Oral anticoagulant safety in family practice: prognostic accuracy of Bleeding Risk Scores (from the CACAO study)

BACKGROUND

To assess bleeding risk of patients treated by oral anticoagulants, several scores have been constructed to assist physicians in the evaluation of the benefit risk. Most of these scores lack a strong enough level of evidence for use in family practice.

OBJECTIVE

To assess the predictive prognostic accuracy of 13 scores designed to assess the risk of major or clinically relevant non-major (CRNM) bleeding events in a French ambulatory cohort receiving Vitamin-K antagonists (VKA) or direct oral anticoagulants (DOACs) in a family practice setting.

METHODS

CACAO (Comparison of Accidents and their Circumstances with Oral Anticoagulants) was a multicentre prospective cohort of ambulatory patients prescribed oral anticoagulants. We selected patients from the cohort who had received an oral anticoagulant because of non-valvular atrial fibrillation (NVAF) and/or venous thromboembolism (VTE) to be followed during one year by their GP. The following scores were calculated: mOBRI, Shireman, Kuijer, HEMORR2HAGES, ATRIA, HAS-BLED, RIETE, VTE-BLEED, ACCP score, Rutherford, ABH-Score, GARFIEL-AF, and Outcomes Registry for Better InformedTreatment of Atrial Fibrillation (ORBIT). Prognostic accuracy was assessed by using receiver operating characteristic curves and c-statistics.

RESULTS

During 1 year, 3,082 patients were followed. All of the scores demonstrated only poor to moderate ability to predict major bleeding or CRNM in NVAF patients on DOACs (c-statistic: 0.41-0.66 and 0.45-0.58), respectively. The results were only slightly better for patients prescribed VKA (0.47-0.66 and 0.5-0.55, respectively) in this indication. The results were also unsatisfactory in patients treated for VTE.

CONCLUSION

None of the scores demonstrated satisfactory discriminatory ability when used in family practice.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov NCT02376777.

Exploring the Prognostic Performance of MECKI Score in Heart Failure Patients with Non-Valvular Atrial Fibrillation Treated with Edoxaban

INTRODUCTION

Risk stratification in heart failure (HF) is essential for clinical and therapeutic management. The Metabolic Exercise test data combined with Cardiac and Kidney Indexes (MECKI) score is a validated prognostic model for assessing cardiovascular risk in HF patients with reduced ejection fraction (HFrEF). From the validation of the score, the prevalence of HF patients treated with direct oral anticoagulants (DOACs), such as edoxaban, for non-valvular atrial fibrillation (NVAF) has been increasing in recent years. This study aims to evaluate the reliability of the MECKI score in HFrEF patients treated with edoxaban for NVAF.

MATERIALS AND METHODS

This study included consecutive outpatients with HF and NVAF treated with edoxaban (n = 83) who underwent a cardiopulmonary exercise test (CPET). They were matched by propensity score with a retrospective group of HFrEF patients with NVAF treated with vitamin K antagonists (VKAs) from the MECKI score registry (n = 844). The study endpoint was the risk of cardiovascular mortality, urgent heart transplantation, or Left Ventricle Assist Device (LVAD) implantation.

RESULTS

Edoxaban patients were treated with a more optimized HF therapy and had different clinical characteristics, with a similar MECKI score. After propensity score, 77 patients treated with edoxaban were successfully matched with the MECKI-VKA control cohort. In both groups, MECKI accurately predicted the composite endpoint with similar area under the curves (AUC = 0.757 vs. 0.829 in the MECKI-VKA vs. edoxaban-treated group, respectively, p = 0.452). The two populations' survival appeared non-significantly different at the 2-year follow-up.

CONCLUSIONS

this study confirms the prognostic accuracy of the MECKI score in HFrEF patients with NVAF treated with edoxaban, showing improved predictive power compared to VKA-treated patients.

Prolonged Secondary Stroke Prevention with Edoxaban: A Long-Term Follow-Up of the SATES Study

BACKGROUND

Little evidence is available on the long-term efficacy and safety of edoxaban, mainly due to the recent release date. The primary objective of the study was to evaluate the safety of edoxaban, defined by the incidence of major bleedings. We then aimed to evaluate the incidence of thromboembolic events and the persistence of edoxaban therapy in the long-term.

METHODS

In this observational cohort study, we included ischemic stroke patients enrolled in a previous study to evaluate the safety and efficacy of long-term edoxaban treatment. Data were collected by a trained investigator through a structured telephone interview.

RESULTS

Sixty-three subjects (median age 81.0 (73.5-88.0) years, 38.1% male) were included in the study, with a mean follow-up of 4.4 ± 0.7 years (range: 3.2-5.5 years). Only one patient (1.6%, 0.4%/year) presented a major extracranial bleeding, and none had cerebral hemorrhage. Six thromboembolic events occurred in five patients (7.9%): three recurrent strokes, two transient ischemic attacks, and one myocardial infarction (2.2%/year). Over a follow-up period of more than three years, 13 patients discontinued edoxaban (20.6%). Conclusions: Edoxaban seems to be effective and safe in the long-term. The persistence rate of edoxaban therapy is optimal after more than three years of treatment.

