Prevention of stroke in patients with nonvalvular atrial fibrillation

Factors associated with non-adherence to the use of coumarin derivatives or direct oral anticoagulants: a systematic review of observational studies

Non-adherence to thromboprophylaxis treatment with oral anticoagulants (OAC) is a public health problem and may be associated with high mortality rates. We sought to synthesize the factors associated with non-adherence to therapy with coumarin derivatives or direct oral anticoagulants. A systematic review was performed at electronic databases Medline, Embase, CINAHL, Lilacs and grey literature (Google Scholar, MedNar, OpenGray, ProQuest Dissertations and Theses and hand search). This study was conducted according to Cochrane's method and PRISMA. The registration on PROSPERO is CRD42020223555. Overall, 1,270 studies were identified and nine studies were selected for this review. In hand search, 77 studies were found, but none included. The associated factors with non-adherence were heterogeneous, and some factors were described as both risk and protection for non-adherence, with few variables showing consistent results among the studies. Variables reported only as risk factors were "male sex"; "hospitalization"; "Charlson score" and "bleeding", while "white race"; CHA₂ DS₂ VASc (score range 2-9)" and "polypharmacy" were reported only as protective factors. Most studies did not present details in the description of concepts and methods to assess non-adherence. In clinical practice, the knowledge on factors associated with non-adherence is helpful to identifying patients at higher risk of complications that would benefit from individualized interventions.

Comprehensive Analysis of Pertinent Genes and Pathways in Atrial Fibrillation

PURPOSE

Atrial fibrillation (AF) is the most frequent arrhythmia in clinical practice. The pathogenesis of AF is not yet clear. Therefore, exploring the molecular information of AF displays much importance for AF therapy.

METHODS

The GSE2240 data were acquired from the Gene Expression Omnibus (GEO) database. The R limma software package was used to screen DEGs. Based on the Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Gene Set Enrichment Analysis (GSEA) databases, we conducted the functions and pathway enrichment analyses. Then, the STRING and Cytoscape software were employed to build Protein-Protein Interaction (PPI) network and screen for hub genes. Finally, we used the Cell Counting Kit-8 (CCK-8) experiment to explore the effect of hub gene knockdown on the proliferation of AF cells.

RESULT

906 differentially expressed genes (DEGs), including 542 significantly upregulated genes and 364 significantly downregulated genes, were screened in AF. The genes of AF were mainly enriched in vascular endothelial growth factor-activated receptor activity, alanine, regulation of histone deacetylase activity, and HCM. The PPI network constructed of significantly upregulated DEGs contained 404 nodes and 514 edges. Five hub genes, ASPM, DTL, STAT3, ANLN, and CDCA5, were identified through the PPI network. The PPI network constructed by significantly downregulated genes contained 327 nodes and 301 edges. Four hub genes, CDC42, CREB1, AR, and SP1, were identified through this PPI network. The results of CCK-8 experiments proved that knocking down the expression of CDCA5 gene could inhibit the proliferation of H9C2 cells.

CONCLUSION

Bioinformatics analyses revealed the hub genes and key pathways of AF. These genes and pathways provide information for studying the pathogenesis, treatment, and prognosis of AF and have the potential to become biomarkers in AF treatment.

Direct Oral Anticoagulant Adherence of Patients With Atrial Fibrillation Transitioned from Warfarin

Background

Reduced time in international normalized ratio therapeutic range (TTR) limits warfarin safety and effectiveness. In patients switched from warfarin to direct oral anticoagulants (DOACs), patient factors associated with low TTR could also increase risk of DOAC nonadherence. We investigated the relationship between warfarin TTR and DOAC adherence in warfarin‐treated patients with atrial fibrillation switched to DOAC.

Methods and Results

Using data from the Veterans Health Administration, we identified patients with atrial fibrillation switched from warfarin to DOAC (switchers) or treated with warfarin alone (non‐switchers). Logistic regression was used to evaluate association between warfarin TTR and DOAC adherence. We analyzed 128 605 patients (age, 71±9; 1.6% women; CHA₂DS₂‐VASc 3.5±1.6); 32 377 switchers and 96 228 non‐switchers. In 8016 switchers with international normalized ratio data to calculate 180‐day TTR before switch, TTR was low (median 0.45; IQR, 0.26–0.64). Patients with TTR <0.5 were more likely to be switched to DOAC (odds ratio [OR],1.68 [95% CI,1.62–1.74], P<0.0001), as were those with TTR <0.6 or TTR <0.7. Proportion of days covered ≥0.8 was achieved by 76% of switchers at 365 days. In low‐TTR individuals, proportion of days covered ≥0.8 was achieved by 70%, 72%, and 73% of switchers with TTR <0.5, 0.6, and 0.7, respectively. After multivariable adjustment, TTR <0.5 decreased odds of achieving 365‐day proportion of days covered ≥0.8 (OR, 0.49; 0.43–0.57, P<0.0001), with similar relationships for TTR <0.6 and TTR <0.7. In non‐switchers with TTR <0.5, long‐term TTR remained low.

Conclusions

In patients with atrial fibrillation switched from warfarin to DOAC, most achieved adequate DOAC adherence despite low pre‐switch TTRs. However, TTR trajectories remained low in non‐switchers. Patients with low warfarin TTR more consistently achieved treatment targets after switching to DOACs, although adherence‐oriented interventions may be beneficial.

Clinical Outcomes Associated With Left Atrial Appendage Occlusion Versus Direct Oral Anticoagulation in Atrial Fibrillation

OBJECTIVES

This study sought to investigate clinical outcomes associated with left atrial appendage occlusion (LAAO) versus direct oral anticoagulants (DOACs) in patients with high-risk atrial fibrillation (AF).

