Potentially Preventable Strokes in High-Risk Patients With Atrial Fibrillation Who Are Not Adequately Anticoagulated

2018 Focused Update of the Canadian Cardiovascular Society Guidelines for the Management of Atrial Fibrillation

The Canadian Cardiovascular Society (CCS) Atrial Fibrillation Guidelines Committee provides periodic reviews of new data to produce focused updates that address clinically important advances in atrial fibrillation (AF) management. This 2018 Focused Update addresses: (1) anticoagulation in the context of cardioversion of AF; (2) the management of antithrombotic therapy for patients with AF in the context of coronary artery disease; (3) investigation and management of subclinical AF; (4) the use of antidotes for the reversal of non-vitamin K antagonist oral anticoagulants; (5) acute pharmacological cardioversion of AF; (6) catheter ablation for AF, including patients with concomitant AF and heart failure; and (7) an integrated approach to the patient with AF and modifiable cardiovascular risk factors. The recommendations were developed using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) standards. Individual studies and literature were reviewed for quality and bias; the literature review process and evidence tables are included as Supplementary Material and are available on the CCS Web site. Details of the updated recommendations are presented, along with their background and rationale. This document is linked to an updated summary of all CCS AF guidelines recommendations, from 2010 to the present 2018 Focused Update, which is provided in the Supplementary Material.

The Guideline-Policy Gap in Direct-Acting Oral Anticoagulants Usage in Atrial Fibrillation: Evidence, Practice, and Public Policy Considerations

Atrial fibrillation has a high disease burden-both in prevalence and associated consequences. Despite anticoagulation being an effective treatment in atrial fibrillation, stroke prevention is slow to reflect evidence-based practice. Real-world data reveal a substantial portion of patients who would benefit from anticoagulation, yet do not receive it adequately or at all. A large part of this suboptimal treatment is due to the underutilization of direct oral anticoagulants (DOACs). In response to abundant evidence published over a short timeframe, international guidelines have adopted DOAC usage ahead of policy and fund holders. This paper reviews the evidence and values that influence published guidelines, patient-physician decision making, and policy framework on DOAC usage. An important factor is the access gap between patients who qualify for DOAC according to evidence-based guidelines and the subset of this cohort who are eligible for DOAC based on government funded policy. We analyse the Canadian health system in detail-including drug approval and funding process. Health care systems in other countries are explored, with emphasis on similar universal health care systems that may help overcome barriers common to Canada. We will discuss strategies to: (1) improve awareness of the risk and preventability of stroke; (2) enable physicians to provide evidence-based DOAC usage; (3) empower patients to improve adherence and persistence; (4) collect real-life data that encourages patient self-monitoring, physician outcomes auditing, and building evidence that is useful for policy makers; and (5) use postmarketing data in negotiating shared risk management between pharmaceuticals and government to improve access to DOACs.

Arrhythmias in Adults With Congenital Heart Disease: What the Practicing Cardiologist Needs to Know

The expanding population of adults with congenital heart disease (CHD) combined with the pervasiveness of arrhythmias has resulted in the rapid growth of a dedicated sector of cardiology at the intersection between 2 subspecialties: electrophysiology and adult CHD. Herein, practical considerations are offered regarding urgent referral for catheter ablation of atrial arrhythmias, anticoagulation, and primary prevention implantable cardioverter-defibrillators (ICDs). Patients with Ebstein anomaly and ventricular pre-excitation should be referred promptly due to the high prevalence of multiple accessory pathways and increased incidence of atrial tachyarrhythmias, which may be poorly tolerated. In patients with transposition of the great arteries and atrial switch surgery, atrial arrhythmias should be managed without delay because they could provoke ventricular arrhythmias and sudden death. Other settings in which atrial arrhythmias can be poorly tolerated include single ventricle physiology and Eisenmenger syndrome. Long-term anticoagulation is generally indicated in patients with sustained intra-atrial reentrant tachycardia or atrial fibrillation and a mechanical valve, moderate or severe systemic atrioventricular valve stenosis, traditional risk factors for stroke, and/or moderate or complex CHD. The only class I indication for a primary prevention ICD is a systemic left ventricular ejection fraction ≤ 35%, with biventricular physiology, and New York Heart Association class II or III symptoms. ICD therapy is reasonable in selected adults with tetralogy of Fallot and multiple risk factors for sudden death identified by observational studies. Indications for ICDs in patients with systemic right ventricles and univentricular hearts are less well established, underscoring the need for future research to inform risk stratification.

The impact of nurse-led atrial fibrillation clinics on patient and healthcare outcomes: a systematic mixed studies review

Background:

Atrial fibrillation, the most common arrhythmia worldwide, continues to increase as the population ages. Patients with atrial fibrillation, particularly those newly diagnosed or who have multiple comorbidities, have high healthcare utilisation rates. Nurse-led atrial fibrillation clinics have developed to improve care and guidance for atrial fibrillation patients, with the potential to reduce hospital presentations and healthcare utilisation. Atrial fibrillation clinics that provide specialised and patient-centred care have improved patient symptom management, quality of life and reduced healthcare utilisation and costs.

Aims:

The aim of this study was to provide the first synthesis of evidence for the impact of nurse-led atrial fibrillation clinics on patient, healthcare utilisation, and quality of care outcomes.

Methods:

This systematic mixed studies review examined citations from three databases: Medline, CINAHL and Embase, using the search terms ‘atrial fibrillation’ and ‘clinic’, and related concepts. Seventeen moderate to high quality articles were selected.

Results:

Overall, atrial fibrillation clinics were more cost effective, had shorter wait times and reduced hospitalisation and emergency department visits. Symptoms and sinus rhythm restoration were comparable in the nurse-led compared to physician-led cardioversion clinics. Findings related to patient knowledge and patient satisfaction were mixed, while mortality rates were lower, and patient medication adherence was higher in nurse-led atrial fibrillation compared to usual care. Quality of life and guideline adherence was increased in patients receiving nurse-led atrial fibrillation care compared to usual care.

Conclusion:

Nurse-led clinics improved healthcare, patient and quality care outcomes. Future research might examine the role of technology in delivery of nurse-led clinics in rural/remote areas as well as patient experiences with nurse-led clinics.

Preceding Antithrombotic Treatment is Associated With Acute Ischemic Stroke Severity and Functional Outcome at 90 Days Among Patients With Atrial Fibrillation

BACKGROUND

Antithrombotic therapies are known to prevent ischemic stroke (IS) for patients with atrial fibrillation (AF), but are often underused in clinical practice. The aim of present study was to investigate the prevalence of patients with acute IS with known history of AF who were not receiving antithrombotic treatment before stroke and to evaluate the association of preceding antithrombotic treatment with stroke severity and outcomes at 90 days after admission.

MATERIALS AND METHODS

This was a retrospective, multi-center, observational study of 748 patients with acute IS and known history of AF admitted to 6 participating hospitals between March 2016 and October 2017. The primary outcome was stroke severity at admission as assessed using National Institutes of Health Stroke Scale (NIHSS) score. The secondary outcome was functional outcome at 90 days after admission as measured by modified Rankin Scale (mRS) score.

RESULTS

A total of 748 patients, 54 (7.2%) were receiving therapeutic warfarin (international normalized ratio [INR] ≥ 2) and 100 (13.4%) had subtherapeutic warfarin anticoagulation (INR < 2), 340 (45.5%) were receiving antiplatelet treatment, and 254 (34.0%) were not receiving any antithrombotic treatment prior to stroke. Compared with no antithrombotic treatment, therapeutic warfarin (OR: 0.64; 95% CI: 0.52-0.82; P = .022), and antiplatelet therapy only (OR: 0.89; 95% CI: 0.76-0.96; P = .041) were associated with lower odds ratio of moderate or severe stroke (NIHSS ≥ 16). Patients receiving preceding therapeutic warfarin (OR: 1.32; 95% CI: 1.22-3.57; P = .025), antiplatelet therapy only (OR: 1.13; 95% CI: 1.07-2.59; P = .043), and subtherapeutic warfarin with INR 1.5 to 1.99 (OR: 1.15; 95% CI: 1.10-2.66; P = .042) had higher odds ratio of better functional outcome (mRS ≤ 2) at 90 days.

