Use of antithrombotic measures for stroke prevention in atrial fibrillation

Anticoagulation therapy in patients with stroke and atrial fibrillation: a registry-based study of acute stroke care in Surrey, UK

INTRODUCTION

Because of their high risk of stroke, anticoagulation therapy is recommended for most patients with atrial fibrillation (AF). The present study evaluated the use of anticoagulants in the community and in a hospital setting for patients with AF and its associations with stroke.

METHODS

Patients admitted with stroke to four major hospitals in County of Surrey, England were surveyed in the 2014-2016 Sentinel Stroke National Audit Programme. Descriptive statistics was used to summarise subject characteristics and χ² test to assess differences between categorical variables.

RESULTS

A total of 3309 patients, 1656 men (mean age: 73.1 years±SD 13.2) and 1653 women (79.3 years±13.0) were admitted with stroke (83.3% with ischaemic, 15.7% haemorrhagic stroke and 1% unspecified). AF occurred more frequently (χ²=62.4; p<0.001) among patients admitted with recurrent (30.2%) rather than with first stroke (17.1%). There were 666 (20.1%) patients admitted with a history of AF, among whom 304 (45.3%) were anticoagulated, 279 (41.9%) were untreated and 85 (12.8%) deemed unsuitable for anticoagulation. Of the 453 patients with history of AF admitted with a first ischaemic stroke, 138 (37.2%) were on anticoagulation and 41 (49.6%) were not (χ² = 6.3; p<0.043) and thrombolysis was given more frequently for those without prior anticoagulation treatment (16.1%) or unsuitable for anticoagulation (23.6%) compared with those already on anticoagulation treatment (8.3%; χ²=10.0; p=0.007). Of 2643 patients without a previous history of AF, 171 (6.5%) were identified with AF during hospitalisation. Of patients with AF who presented with ischaemic stroke who were not anticoagulated or deemed unsuitable for anticoagulation prior to admission, 91.8% and 75.0%, respectively, were anticoagulated on discharge.

CONCLUSIONS

The study highlights an existing burden for patients with stroke and reflects inadequate treatment of AF which results in an increased stroke burden. There is significant scope to improve the rates of anticoagulation.

Evaluation of anticoagulation status for atrial fibrillation on early ischaemic stroke outcomes: a registry-based, prospective cohort study of acute stroke care in Surrey, UK

OBJECTIVE

The relationship of anticoagulation therapies with stroke severity and outcomes have been well documented in the literature. However, none of the previous research has reported the relationship of atrial fibrillation (AF)/anticoagulation therapies with urinary tract infection (UTI), pneumonia and length of stay in hyperacute stroke units (HASUs). The present study aimed to evaluate AF and anticoagulation status in relation to early outcomes in 1387 men (median age=75 years, IQR=65-83) and 1371 women (median age=83 years, IQR=74-89) admitted with acute ischaemic stroke to HASUs in Surrey between 2014 and 2016.

METHODS

We conducted this registry-based, prospective cohort study using data from the Sentinel Stroke National Audit Programme. Association between AF anticoagulation status with severe stroke on arrival (National Institutes of Health Stroke Scale score ≥16), prolonged HASU stay (>3 weeks), UTI and pneumonia within 7 days of admission, severe disability on discharge (modified Rankin Scale score=4 and 5) and inpatient mortality was assessed by logistic regression, adjusted for age, sex, hypertension, congestive heart failure, diabetes and previous stroke.

RESULTS

Compared with patients with stroke who are free from AF, those with AF without anticoagulation had an increased adjusted risk of having more severe stroke: 5.8% versus 14.0%, OR=2.4 (95% CI 1.6 to 3.6, P<0.001), prolonged HASU stay: 21.5% versus 32.0%, OR=1.4 (1.0-2.0, P=0.027), pneumonia: 8.2% versus 19.1%, OR=2.1 (1.4-2.9, P<0.001), more severe disability: 24.2% versus 40.4%, OR=1.6 (1.2-2.1, P=0.004) and mortality: 9.3% versus 21.7%, OR=1.9 (1.4-2.8, P<0.001), and AF patients with anticoagulation also had greater risk for having UTI: 8.6% versus 12.3%, OR=1.9 (1.2-3.0, P=0.004), pneumonia: 8.2% versus 11.5%, OR=1.6 (1.1-2.4, P=0.025) and mortality: 9.7% versus 21.7%, OR=1.9 (1.4-2.8, P<0.001). The median HASU stay for stroke patients with AF without anticoagulation was 10.6 days (IQR=2.8-26.4) compared with 5.8 days (IQR=2.3-17.5) for those free from AF (P<0.001).

CONCLUSIONS

Patients with AF, particularly those without anticoagulation, are at increased risk of severe stroke, associated with prolonged HASU stay and increased risk of early infection, disability and mortality.

Using an Atrial Fibrillation Decision Support Tool for Thromboprophylaxis in Atrial Fibrillation: Effect of Sex and Age

OBJECTIVES

To assess the appropriateness of oral anticoagulant therapy (OAT) in women and elderly adults, looking for patterns of undertreatment or unnecessary treatment.