BACKGROUND

LAAO has been shown to be noninferior to warfarin for stroke prevention in AF. However, anticoagulation with DOACs is now preferred over warfarin as thromboprophylaxis in AF.

METHODS

Patients with AF enrolled in the Amulet Observational Registry (n = 1,088) who had successful LAAO with the Amplatzer Amulet device (n = 1,078) were compared with a propensity score-matched control cohort of incident AF patients (n = 1,184) treated by DOACs identified from Danish national patient registries. Propensity score matching was based on the covariates of the CHA₂DS₂-VASc (congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, prior stroke or transient ischemic attack or thromboembolism, vascular disease, age 65-74 years, sex category) and HAS-BLED (hypertension, abnormal renal or liver function, stroke, bleeding, labile international normalized ratio, elderly, drugs or alcohol) scores for predicting stroke and bleeding. The primary outcome was a composite of ischemic stroke, major bleeding (Bleeding Academic Research Consortium ≥3), or all-cause mortality, and follow-up was 2 years.

RESULTS

AF patients treated with LAAO had a significantly lower risk of the primary composite outcome as compared with patients treated with DOACs (hazard ratio [HR]: 0.57; 95% confidence interval [CI]: 0.49 to 0.67). Total events and event rates per 100 patient-years were (LAAO vs. DOACs) 256 vs. 461 and 14.5 vs. 25.7, respectively. The risk of ischemic stroke was comparable between groups (HR: 1.11; 95% CI: 0.71 to 1.75), while risk of major bleeding (HR: 0.62; 95% CI: 0.49 to 0.79) and all-cause mortality (HR: 0.53; 95% CI: 0.43 to 0.64) were significantly lower in patients treated with LAAO.

CONCLUSIONS

Among high-risk AF patients, LAAO in comparison with DOACs may have similar stroke prevention efficacy but lower risk of major bleeding and mortality.

Low Quality of Warfarin Therapy is Associated With Female Gender but Not With Polypharmacy in Patients With Atrial Fibrillation

Background: We examined the impact of polypharmacy on the quality of the anticoagulation therapy in patients with atrial fibrillation. We also examined the factors that affect the stability of warfarin therapy.

Methods and Results: This retrospective study was conducted using data from 157 consecutive outpatients with atrial fibrillation in a single tertiary referral hospital. Patients who were prescribed warfarin continuously and for whom PT-INR was examined at least three times in a year were included in this study. We examined the quality of warfarin therapy using time in the therapeutic INR range (TTR), percentage of PT-INR determinations in range (PINRR), and the coefficient variation (CV) of PT-INR. We found that the number of prescribed medicines was significantly associated with high BMI and low eGFR, but not with TTR, PINRR, and the coefficient variation of PT-INR in patients with atrial fibrillation. We also found that female gender was independently associated with low PINRR in this study population.

Conclusion: Polypharmacy did not deteriorate the quality of warfarin therapy in patients with atrial fibrillation treated in the tertiary referral hospital. Female gender was an independent predictor of the low quality of warfarin therapy.

Antithrombotic therapy for stroke prevention in patients with atrial fibrillation in Japan

INTRODUCTION

Stroke remains one of the major public health problems in Japan. The number of patients with atrial fibrillation (AF) has been steadily increasing with the aging of the Japanese population. Appropriate oral antithrombotic therapy is necessary to prevent AF-related stroke and bleeding complications.

AREAS COVERED

The authors summarize the Japanese guidelines for antithrombotic therapy, as well as the current status of antithrombotic therapy, and future perspectives for antithrombotic therapy for patients with AF in Japan.

EXPERT OPINION

Further improvement in adherence to guideline-recommended warfarin therapy may be difficult to achieve. After the introduction of direct oral anticoagulants (DOACs) into clinical practice, the proportion of patients with AF receiving oral anticoagulant therapy has increased in Japan. However, the proportion of patients treated with inappropriately reduced doses of DOACs has also been increasing. Inappropriate dose reduction of DOACs simply because of advanced age should be avoided to reduce stroke events in patients with AF. Among patients with AF receiving anticoagulant therapy who have coronary artery disease, inappropriately prolonged triple therapy or dual therapy should be avoided to reduce major bleeding complications. Shortening the duration of triple therapy or dual therapy may be promoted by simplified recommendations in the 2020-updated guidelines supported by solid evidence.

Low Consultation Rate of General Population with Atrial Fibrillation

In order to prevent ischemic stroke, it is important to identify and treat patients with atrial fibrillation (AF) who do not consult a doctor in a medical institution. The aim of this study was to determine the consultation rate at medical institutions for patients with AF in group medical examinations conducted in a city in western Japan. Of 6101 examinees of group medical examinations (40 years of age or older) conducted in Ibara City, Okayama Prefecture, Japan, from 2012 to 2014, 4338 participants (71.1%) who were evaluated by electrocardiogram (ECG) gave written informed consent and responded to surveys in the form of questionnaires through a personal interview conducted by nurses were included in the Ibara-AF study. A cumulative total of 82 subjects were diagnosed as having AF by ECG (prevalence of AF = 1.89%), and 51 individuals had AF during the three-year period.15 (29.4%) of the 51 patients with AF did not regularly visit medical institutions. Among them, 46.7% (n = 7) and 53.3% (n = 8) of the patients were symptomatic and asymptomatic, respectively, and 73.3% of the patients had a CHADS₂ score of more than one point. There were no significant differences in patients' characteristics between regular and non-regular visit groups. In conclusion, about one-third of the patients with AF did not regularly see a doctor in a medical institution and most of them had a CHADS₂ score of more than one point in a Japanese rural area. Educating the public about the risks of AF is required.

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.