CONCLUSIONS

Among patients with AF who had experienced an acute IS, inadequate therapeutic warfarin preceding the stroke was very prevalent in China. Therapeutic warfarin was associated with less severe stroke and better functional outcome at 90 days.

How I manage anticoagulant therapy in older individuals with atrial fibrillation or venous thromboembolism

Anticoagulant therapy is the most effective strategy to prevent arterial and venous thromboembolism, but treating older individuals is challenging, because increasing age, comorbidities, and polypharmacy increase the risk of both thrombosis and bleeding. Warfarin and non-vitamin K antagonist oral anticoagulants are underused and often underdosed in the prevention of stroke in older patients with atrial fibrillation because of concerns about the risk of bleeding. Poor adherence to anticoagulant therapy is also an issue for older patients with atrial fibrillation and those at risk of recurrent pulmonary embolism. In this review, we present 5 clinical cases to illustrate common challenges with anticoagulant use in older patients and discuss our approach to institute safe and effective antithrombotic therapy.

Diagnostic accuracies of screening for atrial fibrillation by cardiac nurses versus radiographers

Aim

We examined the diagnostic accuracy of single-lead ECG as assessed by radiographers and 12-lead ECG as assessed by cardiac nurses for the diagnosis of atrial fibrillation (AF).

Methods

Based on the Danish Cardiovascular Screening Trial, we conducted a population-based, cross-sectional study of 1338 randomly selected Danish men aged 65–74 years with no exclusion criteria. The participants were screened with single-lead ECG during a CT scan assessed by radiographers and 12-lead ECG assessed by cardiac nurses. The diagnostic accuracy was evaluated compared with that produced by a 12-lead ECG assessed by two consenting cardiologists.

Results

The study identified 68 participants with ongoing AF, of whom 60 had self-reported AF and 8 had AF detected in the screening. Single-lead ECG assessed for AF by radiographers had a sensitivity of 60.3% (95% CI 47.7 to 72.0), specificity of 97.2% (95% CI 96.2 to 98.1), positive predictive value (PPV) of 53.9% (95% CI 42.1 to 65.5) and negative predictive value (NPV) of 97.9% (95% CI 96.9 to 98.6). 12-lead ECG assessed by cardiac nurses had a sensitivity of 97.1% (95% CI 89.8 to 99.6), specificity of 100% (95% CI 99.7 to 100), PPV of 100% (95% CI 94.6 to 100) and NPV of 99.8% (95% CI 99.4 to 100).

Conclusions

Single-lead ECG assessed by radiographers had a moderate sensitivity and PPV but a very high specificity and NPV. Using radiographers may be acceptable for opportunistic screening, in particular if radiographers are thoroughly trained. Thus, 12-lead ECG assessed by cardiac nurses is a potential diagnostic method for the detection of AF.

Impact of cost on use of non-vitamin K antagonists in atrial fibrillation patients in Ontario, Canada

Canadian guidelines recommend non vitamin K antagonists (NOACs) in preference to vitamin K antagonists (VKAs) for stroke prevention in patients with atrial fibrillation (AF), but NOACs are more expensive than VKAs. Canada has a universal healthcare system that covers the cost of NOACs for select patient groups. Ability to pay for NOACs may influence their use. We reviewed medical charts of Hamilton General Hospital outpatients under the age of 65 with a new diagnosis of AF who were referred for initiation of OAC therapy. We contacted these patients by phone and asked them to complete a questionnaire regarding their OAC choice, economic factors that may have influenced this choice (income, insurance) and the financial burden of OAC therapy. We included 110 patients, mean age 56 years, and 26.4% females. NOAC users had a higher median neighborhood income than VKA users (p = 0.0144, n = 110). 73 patients responded to the questionnaire. NOAC users reported higher annual household income (p = 0.0038, n = 73). Patients with private insurance were more likely to use NOACs than those without insurance (p = 0.0496, n = 73). The cost of NOACs and ability to pay is a determinant of their use Ontario patients under the age of 65. This two tiered provision of care appears to contradict the values of Canada's universal healthcare system.

Atrial high rate episodes in patients with cardiac implantable electronic devices: implications for clinical outcomes

Background

Atrial high rate episodes (AHREs) detected by cardiac implantable electronic devices (CIEDs) are associated with an increased risk of stroke. However, the impact of AHRE on improving stroke risk stratification scheme remains uncertain.

Objective

The purpose of this study was to assess the impact of AHRE on prognosis in relation with cardiovascular events and risk stratification.

Methods

A total of 856 consecutive patients who had dual-chamber CIEDs implanted were retrospectively analyzed. To detect AHREs, they were monitored for 6 months after CIEDs’ implantation and were followed for a mean of 4.0 years for clinical outcomes such as thromboembolism or death.

Results

Overall, 125 (14.6%) of patients developed AHREs within the first 6 months (median age 72.0 years, 39.3% female). Patients with AHREs had a high rate of thromboembolism (2.6%/year) and mortality (3.0%/year). On multivariate analysis, AHRE was significantly associated with increased risk of thromboembolism [hazard ratio (HR) 3.40; 95% confidence interval (CI) 1.38–8.37, P = 0.01] and death (HR 3.47; 95% CI 1.51–7.95; P < 0.01). The predictive abilities of the CHADS₂ and CHA₂DS₂-VASc scores were modest, with no significant improvements by adding AHRE to those scores. However, the integrated discrimination improvement and net reclassification improvement showed that the addition of AHRE to the CHADS₂ and CHA₂DS₂-VASc scores statistically improved their predictive ability for the composite outcome.

Conclusions

AHRE was an independent factor associated with increased risk of clinical outcomes. The addition of AHRE to the clinical risk scores significantly improved discrimination for thromboembolism or death.

Electronic supplementary material

The online version of this article (10.1007/s00392-019-01432-y) contains supplementary material, which is available to authorized users.

Facing real-life with direct oral anticoagulants in patients with nonvalvular atrial fibrillation: outcomes from the first observational and prospective study in a Spanish population

Aim: To analyze the effectiveness and safety of direct oral anticoagulants (DOACs) in atrial fibrillation (AF) patients attended in clinical practice. Methods: Observational and prospective study of AF patients that started treatment with DOACs. Results: 1443 patients (age 77.2 ± 9.7 years, CHA2DS2-VASc = 4.1 ± 1.5) were included. 46.0% were taking rivaroxaban, 24.4% dabigatran, 22.5% apixaban and 7.1% edoxaban. Patients taking dabigatran were younger, had lower CHA2DS2-VASc and lesser renal insufficiency. Patients taking apixaban had higher CHA2DS2-VASc and more renal insufficiency. Rates of stroke/major bleeding/intracranial bleeding were 0.7/1.3/0.2 events/100 patient-years, respectively. Conclusion: This was the first prospective study that analyzed the use of all DOACs in AF patients in Spain, showing a good profile in terms of safety and effectiveness in accordance with pivotal studies.

Health Care Costs and Utilization of Dabigatran Compared With Warfarin for Secondary Stroke Prevention in Patients With Nonvalvular Atrial Fibrillation: A Retrospective Population Study

BACKGROUND

It remains unclear whether the use of new oral anticoagulants, compared with warfarin, is economically beneficial in Asian countries.

OBJECTIVE

The objective of this study is to compare the health care costs and utilization between dabigatran and warfarin in a real-world nonvalvular atrial fibrillation (NVAF) population.

RESEARCH DESIGN

Data were obtained from the Taiwan National Health Insurance Database, and patients with an NVAF diagnosis between June 1, 2012, and May 31, 2014, were identified using the International Classification of Diseases, Ninth Revision code of 427.31. The patients in the dabigatran cohort were matched 1:2 to those in the warfarin cohort by sex, age, residential region, and a propensity score that incorporated a major bleeding history, CHADS2 score, and Charlson Comorbidity Index. The all-cause health care utilization and associated costs of the 2 treatment groups were compared at 3 and 12 months.

