Frequency of major complications of aspirin, warfarin, and intravenous heparin for secondary stroke prevention. A population-based study

The efficacy of virtual reality for upper limb rehabilitation in stroke patients: a systematic review and meta-analysis

BACKGROUND

Stroke frequently gives rise to incapacitating motor impairments in the upper limb. Virtual reality (VR) rehabilitation has exhibited potential for augmenting upper extremity recovery; nonetheless, the optimal techniques for such interventions remain a topic of uncertainty. The present systematic review and meta-analysis were undertaken to comprehensively compare VR-based rehabilitation with conventional occupational therapy across a spectrum of immersion levels and outcome domains.

METHODS

A systematic search was conducted in PubMed, IEEE, Scopus, Web of Science, and PsycNET databases to identify randomized controlled trials about upper limb rehabilitation in stroke patients utilizing VR interventions. The search encompassed studies published in the English language up to March 2023. The identified studies were stratified into different categories based on the degree of immersion employed: non-immersive, semi-immersive, and fully-immersive settings. Subsequent meta-analyses were executed to assess the impact of VR interventions on various outcome measures.

RESULTS

Of the 11,834 studies screened, 55 studies with 2142 patients met the predefined inclusion criteria. VR conferred benefits over conventional therapy for upper limb motor function, functional independence, Quality of life, Spasticity, and dexterity. Fully immersive VR showed the greatest gains in gross motor function, while non-immersive approaches enhanced fine dexterity. Interventions exceeding six weeks elicited superior results, and initiating VR within six months post-stroke optimized outcomes.

CONCLUSIONS

This systematic review and meta-analysis demonstrates that adjunctive VR-based rehabilitation enhances upper limb motor recovery across multiple functional domains compared to conventional occupational therapy alone after stroke. Optimal paradigms likely integrate VR's immersive capacity with conventional techniques.

TRIAL REGISTRATION

This systematic review and meta-analysis retrospectively registered in the OSF registry under the identifier [ https://doi.org/10.17605/OSF.IO/YK2RJ ].

Antithrombotics and Gastrointestinal Prophylaxis: A Systematic Review

Antithrombotic medications include both antiplatelet and anticoagulants and are used for a wide variety of cardiovascular conditions. A common complication of antithrombotic use is gastrointestinal bleeding. As a result, gastrointestinal prophylaxis is a common consideration for patients on a single or combination antithrombotic regimen. Prophylaxis is typically achieved through use of either proton pump inhibitors or histamine 2 receptor antagonists. Current recommendations for use of gastrointestinal prophylaxis with concomitant use of antithrombotic medications are scarce. In this systematic review, we explore the current evidence and recommendations regarding gastrointestinal prophylaxis for patients on antiplatelet or anticoagulant therapy as well as combination regimens.

Reduced Time to Procedure for Gastrointestinal Bleeding After Warfarin Reversal With Four-Factor Complex Concentrate as Compared to Plasma

Background

Bleeding is a serious adverse effect of vitamin K antagonists (VKAs). Anticoagulation reversal is required in some acute cases. This is usually accomplished by plasma transfusion or four-factor prothrombin complex concentrate (4F-PCC). The aim of this study was to gain insight into the clinical course of patients with gastrointestinal (GI) bleeding who require VKA reversal.

Methods

Medical records were collected from two centers from patients who presented to the emergency department (ED) for GI bleeding and received 4F-PCC or plasma for VKA reversal between January 2015 and December 2020. ED, hospital, intensive care unit (ICU) length of stay (LOS) as well as time from admission to GI procedure were determined.

Results

4F-PCC patients (n = 49) as compared to plasma (n = 63) patients were found to have a greater number of comorbidities (average of 4.2 vs. 2.7 comorbidities/patient) and more ICU admissions (47% vs. 21%). Time to GI procedure was significantly decreased in the 4F-PCC group (median (interquartile range (IQR)) 19.47 (9.23 - 30.25) vs. 27.88 (21.38 - 45.00) h; P = 0.01). When adjusting for comorbidities, differences in time to GI procedures were also significant in favor of 4F-PCC regardless of any comorbidities (P = 0.014), in atrial fibrillation (P = 0.045) and in hypertension (P = 0.02). The 4F-PCC patients had shorter LOS in the ED and ICU.

Conclusions

Our study demonstrated that compared to plasma, 4F-PCC was utilized in more acutely ill patients with higher rates of comorbidities and ICU admission. Nevertheless, the patients who received 4F-PCC had faster access to GI procedure and shorter ED and ICU LOS.

Clinical burden, risk factor impact and outcomes following myocardial infarction and stroke: A 25-year individual patient level linkage study

BACKGROUND

Understanding trends in the incidence and outcomes of myocardial infarction and stroke, and how these are influenced by changes in cardiovascular risk factors can inform health policy and healthcare provision.

METHODS

We identified all patients 30 years or older with myocardial infarction or stroke in Scotland. Risk factor levels were determined from national health surveys. Incidence, potential impact fractions and burden attributable to risk factor changes were calculated. Risk of subsequent fatal and non-fatal events (myocardial infarction, stroke, bleeding and heart failure hospitalization) were calculated with multi-state models.

FINDINGS

From 1990 to 2014, there were 372,873 (71±13 years) myocardial infarctions and 290,927 (74±13 years) ischemic or hemorrhagic strokes. Age-standardized incidence per 100,000 fell from 1,069 (95% confidence interval, 1,024-1,116) to 276 (263-290) for myocardial infarction and from 608 (581-636) to 188 (178-197) for ischemic stroke. Systolic blood pressure, smoking and cholesterol decreased, but body-mass index increased, and diabetes prevalence doubled. Changes in risk factors accounted for a 74% (57-91%) reduction in myocardial infarction and 68% (55-83%) reduction in ischemic stroke. Following myocardial infarction, the risk of death decreased (30% to 20%), but non-fatal events increased (20% to 24%) whereas the risk of both death (47% to 34%) and non-fatal events (22% to 17%) decreased following stroke.

INTERPRETATION

Over the last 25 years, substantial reductions in myocardial infarction and ischemic stroke incidence are attributable to major shifts in risk factor levels. Deaths following the index event decreased for both myocardial infarction and stroke, but rates remained substantially higher for stroke.

FUNDING

British heart foundation.

Comparison of efficiency and safety of rivaroxaban, apixaban and enoxaparin for thromboprophylaxis after arthroplastic surgery: a meta-analysis

OBJECTIVE

To compare the efficacy and safety of rivaroxaban, apixaban and enoxaparin for thromboprophylaxis after arthroplastic surgery.

METHODS

We conducted a meta-analysis containing a wide range of randomized controlled trials about efficiency and safety of rivaroxaban, apixaban and enoxaparin for thromboprophylaxis after arthroplastic surgery in the recent decade from January 2006 to June 2018. The present study separately analyzed the following key components: the different efficiency and safety for rivaroxaban and enoxaparin; apixaban and enoxaparin; and enoxaparin and other new developed anticoagulants.

