in AF in Spain. At inclusion, all patients naïve for oral anticoagulation were started with VKAs for the first time. For the analysis, the first month of anticoagulation and those patients with <3 INR determinations were disregarded. Patients were followed up during 1 year. A total of 870 patients (53.9% male, the mean age of 73.6 ± 9.2 years, mean CHA2DS2-VASc and HAS-BLED of 3.3 ± 1.5 and 1.4 ± 0.9, respectively) were included in the full analysis set. In overall, 7889 INR determinations were available. At 1-year, the mean TTR was 63.1 ± 22.1% and 49.2% patients had a TTR < 65%. Multivariate Cox regression analysis showed that coronary artery disease [odds ratio (OR) 1.81, 95% confidence interval (CI) 1.14-2.87; P = 0.012] and amiodarone use (OR 1.54, 95% CI 1.01-2.34; P = 0.046) were independently associated with poor quality of anticoagulation (TTR <65%).

CONCLUSION

This study demonstrated that the quality of anticoagulation in AF patients newly starting VKAs is sub-optimal. Previous coronary artery disease and concomitant use of amiodarone were identified as independent variables affecting the poor quality of VKA therapy during the first year.

The Characteristics, Long-Term Outcomes, Risk Factors, and Antithrombotic Therapy in Chinese Patients With Atrial Fibrillation and Bioprosthetic Valves

Introduction: There were few data about the clinical profiles and long-term outcomes in Chinese patients with atrial fibrillation (AF) and bioprosthetic valves.

Methods: The retrospective study enrolled 903 patients with bioprosthetic valve replacement at our hospital and discharged with a diagnosis of AF from January 2010 to December 2018.

Results: The median age was 65.6 (61.9–69.1) years, and 548 (60.7%) patients were women. During a follow-up period of 3.84 (2.64–5.51) years, 68 (1.8 per 100 person-years) patients died, 81 (2.1 per 100 person-years) patients developed thromboembolism, and 23 (0.6 per 100 person-years) patients experienced major bleeding. The CHA₂DS₂-VASc score, as a categorical variable (low, moderate, or high risk), predicted the risk of thromboembolism with the C-statistic of 0.6 (95% CI: 0.511–0.689, p = 0.046). The incidence of the CHA₂DS₂-VASc score increment was 11.6 per 100 person-years, and the annual reclassification rate of stroke risk (from a low or moderate group to a higher group) was 12.7%. The current proportion of oral anticoagulants was 52.3, 59, and 63.2%, respectively, in the low, moderate, and high stroke risk groups. Age (OR: 1.04, 95% CI: 1.01–1.06, p = 0.01), left atrial size (OR: 1.05, 95% CI: 1.03–1.08, p < 0.001), and rheumatic heart disease (OR: 1.49, 95% CI: 1.05–2.10, p = 0.025) were positively associated with the use of oral anticoagulants. The history of chronic kidney disease (OR: 0.20, 95% CI: 0.05–0.76, p = 0.018), prior surgical ablation (OR: 0.33, 95% CI: 0.24–0.47, p < 0.001), and antiplatelet agent use (OR: 0.08, 95% CI: 0.05–0.13, p < 0.001) were inversely related to the use of oral anticoagulants. Higher admission estimated glomerular filtration rate (HR: 0.515, 95% CI: 0.311–0.853, p = 0.01), left ventricular ejection fraction (HR: 0.961, 95% CI: 0.931–0.992, p = 0.014), concomitant surgical ablation (HR: 0.348, 95% CI: 0.171–0.711, p = 0.004), and rheumatic heart disease history (HR: 0.515, 95% CI: 0.311–0.853, p = 0.01) were associated with a lower risk of death. Surgical ablation (HR: 0.263, 95% CI: 0.133–0.519, p < 0.001) and oral anticoagulants (HR: 0.587, 95% CI: 0.375–0.918, p = 0.019) were related to a lower risk of thromboembolism.

Conclusion: Chinese patients with AF and bioprosthetic valve(s) were relatively young and had a high prevalence of rheumatic heart disease with few comorbidities. The percentage of mitral bioprosthetic valve replacement was high. The proportion of concomitant surgical ablation or surgical left atrial appendage occlusion or exclusion was relatively low. The thromboembolic events were the major long-term adverse events. The anticoagulation therapy was underused in patients at moderate or high stroke risk. The CHA₂DS₂-VASc score was verified to be used for predicting stroke risk in this population. The stroke risk dynamically changed; it needed to be reestimated once the risk factor changed.

Anticoagulation Control with Acenocoumarol or Warfarin in Non-Valvular Atrial Fibrillation in Primary Care (Fantas-TIC Study)

Introduction: The use of vitamin K antagonists (VKAs) in non-valvular atrial fibrillation (NVAF) is complicated due to the narrow therapeutic margin they present and their unpredictable dose–response relationship. Most studies are based on warfarin, with the results being extrapolated to acenocoumarol. However, studies comparing the two treatments in terms of the degree of anticoagulation control are scarce, justifying the present study. Main factors associated with poor control of time in therapeutic range (TTR) of anticoagulated patients are also studied. Methods: Cross-sectional study, with real-world data from patients treated in primary care (PC). Data were obtained from the System for the Improvement of Research in PC (SIDIAP) database, covering 60,978 NVAF-anticoagulated patients from 287 PC centres in 2018. Descriptive statistics were derived, and odds ratios were estimated by multivariate logistic regression. Results: 41,430 patients were considered: 93% were being treated with acenocoumarol and 7% with warfarin. There was no difference in poor control of TTR between the two types of VKA treatment, acenocoumarol and warfarin (38.9 vs. 38.4; p = 0.610). Poor anticoagulation control was mainly associated with advanced alcoholism (OR = 1.38), liver failure (OR = 1.37) and intracranial haemorrhage (OR = 1.35) as well as female sex, age < 60 years, cardiovascular history, diabetes mellitus and other variables. Conclusions: There is no association between poor anticoagulation control and the type of VKA treatment administered. Factors associated with poor control of TTR must be considered in clinical practice to improve control and decision-making.

