Stroke due to atrial fibrillation and the attitude to prescribing anticoagulant prevention in Italy.: A prospective study of a consecutive stroke population admitted to a comprehensive stroke unit

Profiling of patients with non-valvular atrial fibrillation and moderate-to-high risk of stroke not receiving oral anticoagulation in Spain

OBJECTIVE

In non-valvular atrial fibrillation (NVAF) with embolic risk, the guidelines recommend oral anticoagulation (OAC), although not all patients receive it. In this study, an attempt is made to identify these patients, and to study factors related to non-anticoagulation.

MATERIAL AND METHODS

Non-interventional, cross-sectional, multicentre study was performed on a population of patients ≥18 years with a NVAF diagnosis, moderate-high embolic risk (CHADS₂ score≥2), not treated with OAC. Atrial fibrillation (AF) prevalence was also collected.

RESULTS

AF prevalence was 4.5%, and 80.7% of the patients had NVAF (20.0% did not receive OAC). A total of 1310 non-OAC-treated patients were included (51.8% male, mean age: 76.0 years). The mean time since AF diagnosis was 58.4 months. The main therapeutic decision for stroke prevention was prescription of antiplatelet agents (82.4%, n=1078), and the main reasons were: patient refusal to monitoring (37.3%), high bleeding risk (31.1%), uncontrolled hypertension (27.9%), and frequent falls (27.6%). The mean CHA₂DS₂-VASc score was 4.6, and the HAS-BLED was 2.7 (55.9% of patients scoring HAS-BLED≥3). The most common thromboembolic risk factors were: hypertension (89.1%), age≥75 years (61.5%); the haemorrhagic factors: use of drugs increasing the bleeding risk (41.2%), uncontrolled blood pressure (33.7%).

CONCLUSIONS

About 20% of Spanish NVAF patients do not receive OAC in the clinical practice and are treated with antiplatelet agents, which do not reduce haemorrhagic risk. Most patients do not clearly show a contraindication to OACs, particularly considering that there are other available options (direct oral anticoagulant drugs [DOACs]).

Low Use of Oral Anticoagulant Prescribing for Secondary Stroke Prevention: Results From the Ontario Stroke Registry

BACKGROUND

Oral anticoagulation reduces the risk of stroke in atrial fibrillation but is often underused.

OBJECTIVES

To identify factors associated with oral anticoagulant prescribing and adherence after stroke or transient ischemic attack (TIA).

RESEARCH DESIGN

Retrospective cohort study using linked Ontario Stroke Registry and prescription claims data.

SUBJECTS

Consecutive patients with atrial fibrillation and ischemic stroke/TIA admitted to 11 stroke centers in Ontario, Canada between 2003 and 2011.

MEASURES

We used modified Poisson regression models to determine predictors of anticoagulant prescribing and multiple logistic regression to determine predictors of 1-year adherence.

RESULTS

Of the 5781 patients in the study cohort, 4235 (73%) were prescribed oral anticoagulants at discharge. Older patients were less likely to receive anticoagulation [adjusted relative risk (aRR) for each additional year=0.997; 95% confidence interval (CI), 0.995-0.998], as were those with TIA compared with ischemic stroke (aRR=0.904; 95% CI, 0.865-0.945), prior gastrointestinal bleed (aRR=0.778; 95% CI, 0.693-0.873), dementia (aRR=0.912; 95% CI, 0.856-0.973), and those from a long-term care facility (aRR=0.810; 95% CI, 0.737-0.891). After limiting the sample to those without obvious contraindications to anticoagulation, age, dementia, and long-term care residence continued to be associated with lower prescription of oral anticoagulants. One-year adherence to therapy was similar across most patient groups.

CONCLUSIONS

Age, dementia, and long-term care residence are predictors of lower oral anticoagulant use for secondary stroke prevention and represent key target areas for quality improvement initiatives.