RESULTS

Sixteen studies containing 58885 patients were included. In results of efficacy outcomes, total events occurred in 4.89% patients of rivaroxaban group and 9.55% patients of the control group; however, no significant difference was observed in apixaban groups of their efficacy outcomes. Primary events didn't show significant difference when comparing apixaban with the control or comparing enoxaparin with the control. In analysis of safety outcomes, bleeding events occurred in 3.41% patients of rivaroxaban group compared with 2.84% patients of the control groups; bleeding events in apixaban groups were 4.09% compared with the control groups 4.64%. Bleeding events occurred in 3.51% patients of enoxaparin group, slightly lower than 5.82% of the control group.

CONCLUSION

Direct oral anticoagulant, rivaroxaban might have better efficacy outcomes in thromboprophylaxis after arthroplastic surgery; however, apixaban showed no significantly different efficacy outcomes compared with enoxaparin, and enoxaparin may have equal or even better safety outcomes compared with direct oral anticoagulants.

Serious hemorrhages after ischemic stroke or TIA - Incidence, mortality, and predictors

Background

Data are lacking on the risk and impact of a serious hemorrhage on the prognosis after ischemic stroke (IS) or transient ischemic attack (TIA). We aimed to estimate the incidence of serious hemorrhage, analyze the impact on mortality, and identify predictors of hemorrhage after discharge from IS or TIA.

Methods and findings

All patients admitted to Östersund Hospital for an IS or TIA in 2010–2013 were included (n = 1528, mean age: 75.1 years). Serious hemorrhages were identified until 31^st December 2015. Incidence rates were calculated. The impact on mortality (stratified by functional level) was determined with Kaplan-Meier analysis. Non-parametric estimation under the assumption of competing risk was performed to assess the cumulative incidence and predictors of serious hemorrhages.

The incidence rates of serious (n = 113) and intracranial hemorrhages (n = 45) after discharge from IS and TIA were 2.48% and 0.96% per year at risk, respectively. Patients with modified Rankin Scale (mRS) scores of 3–5 exhibited 58.9% mortality during follow-up and those with mRS scores of 0–2 exhibited 18.4% mortality. A serious hemorrhage did not affect mortality in patients with impaired functional status, but it increased the risk of death in patients with mRS scores of 0–2. Hypertension was associated with increased risk of serious hemorrhage.

Conclusions

We found that, after discharge from an IS or TIA, serious hemorrhages were fairly common. Impairments in function were associated with high mortality, but serious hemorrhages only increased the risk of mortality in patients with no or slight disability. Improved hypertension treatment may decrease the risk of serious hemorrhage, but in patients with low functional status, poor survival makes secondary prevention challenging.

Bleeding with anticoagulant treatments

Anticoagulation with vitamin K antagonists (VKAs) is effective in the prevention and treatment of thrombotic complications in many clinical conditions, including atrial fibrillation (that represents today the most frequent indication for anticoagulant treatment), venous thromboembolism, acute coronary syndromes and after invasive cardiac procedures. Bleeding is the most important complication of VKAs and a major concern for both physicians and patients, limiting a more widespread prescription of the treatment. As a result, a non negligible proportion of all the subjects who would have a clear clinical indication for anticoagulation do not receive an effective treatment.

This review analyses the treatment- and person-associated risk factors for bleeding during VKAs. New oral anticoagulant drugs seems to overcome at least some of the limitations of VKAs. Potentially, they can allow a less demanding and more stable anticoagulant treatment, with less side-effects allowing that more patients can receive an appropriate anticoagulant treatment. Based on the so far available phase III clinical studies, it is possible to assume that these new drugs are associated with a risk of bleeding, that is probably related to the intensity of treatment.

Secondary Prevention of Ischemic Cerebrovascular Disease. What Is the Evidence?

Patients who had a transient ischemic attack or stroke are at increased risk of experiencing recurrent cerebrovascular events. For this reason, secondary prevention of ischemic cerebrovascular disease is essential. Several modifiable, lifestyle-associated risk factors have been implicated, such as physical activity, smoking, and alcohol consumption. Established and emerging vascular risk factors are associated with an increased risk of stroke. Pharmacologic treatment, including the use of antiplatelet, antihypertensive, and lipid-lowering agents, has also been shown to reduce the risk of secondary cerebrovascular events. Surgical intervention, either open or endovascular, may be the preferred therapeutic option in well-defined subsets of patients. It is important to establish specific measures for the early detection and prevention of recurrent cerebrovascular disease. Therefore, further research and greater awareness in this field are needed.

Cost-Effectiveness of Echocardiography to Identify Intracardiac Thrombus among Patients with First Stroke or Transient Ischemic Attack

Background and Purpose . Echocardiography to select stroke patients for targeted treatments, such as anticoagulation (AC), to reduce recurrent stroke risk is controversial. The authors' objective was to evaluate the cost-effectiveness of imaging strategies that use transthoracic (TTE) and transesophageal (TEE) echocardiography for identifying intracardiac thrombus in new stroke patients. Methods . Model-based cost-effectiveness analysis of 7 echocardiographic imaging strategies and 2 nontesting strategies with model parameters based on systematic evidence review related to effectiveness of echocardiography in newly diagnosed ischemic stroke patients (white males aged 65 years in base case). Primary outcome was cost per quality-adjusted life year (QALY). Results . All strategies containing TTE were dominated by others and were eliminated from the analysis. Assuming that AC reduces recurrent stroke risk from intracardiac thrombus by 43% over 1 year, TEE generated a cost per QALY of $137,000 (relative to standard treatment) among patients with 5% thrombus prevalence. Cost per QALY dropped to $50,000 in patients with at least 15% intracardiac thrombus prevalence, or, if an 86% relative risk reduction with AC is assumed, in patients with thrombus prevalence of at least 6%. Probabilistic analyses indicate considerable uncertainty around the cost-effectiveness of echocardiography across a wide range of intracardiac thrombus prevalence (pretest probability). Conclusions . Current evidence on cost-effectiveness is insufficient to justify widespread use of echocardiography in stroke patients. Additional research on recurrent stroke risk in patients with intracardiac thrombus and on the efficacy of AC in reducing that risk may contribute to a better understanding of the circumstances under which echocardiography will be cost-effective. Key words: cost-effectiveness; decision analysis; stroke; transesophageal echocardiography; transthoracic echocardiography; diagnostic imaging. (Med Decis Making 2007;27:161—177)

A Randomized Trial of Pharmacogenetic Warfarin Dosing in Naïve Patients with Non-Valvular Atrial Fibrillation

Genotype-guided warfarin dosing have been proposed to improve patient’s management. This study is aimed to determine whether a CYP2C9- VKORC1- CYP4F2-based pharmacogenetic algorithm is superior to a standard, clinically adopted, pharmacodynamic method. Two-hundred naïve patients with non-valvular atrial fibrillation were randomized to trial arms and 180 completed the study. No significant differences were found in the number of out-of-range INRs (INR<2.0 or >3.0) (p = 0.79) and in the mean percentage of time spent in the therapeutic range (TTR) after 19 days in the pharmacogenetic (51.9%) and in the control arm (53.2%, p = 0.71). The percentage of time spent at INR>4.0 was significantly lower in the pharmacogenetic (0.7%) than in the control arm (1.8%) (p = 0.02). Genotype-guided warfarin dosing is not superior in overall anticoagulation control when compared to accurate clinical standard of care.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01178034.