Registry of Japanese patients with atrial fibrillation focused on anticoagulant therapy in the new era: The RAFFINE registry study design and baseline characteristics

BACKGROUND

The management of atrial fibrillation (AF) has evolved with the development of direct oral anticoagulants (DOACs), but data on their clinical effectiveness and safety outside clinical trial settings are limited.

METHOD

The RAFFINE registry is an observational, multicenter, prospective registry of Japanese patients with AF, designed to follow clinical events over 3 years. Patient enrollment was conducted from 2013 to 2015 at university hospitals, general hospitals, and private clinics to ensure inclusion of a broad spectrum of representative AF patients. The primary outcome events in this study will be ischemic stroke, systemic embolism, and major bleeding.

RESULT

We enrolled 3901 ambulatory patients with AF from 4 university hospitals and 50 general hospitals/clinics in Japan. The mean patient age was 72.6 years and 68.5% were male. The type of AF was paroxysmal in 37.8%, persistent in 9.3%, and permanent in 51.7%. Major coexisting diseases were hypertension (72.7%), diabetes mellitus (30.3%), congestive heart failure (23.8%), history of ischemic stroke or transient ischemic attack (15.1%), and coronary artery disease (13.7%). Of the entire cohort, 44.6% were treated with warfarin and 43.0% were treated with DOACs. The prescription of DOACs exceeded that of warfarin in the general hospitals and clinics. Risk scores such as CHADS₂ score, CHA₂DS₂-VASc score, and HAS-BLED score were higher in patients at university hospitals than in patients at general hospitals or clinics.

CONCLUSION

The RAFFINE registry at baseline described the current status of anticoagulation therapy in Japan and long-term follow-up data will identify how outcomes vary between stratified groups in patients with AF in the DOAC era (UMIN Clinical Trials Registry UMIN000009617).

Clinical background including anticoagulant therapy in patients with atrial fibrillation in a community-based survey: the Saitama AF Registry

Atrial fibrillation (AF) is one of the most common cardiac arrhythmias, and carries an increased risk of cardiogenic embolism. Oral anticoagulants (OACs) including warfarin and/or non-vitamin K antagonists can prevent the majority of these events. The Saitama AF Registry was a community-based survey of patients with AF in Saitama City, which represents an urban community in Japan. A total of 75 institutions participated in the registry and attempted to enroll consecutive patients with AF from September 2014 to August 2015. The aim of the present study was to examine the clinical characteristics of patients with AF using data of the Saitama AF Registry. In addition, we investigated the difference in clinical characteristics of the patients between small-sized hospitals and large-sized hospitals. A total of 3591 patients were enrolled; 57.7% of all patients were enrolled from small-sized hospitals, whereas 42.3% were from large-sized hospitals. The patients from small-sized hospitals had higher CHADS₂ score than those from large-sized hospitals. Approximately, 80% of all patients were treated with OACs, and the prescription rate was higher in patients with CHADS₂ score ≥ 2 from both small-sized hospitals and large-sized hospitals. In conclusion, the present study demonstrated an appropriate use of OACs for high-risk patients with CHADS₂ score ≥2 in Saitama City regardless of hospital size.

Risk factors associated with bleeding after multi antithrombotic therapy during implantation of cardiac implantable electronic devices

Previous studies showed that continuous anticoagulation or single antiplatelet therapy during implantations of cardiac implantable electronic devices (CIED) was relatively safe. However, the safety of continuous multi antithrombotic therapy (AT) in patients undergoing CIED interventions has not been clearly defined. We sought to evaluate the safety of this therapy during CIED implantations. A total of 300 consecutive patients (mean 69 years old, 171 males) with CIED implantations were enrolled in this study. The patients were divided into 6 groups [No-AT, oral anticoagulant therapy (OAT), single antiplatelet therapy (SAPT), OAT and SAPT, dual antiplatelet therapy (DAPT), triple AT (TAT)], and the perioperative complications were evaluated. Clinically significant pocket hematomas (PH) were defined as PH needing surgical intervention, prolonged hospitalizations, interruption of AT, or blood product transfusions. There were 129, 89, 49, 20, 10, and 3 patients in No-AT, OAT, SAPT, OAT + SAPT, DAPT, and TAT groups, respectively. The occurrence of clinically significant PH and thromboembolism did not differ among 6 groups (p = 0.145 and p = 0.795, respectively). However, high HAS-BLED score and valvular heart disease (VHD) were associated with clinically significant PH (p = 0.014 and p = 0.015, respectively). Continuous multi AT may be tolerated, but patients with high HAS-BLED score or VHD would require a careful attention during CIED implantations.

Out-of-range international normalized ratio values and healthcare cost among new warfarin patients with non-valvular atrial fibrillation

BACKGROUND

Patients with out-of-range international normalized ratio (INR) values <2.0 and >3.0 have been associated with increased risk of thromboembolic and bleeding events. INR monitoring is costly, because of associated physician and nurse time, laboratory resource use, and dose adjustments.

OBJECTIVES

This study assessed the healthcare cost burden associated with out-of-range INR among warfarin initiator patients diagnosed with non-valvular atrial fibrillation (NVAF) in the US Veterans Health Administration (VHA) population.

METHODS

Adult NVAF patients (≥18 years) initiating warfarin were selected from the VHA dataset for the study period October 1, 2007-September 30, 2012. Only valid INR measurements (0.5 ≤ INR ≤ 20) were examined for the follow-up period, from the index date (warfarin initiation date) until the end of warfarin exposure or death. All-cause healthcare costs within 30 days were measured starting from the second month (31 days post-index date) to the end of the study period. Costs for inpatient stays, emergency room, outpatient facility, physician office visits, and other services were computed separately. Multiple regression was performed using the generalized linear model for overall cost analysis.