DESIGN

Retrospective cohort study.

SETTING

Primary care practices of an academic healthcare system.

PARTICIPANTS

Adults (aged 28-93) with nonvalvular atrial fibrillation (AF) seen between March 2013 and February 2014 (N = 1,585).

MEASUREMENTS

Treatment recommendations were made using an AF decision support tool (AFDST) based on projections of quality-adjusted life expectancy calculated using a decision analytical model that integrates individual-specific risk factors for stroke and hemorrhage.

RESULTS

Treatment was discordant from AFDST-recommended treatment in 45% (326/725) of women and 39% (338/860) of men (P = .02). Although current treatment was discordant from recommended in 35% (89/258) of participants aged 85 and older and in 43% (575/1,328) of those younger than 85 (P = .01), many undertreated elderly adults were receiving aspirin as the sole antithrombotic agent.

CONCLUSION

Physicians should understand that female sex is a significant risk factor for AF-related stroke and incorporate this into decision-making about thromboprophylaxis. Treating older adults with aspirin instead of OAT exposes them to significant risk of bleeding with little to no reduction in AF-related stroke risk.

Impact of an Atrial Fibrillation Decision Support Tool on thromboprophylaxis for atrial fibrillation

BACKGROUND

Appropriate thromboprophylaxis for patients with atrial fibrillation (AF) remains a national challenge.

METHODS

We hypothesized that provision of decision support in the form of an Atrial Fibrillation Decision Support Tool (AFDST) would improve thromboprophylaxis for AF patients. We conducted a cluster randomized trial involving 15 primary care practices and 1,493 adults with nonvalvular AF in an integrated health care system between April 2014 and February 2015. Physicians in the intervention group received patient-level treatment recommendations made by the AFDST. Our primary outcome was the proportion of patients with antithrombotic therapy that was discordant from AFDST recommendation.

RESULTS

Treatment was discordant in 42% of 801 patients in the intervention group. Physicians reviewed reports for 240 patients. Among these patients, thromboprophylaxis was discordant in 63%, decreasing to 59% 1 year later (P = .02). In nonstratified analyses, changes in discordant care were not significantly different between the intervention group and control groups. In multivariate regression models, assignment to the intervention group resulted in a nonsignificant trend toward decreased discordance (P = .29), and being a patient of a resident physician (P = .02) and a higher HAS-BLED score predicted decreased discordance (P = .03), whereas female gender (P = .01) and a higher CHADSVASc score (P = .10) predicted increased discordance.

CONCLUSIONS

Among patients whose physicians reviewed recommendations of the decision support tool discordant therapy decreased significantly over 1 year. However, in nonstratified analyses, the intervention did not result in significant improvements in discordant antithrombotic therapy.

Characterization of the proportion of untreated and antiplatelet therapy treated patients with atrial fibrillation

Despite the efficacy of oral anticoagulants for stroke prevention in atrial fibrillation (AF), evidence suggests that many patients with AF who should be treated with vitamin K antagonists (VKAs) are treated with antiplatelet therapy or remain untreated. The aims of this study were to determine the proportion of patients with AF in each treatment category in clinical practice and to ascertain whether treatment is appropriate for stroke risk. An extensive search of the biomedical research published since 1994 was performed. Studies delineating the treatment of patients with AF were captured. Seventy-eight studies pertaining to the treatment of patients with AF were identified; 56 studies, containing data from 1980 to 2007, met the inclusion criteria. Over time, the use of VKA therapy for stroke prevention increased, while the proportion of untreated patients decreased; antiplatelet use remained static. Looking at the more recent data, (collected from 2000 onward), the proportion of patients receiving no therapy ranged from 4% to 48% (median 18%), antiplatelet therapy from 10% to 56% (median 30%), and VKA therapy from 9% to 86% (median 52%). Although most studies showed a decrease in the proportion of antiplatelet-treated and untreated patients with increasing stroke risk (12 of 14 studies), many patients at moderate or high risk for stroke were not treated according to guidelines. In conclusion, this review shows that up to 56% of patients with AF are treated with antiplatelet therapy, and up to 48% receive no therapy regardless of stroke risk level. This may reflect the inconvenience associated with VKA use, inadequate assessment of stroke risk, or poor adherence to treatment guidelines.

Use of antithrombotic medications among elderly ischemic stroke patients

BACKGROUND

The use of antithrombotic medications after ischemic stroke is recommended for deep vein thrombosis prophylaxis and secondary stroke prevention. We assessed the rate of receipt of these therapies among eligible ischemic stroke patients age ≥65 years and determined the effects of age and other patient characteristics on treatment.