Intracranial Hemorrhage After Ischemic Stroke: Incidence, Time Trends, and Predictors in a Swedish Nationwide Cohort of 196 765 Patients

BACKGROUND

Epidemiological data on the risk of intracranial hemorrhage (ICrH) after ischemic stroke are sparse. The aims of this study were to describe incidence, trends over time, and predictors of ICrH within 1 year after ischemic stroke.

METHODS AND RESULTS

All patients registered in the Swedish stroke register Riksstroke for 1998 to 2009 were included (n=196 765), and data were combined with the National Patient Register to identify ICrH occurrence. A matched reference population was obtained. Incidence rates and cumulative incidences were calculated. Multivariable regression analyses were used to identify predictors. Analyses were performed separately for the first 30 days and days 31 to 365 after ischemic stroke. The incidence rate was 1.97% per year at risk for the first year (0.13% in the reference population) and 0.85% excluding the first 30 days. Over time, the cumulative incidence increased the first 30 days but decreased over days 31 to 365. Thrombolysis, previous ICrH, atrial fibrillation, and male sex were associated with increased risk of ICrH during the first 30 days. Previous ICrH, increasing age, and male sex were associated with increased risk during days 31 to 365. Statins and antithrombotic treatment did not independently predict ICrH occurrence.

CONCLUSIONS

The incidence of ICrH within 1 year after ischemic stroke was ≈2% per year at risk, about 15 times higher compared with the reference population. Over the study period, ICrH risk increased within the first 30 days but decreased thereafter. Previous ICrH, thrombolysis, and male sex affected the risk, whereas an increased use of antithrombotic treatments and statins did not.

Market Access Advancements and Challenges in "Drug-Companion Diagnostic Test" Co-Development in Europe

The pharma ecosphere is witnessing a measured transformation from the one-size-fits-all or blockbuster model of drugs to more informed and tailored personalized treatments that facilitate higher safety and efficacy for a relevant sub-population. However, with several breakthroughs still in a nascent stage, market access becomes a crucial factor for commercial success, especially when it comes to co-creating value for pertinent stakeholders. This article highlights diverse issues from stakeholder perspectives in Europe, specifically the ones which require immediate resolution. Furthermore, the article also discusses case studies articulating potential solutions for the issues discussed.

Drug adherence in patients taking oral anticoagulation therapy

Oral anticoagulation has proven to reduce mortality and morbidity of thromboembolic events. One of the most important determinants of the effectiveness and safety of anticoagulation therapy is the adherence to the prescribed therapy. Vitamin K antagonists are characterized by under-utilization, a narrow therapeutic window and multiple food and drug interactions which contribute to a variable dose-response relationship with the risk of insufficient protection and/or increased bleeding risk. The "new" direct oral anticoagulants have demonstrated equal or superior protection and reduced bleeding risks compared to warfarin and are easier to use because of fixed dosing without monitoring of anticoagulation. Controlling of adherence to the direct oral anticoagulants is difficult. Therefore, continuous and regular medication intake represents a pre-requisite for achieving optimal protection. The present review aims to give an overview about the factors that affect drug adherence in patients taking oral anticoagulation drugs and discusses strategies to improve drug adherence.

Hemorrhage after ischemic stroke - relation to age and previous hemorrhage in a nationwide cohort of 58,868 patients

BACKGROUND

In randomized controlled trials of secondary prevention after stroke, the risk of hemorrhage varies between 1% and 5% per year in patients with antithrombotic therapy, i.e. anticoagulants and antiplatelets.

AIM

To explore the rate and the risk of hemorrhage after stroke in a nationwide cohort.

METHODS

We identified 58 868 first ever ischemic stroke patients in the Swedish Stroke Register during 2001 to 2005 (=index stroke) and followed them by record linkage to the National Patient Register. Rates of hemorrhage and hazard ratios, for comparisons of rates between subgroups, were calculated.

RESULTS

Of the 58 586 ischemic stroke patients identified, 5527 (9·4%) had a history of hemorrhage. During follow-up (mean 2·0 years), 2876 patients endured a hemorrhage, giving an average hemorrhage rate of 2·6 (95% confidence interval 2·5-2·7) per 100 person-years. After index stroke, 11% of the patients were discharged with anticoagulants, and 79% with antiplatelets. Given the differences in baseline characteristics, the hemorrhage rates (per 100 person-years) were 2·5 (95% confidence interval 2·2-2·8), 2·4 (95% confidence interval 2·3-2·5), and 3·8 (95% confidence interval 3·5-4·2) in patients prescribed anticoagulants, antiplatelets, and no antithrombotics, respectively. There was an increased risk of hemorrhage in patients ≥75 years compared with those <75 years (hazard ratio = 1·61, 95% confidence interval 1·49-1·73) and in patients with previous hemorrhages compared with those without (hazard ratio = 1·82, 95% confidence interval 1·64-2·02).

CONCLUSIONS

When antithrombotics were used in large-scale clinical practice, the observed rates of hemorrhage were similar with anticoagulant therapy but increased with antiplatelet therapy compared with rates reported in randomized controlled trials. Old age and previous hemorrhage were associated with an increased risk of hemorrhage after an ischemic stroke.

Appropriateness of treatment recommendations for PPI in hospital discharge letters

Purpose

The reasons for the dramatic increase in proton pump inhibitors (PPI) prescriptions remain unclear and cannot be explained solely by increased morbidity, new indications or a decrease in alternative medication. Inappropriate use and discharge recommendations in hospitals are considered to be possible explanations. As the quality of PPI recommendations in hospital discharge letters in Germany has not been investigated to date, we have studied the appropriateness of these referrals.

Methods

Hospital discharge letters with recommendations for PPI medication from 35 primary care practices in the county of Mecklenburg-Western Pomerania (MV; North-east Germany) were collected and analysed, and the appropriateness of the PPI indication was rated.

Results

No information justifying the recommendation for continuous PPI medication could be identified in 54.5% of the discharge letters; in 12.7%, the indication was uncertain, and in 32.7%, we found an evidence-based indication for PPI medication. The most common indication for adequate PPI use was nonsteroidal anti-inflammatory drug-prophylaxis in high-risk patients.

Conclusions

Inadequate recommendations for PPIs in discharge letters are frequent. This may lead to a continuation of this therapy in primary care, thereby unnecessarily increasing polypharmacy and the risk of adverse events as well as burdening the public health budget. Hospitals should therefore critically review recommendations for PPI medication and the dosage thereof in their discharge letters and clearly document the reason for PPI use and the need for continuous prescription in primary care.