Adherence to Guidelines for Antithrombotic Therapy in Patients with Atrial Fibrillation According to CHADS2 Score before and after Stroke: A Multicenter Observational Study from Korea

Background and Purpose

A substantial proportion of patients with atrial fibrillation (AF) are not treated optimally; however, the inappropriateness of drug therapy has never been evaluated before or after a stroke event. We investigated the adherence to guidelines for therapy in AF patients hospitalized with acute ischemic stroke (AIS) before stroke onset and at discharge, with the aim of identifying the factors associated with inappropriate therapy.

Methods

AIS patients with AF hospitalized within 7 days of onset were identified from a prospective nine-center stroke registry database. Two cohorts were defined: patients diagnosed with AF prior to the stroke event (admission cohort) and patients diagnosed with AF at discharge from hospital (discharge cohort). Any of the following conditions were regarded as nonadherence to guidelines in this study: use of anticoagulant or nonuse of antithrombotics with CHADS2 score=0, nonuse of antithrombotics with CHADS2 score=1, or nonuse of anticoagulant with CHADS2 score ≥2.

Results

Overall, 406 patients were enrolled in the admission cohort and 518 in the discharge cohort. The rates of nonadherence before a stroke event and at discharge were 77.8% and 33.3%, respectively. These rates varied widely for both cohorts, with interhospital differences being statistically significant. Multivariable analysis revealed that old age, stroke history, and congestive heart failure were associated with nonadherence before stroke. At discharge, males, coronary heart disease, inappropriate antithrombotic use before stroke, and functional disability at discharge were associated with nonadherence.

Conclusions

This study shows that antithrombotic use in AIS patients with AF might be not optimal before and after stroke in Korea.

Underuse of anticoagulation in stroke patients with atrial fibrillation--the FibStroke Study

BACKGROUND AND PURPOSE

Current guidelines recommend oral anticoagulation (OAC) for patients with atrial fibrillation (AF) and increased risk of thromboembolic events. The reasons for not using OAC in AF patients suffering stroke or transient ischaemic attack (TIA) were assessed.

METHODS

This retrospective registry included 3404 patients with previously diagnosed AF who suffered a total of 2955 ischaemic strokes and 895 TIAs during 2003-2012.

RESULTS

A CHA2DS2-VASc score ≥2 and a CHADS2 score ≥2 was observed in 3590 (93.2%) and in 2784 (72.3%) of the events, respectively. Of the high-risk patients (CHADS2 ≥2) only 55.1% were on OAC before the onset of stroke or TIA. The most frequently documented reasons for withholding OAC were infrequent paroxysms of AF (14%), previous bleeding episodes (13%) and the patient's decline/independent discontinuation of treatment (9%). Moreover, patients with paroxysmal AF (40% using OAC), previous bleeding (26% using OAC) and alcohol abuse (30% using OAC) were using OAC significantly less often than patients without these characteristics. A significant increase in the proportion of high-risk patients using OAC from 49% in 2003 to 65% in 2012 was seen.

CONCLUSIONS

Underuse of anticoagulation is a common contributor to ischaemic strokes and TIA episodes in patients with AF. Infrequent AF episodes, previous bleeds, patient preference and alcohol abuse were the most common reasons for not using OAC.

Validation of a simple method for atrial fibrillation screening in patients with stroke