METHODS AND RESULTS

The analysis included Medicare fee-for-service beneficiaries discharged with ischemic stroke (ICD 433.x1, 434.x1, 436) randomly selected for inclusion in the Medicare Health Care Quality Improvement Program's National Stroke Project 1998 to 1999, 2000 to 2001. Patients discharged from nonacute facilities, transferred, or terminally ill were excluded. Receipt of in-hospital pharmacological deep vein thrombosis prophylaxis, antiplatelet medication, anticoagulants for atrial fibrillation, and antithrombotic medications at discharge were assessed in eligible patients, stratified by age (65 to 74, 75 to 84, and 85+ years). Descriptive models identified characteristics associated with treatment. Among 31 554 patients, 14.9% of those eligible received pharmacological deep vein thrombosis prophylaxis, 83.9% antiplatelet drugs, 82.8% anticoagulants for atrial fibrillation, and 74.2% were discharged on an antithrombotic medication. Rates of treatment decreased with age and were lowest for patients ages 85 years or older. Admission from a skilled nursing facility and functional dependence were associated with lower treatment rates.

CONCLUSIONS

There was substantial underutilization of antithrombotic therapies among elderly ischemic stroke patients, particularly among the very elderly, those admitted from skilled nursing facilities, and patients with functional dependence. The reasons for low use of antithrombotic therapies, including the apparent underutilization of deep vein thrombosis prophylaxis in otherwise eligible patients, require further investigation.

Value of trans-oesophageal echocardiography as a method of encouraging patients with chronic atrial fibrillation to use anticoagulation therapy

BACKGROUND

Despite the indisputable role of anticoagulation therapy for atrial fibrillation (AF) patients at risk for stroke, anticoagulants remain under-used in everyday clinical practice. We assumed that by performing trans-oesophageal echocardiography (TEE) on patients with AF who were not on anticoagulation treatment prior to the procedure, and by explaining to them the TEE images obtained, as well as the possible consequences of these findings, we could convince patients to start anticoagulation therapy. The main objective of the study was to assess the examined patients' adherence to warfarin therapy over a two-year period.

METHODS AND RESULTS

We conducted a prospective TEE study from February 2006 to December 2008 on 70 patients with chronic AF who were not on anticoagulation treatment. Mean patient age was 65.85 ± 10.02 years and 68.57% were women. Thrombus in the left atrial appendage was found in 25 (35.71%) patients. Fifty-four (77.14%) patients had thrombi or spontaneous echo contrast in at least one of their supraventricular cavities. Following the procedure and with detailed explanation to the patients of their TEE findings, we managed to start anticoagulation therapy on 60 (85.71%) patients. At the end of the follow-up period of 23.76 ± 2.8 months, 53 (75.71%) patients remained on warfarin therapy. The rest of the surviving patients settled for thrombo-prophylaxis with aspirin.

CONCLUSION

TEE is a valuable method that, in addition to its diagnostic possibilities, could also serve as a convincing visual method of putting atrial fibrillation patients onto an anticoagulation regimen.

Influence of age on the prescription of vitamin K antagonists in outpatients with permanent atrial fibrillation in France

PURPOSE

The aim of the study was to describe the current rate and determinants of the prescription of antithrombotics in outpatients with permanent atrial fibrillation, with a pre-specified emphasis on the influence of age on the prescription of vitamin K antagonists.

METHODS

This was a prospective observational survey in France among 5893 consecutive outpatients with documented permanent atrial fibrillation being seen by 770 physicians from August to December 2002. We recruited physicians from two random lists of general practitioners and cardiologists, respectively, stratified according to their administrative region, from the list of all French private general practitioners and cardiologists.

RESULTS

The mean age of patients was 75.8 years. Mean duration since diagnosis of atrial fibrillation was 5.0 years; 31.7% of patients had valvular heart disease and 60.3% hypertension. An antithrombotic was prescribed to 95.5% of patients at the time of consultation. The percentage of patients treated with vitamin K antagonists was 76.4%; it decreased from 86.0% in patients aged 60-70 years to 63.5% in patients aged 80 years or above. On multivariate analysis, high age was a significant predictor (p = 0.001) for the non-prescription of vitamin K antagonists. In patients above 70 years currently receiving an antithrombotic, the probability of prescription of vitamin K antagonists decreased on average by 9.6% per year.

CONCLUSIONS

Vitamin K antagonists are administered to most outpatients with permanent atrial fibrillation at high thromboembolic risk seen by French physicians in private practice. However, their use decreases with age.

Oral anticoagulation in atrial fibrillation: A pan-European patient survey

BACKGROUND

Anticoagulation with vitamin K antagonists (VKAs) provides effective stroke prophylaxis in patients with atrial fibrillation (AF). Optimisation of such therapy requires frequent monitoring, dose adjustments and stringent lifestyle restrictions. We conducted a large multinational survey in patients with chronic AF to gain insights into their perceptions and understanding of VKA use.

METHODS

Eligible patients were adults with AF who had been prescribed VKAs for at least 1 year. A total of 711 patient interviews were conducted in seven European countries during June and July 2004.

RESULTS

The majority of patients (58% male; mean age 68 years) claimed to understand their treatment programme; despite this, only 7% knew that VKA use is aimed at preventing strokes and 24% stated that they would have liked more information. Patients attended an average of 14 monitoring sessions in the previous year; however, 21% missed appointments, especially younger patients (<65 years). The International Normalized Ratio (INR) was within the target range in most or all of the last five to ten visits in 64% of patients; nonetheless, 38% were not aware that an INR outside the target range is associated with health risks. On average, patients required dose adjustments every four sessions. VKA treatment impacted 67% of patients in terms of diet, socialising, career and independence, especially younger patients (74%).