RESULTS

A total of 1149 patients taking dabigatran were identified and matched with 2298 warfarin users. During the 3-month observation period, the likelihood of having at least 1 hospitalization among dabigatran users was significantly lower than that of warfarin users (odds ratio=0.78; P=0.001). Patients in the dabigatran group incurred lower mean emergency department costs ($2383.1 vs. $3033.6), mean ischemic stroke-related hospitalization costs ($8869.5 vs. $13,990.5), and mean all-cause hospitalization costs ($32,402.2 vs. $50,669.9) at 3 months. However, both the mean and median outpatient costs of warfarin users were consistently lower than those of dabigatran users ($17,161.2 vs. $24,931.4 and $10,509.0 vs. $20,671.5, respectively). Similar trends were observed at 12 months, except that the 2 groups had comparable total health care costs.

CONCLUSIONS

The use of dabigatran is associated with lower emergency department and all-cause hospitalization costs but greater outpatient costs in a real-world, NVAF patient population compared with warfarin.

Electronic physician notifications to improve guideline-based anticoagulation in atrial fibrillation: a randomized controlled trial

BACKGROUND

Oral anticoagulants reduce the risk of stroke in patients with atrial fibrillation. However, many patients with atrial fibrillation at elevated stroke risk are not treated with oral anticoagulants.

OBJECTIVE

To test whether electronic notifications sent to primary care physicians increase the proportion of ambulatory patients prescribed oral anticoagulants.

DESIGN

Randomized controlled trial conducted from February to May 2017 within 18 practices in an academic primary care network.

PARTICIPANTS

Primary care physicians (n = 175) and their patients with atrial fibrillation, at elevated stroke risk, and not prescribed oral anticoagulants.

INTERVENTION

Patients of each physician were randomized to the notification or usual care arm. Physicians received baseline email notifications and up to three reminders with patient information, educational material and primary care guidelines for anticoagulation management, and surveys in the notification arm.

MAIN MEASURES

The primary outcome was the proportion of patients prescribed oral anticoagulants at 3 months in the notification (n = 972) vs. usual care (n = 1364) arms, compared using logistic regression with clustering by physician. Secondary measures included survey-based physician assessment of reasons why patients were not prescribed oral anticoagulants and how primary care physicians might be influenced by the notification.

KEY RESULTS

Over 3 months, a small proportion of patients were newly prescribed oral anticoagulants with no significant difference in the notification (3.9%, 95% CI 2.8-5.3%) and usual care (3.2%, 95% CI 2.4-4.2%) arms (p = 0.37). The most common, non-exclusive reasons why patients were not on oral anticoagulants included atrial fibrillation was transient (30%) or paroxysmal (12%), patient/family declined (22%), high bleeding risk (20%), fall risk (19%), and frailty (10%). For 95% of patients, physicians stated they would not change their management after reviewing the alert.

CONCLUSIONS

Electronic physician notification did not increase anticoagulation in patients with atrial fibrillation at elevated stroke risk. Primary care physicians did not prescribe anticoagulants because they perceived the bleeding risk was too high or stroke risk was too low.

TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT02950285.

Electronic Decision support for Improvement of Contemporary Therapy for Stroke Prevention

BACKGROUND

Despite ample clinical trial data demonstrating that oral anticoagulation (OAC) treatment is highly effective in reducing stroke for patients with atrial fibrillation (AF), OAC treatment remains underutilized in current clinical practice. Targeting hospitalist and emergency department providers with electronic decision support represents a potential quality improvement opportunity in the use of OAC medication in AF patients.

METHODS

We conducted a 3-center study in which 2 sites utilized an electronic alert (EA) embedded in the electronic health record and 1 site provided usual care. The EA calculated the CHA₂DS₂-VASc score for clinicians. Patients were tracked following discharge from either the emergency department or hospital. We hypothesized that the EA would increase the rate of OAC use by 15% compared to usual care, with a study sample size of 360 patients. Study exclusions included severe heart valve disease, advanced renal disease, and severe dementia. The primary endpoint was OAC use at the time of hospital discharge or 30 days after hospital discharge (whichever was the last observation recorded).

RESULTS

Among 309 patients included for analysis (mean age 70.2 years), the median CHA₂DS₂-VASc score was 3.5. The frequency of OAC use at follow-up at the usual care hospital was 55.9% (95% confidence interval 47.4-67.9). At the 2 EA sites, the rate of OAC use at the last observation point was 43.9% (P = .06). Aspirin use at follow-up was similar at the usual care site and the EA sites (53.8% versus 46.3%). The rate of OAC use in patients greater than 75 years was 60.0% in the usual care site and 48.4% (P = .09) at the EA sites.

CONCLUSIONS

The EA in our study was not sufficient to ameliorate therapeutic inertia in the use of OAC for stroke prevention in AF.

Impact of pre-admission oral anticoagulation on ischaemic stroke volume, lesion pattern, and frequency of intracranial arterial occlusion in patients with atrial fibrillation

Aims

Therapeutic oral anticoagulation on hospital admission reduces morbidity and mortality after acute ischaemic stroke in patients with atrial fibrillation (AF). The underlying mechanism is not fully understood. In order to assess the impact of INR-level on admission on stroke volume, lesion pattern and the frequency of intracranial arterial occlusion, we analysed serial MRI measurements in AF patients suffering acute ischaemic stroke.

Methods and results

This subgroup analysis of the prospective '1000Plus' study included patients with acute ischaemic stroke and known AF or a first episode of AF in hospital. All patients underwent serial brain magnetic resonance imaging. Stroke patients were categorized as follows: Group1, phenprocoumon intake, international normalized ratio (INR) ≥1.7 on admission, no thrombolysis; Group2, INR < 1.7 on admission, thrombolysis; and Group3, INR < 1.7, no thrombolysis. In 98 AF patients {77 ± 9 years, 60% male; median National Institute of Health Stroke Scale [NIHSS] score on admission 5 (interquartile range [IQR] 2-8)} with known AF before admission, territorial infarction was less often found in Group 1 (n = 20) compared with Group 2 + 3 (20% vs. 47%, P = 0.022). Arterial occlusion rate on admission differed among groups (30%, 75%, and 35%, respectively, P = 0.004) but not between Group 1 vs. Group 2 + 3 (30% vs. 45%, P = 0.31). Median FLAIR volume on Days 5-7 was lower in Group1 compared with Group 2 (n = 20) [3.2 cm3 (IQR 1.1-11.3) vs. 18.6 cm3 (IQR 8.2-49.4); P = 0.009] but not compared with Group 2 + 3 [7.8 cm3 (IQR 1.6-25.9); P = 0.23]. An INR ≥ 1.7 on admission was not associated with smaller stroke volume in multivariable regression analysis. Adding 57 patients with a first AF episode during the in-hospital stay, similar results were observed in 155 AF patients.

Conclusion

In this AF cohort, an INR ≥ 1.7 at stroke onset affects lesion pattern but does not affect significantly lower stroke volume and the frequency of arterial occlusion on admission.

[Left atrial appendage occlusion in elderly]

Left atrial appendage occlusion (LAAO) is an alternative option to oral anticoagulation therapy in patients with non-valvular atrial fibrillation. According to French regulations, this procedure is currently reserved for patients with formal contraindications to VKA and direct thrombin inhibitors. LAAO procedures reduce ischemic and stroke risks compared to no treatment and also reduce bleeding events compared to VKA therapy in eligible patients. The peri-procedural complications risk has been reported to be limited in the different series published so far. Although elderly patients (>75 years) have either higher ischemic and bleeding risk than younger subjects, they hardly benefit from optimal anticoagulation. Thus, these subjects might greatly benefit from LAAO. Published studies reported excellent feasibility and efficiency of LAAO procedure in elderly patients. Yet there is a trend towards a higher incidence of peri-procedural complications (including tamponade), long-term safety is excellent and comparable to what is observed in patients<75 years. Therefore, interventional percutaneous LAAO is an attractive strategy in elderly patients with atrial fibrillation that should be incorporated in a multidisciplinary management.