The Distribution of the Genotypes of ABCB1 and CES1 Polymorphisms in Kazakhstani Patients with Atrial Fibrillation Treated with DOAC

Nowadays, direct oral anticoagulants (DOACs) are the first-line anticoagulant strategy in patients with non-valvular atrial fibrillation (NVAF). We aimed to identify the influence of polymorphisms of the genes encoding P-glycoprotein (ABCB1) and carboxylesterase 1 (CES1) on the variability of plasma concentrations of DOACs in Kazakhstani patients with NVAF. We analyzed polymorphisms rs4148738, rs1045642, rs2032582 and rs1128503 in ABCB1 and rs8192935, rs2244613 and rs71647871 CES1 genes and measured the plasma concentrations of dabigatran/apixaban and biochemical parameters in 150 Kazakhstani NVAF patients. Polymorphism rs8192935 in the CES1 gene (p = 0.04), BMI (p = 0.01) and APTT level (p = 0.01) were statistically significant independent factors of trough plasma concentration of dabigatran. In contrast, polymorphisms rs4148738, rs1045642, rs2032582 and rs1128503 in ABCB1 and rs8192935, rs2244613 and rs71647871 CES1 genes did not show significant influence on plasma concentrations of dabigatran/apixaban drugs (p > 0.05). Patients with GG genotype (138.8 ± 100.1 ng/mL) had higher peak plasma concentration of dabigatran than with AA genotype (100.9 ± 59.6 ng/mL) and AG genotype (98.7 ± 72.3 ng/mL) (Kruskal-Wallis test, p = 0.25). Thus, CES1 rs8192935 is significantly associated with plasma concentrations of dabigatran in Kazakhstani NVAF patients (p < 0.05). The level of the plasma concentration shows that biotransformation of the dabigatran processed faster in individual carriers of GG genotype rs8192935 in the CES1 gene than with AA genotype.

Delaying clinical events among patients with non-valvular atrial fibrillation treated with oral anticoagulants: Insights from the ARISTOPHANES study

BACKGROUND

Oral anticoagulants (OACs) mitigate stroke and systemic embolism (SE) risk in non-valvular atrial fibrillation (AF) patients but can increase the risk of major bleeding (MB). This study analyzed the gains in event-free time for these outcomes among OAC treatment options represented in the ARISTOPHANES study.

METHODS

This sub-analysis consisted of NVAF patients who initiated warfarin, apixaban, dabigatran, or rivaroxaban from 01JAN2013-30SEP2015, with data pooled from Medicare and 4 US commercial claims databases. Propensity score matching was conducted between non-vitamin K antagonist OAC (NOAC) and warfarin cohorts in each database and results were pooled. Laplace regression was used to evaluate the delay in time to stroke/SE and MB events between NOACs and warfarin and between NOACs after the first 12-months of follow-up.

RESULTS

The population included 466,991 patients (167,413 warfarin; 108,852 apixaban; 37,724 dabigatran; and 153,002 rivaroxaban). Event-free time gain (95% confidence interval) for apixaban versus warfarin was 101 days (78- 124) for stroke/SE and 116 (103- 130) days for MB. The gain in event-free time for dabigatran versus warfarin was 45 days (3- 87) for stroke/SE and 92 (68- 116) days for MB. The gain in event-free time for rivaroxaban versus warfarin was 63 days (42- 84) for stroke/SE but event-free time decreased by 18 (-31-6) days for MB.

CONCLUSIONS

Over 12 months after initiation, apixaban and dabigatran conferred progressive increases in event free time for stroke/SE and MB vs warfarin, whereas rivaroxaban conferred an increase in stroke/SE-free time but a loss in MB-free time vs warfarin.

Safety and effectiveness of rivaroxaban for prevention of stroke in patients with nonvalvular atrial fibrillation: analysis of routine clinical data from four countries

BACKGROUND

The safety and effectiveness of rivaroxaban versus vitamin K antagonists (standard of care [SOC]) for stroke prevention in patients with nonvalvular atrial fibrillation (NVAF) was evaluated in Europe.

RESEARCH DESIGN AND METHODS

Observational studies were conducted in the UK, the Netherlands, Germany, and Sweden. Primary safety outcomes were hospitalization for intracranial hemorrhage, gastrointestinal bleeding, or urogenital bleeding among new users of rivaroxaban and SOC with NVAF; outcomes were analyzed using cohort (rivaroxaban or SOC use) and nested case-control designs (current vs nonuse). Statistical analyses comparing rivaroxaban and SOC cohorts were not performed.