RESULTS

In total, 29,463 patients were included in the study sample. Mean costs for out-of-range INR ranged from $3419 to $5126. Inpatient, outpatient, outpatient pharmacy, and total costs were significantly higher after patients experienced out-of-range results (INR < 2, INR > 3), compared with in-range INR (2 ≤ INR ≤ 3). When exposed to out-of-range INR, patients also incurred higher mean total costs within 2-6 months ($3840-$5820) than after the first 6 months ($2789-$3503) of warfarin therapy.

CONCLUSION

In the VHA population, INR measures outside of the 2-3 range were associated with significantly higher healthcare costs. Increased costs were especially apparent when INR values were below 2, although INR measures above 3 were also associated with higher costs relative to in-range values.

Preoperative atrial fibrillation is an independent risk factor for mid-term mortality after concomitant aortic valve replacement and coronary artery bypass graft surgery

OBJECTIVES

Preoperative atrial fibrillation (PAF) has been associated with poorer early and mid-term outcomes after isolated valvular or coronary artery bypass graft surgery. Few studies, however, have evaluated the impact of PAF on early and mid-term outcomes after concomitant aortic valve replacement and coronary aortic bypass graft (AVR-CABG) surgery.

METHODS

Data obtained prospectively between June 2001 and December 2009 by the Australian and New Zealand Society of Cardiac and Thoracic Surgeons National Cardiac Surgery Database Program was retrospectively analysed. Patients who underwent concomitant atrial arrhythmia surgery/ablation were excluded. Demographic and operative data were compared between patients undergoing concomitant AVR-CABG who presented with PAF and those who did not using chi-square and t-tests. The independent impact of PAF on 12 short-term complications and mid-term mortality was determined using binary logistic and Cox regression, respectively.

RESULTS

Concomitant AVR-CABG surgery was performed in 2563 patients; 322 (12.6%) presented with PAF. PAF patients were generally older (mean age 76 vs 74 years; P < 0.001) and presented more often with comorbidities including congestive heart failure, chronic pulmonary disease and cerebrovascular disease (all P < 0.05). PAF was associated with 30-day mortality on univariate analysis (P = 0.019) but not multivariate analysis (P = 0.53). The incidence of early complications was not significantly higher in the PAF group. PAF was independently associated with reduced mid-term survival (HR, 1.58; 95% CI, 1.14-2.19; P = 0.006).

CONCLUSIONS

PAF is associated with reduced mid-term survival after concomitant AVR-CABG surgery. Patients with PAF undergoing AVR-CABG should be considered for a concomitant surgical ablation procedure.

[Acute massive gastrointestinal bleeding in the elderly]

AIM

Acute massive gastrointestinal bleeding appears to be becoming more frequent and complex in elderly patients with increasing longevity and a variety of diseases. because of long-term medication such as anti-thrombotic agents (ATA) for the prevention of cardiovascular diseases, anti-dementia drugs for the treatment of dementia, with increasing longevity and a variety of diseases. We, therefore, conducted a study to clarify these problems from a clinical view point in geriatric medicine.

METHODS

The bleeding sites and the causes were studied in 85 consecutive patients with melena, hematemesis or acute blood loss, on the basis of clinical and emergency endoscopic findings.

RESULTS

The patients were aged 66 to 95 (40 men and 45 women), and the underlying diseases were mainly cerebral infarction in the chronic phase, osteoarthropathy, atrial fibrillation, and dementia. Ten patients had a previous history of peptic ulcer. As initial symptoms, melena, hematemesis and acute anemia were seen in 49, 18 and 18 patients, respectively. Based on assessable endoscopic findings n=83), the bleeding sites were a gastroduodenal ulcer, reflux esophagitis/acute gastric mucosal lesion, colon diverticulum, or alimentary tract cancers in 43.4%, 13.2%, 16.9%, and 16.9%, respectively. A total of 75 patients were treated with some medications (on average 5.3 kinds of medication per patient). Non-steroidal anti-inflammatory drugs (NSAIDs) and/or ATA were common in 63.5% of 85 patients; particularly two thirds of the patients with hemorrhagic gastroduodenal ulcer had used non-aspirin NSAIDs for treatment of osteoarthropathy or acute upper respiratory inflammation, and/or low-dose aspirin for prevention of vascular events. Patients taking ATA over a long period had bleeding from various sites. Steroids, acetylcholinesterase inhibitor (AchEI), selective serotonin-reuptake inhibitor (SSRI), and bisphosphonates were taken by 5, 9, 3 and 3 patients, respectively, frequently in combination with NSAIDs or ATA. Cerebral infarction occurred in 3 of 38 patients after withdrawal of ATA.

CONCLUSIONS

AchEI, SSRI and bisphosphonates, a newly developed group of drugs, have become widely available as geriatric medication. However, it appears that the incidence of drug-related gastrointestinal bleeding is extremely high not only in patients who underwent long-term treatment with NSAIDs or ATA, but also in patients treated chronically with AchEI, SSRI or bisphosphonates in combination with occasional use of NSAIDs. Therefore, to manage elderly patients safely, it is necessary to clarify both the drug and previous histories and consider NSAIDs use with caution even when they are indicated.

Heart and vessel pathology underlying brain infarction in 142 stroke patients

OBJECTIVE

This study was designed to determine the histopathological characteristics of cardiac and vascular lesions responsible for various subtypes of ischemic stroke.

METHODS

Postmortem pathological examination was performed on 142 patients who died within 30 days of the onset of ischemic stroke in the National Cardiovascular Center, Osaka, Japan.