Pharmacogenetics in cardiovascular antithrombotic therapy

Thrombosis is the most important underlying mechanism of coronary artery disease and embolic stroke. Hence, antithrombotic therapy is widely used in these scenarios. However, not all patients achieve the same degree of benefit from antithrombotic agents, and a considerable number of treated patients will continue to experience a new thrombotic event. Such lack of clinical benefit may be related to a wide variability of responses to antithrombotic treatment among individuals (i.e., interindividual heterogeneity). Several factors have been identified in this interindividual heterogeneity in response to antithrombotic treatment. Pharmacogenetics has emerged as a field that identifies specific gene variants able to explain the variability in patient response to a given drug. Polymorphisms affecting the disposition, metabolism, transporters, or targets of a drug all can be implicated in the modification of an individual's antithrombotic drug response and therefore the safety and efficacy of the aforementioned drug. The present paper reviews the modulating role of different polymorphisms on individuals' responses to antithrombotic drugs commonly used in clinical practice.

Pharmacogenetic relevance of CYP4F2 V433M polymorphism on acenocoumarol therapy

VKORC1 and CYP2C9 polymorphisms are used to predict the safe dose of oral anticoagulant therapy. A new variant of CYP4F2 (V433M) has recently been related to the required warfarin dose. We evaluated its influence in earliest response to acenocoumarol in 100 selected men who started anticoagulation (3 mg for 3 consecutive days). V433M genotype exerted a gene dosage-dependent effect on the decrease of factors II, VII, IX, and X in the earliest response to acenocoumarol, with homozygous 433V subjects being the most sensitive. Similarly, after the initiation of therapy, international normalized ratio also experienced a gene dosage-dependent effect (P = .015), and 433V subjects needed 4 mg/week less than 433M carriers to achieve a steady anticoagulation (P = .043). Multivariate linear regression analysis revealed a significant contribution of V433M polymorphism to variability of both early international normalized ratio value (R2 = 0.14) and dose requirements (R2 = 0.19). Our data underline the relevant role of CYP4F2 V433M polymorphism in the pharmacogenetics of coumarin anticoagulants.

Ethnic differences in warfarin maintenance dose requirement and its relationship with genetics

Warfarin is a highly efficacious drug, but management of warfarin is difficult, in part because of the large interindividual maintenance dose differences. Warfarin dose requirements differ by race and it has been suggested that some of these differences are owing to genetic diversity. For example, persons of African descent have lower allele frequencies of the CYP2C9*2 and *3 and VKORC1 1173T allele, which have been associated with lower warfarin dose requirements in Caucasians. Since there is currently debate whether genetic information should be used in clinical practice to determine the starting dose for a warfarin initiator, it is of great importance to determine whether everyone will benefit from this knowledge.

Gastrointestinal bleeding in the setting of anticoagulation and antiplatelet therapy

GOAL

To review the literature on the significance, risk factors, and management of occult and gross gastrointestinal (GI) bleeding in patients on antiplatelets and/or anticoagulants.

STUDY

Relevant original and review articles and their bibliographies were analyzed. Estimates of risks and therapeutic outcomes were obtained from randomized trials, whereas risk factor identification was gathered from cross-control and prospective cohort studies.

RESULTS

Antiplatelets and anticoagulants do not diminish the positive predictive value of fecal occult blood testing to find GI pathology. They increase the risk of gross GI bleeding, and predictors of hemorrhage include history of GI bleeding or ulcer disease, higher intensity of anticoagulation, combination therapy, and presence of comorbid conditions. A bleeding site is identified in most patients with peptic ulcer being the most common. In case of significant bleeding, complete or partial reversal of anticoagulation is undertaken on the basis of the balance of risks between bleeding and thromboembolic events. Early endoscopy can reveal lesions requiring endoscopic hemostasis, which can be performed in the setting of low-intensity anticoagulation. In patients with history of peptic disease or bleeding from an acid-related lesion, proton-pump inhibitors and Helicobacter pylori eradication reduce the risk of upper GI bleeding even when antiplatelet therapy is continued.

CONCLUSIONS

Predictors of bleeding on antiplatelets and/or antithrombotics therapy have been identified, but formulation and validation of a GI bleeding index for stratification of risk in individual patients is suggested. Reversal of anticoagulation in bleeding patients is associated with a low risk of thromboembolic events and permits the performance of diagnostic and therapeutic endoscopy. Proton-pump inhibitors and H. pylori eradication reduce the risk of rebleeding in those with acid-related disease.

Use of antiplatelet agents for prevention of ischemic stroke

Overall management to lower risk for ischemic stroke is multifaceted. Management includes measures to treat risk factors for accelerated atherosclerosis and stroke, antithrombotic therapies to lower the risk for thromboembolism, and surgery to treat a defined arterial or cardiac lesion. Treatment decisions are made on a case-by-case basis, with most patients receiving some combination of medication and recommendations for lifestyle modification. Some patients will also undergo surgical or endovascular interventions. This article discusses antithrombotic treatment for ischemic stroke prevention, placing major emphasis on the indications for and administration of antiplatelet therapy.

Warfarin therapy: in need of improvement after all these years

BACKGROUND

Warfarin therapy has been used clinically for over 60 years, yet continues to be problematic because of its narrow therapeutic index and large inter-individual variability in patient response. As a result, warfarin is a leading cause of serious medication-related adverse events, and its efficacy is also suboptimal.

OBJECTIVE

To review factors that are responsible for variable response to warfarin, including clinical, environmental, and genetic factors, and to explore some possible approaches to improving warfarin therapy.

RESULTS

Recent efforts have focused on developing dosing algorithms that included genetic information to try to improve warfarin dosing. These dosing algorithms hold promise, but have not been fully validated or tested in rigorous clinical trials. Perhaps equally importantly, adherence to warfarin is a major problem that should be addressed with innovative and cost-effective interventions.

CONCLUSION

Additional research is needed to further test whether interventions can be used to improve warfarin dosing and outcomes.

CYP4F2 genetic variant alters required warfarin dose

Warfarin is an effective, commonly prescribed anticoagulant used to treat and prevent thrombotic events. Because of historically high rates of drug-associated adverse events, warfarin remains underprescribed. Further, interindividual variability in therapeutic dose mandates frequent monitoring until target anticoagulation is achieved. Genetic polymorphisms involved in warfarin metabolism and sensitivity have been implicated in variability of dose. Here, we describe a novel variant that influences warfarin requirements. To identify additional genetic variants that contribute to warfarin requirements, screening of DNA variants in additional genes that code for drug-metabolizing enzymes and drug transport proteins was undertaken using the Affymetrix drug-metabolizing enzymes and transporters panel. A DNA variant (rs2108622; V433M) in cytochrome P450 4F2 (CYP4F2) was associated with warfarin dose in 3 independent white cohorts of patients stabilized on warfarin representing diverse geographic regions in the United States and accounted for a difference in warfarin dose of approximately 1 mg/day between CC and TT subjects. Genetic variation of CYP4F2 was associated with a clinically relevant effect on warfarin requirement.

Creating and synthesizing evidence with decision makers in mind: integrating evidence from clinical trials and other study designs

BACKGROUND

Randomized controlled trials (RCTs) remain the accepted "gold standard" for determining the efficacy of new drugs or medical procedures. Randomized trials alone, however, cannot provide all the relevant information decision makers need to determine the relative risks and benefits when choosing the best treatment of individual patients or weighing the implications of particular policies affecting medical therapies.

