Comparative Effectiveness and Safety of Direct Oral Anticoagulants Compared with Warfarin in Patients with Low Bodyweight who have Atrial Fibrillation: A Systematic Review and Meta-analysis

INTRODUCTION

oral anticoagulant (DOAC) agents are becoming the anticoagulation strategy of choice for most clinical risks for which they are indicated. However, residual uncertainty remains regarding their use in preventing stroke in patients with low bodyweight [< 60 kg or body mass index (BMI) < 18 kg/m2]. We have carried out pooled systematic analyses of published studies to determine the efficacy and safety of these agents compared with warfarin in stroke prevention in patients with low bodyweight.

METHODS

We carried out a comprehensive search of electronic databases from inception to June 2023 for eligible studies reporting on the efficacy and safety of direct oral anticoagulants versus warfarin in patients with atrial fibrillation who had low bodyweight. These include PubMed, EMBASE, the Cochrane Database of Systematic Reviews, the Science Citation Index, and the Database of Abstracts of Reviews of Effectiveness. Using the random effects model, derived pooled odd ratios (with their corresponding confidence intervals) of mortality outcomes in patient cohorts exposed to direct oral anticoagulants versus warfarin in patients with atrial fibrillation who had low bodyweight.

RESULTS

Nine studies (n = 159,514 patients) were included in our meta-analysis. DOAC analogs were associated with lower stroke recurrence compared with warfarin [odds ratio (OR) 0.66, 95% confidence interval (CI) 0.49-0.9]; however, there was no significant difference in the composite outcome (OR 0.81, 95% CI 0.59-1.09) and mortality (OR 0.82, 95% CI 0.48-1.41). Additionally, DOAC analogs showed a significant reduction in major bleeding events by 30% compared with warfarin (OR 0.70, 95% CI 0.62-0.80).

CONCLUSION

In this pooled meta-analytical synthesis of studies comprising both real-world and randomized controlled data, the use of DOAC analogs in patients with atrial fibrillation and low bodyweight (< 60 kg or BMI < 18 kg/m2) was associated with a significant reduction in risks of stroke and major bleeding compared with patient cohorts stabilized on warfarin-based therapy. There was uncertainty regarding the composite outcome and mortality point estimate between these two anticoagulation strategies. This finding helps to resolve the uncertainty associated with the use of DOACs in this cohort. Additionally, it suggests the need for confirmatory non-inferiority randomized controlled trials evaluating DOACs versus warfarin in this cohort of patients.

Incidence, clinical features, and outcomes of posterior circulation ischemic stroke: insights from a large multiethnic stroke database

Background

Posterior cerebral circulation ischemic stroke (PCS) comprises up to 25% of all strokes. It is characterized by variable presentation, leading to misdiagnosis and morbidity and mortality. We aim to describe PCS in large multiethnic cohorts.

Methods

A retrospective review of a large national stroke database from its inception on the 1st of January 2014 till 31 December 2020. Incidence per 100,000 adult population/year, demographics, clinical features, stroke location, and outcomes were retrieved. We divided the cohort into patients from MENA (Middle East and North Africa) and others.

Results

In total, 1,571 patients were identified. The incidence of PCS was observed to be rising and ranged from 6.3 to 13.2/100,000 adult population over the study period. Men were 82.4% of the total. The mean age was 54.9 ± 12.7 years (median 54 years, IQR 46, 63). MENA patients comprised 616 (39.2%) while others were 954 (60.7%); of these, the majority (80.5%) were from South Asia. Vascular risk factors were prevalent with 1,230 (78.3%) having hypertension, 970 (61.7%) with diabetes, and 872 (55.5%) having dyslipidemia. Weakness (944, 58.8%), dizziness (801, 50.5%), and slurred speech (584, 36.2%) were the most commonly presenting symptoms. The mean National Institute of Health Stroke Score (NIHSS) score was 3.8 ± 4.6 (median 3, IQR 1, 5). The overall most frequent stroke location was the distal location (568, 36.2%). The non-MENA cohort was younger, less vascularly burdened, and had more frequent proximal stroke location (p < 0.05). Dependency or death at discharge was seen in 39.5% and was associated with increasing age, and proximal and multilocation involvement; while at 90 days it was 27.4% and was associated with age, male sex, and having a MENA nationality (p < 0.05).

Conclusion

In a multiethnic cohort of posterior circulation stroke patients from the MENA region and South Asia, we noted a rising incidence over time, high prevalence of vascular risk factors, and poor outcomes in older men from the MENA region. We also uncovered considerable disparities between the MENA and non-MENA groups in stroke location and outcome. These disparities are crucial factors to consider when tailoring individualized patient care plans. Further research is needed to thoroughly investigate the underlying reasons for these variations.