CONCLUSIONS

Monitoring, dose adjustments and lifestyle restrictions to optimise the intensity of anticoagulation with VKAs are problematic for patients with AF, and their knowledge of the consequences of such therapy is often poor.

Pre-admission warfarin use in patients with acute ischemic stroke and atrial fibrillation: The appropriate use and barriers to oral anticoagulant therapy

INTRODUCTION

Warfarin reduces the risk of stroke in patients with atrial fibrillation. Despite strong guideline recommendations, studies continue to demonstrate the under-use of warfarin in clinical practice.

PURPOSE

To determine the prevalence and predictors of warfarin use in patients presenting with atrial fibrillation and acute ischemic stroke who do not have a documented contraindication to anticoagulants.

METHODS

We conducted a retrospective chart review of all patients admitted to the Hamilton General Hospital with a primary diagnosis of ischemic stroke and a coded diagnosis of atrial fibrillation between 1999 and 2004. Using a standardized data abstraction form, the following variables were recorded: baseline demographics, past medical history including risk factors for stroke and major bleeding and known predictors of warfarin under-use. In cases where warfarin was not prescribed, charts were also reviewed for documented contraindications to warfarin use. The following were considered valid contraindications to warfarin: patient refusal, non-compliance with INR monitoring, bleeding diathesis, history of major bleeding or significant alcohol consumption.

RESULTS

In total, 196 patients with ischemic stroke and atrial fibrillation were identified. Of these patients, 106 were considered to be appropriate candidates for anticoagulation after excluding patients with no known diagnosis of atrial fibrillation prior to admission (N=59), a valid contraindication to warfarin use (N=18), a CHADS2 score <1 (N=6) or a competing diagnosis for warfarin use (N=7). Of the patients deemed to be suitable candidates for warfarin, 57 (54%) were receiving warfarin therapy on admission. On multivariable analyses, increasing age (OR 0.7; 95% CI 0.5-0.9) was associated with a reduced odds of warfarin use while a history of stroke or TIA (OR 2.6; 95% CI 1.1-6.5) and a history of congestive heart failure (OR 3.2; 95% CI 1.1-9.0) were associated with an increased odds of warfarin use in patients without a contraindication to warfarin. While 75% of patients <75 years old were anticoagulated, only 33% of those >85 years were prescribed warfarin on admission to hospital.

CONCLUSIONS

early half of all patients presenting with atrial fibrillation and acute ischemic stroke who were suitable candidates for anticoagulation were not prescribed warfarin. In patients not prescribed warfarin, very few had a documented contraindication. Advanced age appears to be the strongest predictor of warfarin non-use.

Regression of warfarin-resistant left atrial appendage thrombus after ablation of atrial fibrillation and permanent pacing

Atrial fibrillation is the most common rhythm disturbance and can also occur in absence of true cardiac disease. However, also in these cases, it can generate left atrial appendage thrombi with systemic embolic potential. A regular and well conducted anticoagulant therapy with dicoumarol derivatives, as indicated in these patients, is not always successful. We report the case of a patient with lone atrial fibrillation and a left atrial appendage thrombus resistant to anticoagulant therapy with warfarin, which disappeared after catheter ablation of atrial fibrillation by electrical disconnection of the pulmonary veins, restoration of sinus rhythm and dual-chamber pacemaker implantation.

Rationale and design of ACTIVE: the atrial fibrillation clopidogrel trial with irbesartan for prevention of vascular events

BACKGROUND

Atrial fibrillation (AF) is the most frequently occurring cardiac arrhythmia with often serious clinical consequences. Many patients have contraindications to anticoagulation, and it is often underused in clinical practice. The addition of clopidogrel to aspirin (ASA) has been shown to reduce vascular events in a number of high-risk populations. Irbesartan is an angiotensin receptor-blocking agent that reduces blood pressure and has other vascular protective effects.

METHODS AND RESULTS

ACTIVE W is a noninferiority trial of clopidogrel plus ASA versus oral anticoagulation in patients with AF and at least 1 risk factor for stroke. ACTIVE A is a double-blind, placebo-controlled trial of clopidogrel in patients with AF and with at least 1 risk factor for stroke who receive ASA because they have a contraindication for oral anticoagulation or because they are unwilling to take an oral anticoagulant. ACTIVE I is a partial factorial, double-blind, placebo-controlled trial of irbesartan in patients participating in ACTIVE A or ACTIVE W. The primary outcomes of these studies are composites of vascular events. A total of 14000 patients will be enrolled in these trials.

CONCLUSIONS

ACTIVE is the largest trial yet conducted in AF. Its results will lead to a new understanding of the role of combined antiplatelet therapy and the role of blood pressure lowering with an angiotensin II receptor blocker in patients with AF.