RESULTS

Overall, 162,919 rivaroxaban users and 177,758 SOC users were identified. In the cohort analysis, incidence ranges for rivaroxaban users were 0.25-0.63 events per 100 person-years for intracranial bleeding, 0.49-1.72 for gastrointestinal bleeding, and 0.27-0.54 for urogenital bleeding. Corresponding ranges for SOC users were 0.30-0.80, 0.30-1.42, and 0.24-0.42, respectively. In the nested case-control analysis, current SOC use generally presented a greater risk of bleeding outcomes than nonuse. Rivaroxaban use (vs nonuse) was associated with a higher risk of gastrointestinal bleeding, but a similar risk of intracranial or urogenital bleeding, in most countries. Ischemic stroke incidence ranged from 0.31 to 1.52 events per 100 person-years for rivaroxaban users.

CONCLUSIONS

Incidences of intracranial bleeding were generally lower with rivaroxaban than with SOC, whereas incidences of gastrointestinal and urogenital bleeding were generally higher. The safety profile of rivaroxaban for NVAF in routine practice is consistent with findings from randomized controlled trials and other studies.

Efficacy of R2CHA2DS2-VA score for predicting thromboembolism in Thai patients with non-valvular atrial fibrillation

Background

There is no data specific to the addition of renal dysfunction and age 50–64 years as risk parameters to the CHA₂DS₂-VA score, which is known as the R₂CHA₂DS₂-VA score, among NVAF patients. Accordingly, the aim of this study was to validate the R₂CHA₂DS₂-VA score for predicting thromboembolism in Thai NVAF patients.

Methods

Thai NVAF patients were prospectively enrolled in a nationwide multicenter registry from 27 hospitals during 2014–2020. Each component of the CHA₂DS₂-VA and R₂CHA₂DS₂-VA scores was scored and recorded. The main outcomes were thromboembolism, including ischemic stroke, transient ischemic attack (TIA), and/or systemic embolism. The annual incidence rate of thromboembolism among patients in each R₂CHA₂DS₂-VA and CHA₂DS₂-VA risk score category is shown as hazard ratio (HR) and 95% confidence interval (95% CI). The performance of the R₂CHA₂DS₂-VA and CHA₂DS₂-VA scores was demonstrated using c-statistics. Net reclassification index was calculated. Calibration plat was used to assess agreement between observed probabilities and predicted probabilities of both scoring system.

Results

A total of 3402 patients were enrolled during 2014–2020. The average age of patients was 67.38 ± 11.27 years. Of those, 46.9% had renal disease, 30.7% had a history of heart failure, and 17.1% had previous stroke or TIA. The average R₂CHA₂DS₂-VA and CHA₂DS₂-VA scores were 3.92 ± 1.92 and 2.98 ± 1.43, respectively. Annual thromboembolic risk increased with incremental increase in R₂CHA₂DS₂-VA and CHA₂DS₂-VA scores. Oral anticoagulants had benefit in stroke prevention in NVAF patients with an R₂CHA₂DS₂-VA score of 2 or more (adjusted HR: 0.630, 95% CI 0.413–0.962, p = 0.032). The c-statistics were 0.630 (95% CI 0.61–0.65) and 0.627 (95% CI 0.61–0.64), for R₂CHA₂DS₂-VA and CHA2DS2-VA scores respectively. NRI was 2.2%. The slope and R2 of the calibration plot were 0.73 and 0.905 for R₂CHA₂DS₂-VA and 0.70 and 0.846 for CHA₂DS₂-VA score respectively.

Conclusions

R₂CHA₂DS₂-VA score was found to be at least as good as CHA₂DS₂-VA score for predicting thromboembolism in Thai patients with NVAF. Similar to CHA₂DS₂-VA score, thromboembolism increased with incremental increase in R₂CHA₂DS₂-VA score.

Using Artificial Intelligence With Natural Language Processing to Combine Electronic Health Record's Structured and Free Text Data to Identify Nonvalvular Atrial Fibrillation to Decrease Strokes and Death: Evaluation and Case-Control Study

BACKGROUND

Nonvalvular atrial fibrillation (NVAF) affects almost 6 million Americans and is a major contributor to stroke but is significantly undiagnosed and undertreated despite explicit guidelines for oral anticoagulation.

OBJECTIVE

The aim of this study is to investigate whether the use of semisupervised natural language processing (NLP) of electronic health record's (EHR) free-text information combined with structured EHR data improves NVAF discovery and treatment and perhaps offers a method to prevent thousands of deaths and save billions of dollars.

METHODS

We abstracted 96,681 participants from the University of Buffalo faculty practice's EHR. NLP was used to index the notes and compare the ability to identify NVAF, congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, stroke or transient ischemic attack, vascular disease, age 65 to 74 years, sex category (CHA₂DS₂-VASc), and Hypertension, Abnormal liver/renal function, Stroke history, Bleeding history or predisposition, Labile INR, Elderly, Drug/alcohol usage (HAS-BLED) scores using unstructured data (International Classification of Diseases codes) versus structured and unstructured data from clinical notes. In addition, we analyzed data from 63,296,120 participants in the Optum and Truven databases to determine the NVAF frequency, rates of CHA₂DS₂‑VASc ≥2, and no contraindications to oral anticoagulants, rates of stroke and death in the untreated population, and first year's costs after stroke.