Relationship of adverse events to quality of anticoagulation control in atrial fibrillation patients with diabetes: real-world data from the FANTASIIA Registry

BACKGROUND

Atrial fibrillation (AF) patients with diabetes (DM) have high risk of cardiovascular events.

PURPOSE

To compare clinical characteristics, adverse outcomes and quality of anticoagulation in AF patients regarding DM status.

METHODS

AF patients from FANTASIIA registry were included. Baseline characteristics and comorbidities were recorded. After 2-years follow-up, the association between adverse events and DM was evaluated.

RESULTS

1956 patients (mean age 73.8 ± 9.5 years, 56% male) were analyzed; 574 (29.3%) had DM. Diabetic patients had also high prevalence of hypertension (90.6% vs 76.1%; p < .001) or renal disease (21.4% vs 15.9%; p < .001). After median follow-up of 1077 days (IQR 766-1113 days), diabetic patients had high total mortality (16.9%/year vs 11.4%/year; p < .001), cardiovascular mortality (9.1%/year vs 3.9%/year; p < .001) and MACE (12.9%/year vs 6.8%/year; p < .001). DM patients had poor anticoagulation control (time in therapeutic range: 58.52 ± 24.37% vs 62.68 ± 25.31%; p = .002). DM with lower TTR showed higher cardiovascular death and MACE. Multivariate analysis showed an independent association between DM and cardiovascular mortality [HR 1.73 (IC95% 1.07-2.80); p = .024].

CONCLUSION

AF Diabetic patients have higher comorbidities and poorer TTR than nondiabetic patients. Low TTR was associated with adverse events. The risk of cardiovascular outcomes was higher in DM patients, with independent association between DM and mortality risk.

Mobile Health Technology to Improve Care for Patients With Atrial Fibrillation

BACKGROUND

Current management of patients with atrial fibrillation (AF) is limited by low detection of AF, non-adherence to guidelines, and lack of consideration of patients' preferences, thus highlighting the need for a more holistic and integrated approach to AF management.

OBJECTIVE

The objective of this study was to determine whether a mobile health (mHealth) technology-supported AF integrated management strategy would reduce AF-related adverse events, compared with usual care.

METHODS

This is a cluster randomized trial of patients with AF older than 18 years of age who were enrolled in 40 cities in China. Recruitment began on June 1, 2018 and follow-up ended on August 16, 2019. Patients with AF were randomized to receive usual care, or integrated care based on a mobile AF Application (mAFA) incorporating the ABC (Atrial Fibrillation Better Care) Pathway: A, Avoid stroke; B, Better symptom management; and C, Cardiovascular and other comorbidity risk reduction. The primary composite outcome was a composite of stroke/thromboembolism, all-cause death, and rehospitalization. Rehospitalization alone was a secondary outcome. Cardiovascular events were assessed using Cox proportional hazard modeling after adjusting for baseline risk.

RESULTS

There were 1,646 patients allocated to mAFA intervention (mean age, 67.0 years; 38.0% female) with mean follow-up of 262 days, whereas 1,678 patients were allocated to usual care (mean age, 70.0 years; 38.0% female) with mean follow-up of 291 days. Rates of the composite outcome of 'ischemic stroke/systemic thromboembolism, death, and rehospitalization' were lower with the mAFA intervention compared with usual care (1.9% vs. 6.0%; hazard ratio [HR]: 0.39; 95% confidence interval [CI]: 0.22 to 0.67; p < 0.001). Rates of rehospitalization were lower with the mAFA intervention (1.2% vs. 4.5%; HR: 0.32; 95% CI: 0.17 to 0.60; p < 0.001). Subgroup analyses by sex, age, AF type, risk score, and comorbidities demonstrated consistently lower HRs for the composite outcome for patients receiving the mAFA intervention compared with usual care (all p < 0.05).

CONCLUSIONS

An integrated care approach to holistic AF care, supported by mHealth technology, reduces the risks of rehospitalization and clinical adverse events. (Mobile Health [mHealth] technology integrating atrial fibrillation screening and ABC management approach trial; ChiCTR-OOC-17014138).

Type 2 Diabetes, Atrial Fibrillation, and Direct Oral Anticoagulation

Type 2 diabetes (T2D) is an independent risk factor of stroke and systemic embolism in patients with atrial fibrillation (AF), and T2D patients with AF-associated stroke seem to have worse clinical outcome and higher risk of unfavorable clinical course compared to individuals without this metabolic disorder. Long-term anticoagulation is indicated in majority of T2D patients with AF to prevent adverse AF-associated embolic events. Direct oral anticoagulants (DOACs), direct oral thrombin inhibitor dabigatran, and direct oral factor Xa inhibitors, rivaroxaban, apixaban, and edoxaban, have emerged as a preferred choice for long-term prevention of stroke in AF patients offering potent and predictable anticoagulation and a favorable pharmacology with low risk of interactions. This article reviews the current data regarding the use of DOACs in individuals with T2D and AF.