Monitored atrial fibrillation duration predicts arterial embolic events in patients suffering from bradycardia and atrial fibrillation implanted with antitachycardia pacemakers

OBJECTIVES

The aim of our study was to evaluate arterial embolism (AE) occurrence rates and predictors in patients suffering from bradycardia and wearing a pacemaker with antitachycardia pacing therapies.

BACKGROUND

Atrial fibrillation (AF) is associated with a high incidence of AE.

METHODS

A total of 725 patients (360 men, age 71 +/- 11 years) were implanted with a DDDRP pacemaker (Medtronic AT500, Medtronic Inc., Minneapolis, Minnesota). At baseline 225 (31.0%) patients received antiplatelet therapy and 264 (36.4%) patients received anticoagulation agents.

RESULTS

Over a median 22-month follow-up (25th to 75th interquartile range 16 to 30 months), AE occurred in 14 (1.9%) patients: 7 patients suffered a nonfatal ischemic stroke (0.6% per year), 4 patients had transient ischemic attack (0.34% per year), and 3 patients had embolic complications. Among baseline patients' characteristics, multivariate logistic analysis showed that embolic events are independently associated to ischemic heart disease (7.0 odds ratio [OR], 95% confidence interval [CI] 2.3 to 21.3, p = 0.001), prior embolic event (7.3 OR, 95% CI 1.2 to 43.9, p = 0.029), diabetes (5.0 OR, 95% CI 1.2 to 15.7, p = 0.032), and hypertension (4.1 OR, 95% CI 1.1 to 15.6, p = 0.036). The risk of embolism, adjusted for known risk factors, was 3.1 times increased (95% CI 1.1 to 10.5, p = 0.044) in patients with device-detected atrial fibrillation episodes longer than one day during follow-up.

CONCLUSIONS

In a cohort of patients with bradycardia and AF, arterial embolism was common in patients with ischemic cardiopathy, hypertension, diabetes mellitus, and in patients with known stroke risk factors. Atrial fibrillation occurrences longer than one day were independently associated with embolic events.

Atrial fibrillation management: a prospective survey in ESC Member Countries

AIMS

To describe atrial fibrillation (AF) management in member countries of the European Society of Cardiology (ESC) and to verify cardiology practices against guidelines.

METHODS AND RESULTS

Among 182 hospitals in 35 countries, 5333 ambulant and hospitalized AF patients were enrolled, in 2003 and 2004. AF was primary or secondary diagnosis, and was confirmed on ECG in the preceding 12 months. Clinical type of AF was reported to be first detected in 978, paroxysmal in 1517, persistent in 1167, and permanent in 1547 patients. Concomitant diseases were present in 90% of all patients, causing risk factors for stroke to be also highly prevalent (86%). As many as 69% of patients were symptomatic at the time of the survey; among asymptomatic patients, 54% were previously experienced symptoms. Oral anticoagulation was prescribed in 67 and 49% of eligible and ineligible patients, respectively. A rhythm control strategy was applied in 67% of currently symptomatic patients and in 44% of patients who never experienced symptoms.

CONCLUSION

This survey provides a unique snapshot of current AF management in ESC member countries. Discordance between guidelines and practice was found regarding several issues on stroke prevention and antiarrhythmic therapy.

Admissions with atrial fibrillation in a multiracial population in Kuala Lumpur, Malaysia

BACKGROUND

There are established differences in cardiovascular disease in different racial groups. Worldwide, the literature regarding the clinical epidemiology of atrial fibrillation in non-white populations is scarce.

OBJECTIVES

To document the prevalence of atrial fibrillation (AF) in the multiracial population of Malaysia, and to describe the clinical features and management of these patients.

SETTING

Busy city centre general hospital in Kuala Lumpur, Malaysia, over a 1-month period.

SUBJECTS

One-thousand four hundred and thirty-five acute medical admissions, of whom 40 patients (2.8%) had AF.

RESULTS

Of 1435 acute medical admissions to Kuala Lumpur General Hospital over the 4-week study period, 40 had AF (21 male, 19 female; mean age 65 years). Of these, 18 were Malay, 16 Chinese and six Indian. Nineteen patients had previously known AF (seven with paroxysmal AF) and 21 were newly diagnosed cases. The principal associated medical conditions were ischaemic heart disease (42.5%), hypertension (40%) and heart failure (40%). Dyspnoea was the commonest presentation, whilst stroke was the cause of presentation in only two patients. Investigations were under-utilised, with chest X-ray and echocardiography in only 62.5% of patients and thyroid function checked in 15%. Only 16% of those with previously diagnosed AF were on warfarin, with a further three on aspirin. Anticoagulant therapy was started in 13.5% of patients previously not on warfarin, and aspirin in 8%. Records of contraindications to warfarin were unreliable, being identified in only 25%. For those with known AF, 58% were on digoxin. For new onset AF, digoxin was again the most common rate-limiting treatment, initiated in 38%, whilst five patients with new onset AF were commenced on amiodarone. DC cardioversion was not used in any of the patients with new onset AF.