RESULTS

The numbers of cases with autopsy-proven diagnoses of atherothrombotic, cardioembolic, and lacunar strokes, ischemic stroke of other determined causes, and ischemic stroke of undetermined cause were 17, 107, 2, 12, and 4, respectively. Thrombi that developed at the culprit plaques of the cerebral arteries were responsible for atherothrombotic stroke. In 70% of the cases with cardioembolic stroke, the presence of thrombi as potential embolic sources were confirmed in the heart or, in some cases, in the venous circulation of patients with patent foramen ovale and tetralogy of Fallot.

INTERPRETATION

In most atherothrombotic strokes, fibrin- and platelet-rich thrombi of various thicknesses develop at the culprit plaques of the cerebral arteries, which are finally occluded with fibrin- and red-cell-rich thrombi (red thrombi). In most cardioembolic strokes, red thrombi generated in the heart or peripheral veins are dislodged to embolize the cerebral arteries.

[Anticoagulation for stroke prevention. An update]

Given the projected rising prevalence of atrial fibrillation in the near future, an increasing number of older patients will have to be treated in order to prevent stroke and systemic embolism. This article summarizes recent developments in antithrombotic treatment and risk stratification for patients with atrial fibrillation and intends to abate the still prevailing reluctance towards anticoagulation in elderly patients.

Effect of on-admission antiplatelet treatment on patients with cerebral hemorrhage

BACKGROUND

Antiplatelet treatment remains the first choice for primary and secondary prevention of vascular diseases; even so, expected benefits may be offset by risk of bleeding, particularly cerebral hemorrhage. The aim of this study was to assess the influence of antiplatelet treatment on clinical outcome at hospital discharge.

MATERIALS AND METHODS

Consecutive patients with first-ever stroke due to a primary intraparenchymal hemorrhage were prospectively identified over a 4-year period (2000-2003). Data on hemorrhage location, vascular risk factors, and antiplatelet and anticoagulant treatment were collected. At discharge, outcome was measured using the modified Rankin Scale (disabling stroke > or =3). Patients treated with anticoagulant therapy were excluded from the study.

RESULTS

Of 457 consecutive patients with cerebral hemorrhage, 94 (20.5%) had been taking antiplatelet agents. The treated patients (mean age for antiplatelet group 78.9 +/- 9.0 years) were older than the nontreated patients (73.8 +/- 9.4, p = 0.02). In-hospital mortality was 23.4 and 23.1% (p = n.s.) for patients who had been taking antiplatelet agents or no treatment. Poor outcome at discharge was found in 52.1 and 59.7% (p = n.s.), respectively. Univariate analysis showed that age and coma at admission were predictors of disability at discharge, but antiplatelet treatment was not. Additionally, age and coma were shown to be determinants of disability at discharge after multivariate analysis: OR 1.03 per year (95% CI: 1.018-1.049), p < 0.001 and OR 1.68 (95% CI: 1.138-2.503), p = 0.009, respectively.

CONCLUSIONS

Hemorrhagic stroke continues to be responsible for a high percentage of disability and death. Furthermore, it was seen here that functional outcome was independent of previous antiplatelet treatment.

The cost of monitoring warfarin in patients with chronic atrial fibrillation in primary care in Sweden

Background

Warfarin is used for the prevention of stroke in chronic atrial fibrillation. The product has a narrow therapeutic index and to obtain treatment success, patients must be maintained within a given therapeutic range (International Normalised Ratio;INR). To ensure a wise allocation of health care resources, scrutiny of costs associated with various treatments is justified. The objective of this study was to estimate the health care cost of INR controls in patients on warfarin treatment with chronic atrial fibrillation in primary care in Sweden.

Methods

Data from various sources were applied in the analysis. Resource consumption was derived from two observational studies based on electronic patient records and two Delphi-panel studies performed in two and three rounds, respectively. Unit costs were taken from official databases and primary health care centres.

Results

The mean cost of one INR control was SEK 550. The mean costs of INR controls during the first three months, the first year and during the second year of treatment were SEK 6,811, SEK 16,244 and SEK 8,904 respectively.

Conclusion

INR controls of patients on warfarin treatment in primary care in Sweden represent a substantial cost to the health care provider and they are particularly costly when undertaken in home care. The cost may however be off-set by the reduced incidence of stroke.

Resource consumption and management associated with monitoring of warfarin treatment in primary health care in Sweden

BACKGROUND

Warfarin is used for the prevention and treatment of various thromboembolic complications. It is an efficacious anticoagulant, but it has a narrow therapeutic range, and regular monitoring is required to ensure therapeutic efficacy and at the same time avoid life-threatening adverse events. The objective was to assess management and resource consumption associated with patient monitoring episodes during warfarin treatment in primary health care in Sweden.

METHODS

Delphi technique was used to systematically explore attitudes, demands and priorities, and to collect informed judgements related to monitoring of warfarin treatment. Two separate Delphi-panels were performed in three and two rounds, respectively, one concerning tests taken in primary health care centres, involving 34 GPs and 10 registered nurses, and one concerning tests taken in patients' homes, involving 49 district nurses.

RESULTS

In the primary health care panel 10 of the 34 GPs regularly collaborated with a registered nurse. Average time for one monitoring episode was estimated to 10.1 minutes for a GP and 21.4 minutes for a nurse, when a nurse assisted a doctor. The average time for monitoring was 17.6 minutes for a GP when not assisted by a nurse. Considering all the monitoring episodes, 11.6% of patient blood samples were taken in the individual patient's home. Average time for such a monitoring episode was estimated to 88.2 minutes. Of all the visits, 8.2% were performed in vain and took on average 44.6 minutes. In both studies, approximately 20 different elements of work concerning management of patients during warfarin treatment were identified.

CONCLUSION

Monitoring of patients during treatment with warfarin in primary health care in Sweden involves many elements of work, and demands large resources, especially when tests are taken in the patient's home.