RESULTS

The structured-plus-unstructured method would have identified 3,976,056 additional true NVAF cases (P<.001) and improved sensitivity for CHA₂DS₂-VASc and HAS-BLED scores compared with the structured data alone (P=.002 and P<.001, respectively), causing a 32.1% improvement. For the United States, this method would prevent an estimated 176,537 strokes, save 10,575 lives, and save >US $13.5 billion.

CONCLUSIONS

Artificial intelligence-informed bio-surveillance combining NLP of free-text information with structured EHR data improves data completeness, prevents thousands of strokes, and saves lives and funds. This method is applicable to many disorders with profound public health consequences.

Age-Related Clinical Outcomes of Patients with Non-Valvular Atrial Fibrillation: Insights from the COOL-AF Registry

Purpose

We aimed to compare the rate of clinical outcomes among three age groups (<65, 65–74, and ≥75 years) of adult patients with non-valvular atrial fibrillation (NVAF).

Patients and Methods

We prospectively enrolled NVAF patients from 27 Thailand medical centers. The following were collected at baseline: demographic data, risk factors, comorbid conditions, laboratory data, and medications. The clinical outcomes were ischemic stroke (IS) or transient ischemic attack (TIA), major bleeding (MB), intracerebral hemorrhage (ICH), heart failure (HF), and death. All events were adjudicated. Patients were categorized according to age group into three groups; age <65, 65–74, and ≥75 years.

Results

Among the 3402 patients that were enrolled during 2014–2017, the mean age was 67.4±11.3 years, and 2073 (60.9%) were older. The average follow-up was 25.7±10.6 months. Oral anticoagulants were given in 75.4% of patients (91.1% of OAC was warfarin). The incidence rate of IS/TIA, MB, ICH, HF, and death was 1.43 (1.17–1.74), 2.11 (1.79–2.48), 0.70 (0.52–0.92), 3.03 (2.64–3.46), and 3.77 (3.33–4.24) per 100 person-years, respectively. The risk of IS/TIA, MB, ICH, HF, and death increased with age both before and after adjustment for potential confounders. Even though OAC reduced the risk of IS/TIA, it increased the risk of MB. Net clinical benefit (NCB) analysis favored oral anticoagulant (OAC) in the high-risk subset of older adults.

Conclusion

Older adult NVAF patients had a significantly increased risk of IS/TIA, MB, ICH, HF, and death compared to younger NVAF before and after adjustment for potential confounders. Strategies to reduce overall risk, including OAC use and choice and integrated care, should be implemented.

Incidence Rates of Bleeding and Emergency Surgery Due to Trauma or Fracture Among Japanese Patients with Non-valvular Atrial Fibrillation Receiving Oral Anticoagulation Therapy

Introduction

In patients with nonvalvular atrial fibrillation (NVAF) receiving oral anticoagulants (OACs), reversal of coagulopathy can be achieved with specific reversal drugs such as idarucizumab, which is indicated for use in patients treated with dabigatran for cases of life-threatening or uncontrolled bleeding or during emergency procedures that may cause serious bleeding. This study examined the incidence rate (IR) of emergency surgeries and major bleeding episodes associated with fractures and trauma in Japanese patients with NVAF receiving OACs.

Methods

This retrospective, non-interventional analysis of health insurance claims was conducted using data from 62,888 OAC-naive adult patients with NVAF who initiated dabigatran, warfarin, apixaban, rivaroxaban, or edoxaban between March 2011 and June 2016. The primary endpoint was overall IR of emergency surgery or major bleeding due to fracture or trauma.

Results

Overall IR of emergency surgery or major bleeding due to fracture or trauma considering outcomes until OAC discontinuation was 0.489 per 100 patient-years (PY) (95% confidence interval [CI] 0.406–0.572). Considering first OAC exposure only, the IR was 0.483 per 100 PY (95% CI 0.394–0.573). Emergency surgery/major bleeding events due to fracture or trauma was highest in those aged ≥ 75 years (0.611 per 100 PY [95% CI 0.481–0.741]).

Conclusions

Fewer than one in 200 patients per year with NVAF receiving OACs experience emergency surgeries and major bleeding episodes associated with fractures and trauma; however, the IR of these events is markedly higher in patients of advanced age.

Trial registration

ClinicalTrials.gov 207, NCT03254147.

Patients with an abnormal heart rhythm (nonvalvular atrial fibrillation [NVAF]) have a higher risk of blood clots and stroke (which is when the blood supply to part of the brain is blocked). To reduce these risks, patients can take anticoagulants that slow or prevent the formation of blood clots. However, if the patient needs major emergency surgery or has a severe injury, the anticoagulants can increase their risk of bleeding, which can sometimes be life-threatening. There are drugs (e.g., idarucizumab) that can be used to reverse the effects of anticoagulants in this type of emergency. What we don’t know is how many NVAF patients in Japan who are on anticoagulants have emergency surgeries or major bleeding after an injury, and therefore may require a reversal drug. The authors looked at Japanese health insurance claim data from 62,888 adult patients with NVAF who started taking an anticoagulant. They found that, annually, approximately 0.5% of the patients had emergency surgery or a major bleed associated with a fracture or injury. In very elderly patients (aged at least 75 years), the annual percentage was approximately 0.6%, which was almost double the annual percentage in patients aged less than 65 years. The authors concluded that, even though the number of people requiring a reversal agent are quite small, it is important to have an effective reversal agent for patients on anticoagulants, particularly older patients.