OBJECTIVES

To demonstrate the limitations of RCTs in providing the information needed by medical decision makers, and to show how information from observational studies can supplement evidence from RCTs.

METHODS

Qualitative description of the limitations of RCTs in providing the information needed by medical decision makers, and demonstration of how evidence from additional sources can aid in decision making, using the examples of deciding whether a 60-year-old woman with mildly elevated blood pressure should take daily low-dose aspirin, and whether a hospital network should implement carotid artery surgery for asymptomatic patients.

CONCLUSIONS

Even the most rigorously designed RCTs leave many questions central to medical decision making unanswered. Research using cohort and case-control designs, disease and intervention registries, and outcomes studies based on administrative data can all shed light on who is most likely to benefit from the treatment, and what the important tradeoffs are. This suggests the need to revise the traditional evidence hierarchy, whereby evidence progresses linearly from basic research to rigorous RCTs. This revised hierarchy recognizes that other research designs can provide important evidence to strengthen our understanding of how to apply research findings in practice.

Influence of decision aids on patient preferences for anticoagulant therapy: a randomized trial

BACKGROUND

Decision aids have been shown to be useful in selected situations to assist patients in making treatment decisions. Important features such as the format of decision aids and their graphic presentation of data on benefits and harms of treatment options have not been well studied.

METHODS

In a randomized trial with a 3 x 2 factorial design, we investigated the effects of decision aid format (decision board, decision booklet with audiotape, or interactive computer program) and graphic presentation of data (pie graph or pictogram) on patients' comprehension and choices of 3 treatments for anticoagulation, identified initially as "treatment A" (warfarin), "treatment B" (acetylsalicylic acid) and "treatment C" (no treatment). Patients aged 65 years or older without known atrial fibrillation and not currently taking warfarin were included. The effect of blinding to the treatment name was tested in a before-after comparison. The primary outcome was change in comprehension score, as assessed by the Atrial Fibrillation Information Questionnaire. Secondary outcomes were treatment choice, level of satisfaction with the decision aid, and decisional conflict.

RESULTS

Of 102 eligible patients, 98 completed the study. Comprehension scores (maximum score 10) increased by an absolute mean of 3.1 (p < 0.01) after exposure to the decision aid regardless of the format or graphic presentation. Overall, 96% of the participants felt that the decision aid helped them make their treatment choice. Unblinding of the treatment name resulted in 36% of the participants changing their initial choice (p < 0.001).

INTERPRETATION

The decision aid led to significant improvement in patients' knowledge regardless of the format or graphic representation of data. Revealing the name of the treatment options led to significant shifts in declared treatment preferences.

Amaurosis fugax caused by heritable thrombophilia-hypofibrinolysis in cases without carotid atherosclerosis: thromboprophylaxis prevents subsequent transient monocular partial blindness

Nineteen patients (age 60 +/- 14) with amaurosis fugax associated with heritable thrombophilia-hypofibrinolysis without ipsilateral atherosclerotic carotid plaque or other causes of amaurosis fugax were studied. Our hypothesis was that case-specific thromboprophylaxis would prevent subsequent amaurosis fugax episodes. Prospective treatment data were available for 13 cases. Thrombophilic disorders included high Factors VIII and XI, G20210A prothrombin heterozygosity, low proteins C and S, MTHFR mutations, and the PL A1/A2 mutation. Hypofibrinolytic disorders included plasminogen activator inhibitor-1 4G4G, and high lipoprotein (a). Treatments included Coumadin; Lovenox, folic acid-vitamin B6-vitamin B12, discontinuation of estrogens-selective estrogen receptor modulators, Glucophage, and aspirin, as appropriate. Usually within 1 month on therapy, patients became asymptomatic and have remained asymptomatic for > or = 1 year on therapy, without adverse treatment side effects. When amaurosis fugax occurs without carotid artery atherosclerosis or other known causes, thrombophilia or hypofibrinolysis, or both are nearly universal, safely treatable, reversible pathoetiologies.

Aortic arch atheroma and the risk of stroke

Brain infarction of unknown cause, known as cryptogenic stroke, represents 30% to 40% of all ischemic strokes, or approximately 400,000 cases each year in western Europe. In this category of patients new potential causes, such as aortic arch atheroma in the elderly, have been investigated in the past two decades.

Polymorphisms in genes encoding acetylsalicylic acid metabolizing enzymes are unrelated to upper gastrointestinal health in cardiovascular patients on acetylsalicylic acid

BACKGROUND

As acetylsalicylic acid is metabolized by UDP-glucuronosyltransferase 1A6 (UGT1A6) and cytochrome P450 2C9 (CYP2C9), interindividual differences in activity of these enzymes may modulate the effects and side-effects of acetylsalicylic acid. The objective of this study was to assess whether polymorphisms in UGT1A6 and CYP2C9 genes are related to the prevalence of upper gastrointestinal symptoms in cardiovascular patients using acetylsalicylic acid for secondary prevention of ischaemic heart disease.

METHODS

Blood samples were taken from acetylsalicylic acid using patients admitted to the Coronary Care Unit. Dyspepsia-related health was evaluated at week 2, using a validated upper gastrointestinal complaint questionnaire. A subset of 160 patients responded to a survey and were eligible to participate in this study. DNA was isolated and UGT1A6 and CYP2C9 genotypes were determined using polymerase chain reaction restricted fragment length polymorphism techniques.

RESULTS

Seventy per cent of the patients returned the questionnaire. UGT1A6 and CYP2C9 variant polymorphisms were found in 103 (63%) and 56 (35%) patients, respectively. There was no association between gastrointestinal symptoms and UGT1A6 (OR = 0.80, 95% CI = 0.41-1.56) or CYP2C9 polymorphisms (OR = 0.85, 95% CI = 0.44-1.67).

CONCLUSIONS

There was no association between polymorphisms in genes encoding for acetylsalicylic acid metabolizing enzymes on the prevalence of gastric complaints in cardiovascular patients on acetylsalicylic acid.

Antiplatelet agents and arterial thrombosis

There is an increase in arterial thrombotic events in the elderly. Elderly patients are more likely to have associated diseases, such as diabetes, hypertension and hypercholesterolemia, and when age is confounded by these other predisposing factors, the risk of an arterial ischemic event increases disproportionately. Antithrombotic therapy for geriatric patients is underused, even when one adjusts for potential drug contraindications. This article focuses on the action of the currently available antiplatelet agents--aspirin, clopidogrel, and glycoprotein IIb/IIIa (GPIIb/IIIa) receptor antagonists, and assesses their effects in different disease states, with special attention to data that examine the geriatric population.