CONCLUSION

Amongst acute medical admissions to a single centre in Malaysia the prevalence of AF was 2.8%. Consistent with previous similar surveys in mainly western (caucasian) populations, standard investigations in this Malaysian cohort were also inadequate and there was underuse of anticoagulation, medication for ventricular rate control and cardioversion to sinus rhythm.

[How suitable is thromboembolism prophylaxis for patients with chronic auricular fibrillation at 3 primary care centers]

OBJECTIVE

To find just how suitable thromboembolism prophylaxis (TEP) is in a group of patients with chronic auricular fibrillation belonging to the primary care environment.

DESIGN

Cross-sectional and descriptive multi-centre study.

SETTING

The study was performed at 3 urban primary care centres in Madrid.

PARTICIPANTS

All the patients recorded up to April 2001 with the diagnosis of chronic auricular fibrillation (n=274) were included. Patients with no clinical history or who had a valve prosthesis were excluded.

MAIN MEASUREMENTS

Demographic variables, existence of factors of risk of embolism, presence of counter-indications for oral anti-coagulants, and the kind of thromboembolic prophylaxis taken were collected.

RESULTS

A total of 274 patients were evaluated. Average age was 75 (SD, 9) and 52% were women. 82% of patients had at least one factor of risk of thromboembolism. The most commonly used kind of TEP was oral anti-coagulants. 45% of patients did not receive suitable TEP. 13.5% of patients at risk of embolism and who had no kind of TEP were found.

CONCLUSIONS

There is a high percentage of patients with chronic auricular fibrillation and a high risk of embolism, who do not receive adequate TEP, in the absence of counter-indications to taking oral anticoagulants. There is great scope for improvement, which is within professionals' possibilities.

Prevention of vascular events in patients with atrial fibrillation: evidence, guidelines, and practice

Atrial fibrillation (AF) is a common arrhythmia that is associated with an increased risk for vascular events, particularly stroke. Two different therapies have been extensively evaluated for prevention of vascular events in AF: oral anticoagulation (such as warfarin), and aspirin. Placebo-controlled trials of warfarin have been performed and summarized in a meta-analysis. There is clear evidence of a benefit, with a relative risk reduction in stroke of 67% and in total vascular events of 42%. Aspirin also has been studied and is effective, but with a more modest benefit (relative risk reduction of 22%). Several studies have compared warfarin and aspirin, and showed a clear benefit in favor of warfarin for reduction of vascular events and stroke. Compared to aspirin, the risk of major hemorrhage with oral anticoagulation is increased by 70% to 100%. Current practice guidelines recommend oral anticoagulation therapy for high-risk patients with AF, unless there is an increased risk for bleeding. Nonetheless, oral anticoagulation therapy with drugs such as warfarin is difficult for both patients and physicians because of the increased risk for bleeding and the need for ongoing monitoring of coagulation status. Many patients do not receive anticoagulation therapy despite its proven benefits.

Quality of blood pressure control and risk of cerebral bleeding in patients with oral anticoagulation

BACKGROUND

We assessed how many patients on long-term oral anticoagulation (OAC) (i) suffer from arterial hypertension (AH), (ii) are aware of AH, (iii) need improvement of their therapy and (iv) suffer from cerebral bleeding.

METHODS

Outpatients on long-term OAC were asked to measure blood pressure at least 4 times. Blood pressure was classified as normotensive if at least 75 % of all measurements were < 139/89 mm Hg; as mild/moderate AH if > 25 % of all measurements were 140 - 179 mm Hg systolic or 90 - 109 mm Hg diastolic; and as severe AH if > 25 % of all measurements were > 180 mm Hg systolic or > 110 mm Hg diastolic. Bleeding complications were registered.

RESULTS

Of the 235 patients (108 female, 67 +/- 12 years), 80 % suffered from AH. Severe AH was present in 5 %. Only 56 % were aware of suffering from AH. An improvement of antihypertensive therapy was needed in 64 %. Over 225 days, only one cerebral bleeding occurred. Blood pressure was normotensive in 30 % with known AH.

CONCLUSIONS

Blood pressure control seems better in OAC patients than in normals, if the patient is aware of AH. Patients with AH on OAC are not aware of AH in > 50 %. Repeated blood pressure measurements in OAC are recommended, even if patients are not aware of AH.

Utilización de anticoagulantes orales en pacientes con fibrilación auricular al alta hospitalaria en el año 2000

INTRODUCTION AND OBJECTIVES

Although there is consensus about the use of oral anticoagulants to prevent thrombi and embolisms in most patients with atrial fibrillation, this treatment is underused in actual practice. Our objective was to determine and analyze the use of acenocoumarol in patients diagnosed as having atrial fibrillation at discharge.

PATIENTS AND METHOD

Between January and July 2000, we retrospectively studied 501 consecutive patients with a diagnosis of atrial fibrillation. We recorded whether they were discharged with or without oral anticoagulation treatment.