Safety and effectiveness of non-vitamin K oral anticoagulants versus warfarin in real-world patients with non-valvular atrial fibrillation: a retrospective analysis of contemporary Japanese administrative claims data

Objective

To assess the safety (ie, risk of bleeding) and effectiveness (ie, risk of stroke/systemic embolism (SE)) separately for four non-vitamin K oral anticoagulants (NOACs; apixaban, dabigatran, edoxaban and rivaroxaban) versus warfarin in Japanese patients with non-valvular atrial fibrillation (NVAF), including those at high risk of bleeding and treated with reduced doses of NOACs.

Methods

We conducted a retrospective analysis of electronic health records and claims data from 372 acute care hospitals in Japan for patients with NVAF newly initiated on NOACs or warfarin. Baseline characteristics were balanced using inverse probability of treatment weighting with stabilised weights (s-IPTW). Bleeding risk and stroke/SE risk were expressed as HRs with 95% CIs. Two sensitivity analyses were conducted.

Results

A total of 73 989 patients were eligible for analysis. Notably, 52.8%-81.9% of patients received reduced doses of NOACs. After applying s-IPTW, patient characteristics were well balanced across warfarin/NOAC cohorts. The mean within-cohort age, CHADS₂ score and CHA₂DS₂-VASc score were 76 years, 2.2-2.3 and 3.8, respectively. In all age categories, the majority of the HRs for major bleeding, any bleeding and stroke/SE were equal to or below 1 for all NOACs versus warfarin. Apixaban was the only NOAC associated with a significantly lower risk of any bleeding. There was a trend towards increased risk reduction with NOACs versus warfarin in patients with body weight ≥60 kg. In patients with renal disease, the HRs for apixaban versus warfarin were below 1 for major bleeding, any bleeding and stroke/SE, with statistical significance observed for the risk reduction in stroke/SE versus warfarin. In the sensitivity analysis, there were no large differences in HRs between the two observational periods.

Conclusions

In patients with NVAF primarily treated with reduced-dose NOACs, the risks of stroke/SE and major bleeding were significantly lower with NOACs versus warfarin.

Commonly used definitions in real-world studies may underestimate the prevalence of renal disease among nonvalvular atrial fibrillation patients

Aim: To describe comorbidities among treated nonvalvular atrial fibrillation (NVAF) patients and assess the impact of using different time ('look back' windows) on the prevalence estimates. Patients & methods: We included all adult nonvalvular atrial fibrillation patients newly initiating treatment in the Clinical Practice Research Datalink. Comorbidities included in the Charlson Comorbidity Index were defined using an all available, 3- and 1-year look back window before the start of treatment. Results: The prevalence of comorbidities was high and increased when using longer look back windows; the largest difference was observed for renal disease (+15.6%). Conclusion: Our findings emphasize the importance of using all available data when characterizing chronic conditions and highlights the high comorbidity burden in this population.

Non-vitamin K oral anticoagulant use in the elderly: a prospective real-world study - data from the REGIstry of patients on Non-vitamin K oral Anticoagulants (REGINA)

Purpose

Numerous studies on thromboembolic prevention for non-valvular atrial fibrillation (NVAF) have shown either equal or better efficacy and safety of non-vitamin K oral anticoagulants (NOACs) compared to warfarin, even for patients aged ≥75 years. Data on elderly patients, in particular, octogenarians, are lacking. Paradoxically, this population is the one with the highest risk of bleeding and stroke with a worse prognosis. This study aims to describe safety and effectiveness of NOACs in an elderly comorbid population.

Patients and methods

REGIstry of patients on Non-vitamin K oral Anticoagulants (REGINA) is a prospective observational study enrolling consecutive NVAF patients started on NOACs and followed up to 1 year (at 1, 6, 12 months). The primary endpoint was the incidence rate of major bleeding (MB) and clinically relevant non-major bleeding (CRNMB). The secondary endpoints were the incidence of 1) stroke or systemic embolism, 2) hospitalization, 3) death, and 4) drug-related adverse events.

Results

We enrolled 227 patients aged 81.6±6.1 years (range 67–95 years; ≥80 years in 59.4%). The median CHA₂DS₂-VASc was 5 (IQR 4–5) and HAS-BLED was 4 (IQR 3–5). The estimated glomerular filtration rate was 59.27±24.12 mL/min. During follow-up, only 10 MB and 23 CRNMB occurred, with a total incidence of 4.4% (95% CI: 1.7%–7.17%) and 5.7% (95% CI: 2.68%–8.72%), respectively. There were 2 cerebral ischemic events, with a total incidence of 0.88% (95% CI: 0.84%–0.92%), 23 NOAC-related hospitalizations, no NOAC-related deaths, and 4 minor drug-related adverse effects.