New treatments in acute ischemic stroke

Since the advent of intravenous thrombolytic therapy with recombinant tissue plasminogen activator (tPA) for acute ischemic stroke, there has been a marked change in our management approach to patients with acute ischemic stroke. Although the major part of our focus in treating patients with stroke remains prevention of complications post-stroke and reduction of stroke recurrence, there is a paradigm shift to immediate "clot" lysis. This concept is being actively promoted through certification of institutions as stroke centers in order to increase the number of patients with stroke treated in an ultra-rapid fashion. However, options for acute treatment remain limited. Other than aspirin, the only US Food and Drug Administration-approved agent for acute ischemic stroke is intravenous tPA. Some physicians treating patients with acute ischemic stroke still frequently use heparin and low-molecular-weight heparinoids, but there are no firm data to support routine use of this drug class. However, a number of new lytic agents and strategies are being pursued. Some of these treatments, such as intra-arterial chemical thrombolysis or mechanical intra-arterial thrombolysis, are available only at specialized stroke centers. In addition, new antithrombotic agents are being studied. Drugs that can rescue neurons from impending hypoxia-ischemia cell death represent the "holy grail" of acute stroke therapy. To date, these "neuroprotectant" strategies have been unsuccessful, although this concept remains under active investigation in animal and human trials.

Inadequate use of acid-suppressive therapy in hospitalized patients and its implications for general practice

Acid-suppressive therapy (AST) is largely prescribed in both hospital and general practice setting but few data are available on appropriateness of AST use in hospitalized patients and its fallout on prescribing in general practice. We assessed AST in patients consecutively admitted to an internal medicine department to determine the type and timing of prescription and indication for use according to widely accepted guidelines. Prescriptions were rated as indicated, acceptable, or not indicated. Overall, 58.7% of 834 admitted patients received AST, mainly proton pump inhibitors. The prescriptions were indicated in 50.1% of patients, not indicated in 41.5%, and acceptable in 6.5%. The main reason for inappropriate use was prophylaxis in low-risk patients (64.8%). On admission, 35.7% of 112 patients already on AST were judged to receive inappropriate prescription; of 348 patients discharged on AST, overuse was identified in 38.5%. No significant difference was observed for inappropriate use at admission, during hospitalization, and at discharge. In 64 inpatients (7.7%) AST, although indicated, mainly for ulcer prophylaxis in high-risk patients, was not prescribed. In conclusion, AST is substantially over-used in both hospital and general practice settings, mainly for ulcer prophylaxis in low-risk patients. On the other hand, AST is underused in a small, but not negligible proportion of high-risk patients.

Amaurosis fugax: associations with heritable thrombophilia

The aim of this study was to prospectively assess associations between amaurosis fugax, inherited thrombophilia, and acquired thrombophilia. Thrombophilia and hypofibrinolysis were studied in 11 cases (eight women, three men; all white) with amaurosis fugax, 57 +/- 17 years old, selected by the absence of abnormal brain magnetic resonance imaging (MRI), magnetic resonance angiography (MRA), magnetic resonance venography (MRV), ipsilateral internal carotid artery plaque, atrial fibrillation, or cardiac thrombus. Cases were compared to 78 healthy adult white controls (53 +/- 18 years old) for serologic measures, and by polymerase chain reaction to 248 healthy white controls (78 adults, 170 children) for gene mutations. All 11 cases had one or more familial thrombophilic coagulation disorder including one heterozygous for the G1691A factor V Leiden mutation, two with low free protein S, four with high factor VIII, three with resistance to activated protein C, three homozygous for the C677T methylenetetrahydrofolate reductase (MTHFR) mutation, two compound C677T-A1298C MTHFR heterozygotes, and three with hypofibrinolytic 4G4G homozygosity for the PAI-1 gene. The case with factor VIII of 160% had two other thrombophilias (compound MTHFR C677T-A1298C heterozygosity, resistance to activated protein C), and hypofibrinolytic high Lp(a). Thrombophilic C677T MTHFR homozygosity or compound C677T-A1298C heterozygosity was present in five of 10 (50%) cases vs. 30 of 248 (12%) controls, Fisher's p (p(f)) = .005. Thrombophilic factor VIII was high in four of 10 (40%) cases vs. 0 of 38 controls, p(f) = .001. Thrombophilic hyperestrogenemia in five of the eight women (four exogenous estrogen, one pregnant) may have interacted with inherited thrombophilia-hypofibrinolysis, promoting thrombus formation. In cases selected by the absence of abnormal brain magnetic resonance imaging, significant ipsilateral internal carotid artery plaque, atrial fibrillation, or cardiac thrombus, we speculate that amaurosis fugax can be caused by reversible (by anticoagulation) retinal artery thrombi associated with heritable thrombophilia and/or hypofibrinolysis, often augmented by estrogen-driven acquired thrombophilia.

Anticoagulation: American College of Chest Physicians guidelines for the prevention and management of postoperative atrial fibrillation after cardiac surgery

Post-cardiac surgery atrial fibrillation (AF) places patients at risk for thromboembolism and stroke, while the surgery and cardiopulmonary bypass alter the multiple factors of coagulation and may increase the tendency to bleed. It is in the context of this complex clinical picture that the physician must make decisions regarding the risks and benefits of anticoagulation therapy to lower the risk for thromboembolism and stroke associated with postoperative AF. Physicians must also weigh the usually transient and self-limited duration of new-onset postoperative AF against the potential for postoperative bleeding if anticoagulation therapy is started. No randomized, controlled clinical trials are available that specifically address the problem of anticoagulation therapy for the postoperative AF. In that context, recommendations are based on the established therapy for nonsurgical situations modified by the potential risk of bleeding in the postoperative patient.

Differences among clinical classification schemes for predicting stroke in atrial fibrillation: implications for therapy in daily practice

BACKGROUND

Several clinical classification schemes (CCSs) for predicting stroke in nonvalvular atrial fibrillation (NVAF) have been developed to help identify patients eligible for anticoagulation.

OBJECTIVES

To estimate the agreement in predicting the risk of stroke among four widespread CCSs, and to determine their implications for thromboprophylaxis in clinical practice.

METHODS

The authors conducted a prospective, multicenter, observational study of adults with NVAF in 12 emergency departments (EDs) in July 2000 and February 2001. The proportions of patients classified as having high, moderate, and low risk of stroke among the following CCSs were compared: the Atrial Fibrillation Investigators (AFI), the Stroke Prevention in Atrial Fibrillation (SPAF), the CHADS(2) (an acronym for congestive heart failure, hypertension, age >75 years, diabetes mellitus, and prior stroke or transient ischemic attack), and the American College of Chest Physicians (ACCP).

RESULTS

One thousand two hundred twenty patients were included. The proportions of patients stratified as having high/moderate/low risk of stroke according to each CCS were: 70%/22%/8% (AFI), 38%/41%/21% (SPAF), 13%/45%/42% (CHADS(2)), and 86%/7%/7% (ACCP). The agreement was medium between AFI and ACCP (kappa = 0.52) and poor among the rest of them (AFI/SPAF, kappa = 0.01; AFI/CHADS(2), kappa = 0.02; SPAF/CHADS(2), kappa = 0.18; SPAF/ACCP, kappa = 0.11; CHADS(2)/ACCP, kappa = 0.03). The agreements in selecting patients as eligible for antiplatelet therapy or anticoagulation were: AFI/SPAF, kappa = 0.45; AFI/CHADS(2), kappa = 0.22; AFI/ACCP, kappa = 0.91; SPAF/CHADS(2), kappa = 0.47; SPAF/ACCP, kappa = 0.11; CHADS(2)/ACCP, kappa = 0.03.