RESULTS

We identified 482 patients with at least one associated thromboembolic risk factor, who comprised the study population. Mean age was 79.3 years, and 33.3% of the patients were men. Forty-six percent were discharged with acenocoumarol, and 36.3% with platelet antiaggregants. Twenty-three percent had a known contraindication for acenoroumarol. Nearly 62% of the patients without contraindications for anticoagulation received treatment with acenocoumarol. Multivariate analysis showed that rheumatic mitral valve disease, previous stroke or thromboembolism and dilated left atrium were associated with a higher probability of receiving anticoagulant treatment. Age over 75 years was associated with a lower likelihood of receiving acenocoumarol.

CONCLUSIONS

Oral anticoagulation was given in an inadequate proportion of patients who were discharged from a secondary-level hospital with atrial fibrillation and no contraindications. Rheumatic mitral valve disease, previous stroke or thromboembolism, and dilated left atrium were associated with a higher probability of anticoagulant treatment. Age over 75 years was related with less frequent use of this therapy.

Atrial fibrillation in a primary care practice: prevalence and management

BACKGROUND

Atrial fibrillation is a common serious cardiac arrhythmia. Knowing the prevalence of atrial fibrillation and documentation of medical management are important in the provision of primary care. This study sought to determine the prevalence of atrial fibrillation in a primary care population and to identify and quantify the treatments being used for stroke prevention in this group of patients.

METHODS

A prevalence study through chart audit was conducted in the family medicine practice at the Sunnybrook campus of the Sunnybrook and Women's College Health Sciences Centre. The main outcome measures were the prevalence of atrial fibrillation in our primary care practice and the use of warfarin for stroke prevention in this population.

RESULTS

261 patients in our practice have atrial fibrillation. The overall prevalence in our family practice unit is 3.9%. When considering patients aged 60 and over, the prevalence rises to 12.2%. 204 of our patients with atrial fibrillation (78.2%) are currently being treated with warfarin. Another 21 patients were previously treated and discontinued for a number of reasons. Of the 57 patients not currently treated with warfarin, 44 are treated with ASA, 2 with ticlopidine, and 11 are receiving no preventative treatment.

CONCLUSIONS

The prevalence of atrial fibrillation in our practice is higher than the range of prevalence reported in the general literature. However, our coverage with warfarin treatment exceeds previous reports in the literature.

Incidence of chronic atrial fibrillation in general practice and its treatment pattern

The object of this article was to estimate the incidence rate of chronic atrial fibrillation (AF) in a general practice setting, to identify factors predisposing to its occurrence, and to describe treatment patterns in the year following the diagnosis. The method used was a population-based cohort study using the General Practice Research Database (GPRD) in the UK. We identified patients aged 40-89 years with a first ever recorded diagnosis of AF. The diagnosis was validated through a questionnaire sent to the general practitioners. A nested case-control analysis was performed to assess risk factors for AF using 1,035 confirmed incident cases of chronic AF and a random sample of 5,000 controls from the original source population. The incidence rate of chronic AF was 1.7 per 1,000 person-years, and increased markedly with age. The age adjusted rate ratio among males was 1.4 (95% CI 1.2-1.6). The major risk factors were age, high BMI, excessive alcohol consumption, and prior cardiovascular comorbidity, in particular, valvular heart disease and heart failure. Digoxin was used in close to 70% of the patients, and close to 15% did not receive any antiarrhythmic treatment. Close to 40% did not receive either warfarin or aspirin in the 3 months period after the diagnosis. Among the potential candidates for anticoagulation only 22% of those aged 70 years or older were prescribed warfarin in comparison to 49% among patients aged 40-69 years. Chronic AF is a disease of the elderly, with women presenting a lower incidence rate than men specially in young age. Age, weight, excessive alcohol consumption, and cardiovascular morbidity were the main independent risk factors for AF. Less than half of patients with chronic AF and no contraindications for anticoagulation received warfarin within the first trimester after the diagnosis.

Evaluation of risk factors for stroke/embolism and of complications due to anticoagulant therapy in atrial fibrillation

BACKGROUND AND PURPOSE

We sought to assess in outpatients with atrial fibrillation and oral anticoagulation (1) whether the complication rate is influenced by the presence of the risk factors age >65 years, arterial hypertension, diabetes, or previous stroke; (2) whether the complication rate is influenced by the number of additional drugs taken by patients; and (3) whether problems and interventions differ between patients with or without complications.

METHODS

- Clinical characteristics, drugs, problems, interventions, and complications were registered during 2 years.

RESULTS

- Three hundred sixty patients (mean age, 68 years; 43% female) were observed for 383 patient-years. Patients aged >65 years had more serious, life-threatening, or fatal complications (11% versus 5.3%/100 patient-years; P=0.0428) than younger patients. Patients with diabetes had more life-threatening and fatal complications (2.8% versus 0.6%/100 patient-years; P=0.0354) than patients without. The complication rate did not differ regarding the presence of previous stroke or hypertension. Patients who took </=3 drugs had fewer complications than patients who took more (4.3% versus 24.4%/100 patient-years; P=0.0041). Patients with complications complained more of chest (48% versus 28%/100 patient-years; P=0.0113) and abdominal pain (30% versus 13%/100 patient-years; P=0.0057), more frequently failed to keep appointments (134% versus 107%/100 patient-years; P=0.0321), had a higher tracking rate (134% versus 105%/100 patient-years; P=0.0272), and took more additional drugs (4.6 versus 3.5 drugs per day; P=0.0063) than patients with no complications.