Conclusion

In a population of aged and clinically complex patients, mainly octogenarians, NOACs were safe and effective.

Advances and Application of a Novel Oral Anticoagulant in Specific Populations: Dabigatran Etexilate

BACKGROUND

Dabigatran etexilate (DE) was approved by the FDA in 2010 to reduce the risk of stroke and systemic embolism in adults with Non-valvular Atrial Fibrillation (NVAF). Compared with warfarin, a traditional anticoagulant drug, DE exhibits a shorter half-life, improved dose-effect relationship, fewer food and drug interactions, and can be taken orally without monitoring the conventional coagulation index. DE can also prevent or reduce the severity of adverse events, such as attenuated drug efficacy or bleeding. It is convenient for patients to take DE due to low levels of individual variation. This review aims to application of Dabigatran etexilate in specific populations.

METHODS

Fifty-five papers were included in the review.

RESULTS

We review the pharmacological mechanisms, pharmacokinetics and drug interactions, as well as the application of DE for different clinical populations, and provide clinical guidelines.

CONCLUSION

When using DE, one should consider the risk of bleeding, age, renal function, drug interactions, and other factors.

Successful Tissue Plasminogen Activator for a Patient with Stroke After Stanford Type A Aortic Dissection Treatment

Some stroke patients with the acute aortic dissection receiving thrombolysis treatment resulted in fatalities. Thus, the concurrent acute aortic dissection is the contraindication for the intravenous recombinant tissue-type plasminogen activator. However, the safety and the effectiveness of the intravenous recombinant tissue-type plasminogen activator therapy are not known in patients with stroke some days after acute aortic dissection treatment. Here, we first report a case of a man with a cardioembolism due to the nonvalvular atrial fibrillation, who received the intravenous recombinant tissue-type plasminogen activator therapy 117 days after the traumatic Stanford type A acute aortic dissection operation. Without the intravenous recombinant tissue-type plasminogen activator therapy, the prognosis was expected to be miserable. However, the outcome was good with no complication owing to the intravenous recombinant tissue-type plasminogen activator therapy. Our case suggests the effectiveness and the safety of the intravenous recombinant tissue-type plasminogen activator therapy to the ischemic stroke some days after acute aortic dissection treatment.

Comparison of all-cause, stroke, and bleed-specific healthcare resource utilization among patients with non-valvular atrial fibrillation (NVAF) and newly treated with dabigatran or warfarin

BACKGROUND

We compared healthcare utilization outcomes and persistence among non-valvular atrial fibrillation (NVAF) patients newly treated with dabigatran or warfarin.

METHODS

Using a nationwide, US administrative claims database, a retrospective matched-cohort of newly diagnosed NVAF patients (age≥18 years) treated with dabigatran or warfarin (propensity score matched 1:1) in 01/01/2011-12/31/2013 was evaluated. All-cause, stroke-, and bleed-specific per patient per month (PPPM) healthcare resource utilization (HCRU), incidence rate of hospitalization for stroke or bleed, 30-day readmission, and persistence were reported.

RESULTS

In total, 18,890 dabigatran patients were matched to corresponding warfarin patients. Compared to warfarin users, dabigatran users PPPM had significantly fewer all-cause hospitalizations (0.04 vs 0.05), total outpatient visits (3.98 vs 5.87), and lower 30-day readmissions (14.5% vs 17.4%, all p < 0.001). Dabigatran users had lower incidence rate for stroke (0.65 vs 1.06) and bleed (1.69 vs 2.20), stroke (0.0006 vs 0.0011, p < 0.001) and bleed-specific hospitalizations (0.002 vs 0.003, p = 0.008), and stroke (0.03 vs 0.04, p < 0.001) and bleed-specific outpatient visits (0.07 vs 0.08, p = 0.018), and significantly lower non-persistence (62.1% vs 66.3%, p < 0.001).

CONCLUSION

Among newly diagnosed newly treated NVAF patients, dabigatran users had significantly lower all-cause, stroke- and bleed-specific HCRU, lower risk of hospitalization for stroke or bleed events, lower 30-day readmissions, and higher persistence than warfarin users.

The cost of warfarin treatment for stroke prevention in patients with non-valvular atrial fibrillation in Russia from a collective perspective

AIMS

Vitamin K antagonists (VKAs) are used for stroke prevention in patients with non-valvular atrial fibrillation (NVAF), but necessitate regular monitoring of prothrombin time via international normalized ratio (INR) testing. This study explores the economic burden of VKA therapy for Russian patients with NVAF.

METHOD

Cardiologists provided clinical characteristics and healthcare resource use data relating to the patient's first year of treatment. Data were used to quantify direct medical costs (INR testing, consultations, drug costs). The same patients completed a questionnaire providing data on direct non-medical costs (travel/expenses for attendance at VKA appointments) and indirect costs (opportunity cost and reduced work productivity). Mean costs per patient per year are described (US dollars).