CONCLUSIONS

In the ED population studied, these CCSs showed relevant differences in the risk of stroke stratification and, therefore, in the identification of patients with NVAF eligible for anticoagulation.

Association of aspirin use with vitamin B12 deficiency (results of the BACH study)

We examined the prevalence of vitamin B(12) deficiency and its association with medication use and characteristics, including infection with Helicobacter pylori (H. pylori), in 255 patients hospitalized for cardiovascular disease. In almost half of the study population, vitamin B(12) deficiency was found; patients using acetylsalicylic acid were more frequently vitamin B(12) deficient in comparison to nonusers (p = 0.02). Fifty-one percent of the patients were infected with H. pylori, and fewer infected patients were vitamin B(12) deficient.

Antithrombotic drugs in secondary stroke prevention among a community dwelling older population

BACKGROUND

Patients who suffer a cerebrovascular event are at high risk of a recurrence. Secondary prevention is crucial in reducing the burden of cerebrovascular disease.

OBJECTIVE

To estimate the percentage of stroke survivors receiving antiplatelet or anticoagulant drugs and to identify factors associated with such treatment.

DESIGN

Cross sectional retrospective cohort study.

METHODS

Data were analysed from a large collaborative observational study, the Italian "silver network" home care project, which collected data (from 1997 to 2001) on patients admitted to home care programmes (n = 5372). Twenty two home health agencies participated in evaluating the implementation of the minimum dataset for home care (MDS-HC) instrument. For the present study, 648 individuals with a diagnosis of stroke were selected and the initial MDS-HC assessment reported.

RESULTS

70% of stroke survivors did not receive any antiplatelet or anticoagulant drugs (95% confidence interval (CI), 66.5 to 73.5). Among all age categories, aspirin and ticlopidine were the two most commonly prescribed drugs. Living alone (odds ratio (OR), 0.49 (95% CI, 0.24 to 0.89)), dependency in activities of daily living (0.66 (0.40 to 0.99)), cognitive impairment (0.58 (0.38 to 0.86)), and low educational level (0.58 (0.34 to 0.98)) were associated with a reduced likelihood of receiving secondary stroke prevention treatment. Cardiac arrhythmias, coronary artery disease, heart failure, and peripheral vascular disease were associated with the use of antiplatelet or anticoagulant treatment.

CONCLUSIONS

Negative attitudes among physicians with respect to secondary stroke prevention are prevalent and reinforce the need for increased awareness of existing data on the risks and benefits for elderly individuals. Social problems and functional impairment may be issues concerning physicians when deciding whether or not the risks of treatment exceed the benefit.

The use of a bolus of intravenous heparin while initiating heparin therapy in anticoagulation following transient ischemic attack or stroke does not lead to increased morbidity or mortality

Intravenous heparin therapy is often used in patients presenting with transient ischemic attack (TIA) or stroke as either bridging therapy for anticoagulation with warfarin, or as primary therapy in suspected intracranial arterial dissection, crescendo TIAs, or suspected hypercoagulable states. We examined the use of a bolus of intravenous heparin at the start of anticoagulation during hospital admission for patients with TIA or stroke. A subgroup analysis of a prospective, single-blinded, randomized clinical trial was undertaken to examine the effect of providing an intravenous bolus of heparin prior to continuous intravenous maintenance heparin therapy. Pre-treatment clinical factors were comparable between subgroups. Thirty-three patients received a bolus at initiation of therapy and 173 patients did not. Patients receiving a bolus had a significantly higher first activated partial thromboplastin time at 6 h after initiation of therapy than patients without bolus (87.6 +/- 36.3 versus 61.0 +/- 8.1 s). Patients receiving bolus achieved an initial activated partial thromboplastin time greater than the minimum threshold for the therapeutic range of anticoagulation (> 60 s) sooner than patients without bolus (9.6 +/- 7.3 versus 14.5 +/- 10.8 h), but did not have a significantly greater chance of achieving therapeutic range (60-90 s). The fraction of time during which anticoagulation was therapeutic was similar between patients receiving bolus or not. There was no significant difference between the number of supratherapeutic coagulation results, total dosage of intravenous heparin received, complications due to anticoagulation, nor the times required for discontinuation of heparin and discharge from hospital between subgroups. The use of an intravenous heparin bolus during initiation of anticoagulation for TIA or stroke does not appear to be associated with greater risks and can achieve a minimum therapeutic range faster than therapy without heparin bolus.

Aortic Source of Brain Embolism

Aortic arch atheroma has more recently been identified as an independent risk factor for ischemic stroke. Initially, this was a result of careful autopsy observations, then followed by a series of in vivo studies in which aortic arch atheroma was identified by transesophageal echocardiography. The association of aortic arch atheroma with ischemic stroke is most likely causal, given that the stroke risk increases with increasing thickness of arch atheroma. There is quite a sharp increase in stroke risk for atheroma of 4 mm or greater compared with lesser thicknesses. The clinical diagnosis is suggested when transient ischemic attack or ischemic stroke has occurred in which no obvious cardiac or arterial source of embolism is found. The presence of aortic arch atheroma is usually detected by transesophageal echocardiography and sometimes by magnetic resonance imaging or computed tomography. There is uncertainty about clinical management, particularly for secondary prevention. Options include the use of antiplatelet agents, anticoagulants, thrombolysis, or surgery. The latter two options have only been described rarely in case reports. Of the less invasive approaches, combination antiplatelet therapy with aspirin and clopidogrel is favored, or the use of warfarin. The Aortic arch Related Cerebral Hazard (ARCH) trial is being conducted to determine which of these is more effective in minimizing a composite outcome cluster of ischemic stroke, intracranial hemorrhage, myocardial infarction, peripheral embolism, or vascular death. Other more general management strategies should include reasonably aggressive risk factor control with blood pressure and lipid-lowering therapies and, if indicated, careful diabetic control.

The morbidity related to atrial fibrillation at a tertiary centre in one year: 9.0% of all strokes are potentially preventable

Atrial fibrillation is a major risk factor for stroke. Anticoagulant therapy reduces this risk but increases the risk of haemorrhage. We aimed to compare the morbidity related to the treatment of atrial fibrillation with warfarin seen in one year at our hospital, with the morbidity in those patients in whom embolism was potentially preventable. There were 111 patients admitted to our hospital in a 12 month period with nonvalvular atrial fibrillation (NVAF) who had stroke, TIA or peripheral embolism. Atrial fibrillation was identified prior to admission in 87 of these 111 (78%) patients with thromboembolism, yet only 14 of these (16%) were receiving warfarin for stroke prophylaxis. Through chart review, a further 56 (64%) patients with embolism could have been receiving anticoagulant therapy if published clinical guidelines(1) were applied. Therefore, 40 episodes of thromboembolism were potentially preventable. Over the same period, there were 18 patients admitted with haemorrhage related to warfarin therapy for stroke prophylaxis in NVAF, including 10 gastrointestinal, five intracerebral, and three peripheral haemorrhages. Most haemorrhages were associated with a high International Normalized Ratio (INR) and the patients were left less disabled than those with embolism. Only one patient with haemorrhage had an absolute contraindication to warfarin therapy (6%). We conclude that the number of preventable strokes far outweighed the morbidity due to warfarin use in the management of NVAF.