Atrial fibrillation (AF) is the most common cardiac arrhythmia in adult and old people and represents a risk factor for stroke. Correct AF individuation bears strong relevance in primary and secondary stroke prevention. Our goal was to evaluate the reliability of a low-cost, non-invasive technology in detecting AF in acute stroke patients. AFib model BP3MQ1-2D (Microlife USA, Dunedin, FL) showed good accuracy in diagnosing AF in a general cardiologic outpatient population. We carried out an observational study in patients with recent stroke. We studied 207 subjects, 103 men, 104 women, mean age (±SD) 77.7 ± 11.34 years, who underwent a test by AFib device with indication of AF or lack of it. The golden standard was a 12-lead EKG done immediately and evaluated by a certified cardiologist. We computed estimates of Sensitivity and Specificity and their 95 % confidence intervals (CI). AF was present in 38 subjects from the sample of 207 (18.4 %). AFib correctly demonstrated AF in 34 and failed diagnosing AF in 4 cases; on the other hand, AFib correctly excluded AF in 167 and caused an erroneous diagnosis of AF in 2 cases. The Sensitivity was 0.895 (95 % CI 0.7597-0.958) and the Specificity was 0.988 (95 % CI 0.958-0.997). The AFib device global accuracy was 0.971 (95 % CI 0.938-0.987). This device was able to detect AF with high specificity and a good sensitivity. This device may be considered as an accurate tool in detecting AF in stroke patients.

Review of challenges in optimizing oral anticoagulation therapy for stroke prevention in atrial fibrillation

Oral anticoagulant therapy is the mainstay of stroke prevention in patients with atrial fibrillation; it is highly effective at reducing stroke risk, but its use can be limited by increased risk of bleeding. As new oral anticoagulants are available, barriers to optimal use of oral anticoagulation therapy warrant consideration by healthcare professionals and administrators who are seeking to optimize the quality of care for patients with atrial fibrillation. Suboptimal use of oral anticoagulation therapy constitutes an important health problem with significant humanistic and economic consequences. Based on a review of the medical literature published between 2000 and 2011, this article summarizes the literature on the barriers to optimal use of oral anticoagulation therapy, describes the clinical and economic burdens that these barriers add to the burden of atrial fibrillation, and discusses how well the new oral anticoagulants may address some of these issues.

Patterns of warfarin use and subsequent outcomes in atrial fibrillation in primary care practices

BACKGROUND

Warfarin is recommended for stroke prevention in high-risk patients with atrial fibrillation. However, it is often underutilized and inadequately managed in actual clinical practice.

OBJECTIVES

To examine the patterns of warfarin use and their relationship with stroke and bleeding in atrial fibrillation patients in community-based primary care practices.

DESIGN

Retrospective longitudinal cohort study.

PARTICIPANTS

A total of 1141 atrial fibrillation patients were selected from 17 primary care practices with a shared electronic medical record and characterized by stroke risk, potential barriers to anticoagulation, and comorbid conditions.

MAIN MEASURES

Duration and number of warfarin exposures, interruptions in warfarin exposure > 45 days, stroke, and bleeding events.

RESULTS

Among 1141 patients with a mean age of 70 years (standard deviation 13.3) and mean follow-up of 3.4 years (standard deviation 3.0), 764 (67%) were treated with warfarin. Warfarin was discontinued within 1 year in 194 (25.4%), and 349 (45.7%) remained on warfarin at the end of follow-up. Interruptions in warfarin use were common, occurring in 32.6% (249 of 764) of patients. Those with two or more interruptions were younger and at lower baseline stroke risk when compared to those with no interruptions. There were 76 first strokes and 73 first-bleeding events in the follow-up period. When adjusted for baseline stroke risk, time to warfarin start, and total exposure time, two or more interruptions in warfarin use was associated with an increased risk of stroke (relative risk, 2.29; 95% confidence interval: 1.29-4.07). There was no significant association between warfarin interruptions and bleeding events.

CONCLUSION

Warfarin was underutilized in a substantial portion of eligible atrial fibrillation patients in these community-based practices. In addition, prolonged interruptions in anticoagulation were common in this population, and multiple interruptions were associated with over twice the risk of stroke when compared to those treated continuously.