CONCLUSIONS

- Patients with increased age or diabetes mellitus or those who take >3 drugs per day have an increased complication rate and thus need especially careful monitoring of oral anticoagulation, including adequate pain control.

Clinical correlates and drug treatment of residents with stroke in long-term care

BACKGROUND AND PURPOSE

Stroke incidence increases with age, and stroke survivors often require nursing home placement. Characteristics of these residents and factors associated with the secondary drug prevention of stroke in nursing homes have yet to be explored.

METHODS

We used a population-based data set of all nursing home residents in 5 states (1992 to 1995). We identified 53 829 (20.4%) with a diagnosis of stroke on the Minimum Data Set assessment. We considered aspirin, dipyridamole, ticlopidine, or warfarin alone or in combination as secondary drug prevention. We used logistic regression modeling to identify independent predictors of drug treatment.

RESULTS

Sixty-seven percent of stroke survivors were not receiving drug therapy for stroke prevention. Among those treated, most received aspirin alone (16%) or warfarin alone (10%). Independent predictors of drug treatment included comorbid conditions (eg, hypertension, atrial fibrillation, depression, Alzheimer's disease, dementia, gastrointestinal bleeding, and peptic ulcer disease). Those over the age of 85 years were less likely to be treated than those 65 to 74 years of age (odds ratio [OR], 0.86; 95% confidence interval [CI], 0.82 to 0.91); black residents were less likely to be treated than whites (OR, 0.80; 95% CI, 0.75 to 0.85); and those with severe cognitive (OR, 0.63; 95% CI, 0.60 to 0.67) or physical impairment (OR, 0.69; 95% CI, 0.64 to 0.75) were also less likely to receive drug treatment.

CONCLUSIONS

Stroke is highly prevalent in long-term care. Despite the increased risk of subsequent stroke in the elderly, many are not being treated. The choice to treat or not to treat may be influenced by age, comorbidity, race/ethnicity, and cognitive or physical functioning.

New-Onset Atrial Fibrillation

Background —Although sex differences in coronary artery disease have received considerable attention, few studies have dealt with sex differences in the most common sustained cardiac arrhythmia, atrial fibrillation (AF). Differences in presentation and clinical course may dictate different approaches to detection and management. We sought to examine sex-related differences in presentation, treatment, and outcome in patients presenting with new-onset AF.

Methods and Results —The Canadian Registry of Atrial Fibrillation (CARAF) enrolled subjects at the time of first ECG-confirmed diagnosis of AF. Participants were followed at 3 months, at 1 year, and annually thereafter. Treatment was at the discretion of the patients’ physicians and was not directed by CARAF investigators. Baseline and follow-up data collection included a detailed medical history, clinical, ECG, and echocardiographic measures, medication history, and therapeutic interventions. Three hundred thirty-nine women and 560 men were followed for 4.14±1.39 years. Compared with men, women were older at the time of presentation, more likely to seek medical advice because of symptoms, and experienced significantly higher heart rates during AF. Compared with older men, older women were half as likely to receive warfarin and twice as likely to receive acetylsalicylic acid. Compared with men on warfarin, women on warfarin were 3.35 times more likely to experience a major bleed.

Conclusions —Anticoagulants are underused in older women with AF relative to older men with AF, despite comparable risk profiles. Women receiving warfarin have a significantly higher risk of major bleeding, suggesting the need for careful monitoring of anticoagulant intensity in women.

Epidemiology and natural history of atrial fibrillation: clinical implications

With a substantial impact on morbidity and mortality, the growing "epidemic" of atrial fibrillation (AF) intersects with a number of conditions, including aging, thromboembolism, hemorrhage, hypertension and left ventricular dysfunction. Currently, the epidemiology and natural history of AF govern all aspects of its clinical management. The ongoing global investigative efforts toward understanding AF are also driven by epidemiologic findings. New developments, by affecting the natural history of the disease, could eventually alter the nature of decision making in patients with AF. The crucial issue of rate versus rhythm control awaits completion of the AF Follow-up Investigation of Rhythm Management trial. The processes of electrical and structural remodeling that perpetuate AF appear to be reversible. In the era of functional genomics, the molecular basis of this ubiquitous arrhythmia is in the process of being defined. Unraveling the molecular genetics of AF might provide new insights into the structural and electrical phenotypes resulting from genetic mutations and, as such, new approaches to treatment of this arrhythmia at the ion channel and cellular levels. Thus, current adverse trends are superimposed on a background of a rapidly developing knowledge base and potentially exciting new therapeutic options. Consequently, an understanding of the epidemiology and natural history of AF is crucial to the future allocation of resources and the utilization of an expanding range of therapies aimed at reducing the impact of this disease on a changing patient population.