Stroke: epidemiology, classification, risk factors, complications, diagnosis, prevention, and medical and dental management

Cerebrovascular accident, or stroke, refers to an acute onset of neurologic deficits lasting more than 24 hours or culminating in death caused by a sudden impairment of cerebral circulation. Stroke is the third leading cause of death and a major cause of long-term disability in the United States. This article provides the dental community with an up-to-date understanding of the epidemiology, classification, risk factors, complications, diagnosis, prevention, and medical and dental management issues pertaining to stroke.

Atrial fibrillation and stroke: from scientific evidence to practice

Nonvalvular atrial fibrillation (NVAF) is the most frequent cause of cardioembolic stroke. Due to the aging of the population, NVAF is becoming an important public health issue. Despite the impressive results of trials with oral anticoagulation (OAC) in primary and secondary prevention of stroke in NVAF patients, OAC remains underused or misused in practice. Beyond the risk of bleeding, there also are several arguments for a lack of knowledge about trials and guidelines. Medical education could then be one of the most effective way to improve stroke prevention in NVAF patients in practice.

Coronary surgery in patients with preexisting chronic atrial fibrillation: early and midterm clinical outcome

BACKGROUND

The purpose of this study was to investigate the effect of preexisting atrial fibrillation on early and midterm clinical outcome in patients undergoing coronary surgery.

METHODS

All elective patients undergoing coronary artery bypass grafting surgery between April 1996 and September 2002 were investigated. Patients were grouped according to their preoperative cardiac rhythm: sinus rhythm (SR) or preexisting atrial fibrillation (AF). In-hospital clinical outcomes and 5-year patient survival and cardiac-related event-free survival were compared using regression methods to adjust for differences between the groups. In all, 5,092 patients were identified, 175 (3.4%) with a history of preexisting AF. These patients were older (median, 64 versus 68 years) and had higher Parsonnet scores (median, 4 versus 8) than the SR group. Previous myocardial infarction, cerebrovascular accident, hypertension, diabetes mellitus, renal impairment, peripheral vascular disease, ejection fraction less than 50%, previous surgery, congestive heart failure, and use of angiotensin-converting enzyme inhibitors were also more common in the AF group.

RESULTS

There were 60 in-hospital deaths (1.2%), with no difference between the two groups (odds ratio 1.02, 95% CI: 0.35 to 2.94). Atrial fibrillation patients were more likely to need intraoperative inotropes (p = 0.044), postoperative intra-aortic balloon pump (p = 0.038), and were less likely to be discharged within 6 days (p = 0.017). The risk of death in the 5 years after surgery was higher in the AF group (relative risk 1.49, 95% CI: 1.06 to 2.08, p = 0.020). In the AF group, 109 (62.2%) patients were cardioverted spontaneously by surgery, but only 69 (39.4%) remained in SR until discharge. Longer-term rhythm follow-up data were available for 48 of these 69 patients, and only 36 remained in SR at a median follow-up of 1,483 days (interquartile range, 1,120 to 2,209). Spontaneous conversion to SR after surgery did not confer a midterm survival benefit (p = 0.91).

CONCLUSIONS

Preexisting AF in patients undergoing coronary artery bypass graft surgery is not associated with increased in-hospital mortality and major morbidity; however, it is a risk factor for reduced 5-year survival. Spontaneous cardioversion to SR during surgery is transient in the majority of patients and is not associated with midterm survival benefit.

Optimal INR for prevention of stroke and death in atrial fibrillation: a critical appraisal

INTRODUCTION

Patients with nonvalvular atrial fibrillation are at increased risk for systemic embolism, predominantly disabling stroke. To study how stroke and mortality rates vary with different degrees of anticoagulation reflected by the international normalised ratio (INR) we critically assess information from different sources.

MATERIALS AND METHODS

1. Computerized search of the medical literature published between 1980 and July 2004 was performed using MEDLINE applied to various combinations of the search terms of atrial fibrillation, warfarin, anticoagulation, anticoagulation intensity, and INR, not restricted by language. 2. We performed a record linkage analysis with death hazard estimated as a continuous function of INR based on 21,967 patients. Similarly the risk of admission to hospital or death due to diseases of the vessels of the brain was estimated. 3. Re-analysis of data earlier published by Hylek et al. from year 2003.

RESULTS AND CONCLUSIONS

1. One randomised study showed a significantly lower risk of stroke for mean INR 2.4 compared to mean INR 1.3 combined with aspirin. Remaining studies found INRs of 2-2.5 to be as efficacious as higher anticoagulation intensities.2. Mortality as well as risk of admission to hospital or death due to diseases of the vessels of the brain followed U-shaped curves with minimum at INR 2.2 and 2.4, respectively. At high INR the risk increased 2.3 times per 1 unit increase of INR for death and 1.7 times for events in the vessels of the brain.3. The re-analysing of data of Hylek et al. indicated that there might be a substantial increase of the risk of intracranial hemorrhage when INR is increased from 2.5 to 4. We conclude that INRs in the interval 2.0--2.5 give the lowest risk of stroke and death in patients with nonvalvular atrial fibrillation.

Low-intensity anticoagulation for stroke prevention in elderly patients with atrial fibrillation: efficacy and safety in actual clinical practice

Low-intensity warfarin (INR 1.5 to 2.5) was started in 63 patients with atrial fibrillation (AF) and they were prospectively followed for 2.3 +/- 1.4 years to determine the efficacy and safety of anticoagulation for stroke prevention in actual clinical practice. Although the patients in this practice were older (76 +/- 7 years), consisted of more women (52%), and had more risk factors for stroke compared with those in clinical trials, the annual event rates of stroke and systemic embolism in this practice were comparable to those of patients receiving warfarin in clinical trials (2.0% vs. 1.4% and 0.7% vs. 0.3%). The rate of major bleeding did not significantly differ between this practice and clinical trials (0.7% vs. 1.3%). The rate of minor bleeding was significantly lower in this practice than in clinical trials (3.4% vs. 7.9%). The data suggest that low-intensity anticoagulation is effective and safe for stroke prevention in elderly patients with AF at stroke risk in actual clinical practice.