Anticoagulant therapy in practice

Atrial fibrillation is a risk factor for ischemic stroke. To prevent stroke oral anticoagulants can be administered. Old and new types of anticoagulants are available. Nowadays, old type, acenocumarol based anticoagulants are used preferentially in Hungary. Aim: The advantages and the disadvantages of anticoagulants are well known, but anticoagulants are underused in many cases. Method: The authors retrospectively examined how frequent atrial fibrillation was and whether the usage of anticoagulants in practice was in accordance with current guidelines among acute stroke cases admitted to the Department of Neurology, Medical and Health Science Centre of Debrecen University in 2009. Results: Of the 461 acute stroke cases, 96 patients had known and 22 patients had newly discovered atrial fibrillation. Half of the patients did not receive proper anticoagulation. Only 8.4% of them had their INR levels within the therapeutic range. Conclusions: The findings are similar to those reported in other studies. Many factors may contribute to the high proportion of improper use of anticoagulants, and further investigations are needed to determine these factors. In any case, elimination of these factors leading to a failure of anticoagulation may decrease the incidence of stroke. Orv. Hetil., 2012, 153, 732–736.

Challenges of Older Patients’ Knowledge About Warfarin Therapy

Objective: To review the challenges of warfarin education for older patients (aged 65 years or older) in terms of knowledge, access to warfarin education, and education resources. Methods: A quasi-systematic review of the literature was performed via electronic database searches (eg, Medline, Embase, Cumulative Index to Nursing and Allied Health Literature, International Pharmaceutical Abstracts, Meditext, and Google Scholar) from 1990 to May 2011. Results: The 62 articles reviewed found that improved patient knowledge results in better anticoagulation control. The review also found that between 50% and 80% of older patients have inadequate knowledge about the basic aspects of warfarin therapy (eg, action, benefits and risks, interactions with other drugs or foods, international normalized ratio management). Demographic factors, such as advancing age, lower family income, and limited health literacy, were found to inversely affect patients’ warfarin knowledge, and access to warfarin education and information resources were often suboptimal in different practice settings. Finally, a number of educational strategies and resources that could be readily incorporated to improve the effectiveness of current warfarin education programs were extracted from the review. Conclusion: This comprehensive review highlights that education about warfarin in older patients is currently suboptimal and may in part contribute to poor therapeutic outcomes. This review article also acknowledges the need to identify, target, and develop educational strategies and resources to further improve older patients’ knowledge about their warfarin therapy.

Underuse of oral anticoagulants in atrial fibrillation: a systematic review

BACKGROUND

Atrial fibrillation is associated with substantial mortality and morbidity from stroke and thromboembolism. Despite an efficacious oral anticoagulation therapy (warfarin), atrial fibrillation patients at high risk for stroke are often under-treated. This systematic review compares current treatment practices for stroke prevention in atrial fibrillation with published guidelines.

METHODS

Literature searches (1997-2008) identified 98 studies concerning current treatment practices for stroke prevention in atrial fibrillation. The percentage of patients eligible for oral anticoagulation due to elevated stroke risk was compared with the percentage treated. Under-treatment was defined as treatment of <70% of high-risk patients.

RESULTS

Of 54 studies that reported stroke risk levels and the percentage of patients treated, most showed underuse of oral anticoagulants for high-risk patients. From 29 studies of patients with prior stroke/transient ischemic attack who should all receive oral anticoagulation according to published guidelines, 25 studies reported under-treatment, with 21 of 29 studies reporting oral anticoagulation treatment levels below 60% (range 19%-81.3%). Subjects with a CHADS(2) (congestive heart failure, hypertension, age >75 years, diabetes mellitus, and prior stroke or transient ischemic attack) score >or=2 also were suboptimally treated, with 7 of 9 studies reporting treatment levels below 70% (range 39%-92.3%). Studies (21 of 54) using other stroke risk stratification schemes differ in the criteria they use to designate patients as "high risk," such that direct comparison is not possible.

CONCLUSIONS

This systematic review demonstrates the underuse of oral anticoagulation therapy for real-world atrial fibrillation patients with an elevated risk of stroke, highlighting the need for improved therapies for stroke prevention in atrial fibrillation.