Advances in Stroke Prevention

There have been recent advances in stroke prevention in nutrition, blood pressure control, antiplatelet therapy, anticoagulation, identification of high-risk asymptomatic carotid stenosis, and percutaneous closure of patent foramen ovale. There is evidence that the Mediterranean diet significantly reduces the risk of stroke and that B vitamins lower homocysteine, thus preventing stroke. The benefit of B vitamins to lower homocysteine was masked by harm from cyanocobalamin among study participants with impaired renal function; we should be using methylcobalamin instead of cyanocobalamin. Blood pressure control can be markedly improved by individualized therapy based on phenotyping by plasma renin and aldosterone. Loss of function mutations of CYP2D19 impair activation of clopidogrel and limits its efficacy; ticagrelor can avoid this problem. New oral anticoagulants that are not significantly more likely than aspirin to cause severe bleeding, and prolonged monitoring for atrial fibrillation (AF), have revolutionized the prevention of cardioembolic stroke. Most patients (~90%) with asymptomatic carotid stenosis are better treated with intensive medical therapy; the few that could benefit from stenting or endarterectomy can be identified by a number of approaches, the best validated of which is transcranial Doppler (TCD) embolus detection. Percutaneous closure of patent foramen ovale has been shown to be efficacious but should only be implemented in selected patients; they can be identified by clinical clues to paradoxical embolism and by TCD estimation of shunt grade. “Treating arteries instead of treating risk factors,” and recent findings related to the intestinal microbiome and atherosclerosis point the way to promising advances in future.

Management of Thrombosis Risk in a Carrier of Hemophilia A with Low Factor VIII Levels with Atrial Fibrillation: A Clinical Case and Literature Review

Nonvalvular atrial fibrillation (AF) is a common age-related arrthymia and a leading cause of stroke in the elderly; with an aging hemophilia population, the number of patients developing AF is increasing. There are no controlled trials on thromboprophylaxis in this group of patients, only consensus opinion was based on small case reports. We present a female patient, carrier for hemophilia and with clinically moderately severe hemophilia who developed FA. We discuss the literature with respect to this group of patients and current recommendations for thromboprophylaxis.

SUPPORT-AF: Piloting a Multi-Faceted, Electronic Medical Record-Based Intervention to Improve Prescription of Anticoagulation

Background Only 50% of eligible atrial fibrillation ( AF ) patients receive anticoagulation ( AC ). Feasibility and effectiveness of electronic medical record (EMR)-based interventions to profile and raise provider AC percentage is poorly understood. The SUPPORT-AF (Supporting Use of AC Through Provider Profiling of Oral AC Therapy for AF) study aims to improve rates of adherence to AC guidelines by developing and delivering supportive tools based on the EMR to providers treating patients with AF. Methods and Results We emailed cardiologists and community-based primary care providers affiliated with our institution reports of their AC percentage relative to peers. We also sent an electronic medical record-based message to these providers the day before an appointment with an atrial fibrillation patient who was eligible but not receiving AC . The electronic medical record message asked the provider to discuss AC with the patient if he or she deemed it appropriate. To assess feasibility, we tracked provider review of our correspondence. We also tracked the change in AC for intervention providers relative to alternate primary care providers not receiving our intervention. We identified 3786, 1054, and 566 patients cared for by 49 cardiology providers, 90 community-based primary care providers, and 88 control providers, respectively. At baseline, the percentage of AC was 71.3%, 63.5%, and 58.3% for these 3 respective groups. Intervention providers reviewed our e-mails and electronic medical record messages 45% and 96% of the time, respectively. For providers responding, patient refusal was the most common reason for patients not being on AC (21%) followed by high bleeding risk (19%). At follow-up 10 weeks later, change in AC was no different for either cardiology or community-based primary care providers relative to controls (0.2% lower and 0.01% higher, respectively). Conclusions Our intervention profiling AC was feasible, but not sufficient to increase AC in our population.

2-phenyl-1-(3-pyrrolidin-1-il-propyl)-1 H-indole hydrochloride (SS-68): Antiarrhythmic and cardioprotective activity and its molecular mechanisms of action (Part I)

Introduction. The problem of heart rhythm disturbances is one of the most urgent topics of modern cardiology. According to the currently available concepts, 1,2- and 1,3-disubstituted aminoindole derivatives, which compound 2-phenyl-1-(3-pyrrolidin-1-il-propyl)-1H-indole hydrochloride (SS-68) belongs to, are a promising chemical group in terms of their cardio-pharmacological activity.

Materials and methods. To study the anti-arrhythmic activity of SS-68 compound, the following models were used: 1) Models of cardiogenic arrhythmia: aconitine-inducedic, calcium chloride-induced, barium chloride-induced, cesium chloride-induced, adrenaline model of arrhythmia, strophanthine-induced arrhythmias, as well as arrhythmias caused by electrostimulation and acute myocardial ischemia; 2) neurogenic arrhythmias: arrhythmias caused by administration of aconitine, strophanthine K, cesium chloride into the IV ventricle of the brain and also by applying carbachol on the somatosensory cortex. To assess the antianginal activity of SS-68 in various models, the effect of this drug and comparators on the intact and ischemic myocardium was studied.

Results. It was found that with cardiogenic arrhythmias, SS-68 compound exhibits a pronounced antiarrhythmic effect and brings to normal the electrophysiological pattern of the heart, in most cases exceeding the analogous effect of reference drugs (amiodarone, lidocaine, aymaline, ethacizine, etmozine, quinidine anaprilin). In neurogenic arrhythmias, SS-68 also had a stopping effect, and, in addition, reduced the epileptiform activity of the brain in the model with the application of carbachol on the somatosensory cortex. In the study of antianginal and coronary vasolidating activities, SS-68 demonstrated pronounced thrombolytic and anti-ischemic activities, manifested in an increase in the coronary blood flow, a positive effect on ST-segment depression, and a decrease in the area of necrosis in experimental myocardial infarction.

Discussion. The antiarrhythmic and antianginal activities of SS-68 compound create the prerequisites for further study of the pharmacological properties of this molecule. In addition, it seems appropriate to continue studying the pharmacodynamics, pharmacokinetics and molecular mechanisms of SS-68 action.

Conclusions. SS-68 compound is a promising pharmacological agent with a high activity towards various electrophysiological disorders in the heart, and, in addition, it has significant antiischemic and coronary vasolidating properties.

Optimizing primary care management of atrial fibrillation: The rationale and methods of the Integrated Management Program Advancing Community Treatment of Atrial Fibrillation (IMPACT-AF) study

The Integrated Management Program Advancing Community Treatment of Atrial Fibrillation (IMPACT-AF) is an investigator designed, prospective, randomized, un-blinded, cluster design clinical trial, conducted in the primary care setting of Nova Scotia, Canada. Its aim is to evaluate whether an electronic Clinical Decision Support System (CDSS) designed to assist both practitioners and patients with evidence-based management strategies for Atrial Fibrillation (AF) can improve process of care and outcomes in a cost-efficient manner as compared to usual AF care. At least 200 primary care providers are being recruited and randomized at the level of the practice to control (usual care) or intervention (eligible to access to CDSS) cohorts. Over 1,000 patients of participating providers with confirmed AF will be managed per their provider's respective assignment. The targeted primary clinical outcome is a reduction in the composite of unplanned cardiovascular (CV) or major bleeding hospitalizations and AF-related emergency department visits. Secondary clinical outcomes, process of care, patient and provider satisfaction as well as economic costs at the system and patient levels are being examined. The trial is anticipated to report in 2018.

Cardioembolic stroke: everything has changed

Historically, because of the difficulty of using warfarin safely and effectively, many patients with cardioembolic stroke who should have been anticoagulated were instead given ineffective antiplatelet therapy (or no antithrombotic therapy). With the arrival of new oral anticoagulants that are not significantly more likely than aspirin to cause severe haemorrhage, everything has changed. Because antiplatelet agents are much less effective in preventing cardioembolic stroke, it is now more prudent to anticoagulate patients in whom cardioembolic stroke is strongly suspected. Recent advances include the recognition that intermittent atrial fibrillation is better detected with more prolonged monitoring of the cardiac rhythm, and that percutaneous closure of patent foramen ovale (PFO) may reduce the risk of stroke. However, because in most patients with stroke and PFO the PFO is incidental, this should be reserved for patients in whom paradoxical embolism is likely. A high shunt grade on transcranial Doppler saline studies, and clinical clues to paradoxical embolism, can help in appropriate selection of patients for percutaneous closure. For patients with atrial fibrillation who cannot be anticoagulated, ablation of the left atrial appendage is an emerging option. It is also increasingly recognised that high levels of homocysteine, often due to undiagnosed metabolic deficiency of vitamin B12, markedly increase the risk of stroke in atrial fibrillation, and that B vitamins (folic acid and B12) do prevent stroke by lowering homocysteine. However, with regard to B12, methylcobalamin should probably be used instead of cyanocobalamin. Many important considerations for judicious application of therapies to prevent cardioembolic stroke are discussed.