RESULTS

Cardiologists (n = 50) provided data on 400 patients (mean age = 63, 47% female), and 351 patients (88%) completed the patient questionnaire. Patients had a mean of nine INR tests. Estimated direct medical costs totaled $151.06, and 18.5% of direct medical costs were attributable to drug costs. Estimated annual direct non-medical costs were $22.89 per patient, and indirect costs were $275.59 per patient.

LIMITATIONS

Included patients had been treated for 12-24 months, so are not fully representative of the broader treatment population.

CONCLUSION

Although VKA drugs costs are relatively low, regular INR testing and consultations drive the economic burden for Russian NVAF patients treated with VKA.

Management and Outcomes of Bleeding Events in Patients in the Emergency Department Taking Warfarin or a Non-Vitamin K Antagonist Oral Anticoagulant

BACKGROUND

Most comparisons of bleeding patients who are taking warfarin or a non-vitamin K oral anticoagulant (NOAC) have been limited to admitted patients and major bleeding events in well-controlled, clinical trial settings.

OBJECTIVES

We describe the clinical characteristics, interventions, and outcomes in patients who are taking warfarin or a NOAC who presented to the emergency department (ED) with any bleeding event.

METHODS

We conducted a structured, retrospective, observational study of nonvalvular atrial fibrillation, pulmonary embolism, or deep vein thrombosis warfarin- or NOAC-treated patients presenting with any bleeding event to a large, academic ED between January 2012 and March 2015. We used descriptive statistics to summarize baseline characteristics, treatments, and outcomes and performed subgroup analyses based on the type of anticoagulant and site of bleeding.

RESULTS

The electronic search yielded 95 cases of patients taking a NOAC (i.e., dabigatran [33], rivaroxaban [32], or abixaban [30]) and 342 patients taking warfarin. Reversal agents were rarely used in all anticoagulant groups. Case fatality rates were similar among warfarin- and NOAC-treated patients for gastrointestinal bleeding (7% vs. 7%) and intracranial hemorrhage (18% vs. 4%), respectively. After adjustment for other factors, only intracranial hemorrhage (odds ratio 4.4; 95% confidence interval 1.4-13.3) was associated with mortality.

CONCLUSIONS

Despite the rare use of reversal strategies, mortality was low and outcomes were comparable among patients with bleeding events presenting to the ED while taking a NOAC compared with warfarin.

Reducing The Risk Of Stroke In Patients With Nonvalvular Atrial Fibrillation With Direct Oral Anticoagulants. Is One Of These Not Like The Others?

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia and increases risk of stroke by nearly 5-fold. While warfarin has been employed successfully to reduce the risk of stroke in these patients, there are a number of challenges with therapy. These include the need for therapeutic monitoring due to variability in patient response, frequent dose adjustments, numerous drug-drug, drug-food, and drug-disease interactions, and a heightened risk of thrombosis and bleeding due to these issues. Current guidelines recommend that the vitamin K antagonists (VKA) or direct oral anticoagulants (DOACs) should be used for thromboprophylaxis in patients with nonvalvular AF at risk for stroke or systemic embolic events. The DOACs include the direct thrombin inhibitor dabigatran and the direct factor Xa inhibitors rivaroxaban, apixaban, and edoxaban. In clinical trials these agents consistently demonstrated a reduction in the risks of hemorrhagic stroke and intracranial hemorrhage compared to VKA. Clinicians now must decide if there are meaningful differences between these agents in order to prescribe the best agent for an individual patient. Therefore, it is critical for clinicians to go beyond information provided in manuscript abstracts, and gain an understanding of the similarities and differences in clinical trial design, patient enrollment, and statistical analysis.

CHADS2 score has a better predictive value than CHA2DS2-VASc score in elderly patients with atrial fibrillation

Aim

The study aims to compare the ability of CHA₂DS₂-VASc (defined as congestive heart failure, hypertension, age ≥75 years [two scores], type 2 diabetes mellitus, previous stroke, transient ischemic attack, or thromboembolism [TE] [doubled], vascular disease, age 65–74 years, and sex category) and CHADS₂ (defined as congestive heart failure, hypertension, age ≥75 years, type 2 diabetes mellitus, previous stroke [doubled]) scores to predict the risk of ischemic stroke (IS) or TE among patients with nonvalvular atrial fibrillation (NVAF).

Methods

A total of 413 patients with NVAF aged ≥65 years, and not on oral anticoagulants for the previous 6 months, were enrolled in the study. The predictive value of the CHA₂DS₂-VASc and CHADS₂ scores for IS/TE events was evaluated by the Kaplan–Meier method.