Comparative Effectiveness and Safety of Direct Oral Anticoagulants in Low Body Weight Patients with Atrial Fibrillation: A Systematic Review and Meta-analysis

INTRODUCTION

Direct oral anticoagulant (DOAC) agents are established as the anticoagulation strategy of choice for a variety of clinical risks. Despite this, uncertainty still exists with regard to their efficacy and safety for the prevention of stroke and systemic embolism in some patient populations; most notably those with low body weight (LBW) (<60 kg or body mass index [BMI] <18 kg/m2). Currently, there is a paucity of trial and non-trial data to support a prescriptive recommendation for their use in these patient cohorts. We have carried out a pooled systematic review of the most up to date published data of patients stabilized on various DOAC analogs with the view to ascertaining the exact matrices of their efficacy and safety in these cohorts of patients.

METHODS

We initially carried out a comprehensive search of databases from inception to June 2023 for eligible studies exploring the efficacy and safety of various analogs of direct oral anticoagulants in patients with atrial fibrillation who had low body weight. Databases accessed include PubMed, EMBASE, the Science Citation Index, the Cochrane Database of Systematic Reviews, and the Database of Abstracts of Reviews of Effectiveness. We carried out a weighted comparison of derived pooled odd ratios (with their corresponding confidence intervals) of mortality outcomes between various DOACs using the random effects model.

RESULTS

Thirteen studies (n = 165,205 patients) were included in our meta-analysis. DOAC analogs were associated with increased stroke-related events, composite outcome, and mortality in low body weight patients compared to non-low body weight patients (odds ratio [OR] 1.50, 95% confidence interval [CI] 1.17-1.92), (OR 1.55, 95% CI 1.29-1.86), (OR 2.92, 95% CI 1.87-4.58), respectively. There was no significant difference in the safety outcome (major bleeding events) between the DOAC analogs (OR 1.19, 95% CI 0.93-1.52).

DISCUSSION

In this meta-analytical review comprising both real-world and randomized controlled studies, the use of DOAC analogs in low body weight patients (body weight of <60 kg or BMI<18 kg/m2) with atrial fibrillation was associated with increased risks of stroke-related events, composite outcomes, and mortality compared to non-low body weight cohorts patients. At the same time, there was no significant difference in terms of major bleeding events. This finding has provided the first resolution of pervading uncertainty surrounding the use of DOAC analogs in these patient cohorts and suggests the need for follow-up confirmatory systematic studies in this group of patients.

Dosage, time, and polytherapy dependent effects of different levetiracetam regimens on cognitive function

OBJECTIVE

Cognitive impairment is a potential drawback of antiseizure medications. This study aimed to evaluate the impact of different levetiracetam drug regimens on cognitive function.

METHODS

A retrospective analysis identified 221 patients diagnosed with seizures who underwent cognitive screening. Patients were categorized into four groups: no medications, non-levetiracetam medications, high and low dose levetiracetam. Composite scores determined low and high levetiracetam groups whereby one point was added for each increment in dosage, duration since uptake, and concurrent anti-seizure medication. Variables known to affect cognition were recorded and classified as demographic, seizure-related, diagnosis-related, and psychopathology. Logistic regression was used to identify variables associated with cognitive scores below cut-off.

RESULTS

Multivariable analysis found being male, non-active in the community, less than 12 years of education, left temporal lobe epilepsy, high seizure frequency, and depression were associated with poor cognitive performance. In a final regression analysis, the high levetiracetam group exhibited a 4.5-fold higher likelihood of scoring below cut-off than the medication-free group (OR 4.5, CI 1.5-13.6, p<.08). Depression (OR 2.1, CI 1.1-3.9, p<.03), being male (OR 2.2, CI 1.1-4.3, p<.02), and not being active in the community (OR 3.8, 1.6-8.7, p <.003) remained significant contributors to the model. Language (p<.05), attention (p<.05), and delayed recall (p<.001) were the most affected cognitive domains.

SIGNIFICANCE

When taken in small doses, for brief periods as monotherapy, levetiracetam minimally influences cognition. At higher doses, as part of long-term seizure management, in conjunction with multiple ASMs, LEV is associated with cognitive impairment.

The impact of enteric coating of aspirin on aspirin responsiveness in patients with suspected or newly diagnosed ischemic stroke: prospective cohort study: results from the (ECASIS) study

Background and purpose

Uncertainty remains regarding the impact of enteric-coated aspirin (EC-ASA) on secondary prevention of ischemic stroke compared to plain aspirin (P-ASA). Hence, this study was designed to investigate the effect of EC formulation on ASA response via evaluating thromboxane B2 (TXB2) levels in patients with suspected or newly diagnosed stroke.