A novel risk prediction score in atrial fibrillation for a net clinical outcome from the ENGAGE AF-TIMI 48 randomized clinical trial

Aims

The choice between initiating a non-vitamin K antagonist oral anticoagulant (NOAC) and a vitamin K antagonist (VKA) in patients with atrial fibrillation (AF) may be challenging. To assist in this decision, we developed a risk score to identify patients for whom a therapeutic benefit of NOACs over VKA is predicted.

Methods and results

ENGAGE AF-TIMI 48 was a randomized clinical trial of edoxaban vs. warfarin in 21 105 patients with AF. Cox proportional hazard models identified factors associated with a serious net clinical outcome (NCO) of disabling stroke, life-threatening bleeding, and all-cause mortality in VKA naïve patients from the warfarin arm. These were used to develop an integer risk score. Performance was assessed by C-indices and validation by bootstrapping. Kaplan-Meier analyses were stratified by three score categories and treatment arm. Over a median of 2.7 years, 457 NCO events occurred in 2898 patients with a total person-time of 7549.5 years (6.05%/year). The risk prediction model (C = 0.693) for the NCO was translated into a 17-point integer score, with annualized event rates for the low, intermediate, and high-risk categories in the warfarin arm of 3.5%, 9.9%, and 20.8%, respectively. Therapeutic benefit of higher- and lower-dose edoxaban over warfarin was demonstrated in the high- and intermediate-risk, with equal benefit in the low-risk categories (P-interaction 0.008 and 0.014, respectively).

Conclusion

In VKA naive patients with AF, the TIMI-AF score can assist in the prediction of a poor composite outcome and guide selection of anticoagulant therapy by identifying a differential clinical benefit with a NOAC or VKA.

Prestroke and Poststroke Antithrombotic Therapy in Patients With Atrial Fibrillation: Results From a Nationwide Cohort

IMPORTANCE

Antithrombotic therapies are effective in both primary and secondary stroke prophylaxis in high-risk patients with atrial fibrillation (AF), but they are often underused in community practice.

OBJECTIVE

To examine prestroke and poststroke antithrombotic treatment patterns and long-term outcomes in patients with AF presenting with ischemic stroke.

DESIGN, SETTING, AND PARTICIPANTS

A retrospective cohort study of Danish patients with AF, with a prestroke CHA2DS2-VASc score of 1 or higher for men and 2 or higher for women, and presenting with ischemic stroke was conducted from January 1, 2004, to January 31, 2017. Data on hospital admission, prescription fillings, and vital status were assessed using several Danish nationwide registries.

EXPOSURES

Patients who survived 100 days after discharge were divided into 3 groups according to poststroke antithrombotic therapy: oral anticoagulation (OAC) therapy, antiplatelet therapy alone, or no antithrombotic therapy.

MAIN OUTCOMES AND MEASURES

Long-term outcomes (thromboembolic events and bleeding complications) were examined using multivariable Cox regression analyses across the 3 groups.

RESULTS

Among 30 626 patients with AF admitted with ischemic stroke, 11 139 patients (36.3%) received OAC therapy (44.3% female; median age, 79 years [interquartile range, 73-85 years]), 11 874 (38.8%) received antiplatelet therapy alone (55.0% female; median age, 82 years [interquartile range, 75-88 years]), and 7613 (24.9%) received no antithrombotic therapy before stroke (53.8% female; median age, 80 years [interquartile range, 71-86 years]). Following stroke, 31.3% of those receiving antiplatelet therapy alone and 43.7% of those receiving no antithrombotic therapy before stroke shifted to OAC therapy. Yet, 37.5% of patients with stroke did not receive OAC therapy following stroke. However, OAC treatment rates increased over time. During a maximum of 10 years of follow-up, 17.5%, 21.2%, and 21.5% experienced a new thromboembolic event and 72.7%, 86.4%, and 86.2% died among those treated with OAC therapy, antiplatelet therapy, or no antithrombotic therapy, respectively. Poststroke OAC therapy was associated with lower risk of recurrent thromboembolic events (adjusted hazard ratio, 0.81; 95% CI, 0.73-0.89) and no significant difference in bleeding complications (adjusted hazard ratio, 0.97; 95% CI, 0.86-1.10), compared with no poststroke antithrombotic therapy. In contrast, there were no significant differences for those treated with poststroke antiplatelet therapy and no antithrombotic therapy.

CONCLUSIONS AND RELEVANCE

Patients with AF receiving poststroke OAC therapy had lower risk of recurrent thromboembolic events. Our findings suggest a substantial opportunity for improving primary and secondary stroke prophylaxis in high-risk patients with AF.

Optimal Thromboprophylaxis in Elderly Chinese Patients with Atrial Fibrillation (ChiOTEAF) registry: protocol for a prospective, observational nationwide cohort study

INTRODUCTION

Atrial fibrillation (AF) is a worldwide healthcare burden that is associated with the ageing population. Elderly patients with AF with multiple comorbidities usually present with a high risk of thromboembolism and bleeding. Limited prospective data are available from Asian cohorts on the epidemiology and complications of AF. The present prospective cohort study aims to explore contemporary antithrombotic strategies among the elderly Chinese population in the new era of non-vitamin K antagonist oral anticoagulants and to compare the clinical characteristics and outcomes between Chinese and European AF populations.

METHODS AND ANALYSIS

The Optimal Thromboprophylaxis in Elderly Chinese Patients with Atrial Fibrillation (ChiOTEAF) registry will recruit 5000 patients with AF over 65 years of age in China. AF-related risks, including stroke/systemic thromboembolism and bleeding outcomes, will be assessed. Medical history, risk factors, demographic information and management will be collected at baseline, and clinical events during 1 year follow-up will be recorded. Follow-up will be conducted for at least 1 year and then annually thereafter. As our registry has a common protocol to the European Society of Cardiology EURObservational Research Programme AF general registry programme, preplanned analyses comparing the clinical profiles and outcomes will be performed. The ChiOTEAF registry offers an opportunity to provide a better understanding of the clinical profiles and adverse outcomes of patients with AF in China and allow for comparisons with a contemporary European population.

ETHICS AND DISSEMINATION

Ethics approval was granted by the Central Medical Ethic Committee of Chinese PLA General Hospital (approval no S2014-065-01). The (inter)national research presentations, peer-reviewed publications and media coverage of the research will be sued for dissemination of the results.

Left Atrial Appendage Occlusion: What Are the Options and Where is the Evidence?

Left atrial appendage occlusion (LAAO) has emerged as an effective site-directed therapy in patients with nonvalvular atrial fibrillation (AF) for stroke prevention, who are ineligible for long-term oral anticoagulation. The objective of this study was to assess the safety, efficacy, and availability of LAAO devices by reviewing the literature and to review the development and effectiveness of LAAO by the transcatheter approach with plugging devices such as WATCHMAN™ (Boston Scientific, Natick, MA, USA); AMPLATZER™ Cardiac Plug and AMPLATZER™ Amulet™ (Abbott Laboratories, Chicago, IL, USA); and the LARIAT® Suture Delivery Device (SentreHEART, Redwood City, CA, USA), which features an entirely unique hybrid (endocardial and epicardial) approach in closing the left atrial appendage (LAA). The conducted literature review ultimately revealed a substantial body of literature supporting the safety and efficacy of various LAAO strategies, including endocardial, epicardial, and hybrid approaches, in AF patients who are not eligible for long-term oral anticoagulant use. Specifically, the most attractive population suitable for LAA closure appears to be patients at high risk for ischemic stroke with a longer life expectancy but a moderate-to-high bleeding risk with long-term oral anticoagulation. The benefit of LAA closure in reducing the incidence of stroke in patients with nonvalvular AF has been evolving gradually, and we are confident that this new field of percutaneous LAA closure will continue to emerge as a game-changer in the treatment of AF.