From evidence to action

Despite the availability of vast quantities of evidence from basic biomedical and clinical studies, a gap often exists between the optimal practice suggested by the evidence and actual practice. For many clinical situations, however, evidence is unavailable, of poor quality or contradictory. Out of necessity, clinicians have become accustomed to relying on non-evidence-based tools to make decisions. Out of habit, they rely on these tools even when high-quality evidence becomes available. Growing out of an increasing awareness of this problem, the evidence-based medicine (EBM) movement sought to empower clinicians to find the evidence most relevant to a specific clinical question. Various organizations have used EBM techniques to develop systematic reviews and practice guidelines to aid physicians in making evidence-based decisions. A systematic review follows a process of asking a clinical question, finding the relevant evidence, critically appraising the evidence and formulating conclusions and recommendations. Results are mixed on whether educating physicians about evidence-based recommendations is sufficient to change physician behavior. Barriers to adopting evidence-based best practice remain, including physician skepticism, patient expectations, fear of legal action, and distorted reimbursement systems. Additionally, despite enormous research efforts there remains a lack of high-quality evidence to guide care for many clinical situations.

Antithrombotic Management after an Ischemic Stroke in French Primary Care Practice: Results from Three Pooled Cross-Sectional Studies

BACKGROUND AND PURPOSE

We aimed at quantifying and explaining the underuse of antithrombotic treatments after an ischemic stroke in patients seen in French primary care.

METHODS

We pooled all ischemic stroke patients included in 3 observational primary care-based observational studies. French general practitioners and cardiologists recruited 14,544 patients with atherothrombotic disease including 4,322 with an ischemic stroke. Antithrombotic therapies and risk factors were prospectively recorded. Patients with atrial fibrillation (AF) were considered appropriate for oral anticoagulants (OAC) and those without AF for antiplatelet drugs.

RESULTS

Out of the 4,322 stroke patients, 3,732 (86.3%) were taking at least one antithrombotic drug. Among the 765 patients with AF, 333 (43.5%) received OAC and 2,718 (86.9%) out of the 3,129 patients appropriate for antiplatelet drug were taking antiplatelet drug. Multivariate analyses did not single out any risk factors for nonuse of OAC and showed that female sex (OR = 1.48; IC 95%: 1.14-1.92) was associated with nonuse of antiplatelet drugs. Conversely, past myocardial infarction (OR = 0.44; IC 95%: 0.26-0.71) and hypercholesterolemia (OR = 0.64; IC 95%: 0.50-0.81) were associated with appropriate use of antiplatelet drugs.

CONCLUSION

More than 50% of stroke patients with AF do not receive OAC and 15% of those without AF do not receive antiplatelet drugs. These findings are not satisfactorily explained by the main patients' characteristics and practitioner's speciality and underline the complexity of the process which allows the transfer of scientific evidence in clinical practice.

Oral anticoagulants for preventing stroke in patients with non-valvular atrial fibrillation and no previous history of stroke or transient ischemic attacks

BACKGROUND

Non-valvular atrial fibrillation (AF) is associated with an increased risk of stroke mediated by embolism of stasis-precipitated thrombi from the left atrial appendage.

OBJECTIVES

The objective is to characterize the efficacy and safety of oral anticoagulants (OACs) for the primary prevention of stroke in patients with chronic AF.

SEARCH STRATEGY

We searched the Cochrane Stroke Group Trials Register (last searched in June 2004). In addition, we searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 4, 2004), MEDLINE (1966 to June 2004), and the reference lists of recent review articles. We also contacted the Atrial Fibrillation Collaboration and experts working in the field to identify unpublished and ongoing trials.

SELECTION CRITERIA

All randomized controlled trials comparing OACs with control in patients with chronic non-valvular atrial fibrillation and no history of transient ischemic attack (TIA) or stroke.

DATA COLLECTION AND ANALYSIS

Trials for inclusion were independently selected by two authors who also extracted each outcome and double-checked the data. The Peto method was used for combining odds ratios. All analysis were, as far as possible, intention-to-treat. Since the published results of four trials included 3% to 8% of participants with prior stroke or TIA, unpublished results excluding these participants were obtained from the Atrial Fibrillation Investigators.

MAIN RESULTS

Of 2313 participants without prior cerebral ischemia from five randomized trials, the mean age was 69 years. Participant features and study quality were similar between trials: the OAC in all five trials was warfarin. About half of participants (n = 1154) were randomized to adjusted-dose warfarin with mean achieved INRs ranging between 2.0 to 2.6. During 1.5 years mean follow up, warfarin was associated with large, highly statistically significant reductions in all strokes (odds ratio (OR) 0.39, 95% confidence interval (CI) 0.26 to 0.59), ischemic stroke (OR 0.34, 95% CI 0.23 to 0.52), all disabling or fatal stroke (OR 0.47, 95% CI 0.28 to 0.80), death (OR 0.69, 95% CI 0.50 to 0.94) and the combined endpoint of all stroke, myocardial infarction or vascular death (OR 0.56, 95% CI 0.42 to 0.76). The observed rates of intracranial and extracranial hemorrhage were not significantly increased by OAC therapy, but the confidence intervals were wide.