Methods

A prospective cohort study on suspected or newly diagnosed ischemic stroke patients who are aspirin-naive was conducted. Patients were received either EC aspirin or plain aspirin for at least 3 days. The primary outcome was the proportion of aspirin non-responsiveness between two groups (level of residual serum TXB2 associated with elevated thrombotic risk (< 99.0% inhibition or TXB2 > 3.1 ng/ml) within 72 h after three daily aspirin doses, while secondary outcomes were the incidence of early gastrointestinal tract (GIT) bleeding with the various aspirin preparations. (Trial registration: Clinicaltrials.gov NCT04330872 registered on 02 April 2020).

Results

Of 42 patients, ischemic strokes were confirmed in both P-ASA (81%) and EC-ASA (67%) arms. ASA non-responsiveness showed no significant difference between the two formulations (P-ASA vs. EC-ASA; 28.6% vs 23.8%; P = 0.726). Univariate and multivariate logistic regression analysis showed that patients treated with EC-ASA were more likely to have a lower rate of non-responders compared to P-ASA (unadjusted OR 0.78; 95% CI 0.20, 3.11); with the risk highest in type 2 diabetic patients with HBA1c > 6.5% (adjusted OR 6; 95% CI 1.02, 35.27; P = 0.047). No incidence of GIT bleeding observed throughout the study.

Conclusion

A significant proportion of ASA non-responsiveness was recorded regardless of ASA formulation administered. The increased risk of ASA non-responsiveness in diabetic patients needs further exploration by larger prospective studies.

Night-Time Non-dipping Blood Pressure and Heart Rate: An Association With the Risk of Silent Small Vessel Disease in Patients Presenting With Acute Ischemic Stroke

Background and Purpose: Nocturnal non-dipping blood pressure and heart rate are associated with an increased risk of cardiovascular disease. The effects of such variance on cerebrovascular disease have not been well studied.

Methods: The 24-h ambulatory blood pressure (ABPM) and heart rate were monitored with B-pro in patients with acute stroke within the initial week of hospital admission. The risk factor profiles, clinical presentation, imaging, and short-term prognosis were compared in nocturnal dippers and non-dippers (more than 10% nocturnal decrease) of blood pressure and heart rate.

Results: We enrolled 234 patients in whom ABPM and MRI data were available. Heart rate data were available in 180 patients. Lacunar sub-cortical stroke was the most common acute lesion (58.9%), while hypertension (74%) and diabetes (41.5%) were the most common associated risk factors. ABPM revealed non-dipping in 69% of patients. On univariate analysis, Small Vessel Disease (SVD) was significantly more frequent in non-dippers vs. dippers (BP: 56.8 vs. 40.3% p = 0.02; heart rate: 57.9 vs. 40.7% p = 0.03). Silent strokes were also more frequent in non-dippers vs. dippers (BP: 40.7 vs. 26.4% p = 0.35; heart rate: 44.6 vs. 25.4% p = 0.01). Multivariate analysis revealed SVD to be significantly related to age, hypertension, blood pressure non-dipping, and severity of symptoms at index event.

Conclusions: The presence of nocturnal non-dipping of blood pressure and heart rate are associated with an increased risk of silent stroke and SVD. Increased use of ABPM may allow for improved diagnosis of non-dippers.

Stroke in the adult Qatari population (Q-stroke) a hospital-based retrospective cohort study

BACKGROUND

Studies assessing the burden of stroke in Qataris are limited. We aim to study stroke in the Qatari population.

METHODS

A retrospective review was undertaken of all Qatari adults presenting with stroke to Hamad Medical Corporation over a 5-year period. Descriptive statistics were used to summarize demographic and all other clinical characteristics of the patients. The primary outcome was the incidence of stroke in the Qatari patients. Comparison was made between the sexes.

RESULTS

862 patients were included, with 58.9% being male. The average incidence of stroke over the 5-year period was 92.04 per 100,000 adult Qatari population. The mean age of the cohort was 64.3±14.4 years, (range 19-105 years). The mean age of first ever cerebrovascular event was 63.2±14.5 years. The diagnosis was ischemic stroke in (73.7%), transient ischemic attack in (13.8%), intracerebral hemorrhage (ICH) in (11.6%), subarachnoid hemorrhage in (0.7%) and (0.2%) cerebral venous sinus thrombosis. Small vessel disease was the most common cause of ischemic stroke accounting for (46.5%), followed by large artery atherosclerosis (24.5%). Hypertension (82.7%) and diabetes (71.6%) were particularly prevalent in this cohort. Females were older (65.8±14.1 vs 63.4±14.5 years), had more hypertension and diabetes and more disability or death at 90 days (p<0.05) compared to Qatari males.