Physician decision making in anticoagulating atrial fibrillation: a prospective survey of a physician notification system for atrial fibrillation detected on cardiac implantable electronic devices of patients at increased risk of stroke

OBJECTIVES

The objectives of this study were to evaluate the effectiveness of a physician notification system for atrial fibrillation (AF) detected on cardiac devices, and to assess predictors of anticoagulation in patients with device-detected AF.

METHODS

In 2013, a physician notification system for AF detected on a patient's CIED [including pacemakers, implantable cardioverter defibrillators (ICD) or cardiac resynchronization therapy (CRT) devices] was implemented, with a recommendation to consider oral anticoagulation in high-risk patients. We prospectively investigated the effectiveness of this system, and evaluated both patient and physician predictors of anticoagulation, as well as factors influencing physician decision making in prescribing anticoagulation. Both uni- and multivariable analysis as well as descriptive statistics were used in the analysis.

RESULTS

We identified 177 patients with device-detected AF, 126 with a CHADS2 ⩾2. Only 41% were prescribed anticoagulation at any point within 12 months. On multivariable analysis, stroke risk as predicted by CHADS2 was not a predictor of anticoagulation. ASA use predicted a lower rate of anticoagulation (OR 0.39, 95% CI 0.16-0.97, p = 0.04); physicians in practice for <20 years were more likely to prescribe anticoagulation (OR 3.39, 95% CI 1.28-8.93, p = 0.01); and physicians who believed both cardiologist and family doctor should be involved in managing anticoagulation were more likely to prescribe anticoagulation (OR 3.28, 95% CI 1.02-10.5, p = 0.05).

CONCLUSIONS

Patients on aspirin were less likely to be anticoagulated. Physicians in practice for <20 years and who believed that both the general practitioner and cardiologist should be involved in managing anticoagulants were more likely to prescribe anticoagulation.

A clinical decision support tool for improving adherence to guidelines on anticoagulant therapy in patients with atrial fibrillation at risk of stroke: A cluster-randomized trial in a Swedish primary care setting (the CDS-AF study)

BACKGROUND

Atrial fibrillation (AF) is associated with substantial morbidity, in particular stroke. Despite good evidence for the reduction of stroke risk with anticoagulant therapy, there remains significant undertreatment. The main aim of the current study was to investigate whether a clinical decision support tool (CDS) for stroke prevention integrated in the electronic health record could improve adherence to guidelines for stroke prevention in patients with AF.

METHODS AND FINDINGS

We conducted a cluster-randomized trial where all 43 primary care clinics in the county of Östergötland, Sweden (population 444,347), were randomized to be part of the CDS intervention or to serve as controls. The CDS produced an alert for physicians responsible for patients with AF and at increased risk for thromboembolism (according to the CHA2DS2-VASc algorithm) without anticoagulant therapy. The primary endpoint was adherence to guidelines after 1 year. After randomization, there were 22 and 21 primary care clinics in the CDS and control groups, respectively. There were no significant differences in baseline adherence to guidelines regarding anticoagulant therapy between the 2 groups (CDS group 70.3% [5,186/7,370; 95% CI 62.9%-77.7%], control group 70.0% [4,187/6,009; 95% CI 60.4%-79.6%], p = 0.83). After 12 months, analysis with linear regression with adjustment for primary care clinic size and adherence to guidelines at baseline revealed a significant increase in guideline adherence in the CDS (73.0%, 95% CI 64.6%-81.4%) versus the control group (71.2%, 95% CI 60.8%-81.6%, p = 0.013, with a treatment effect estimate of 0.016 [95% CI 0.003-0.028]; number of patients with AF included in the final analysis 8,292 and 6,508 in the CDS and control group, respectively). Over the study period, there was no difference in the incidence of stroke, transient ischemic attack, or systemic thromboembolism in the CDS group versus the control group (49 [95% CI 43-55] per 1,000 patients with AF in the CDS group compared to 47 [95% CI 39-55] per 1,000 patients with AF in the control group, p = 0.64). Regarding safety, the CDS group had a lower incidence of significant bleeding, with events in 12 (95% CI 9-15) per 1,000 patients with AF compared to 16 (95% CI 12-20) per 1,000 patients with AF in the control group (p = 0.04). Limitations of the study design include that the analysis was carried out in a catchment area with a high baseline adherence rate, and issues regarding reproducibility to other regions.

CONCLUSIONS

The present study demonstrates that a CDS can increase guideline adherence for anticoagulant therapy in patients with AF. Even though the observed difference was small, this is the first randomized study to our knowledge indicating beneficial effects with a CDS in patients with AF.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02635685.

Physician decision making in anticoagulating atrial fibrillation: a prospective survey of a physician notification system for atrial fibrillation detected on cardiac implantable electronic devices of patients at increased risk of stroke

OBJECTIVES

The objectives of this study were to evaluate the effectiveness of a physician notification system for atrial fibrillation (AF) detected on cardiac devices, and to assess predictors of anticoagulation in patients with device-detected AF.

METHODS

In 2013, a physician notification system for AF detected on a patient's CIED [including pacemakers, implantable cardioverter defibrillators (ICD) or cardiac resynchronization therapy (CRT) devices] was implemented, with a recommendation to consider oral anticoagulation in high-risk patients. We prospectively investigated the effectiveness of this system, and evaluated both patient and physician predictors of anticoagulation, as well as factors influencing physician decision making in prescribing anticoagulation. Both uni- and multivariable analysis as well as descriptive statistics were used in the analysis.

RESULTS

We identified 177 patients with device-detected AF, 126 with a CHADS2 ⩾2. Only 41% were prescribed anticoagulation at any point within 12 months. On multivariable analysis, stroke risk as predicted by CHADS2 was not a predictor of anticoagulation. ASA use predicted a lower rate of anticoagulation (OR 0.39, 95% CI 0.16-0.97, p = 0.04); physicians in practice for <20 years were more likely to prescribe anticoagulation (OR 3.39, 95% CI 1.28-8.93, p = 0.01); and physicians who believed both cardiologist and family doctor should be involved in managing anticoagulation were more likely to prescribe anticoagulation (OR 3.28, 95% CI 1.02-10.5, p = 0.05).

CONCLUSIONS

Patients on aspirin were less likely to be anticoagulated. Physicians in practice for <20 years and who believed that both the general practitioner and cardiologist should be involved in managing anticoagulants were more likely to prescribe anticoagulation.

Stroke Prevention in Atrial Fibrillation: Focus on Asian Patients

Atrial fibrillation (AF) is the most common arrhythmia conferring a fivefold increased risk of stroke. Stroke prevention is the cornerstone of management of patients with AF. Asians have a generally higher incidence of AF-related risks of stroke and bleeding (particularly intracranial bleeding), compared with non-Asians. Despite the well-documented efficacy and relative safety of oral anticoagulation for stroke prevention among Asians, the suboptimal use of oral anticoagulation remains common. The current narrative review aims to provide a summary of the available evidence on stroke prevention among patients with AF focused on the Asia region, regarding stroke and bleeding risk evaluation, the performance of oral anticoagulation, and current use of thromboprophylaxis.

Vitamin K antagonists

For the last decades, anticoagulation for stroke prevention in atrial fibrillation (AF) as well as for the prophylaxis and long-term treatment of venous thromboembolism has been entirely based on vitamin K antagonists (VKA). Although very effective under optimal conditions, long-term treatment with these drugs is flawed by the fact that the time in the therapeutic range frequently is suboptimal due to biological factors, drug interactions and compliance.

The direct thrombin inhibitor dabigatran, as well as the direct FXa inhibitors rivaroxaban and apixaban provide more consistent anticoagulation and have proven their efficacy and safety against VKAs in several large scale randomized clinical trials for stroke prevention in atrial fibrillation as well as for the treatment and prevention of venous thromboembolism. In view of these convincing data and other advantages such as the lack of mandatory monitoring and only few drug interactions,VKAs will most likely be replaced in a majority of patients for these indications. Based on the most recent trial evidence, the current review discusses the role of VKA treatmentand that of the novel anticoagulants.