Results

During a follow-up period of 1.99±1.29 years, 104 (25.2%) patients died and 59 (14.3%) patients developed IS/TE. The CHADS₂ score performed better than the CHA₂DS₂-VASc score in predicting IS/TE as assessed by c-indexes (0.647 vs 0.615, respectively; P<0.05). Non-CHADS₂ risk factors, such as vascular disease and female sex, were not found to be predictive of IS/TE (hazard ratio 1.518, 95% CI: 0.832–2.771; hazard ratio 1.067, 95% CI: 0.599–1.899, respectively). No differences in event rates were found in patients with the CHADS₂ scores of 1 and 2 (7.1% vs 7.8%). It was observed that patients with a CHADS₂ score of ≥3 were most in need of anticoagulation therapy.

Conclusion

In patients with NVAF aged ≥65 years, the CHADS₂ score was found to be significantly better in predicting IS/TE events when compared to the CHA₂DS₂-VASc score. Patients with a CHADS₂ score of ≥3 were associated with high risk of IS/TE events.

Left atrial appendage closure followed by 6 weeks of antithrombotic therapy: a prospective single-center experience

BACKGROUND

Currently, 2 different left atrial appendage (LAA) closure systems are available for stroke prevention in nonvalvular atrial fibrillation but comparative data are lacking.

OBJECTIVES

To prospectively compare procedural data and patient outcome for 2 contemporary LAA closure systems and to investigate an alternative antithrombotic treatment regimen in high-risk patients.

METHODS

Patients with nonvalvular atrial fibrillation, with high risk for stroke, and who either had contraindication or were not willing to accept oral anticoagulation were prospectively enrolled. Watchman (Boston Scientific, Natick, MA; group A) or Amplatzer Cardiac Plug (St Jude Medical, Minneapolis, MN; group B) devices were implanted. All patients received antithrombotic therapy for 6 weeks. After repeat transesophageal echocardiography, patients were switched to aspirin.

RESULTS

Eighty patients were enrolled. There was no statistical difference in patient characteristics in groups A and B: CHA2DS2VASC score: 4.1 ± 1.5 versus 4.5 ± 1.8; HASBLED score: 3.1 ± 1.1 versus 3.1 ± 1.1, respectively. LAA closure was achieved in 78 of 80 patients (98%) (group A: 38 of 40 [95%] vs group B: 40 of 40 [100%]). There was no difference in procedure time (group A: 48 ± 16 minutes vs group B: 47 ± 15 minutes; P = .69) and fluoroscopy time (group A: 6.0 ± 4.7 minutes vs group B: 7.3 ± 4.4 minutes; P = .25). Major complications included 1 air embolism and delayed tamponade in each group. After 6 weeks, 1 device dislodgment and 4 device-related thrombi were detected. Ninety-four percent of the patients (73 of 77) were switched to aspirin after 6 weeks. During a median follow-up of 364 days (Q1-Q3: 283-539 days), no systemic embolism occurred, but 3 patients died (heart failure: n = 2; bleeding: n = 1).

CONCLUSIONS

Implantation of both LAA closure devices can be performed with high success rates in high-risk patients. Postprocedural 6 weeks antithrombotic therapy followed by aspirin therapy needs to be confirmed in a larger study.

Pattern of atrial fibrillation and risk of outcomes: the Loire Valley Atrial Fibrillation Project

BACKGROUND

Risk of stroke and thromboembolism (TE) in patients with non-valvular atrial fibrillation (NVAF) is categorised in stroke risk stratification scores. The role of pattern of NVAF in risk prediction is unclear in contemporary 'real world' cohorts.

METHODS AND RESULTS

Patients with NVAF in a four-hospital-institution between 2000 and 2010 were included. Stroke/TE event rates were calculated according to pattern of AF, i.e. paroxysmal, persistent and permanent. Risk factors were investigated by Cox regression. Among 7156 NVAF patients, 4176 (58.4%) patients with paroxysmal, 376 (5.3%) with persistent and 2604 (36.3%) with permanent patterns of NVAF were included. In non-anticoagulated patients, overall stroke/TE event rate per 100 person-years was 1.29 (95% CI 1.13-1.47). Compared with paroxysmal NVAF, rates of stroke/TE, bleeding and all-cause mortality (p<0.001) were significantly higher in permanent NVAF patients but not in persistent NVAF patients. In multivariate analyses, previous stroke (hazard ratio, HR 2.58, 95% CI 2.08-3.21), vascular disease (HR 1.34, 1.12-1.61), heart failure (HR 1.20, 1.00-1.44), age ≥ 75 years (HR 2.75, 2.16-3.50) and age 65-74 years (HR 1.60, 1.22-2.09) independently increased stroke/TE risk, but not persistent (HR 1.13, 0.76-1.70) and permanent (HR 1.44, 0.96-2.16) NVAF patterns.

CONCLUSION

In this large 'real world' NVAF cohort, rates of stroke, TE, death and bleeding differed significantly by patterns of NVAF. However, only previous stroke, age, heart failure and vascular disease (not pattern of NVAF) independently increased risk of adverse outcomes in multivariate analyses. Thus, stroke risk is similar across all patterns of NVAF and antithrombotic therapy should be based on clinical risk factors, not on arrhythmia pattern.