CONCLUSION

Stroke occurs at a significantly lower age in Qataris compared to the western population. This study has uncovered sex differences that need to be studied further.

Prospective study to optimize the health of patients with TIAS (transient ischemic attack) and stroke admitted to the Hamad General Hospital

INTRODUCTION

Recurrent ischemic strokes (IS) make up to one-third of all strokes. Nine out of 10 strokes are due to modifiable risk factors. Thus, it seems that standard management strategies of modifiable risk factors are yet to improve. Hence, we planned a randomized controlled trial assessing nurses or pharmacists-led aggressive control of comorbidities and their prognostic impact on IS and transient ischemic attacks (TIA).

METHODS/DESIGN

Prospective study to optimize the health of patients with TIAs and stroke admitted to the Hamad General Hospital (PROMOTE HEALTH) is an assessor-blinded, open-label, randomized, two-arm, controlled trial. Eligible patients have IS or TIA, and an additional modifiable risk factor (Hypertension or dyslipidemia) attending the stroke ward or clinic at the Weill Cornell-affiliated Hamad General Hospital. Stroke specialists will offer the control group the currently practiced best risk factor management strategies. Whereas, in the intervention arm, with the assistance of a nurse and a pharmacist, we will make aggressive attempts to meet targets of defined risk factors. The primary outcomes are the mean difference in blood pressure (BP) and low-density lipoprotein. Whereas myocardial infarction, recurrent stroke events, and mortality serve as the study's secondary outcomes. We require 200 patients per study arm to achieve a power of 80% and an alpha level of <0.05. The Medical Research Center and the Institutional Review Board have approved the study, and it was prospectively registered in a trial registry.

DISCUSSION

A significant proportion of strokes are due to modifiable preventable risk factors. Despite having the right preventive strategies aimed at mitigating these risk factors, a sizeable proportion of strokes are due to recurring events. This prompted the medical community to evaluate aggressive means of addressing these risk factors. The nurse or pharmacist-led management of comorbidities has been proven to be of value in the management of diabetes and hypertension. It will be of value to demonstrate the effectiveness of utilizing this additional task force in aggressively managing IS or TIA patients with an overarching goal of improving their prognosis. If our intervention proves to be efficacious, this would have a substantial impact on the current stroke practices and guidelines. Additionally, it will invite further research in the area.

CLINICAL TRIAL REGISTRATION

Clinicaltrials.gov NCT02868723, last updated on September 2018.

Management of relapsing-remitting multiple sclerosis in Qatar: an expert consensus

Healthcare systems vary greatly between countries. International, evidence-based guidelines for the management of multiple sclerosis (MS) may need to be adapted for use in particular countries. Two years ago, the authors published a comprehensive consensus guideline for the management of MS in Qatar. Since that time, the availability of disease-modifying treatments for relapsing-remitting MS (RRMS), and our understanding of how to apply those treatments, has increased. The authors present an update to our guidance, focussing on the management of relapsing-remitting RRMS. In particular, the authors consider the optimal use of different DMTs in patients presenting with mild, medium or high disease activity.

Incidence, clinical features and outcomes of atrial fibrillation and stroke in Qatar

BACKGROUND

Atrial fibrillation is an important risk factor for stroke but there are limited data on atrial fibrillation-related stroke from the Middle East.

METHODS

We interrogated the Qatar Stroke Database to establish the occurrence, clinical features, and outcomes of atrial fibrillation-related stroke at Hamad General Hospital, the sole provider of acute stroke care in Qatar.

RESULTS

A total of 4079 patients (81.4% male, mean age 55.4 ± 13.3 years) were enrolled in the stroke database between January 2014 and 21 October 2017. Atrial fibrillation was present in 260 (6.4%) patients, of whom 106 (2.6%) had newly diagnosed atrial fibrillation. The National Institute of Health Stroke Scale (NIHSS) was significantly higher (7.9 + 7.0 (median 6; IQR 11) vs. 5.9 + 6.4 (median 4; IQR 6), P < 0.001) in atrial fibrillation patients. The modified Rankin Score (mRS) (P < 0.001) and mortality at 90-day follow-up (P = 0.002) were significantly higher in atrial fibrillation compared to non-atrial fibrillation stroke patients.

CONCLUSION

We demonstrate a low rate of atrial fibrillation and stroke in Qatar, perhaps reflecting the relatively young age of these patients. Atrial fibrillation-related strokes had higher admission NIHSS, greater disability, and higher mortality at 90 days when compared to non-atrial fibrillation strokes.