Spotlight on unmet needs in stroke prevention: The PIONEER AF-PCI, NAVIGATE ESUS and GALILEO trials

Atrial fibrillation (AF) is a major healthcare concern, being associated with an estimated five-fold risk of ischaemic stroke. In patients with AF, anticoagulants reduce stroke risk to a greater extent than acetylsalicylic acid (ASA) or dual antiplatelet therapy (DAPT) with ASA plus clopidogrel. Non-vitamin K antagonist oral anticoagulants (NOACs) are now a widely-accepted therapeutic option for stroke prevention in non-valvular AF (NVAF). There are particular patient types with NVAF for whom treatment challenges remain, owing to sparse clinical data, their high-risk nature or a need to harmonise anticoagulant and antiplatelet regimens if co-administered. This article focuses on three randomised controlled trials (RCTs) that are investigating the utility of rivaroxaban, a direct, oral, factor Xa inhibitor, in additional areas of stroke prevention where data for anticoagulants are lacking: oPenlabel, randomized, controlled, multicentre study explorIng twO treatmeNt stratEgiEs of Rivaroxaban and a dose-adjusted oral vitamin K antagonist treatment (PIONEER AF-PCI); New Approach riVaroxoban Inhibition of factor Xa in a Global trial vs Aspirin to prevenT Embolism in Embolic Stroke of Undetermined Source (NAVIGATE ESUS); and Global study comparing a rivAroxaban-based antithrombotic strategy to an antipLatelet-based strategy after transcatheter aortIc vaLve rEplacement to Optimize clinical outcomes (GALILEO). Data from these studies present collaborative efforts to build upon existing registrational Phase III data for rivaroxaban, driving the need for effective and safe treatment of a wider range of patients for stroke prevention.

Role of Antiplatelet Therapy in Stroke Prevention in Patients With Atrial Fibrillation

Patients with atrial fibrillation are at increased risk of having a cardioembolic stroke. The use of oral anticoagulation is now well established to prevent strokes in patients with atrial fibrillation and a CHA2DS2-VASc (congestive heart failure, hypertension, age ≥75 years [2 points], diabetes mellitus, prior stroke/transient ischemic attack or thromboembolism [2 points], vascular disease, age 65 to 74 years, and sex category) score of greater than 1, beyond sex. However, the role of antiplatelet therapy, specifically aspirin in low-risk patients or as an alternative to oral anticoagulation, remains controversial. The most recent US guidelines conflict with the European guidelines, which do not recommend antiplatelet monotherapy for stroke prevention irrespective of stroke risk. The aim of this review is to summarize published studies that question the role of aspirin in preventing strokes associated with atrial fibrillation. Overall, aspirin is found to play a limited role in the prevention of stroke in patients with atrial fibrillation and is associated with a similar risk of hemorrhagic events compared with anticoagulants. The benefit of dual antiplatelet therapy as an alternative to oral anticoagulation requires further study.

Dabigatran versus rivaroxaban for the prevention of stroke and systemic embolism in atrial fibrillation in Canada

Canadian patients with atrial fibrillation (AF) in whom anticoagulation is appropriate have two new choices for anticoagulation for prevention of stroke and systemic embolism – dabigatran etexilate (dabigatran) and rivaroxaban. Based on the RE-LY and ROCKET AF trial results, we investigated the cost-effectiveness of dabigatran (twice daily dosing of 150 mg or 110 mg based on patient age) versus rivaroxaban from a Canadian payer perspective. A formal indirect treatment comparison (ITC) of dabigatran versus rivaroxaban was performed, using dabigatran clinical event rates from RE-LY for the safety-on-treatment population, adjusted to the ROCKET AF population. A previously described Markov model was modified to simulate anticoagulation treatment using ITC results as inputs. Model outputs included total costs, event rates, and quality-adjusted life-years (QALYs). The ITC found when compared to rivaroxaban, dabigatran had a lower risk of intracranial haemorrhage (ICH) (relative risk [RR] = 0.38; 95% confidence interval [CI] 0.21 –0.67) and stroke (RR = 0.62; 95%CI 0.45–0.87). Over a lifetime horizon, the model found dabigatran-treated patients experienced fewer ICHs (0.33 dabigatran vs. 0.71 rivaroxaban) and ischaemic strokes (3.40 vs. 3.96) per 100 patient-years, and accrued more QALYs (6.17 vs. 6.01). Dabigatran-treated patients had lower acute care and long-term follow-up costs per patient ($52,314 vs. $53,638) which more than offset differences in drug costs ($7,299 vs. $6,128). In probabilistic analysis, dabigatran had high probability of being the most cost-effective therapy at common thresholds of willingness-to-pay (93% at a $20,000/QALY threshold). This study found dabigatran is economically dominant versus rivaroxaban for prevention of stroke and systemic embolism among Canadian AF patients.

Risks of stroke and mortality associated with suboptimal anticoagulation in atrial fibrillation patients

Atrial fibrillation (AF) carries an increased risk of ischaemic stroke, and oral anticoagulation with warfarin can reduce this risk. The objective of this study was to evaluate the association between time in therapeutic International Normalised Ratio (INR) range when receiving warfarin and the risk of stroke and mortality. The study cohort included AF patients aged 40 years and older included in the UK General Practice Research Database. For patients treated with warfarin we computed the percentage of follow-up time spent within therapeutic range. Cox regression was used to assess the association between INR and outcomes while controlling for patient demographics, health status and concomitant medication. The study population included 27,458 warfarintreated (with at least 3 INR measurements) and 10,449 patients not treated with antithrombotic therapy. Overall the warfarin users spent 63% of their time within therapeutic range (TTR). This percentage did not vary substantially by age, sex and CHA2DS2-VASc score. Patients who spent at least 70% of time within therapeutic range had a 79% reduced risk of stroke compared to patients with ≤30% of time in range (adjusted relative rate of 0.21; 95% confidence interval 0.18–0.25). Mortality rates were also significantly lower with at least 70% of time spent within therapeutic range. In conclusion, good anticoagulation control was associated with a reduction in the risk of stroke.

Temporal Trends in the Use and Comparative Effectiveness of Direct Oral Anticoagulant Agents Versus Warfarin for Nonvalvular Atrial Fibrillation: A Canadian Population-Based Study

BACKGROUND

Direct oral anticoagulants (DOACs) are noninferior to warfarin for stroke prevention in atrial fibrillation (AF). We aimed to determine the population risk of stroke and death in incident AF, stratified by anticoagulation status and type, and the temporal trends of oral anticoagulation practice in the post-DOAC approval period.

METHODS AND RESULTS

We conducted a population-based cohort study of incident nonvalvular AF cases using administrative health data in Alberta, Canada. We used Cox proportional hazards modeling with anticoagulation status as a time-varying exposure and adjusted for age (continuous), sex, congestive heart failure, hypertension, diabetes mellitus, prior transient ischemic attack or ischemic stroke, myocardial infarction, peripheral artery disease, and chronic kidney disease. Primary outcome was the composite of stroke and death. Among 34 965 patients with incident AF (56.0% male, median age 73 years), relative to warfarin, DOAC use was associated with decreased risk of all stroke and death (hazard ratio: 0.90; 95% confidence interval, 0.83-0.97) and decreased hemorrhagic stroke (hazard ratio: 0.60; 95% confidence interval, 0.40-0.91]) but a similar risk of ischemic stroke (hazard ratio: 1.12; 95% confidence interval, 0.94-1.34]). During this time period, DOAC use increased rapidly, surpassing warfarin, but the total oral anticoagulation use in the population remained stable, even in the subgroup with the highest thromboembolic risk.

CONCLUSIONS

In a real-world population-based study of patients with incident AF, anticoagulation with DOACs was associated with decreased risk of stroke and death compared with warfarin. Despite a rapid uptake of DOACs in clinical practice, the total proportion of AF patients on anticoagulation has remained stable, even in high-risk patients.

A multifaceted intervention to improve treatment with oral anticoagulants in atrial fibrillation (IMPACT-AF): an international, cluster-randomised trial

BACKGROUND

Oral anticoagulation is underused in patients with atrial fibrillation. We assessed the impact of a multifaceted educational intervention, versus usual care, on oral anticoagulant use in patients with atrial fibrillation.