AUTHORS' CONCLUSIONS

Treatment with adjusted-dose warfarin to achieved INRs of 2 to 3 reduces stroke, disabling or fatal stroke, and death for patients with non-valvular AF. The benefits were not substantially offset by increased bleeding among these participants in randomized clinical trials. Limitations include relatively short follow up and imprecise estimates of bleeding risks from the selected participants enrolled in the trials. For primary prevention of stroke in AF patients, about 25 strokes and about 12 disabling or fatal strokes would be prevented yearly for every 1000 atrial fibrillation patients given OACs.

Atrial fibrillation in patients with first-ever stroke: frequency, antithrombotic treatment before the event and effect on clinical outcome

BACKGROUND AND PURPOSES

Atrial fibrillation (AF) is an independent risk factor for stroke. The aims of this study were to assess: (i) the frequency of known or unknown AF in patients admitted to the hospital for a first-ever ischemic stroke and whether AF is associated with an adverse outcome at discharge (death or disability); (ii) the rates and determinants for the use of antithrombotic agents before stroke in patients with known AF and the adherence to the current treatment guidelines; and (iii) whether the lack of adherence to the current guidelines is associated with adverse outcome at discharge.

METHODS

Consecutive patients with acute first-ever stroke admitted to an individual Stroke Unit between January 2000 to December 2003, were included in the study. Twelve-lead electrocardiogram (ECG) was performed in all patients on admission. Functional outcome was measured at discharge according to modified Rankin Score.

RESULTS

A total of 1549 patients were included in the study: 238 patients (15.4%) were known to have AF and 76 (4.9%) were diagnosed with AF (unknown) on ECG performed on admission. At discharge 91 patients (5.9%) had died and 605 patients (39.0%) had died or were functionally dependent. Multivariate analysis showed that AF on admission was correlated with mortality or disability (OR = 1.58, 95% CI 1.09-2.30, P = 0.015). Before stroke, 124 out of 238 patients with known AF (52.1%) were not on antithrombotic therapy, 83 (34.9%) were receiving antiplatelet and 31 (13.0%) anticoagulant treatment. Previous transient ischemic attack, history of ischemic heart disease and hyperlipidemia were associated with the use of antithrombotic therapy. Only 24 out of 114 patients on antithrombotic treatment on admission were adequately treated according to the current guidelines. Of the adequately treated patients, 41.7% died or were disabled at discharge respect to 52.3% of the patients non-adequately treated (RR = 0.80, 95% CI 0.48-1.30).

CONCLUSIONS

AF (on history or new diagnosis) was present in 20.3% of the patients with first-ever stroke admitted to a Stroke Unit and it was associated with increased mortality or disability. Only 10% of patients with known AF were previously receiving an adequate antithrombotic treatment according to current guidelines.

Predictors of anticoagulation prescription in nursing home residents with atrial fibrillation

OBJECTIVES

To determine predictors of oral anticoagulation (OAC) for atrial fibrillation (AF) in long-term care (LTC).

DESIGN

Chart review.

SETTING

Six LTC facilities in a metropolitan area.

PARTICIPANTS

One hundred seventeen residents with AF identified from 934 total residents.

MEASUREMENTS

Data was obtained from the medical chart, pharmacy record, and Minimum Data Set (MDS) regarding demographics, medical conditions, falls, fractures, gastrointestinal bleeding (GIB), peptic ulcer disease, dementia, anemia, and physical/cognitive function scales. The recursive partition algorithm was used to construct a model reflecting physician decision patterns that predict prescription of OAC.

RESULTS

Among those 117 residents (12.5% of 934) who had AF (age, 84.6 +/- 8 years), OAC was prescribed for 54 (46%); aspirin or clopidogrel: 47 (40%); neither OAC nor any antithrombotic treatment (ATT): 25 (21%). Prior stroke was the primary determinant of OAC. Residents with prior stroke were less likely to be prescribed OAC if they had prior GIB, were non-Caucasian, or had no history of coronary artery disease (CAD). Those without a stroke were less likely to be prescribed OAC if they were younger, had dementia or lower functional status.

CONCLUSION

Prior stroke was the primary predictor of OAC use. Our model suggests that physicians may also incorporate concerns of age, bleeding, cognitive and physical function, and ethnicity into the decision-making process. Further study is needed to explore the reasons why 21% of the residents receive neither OAC nor ATT, and why OAC may be less likely to be prescribed to non-Caucasian LTC residents.

Aging and oral anticoagulant therapy using acenocoumarol

We evaluated the influence of aging, gender and indications of anticoagulant therapy on acenocoumarol requirements in 1845 patients from 30 to 99 years old receiving acenocoumarol therapy who were monitored in our hospital outpatient anticoagulation clinic from March 1993 through September 1999. The patients were stratified in seven age groups, comprising older than 80 years and the five decades between 30 years and 80 years. We found a progressive decrease in the acenocoumarol requirements from 30 years to 80 years (rho=-0.98), which was estimated as 2.7 mg/week per decade (11.5% per decade). This decrease was not the consequence of a different range of anticoagulation or differences in body weight. We did not find correlation between the decrease of acenocoumarol requirements and different biochemical parameters including, creatinine, calcium and alanine aminotransferase. We detected a progressive decrease in levels of serum total proteins but changes in this parameter did not correlate with the amount of acenocoumarol requirements. The dose of acenocoumarol (mg/week per patient) of those patients suffering from venous thromboembolism were higher than the remainder of the patients (18.4 +/- 9.3 versus 14.5 +/- 7.8, P <0.0001). This finding was also detected, after stratifying the patients by decades, from 60 years to 80 years. In conclusion, requirements of acenocoumarol decrease with aging; this decrease represents an important amount from 30 years to 80 years and it should be kept in mind to choose the initial dose of acenocoumarol. Patients with venous thromboembolism required a higher dose of acenocoumarol.