Effect of antiplatelet and anticoagulant agents on risk of hospitalization for bleeding among a population of elderly nursing home stroke survivors

BACKGROUND AND PURPOSE

Anticoagulants and antiplatelet agents are underutilized in the nursing home setting, perhaps because trials demonstrating treatment efficacy excluded people resembling those with long-term care needs. We sought to quantify the effect of antiplatelet and anticoagulant agents on risk of hospitalization for bleeding among an elderly nursing home population.

METHODS

We used a case-control design and identified first hospitalizations for bleeds using Medicare claims data from 1992 to 1997 as potential cases. Cases had at least one minimum data set (MDS) assessment within the 6 months before that hospitalization and a diagnosis of stroke. We identified up to 5 controls residing in the same facility during the same year and quarter as the case with a diagnosis of stroke. Our sample consisted of 3433 cases and 13 506 controls. Using the MDS, we identified standing orders for aspirin, dipyridamole, ticlopidine, or warfarin and used conditional logistic regression modeling to estimate the effect of these agents on risk of hospitalization for a bleed.

RESULTS

After adjustment, use of warfarin (odds ratio [OR], 1.26; 95% CI, 1.11 to 1.43) and combination therapy (OR, 1.34; 95% CI, 0.99 to 1.82) were associated with an increased risk of hospitalization for a bleed compared with nonusers. The odds of aspirin use was greater among cases than controls (OR, 1.07; 95% CI, 0.96 to 1.18) after adjustment.

CONCLUSIONS

Although present, the risk associated with use of these agents is small. The numbers needed to treat to harm 1 resident with aspirin and warfarin were 467 and 126, respectively.

Combination of a free radical scavenger and heparin reduces cerebral hemorrhage after heparin treatment in a rabbit middle cerebral artery occlusion model

BACKGROUND AND PURPOSE

We sought to investigate the effects of EPC-K1, a free radical scavenger, on reducing heparin-produced cerebral hemorrhage in a rabbit model of middle cerebral artery (MCA) photothrombosis and to investigate whether the combination of EPC-K1 and heparin enhances neuroprotection from cerebral ischemic damage.

METHODS

In the heparin-alone group (n=8), heparin was administered intravenously for 24 hours, starting from 3 hours after MCA occlusion. In the EPC-K1-alone group (n=8), EPC-K1 was administered as a bolus injection (10 mg/kg) twice at 3 and 6 hours after MCA occlusion. In the combination group (n=8), EPC-K1 and heparin both were administered as in the single-drug procedures. In the vehicle group (n=10), saline were infused for 24 hours.

RESULTS

Heparin prolonged activated partial thromboplastin time by approximately 3 times that of control animals. In the heparin-treated animals, the hemorrhage size was significantly increased (P<0.0001) and neurological symptoms were significantly worse (P<0.01) than in control animals at 48 hours. The combination of EPC-K1 and heparin dramatically reduced heparin-produced cerebral hemorrhage (P<0.0001), with a significant reduction in infarct volume (reduction by 63.2% and 57.2% of heparin-alone and control animals, respectively, P<0.0001) and a significant improvement in neurological symptoms (P<0.01 versus heparin-alone and control animals, respectively).

CONCLUSIONS

These data indicate that free radical formation may play a key role in intracerebral hemorrhage exacerbated by heparin treatment and that the combination of a free radical scavenger and heparin augmented neuroprotection from acute brain ischemia. The results of the present study may suggest a potential clinical approach for the treatment of acute stroke.

The effect of perioperative aspirin therapy in peripheral vascular surgery: a decision analysis

Patients who undergo infrainguinal revascularization surgery are at increased risk for perioperative thrombotic complications. Aspirin decreases thrombotic events in the nonoperative setting; however, aspirin is often discontinued to avoid perioperative hemorrhagic complications. We used a decision analysis to determine whether aspirin should be discontinued before infrainguinal revascularization surgery. Two strategies were compared: aspirin cessation 2 wk before surgery and aspirin continuation throughout the perioperative period. Clinical events examined included myocardial infarction, thrombotic cerebrovascular accident, hemorrhagic cerebrovascular accident, gastrointestinal hemorrhage, and incisional hemorrhagic complications. Event rates and effect of aspirin were obtained by using MEDLINE. The outcomes were perioperative mortality, life expectancy, and quality-adjusted life expectancy. According to the model, continued aspirin use decreased perioperative mortality rates from 2.78% to 2.05%. Continued aspirin use increased life expectancy from 14.83 to 14.89 yr and increased quality-adjusted life expectancy from 14.72 to 14.79 yr. Aspirin increased the number of hemorrhagic complications by 2.46%, primarily because of an increased incidence of non-life-threatening complications.

Helicobacter pylori infection as a risk factor for gastrointestinal symptoms in patients using aspirin to prevent ischaemic heart disease

BACKGROUND

Aspirin use in the secondary prevention of ischaemic heart disease may provoke gastrointestinal discomfort.

OBJECTIVE

To register gastrointestinal symptoms and complications in patients with cardiovascular disease using aspirin and to relate these symptoms to infection with H. pylori.

METHODS

Blood samples were obtained from 398 consecutive patients in the Coronary-Care Unit, University Hospital Nijmegen and analysed for serum antibody levels to H. pylori infection. Questionnaires were sent 2 weeks after discharge to assess gastrointestinal symptoms.

RESULTS

Questionnaires were returned by 314 patients (79%). A total of 183 out of 314 patients (46%) reported gastrointestinal symptoms. Of 238 patients using 80-100 mg aspirin daily, 145 (61%) recorded gastrointestinal symptoms. Besides aspirin, the use of calcium antagonists was correlated with gastrointestinal symptoms. Of the 128 patients using calcium antagonists, 84 (66%) reported gastrointestinal symptoms. The prevalence of gastrointestinal symptoms in H. pylori-positive and -negative patients using aspirin was 48% and 52%, respectively.

CONCLUSIONS

Two weeks after discharge almost 50% of the patients with cardiovascular disease experienced gastrointestinal symptoms, especially patients using aspirin or calcium antagonists. Patients seropositive for H. pylori and using aspirin or calcium antagonists did not have more gastrointestinal discomfort compared to non-infected patients.

Genetic susceptibility to adverse drug reactions

Adverse drug reactions (ADRs) are a major clinical problem. Genetic factors can determine individual susceptibility to both dose-dependent and dose-independent ADRs. Determinants of susceptibility include kinetic factors, such as gene polymorphisms in cytochrome P450 enzymes, and dynamic factors, such as polymorphisms in drug targets. The relative importance of these factors will depend on the nature of the ADR; however, it is likely that more than one gene will be involved in most instances. In the future, whole genome single nucleotide polymorphism (SNP) profiling might allow an unbiased method of determining genetic predisposing factors for ADRs, but might be limited by the lack of adequate numbers of patient samples. The overall clinical utility of genotyping in preventing ADRs needs to be proven by the use of prospective randomized controlled clinical trials.

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.