METHODS

This study was a two-arm, prospective, international, cluster-randomised, controlled trial. Patients were included who had atrial fibrillation and an indication for oral anticoagulation. Clusters were randomised (1:1) to receive a quality improvement educational intervention (intervention group) or usual care (control group). Randomisation was carried out centrally, using the eClinicalOS electronic data capture system. The intervention involved education of providers and patients, with regular monitoring and feedback. The primary outcome was the change in the proportion of patients treated with oral anticoagulants from baseline assessment to evaluation at 1 year. The trial is registered at ClinicalTrials.gov, number NCT02082548.

FINDINGS

2281 patients from five countries (Argentina, n=343; Brazil, n=360; China, n=586; India, n=493; and Romania, n=499) were enrolled from 48 clusters between June 11, 2014, and Nov 13, 2016. Follow-up was at a median of 12·0 months (IQR 11·8-12·2). Oral anticoagulant use increased in the intervention group from 68% (804 of 1184 patients) at baseline to 80% (943 of 1184 patients) at 1 year (difference 12%), whereas in the control group it increased from 64% (703 of 1092 patients) at baseline to 67% (732 of 1092 patients) at 1 year (difference 3%). Absolute difference in the change between groups was 9·1% (95% CI 3·8-14·4); odds ratio of change in the use of oral anticoagulation between groups was 3·28 (95% CI 1·67-6·44; adjusted p value=0·0002). Kaplan-Meier estimates showed a reduction in the secondary outcome of stroke in the intervention versus control groups (HR 0·48, 95% CI 0·23-0·99; log-rank p value=0·0434).

INTERPRETATION

A multifaceted and multilevel educational intervention, aimed to improve use of oral anticoagulation in patients with atrial fibrillation and at risk for stroke, resulted in a significant increase in the proportion of patients treated with oral anticoagulants. Such an intervention has the potential to improve stroke prevention around the world for patients with atrial fibrillation.

FUNDING

Bayer, Boehringer Ingelheim, Bristol-Myers Squibb, Daiichi Sankyo, and Pfizer.

Analysis of Recurrent Stroke Volume and Prognosis between Warfarin and Four Non-Vitamin K Antagonist Oral Anticoagulants' Administration for Secondary Prevention of Stroke

OBJECTIVE

We investigated recurrent stroke volume with nonvalvular atrial fibrillation (NVAF) patients treated with non-vitamin K antagonist oral anticoagulants (NOACs) about clinical backgrounds and number of recurrent stroke.

METHODS

We administered 4 NOACs, dabigatran, rivaroxaban, apixaban, and edoxaban in 101 postcardioembolic strokes with NVAF. In a retrospective study, we measured recurrent stroke volume with magnetic resonance imaging volumetric software and compared them between 10 vitamin K anticoagulant (VKA: warfarin) cases and 13 NOAC cases under anticoagulant therapy.

RESULTS

Of 101 cases, 31 were started with a VKA and switched to NOACs after 10 recurrent strokes. Other 70 cases were directly started with NOACs and 13 cases with NOACs as first anticoagulants had recurrent stroke. The frequency of recurrent stroke during anticoagulant therapy is not different between the VKA group and the 3 NOACs group. Recurrent stroke volume is significantly larger in the VKA group (26.4 cm³) than in the NOACs group (1.2 cm³).

CONCLUSIONS

Secondary prevention with NOACs after stroke might be more beneficial than a VKA by reducing recurrent infarct volume.

Atrial Fibrillation as an Ischemic Stroke Clinical and Economic Burden Modifier: A 15-Year Nationwide Study

BACKGROUND

Atrial fibrillation (AF) is a major risk factor for ischemic stroke (IS). Patients with AF may undergo preventive therapy. Although the AF impact in the clinical burden of IS has been studied, information is lacking in Southern Europe and there are no studies about the impact in potential years of life lost. Moreover, no nationwide or long-term study analyzed the economic burden of IS stratified by AF.

OBJECTIVE

To study the impact of AF in the clinical and economic burden of IS.

METHODS

We conducted a retrospective study using nationwide administrative data for all public hospitalizations in mainland Portugal from 2000 to 2014. We considered IS hospitalizations stratified by the presence of AF as secondary diagnosis.

RESULTS

Of the total 275,173 IS hospitalizations, 22.6% reported AF. The total number of IS hospitalizations increased from 14,836 in 2000 to 19,561 in 2014 (32% increase), with an increase of 138% in the AF group (from 2,411 to 5,727). In-hospital mortality decreased from 13.6% to 11.5% and was consistently higher in the AF group (17.3% vs. 11.1%). Mean charges were also higher in the AF group (€2297 vs. €2191). Age-adjusted potential years of life lost rate was higher in the group without AF (39.6 vs. 7.5).

CONCLUSIONS

AF-associated IS hospitalizations more than doubled in the studied 15-year period. Also, AF was responsible for higher in-hospital mortality and hospitalization charges. These facts highlight the need for early detection of AF and preventive treatment to limit IS occurrence, its associated burden, and poorer health outcomes.

Influence of decision aids on oral anticoagulant prescribing among physicians: a randomised trial

BACKGROUND

Oral anticoagulants (OAC) are underused in treatment of atrial fibrillation (AF), with differences in patient and physician preferences. For risk communication, the graphic showing risks on treatment contains all the information, therefore, the graphic showing risks without treatment may not be necessary. Here, our objective was to assess whether decision aids require information of risks without treatment and specifically whether presentation of 5-year stroke risk in patients with AF increases use of OACs compared with presentation of 1-year risk and whether decisions on treatment are different when physicians decide their own treatment vs. that of the patient.

DESIGN

Randomised controlled trial with 2³ factorial design, performed at 12 university hospitals, one internal medicine course and one national medical conference.

RESULTS

Of 968 physicians who participated, 83·3% prescribed anticoagulation therapy. Treatment decisions were not influenced by the number of graphics or by the time frame of risk estimation, with risk differences of 0·5% (95% confidence interval, -4·0% to 5·4%) and 3·4% (-1·3% to 8·1%). However, physician-to-patient prescription rates were 5·4% (0·2-10·6%) more frequent after seeing the 5-year risk graphic. Physician-to-self intentions to prescribe occurred less frequently, with risk difference of 15·4% (10·8-20%). Physicians considered the baseline risk and the absolute risk reduction only when prescribing to patients but not to themselves.

CONCLUSIONS

Risks could be communicated using decision aids with only one graphic. Showing the risk of stroke at 5 years could increase the prescription of OACs to patients with AF. Faced with the same risk of stroke, physicians prescribed less to themselves than to patients.

Screening for atrial fibrillation in Canadian pharmacies: an economic evaluation

BACKGROUND

Screening for undiagnosed atrial fibrillation may lead to treatment with oral anticoagulation therapy, which can decrease the risk of ischemic stroke. The objective of this study was to conduct an economic evaluation of the Program for the Identification of 'Actionable' Atrial Fibrillation in the Pharmacy Setting (PIAAF-Pharmacy), which screened 1145 participants aged 65 years or more at 30 community pharmacies in Ontario and Alberta between October 2014 and April 2015.

METHODS

We used a 2-part decision model to evaluate the short- and long-term costs and quality-adjusted life-years (QALYs) of a pharmacy screening program for atrial fibrillation compared to no screening. Data from the PIAAF-Pharmacy study were used for the short-term model, and the relevant literature was used to extrapolate the benefits of the PIAAF-Pharmacy study in the long-term model. Costs and QALYs were calculated from a payer perspective over a lifetime horizon and were discounted at 1.5%/year.

RESULTS

Screening for atrial fibrillation in pharmacies was associated with higher costs ($26) and more QALYs (0.0035) compared to no screening, yielding an incremental cost per QALY gained of $7480. Univariate and probabilistic sensitivity analyses confirmed that screening for atrial fibrillation in a pharmacy setting was a cost-effective strategy.

INTERPRETATION

Our results support screening for atrial fibrillation in Canadian pharmacies. Given this finding, efforts should be made by provincial governments and pharmacies to implement such programs in Canada. The addition of atrial fibrillation screening alongside screening and management of other cardiovascular conditions may help to reduce the burden of stroke.