Analysis of Recurrent Stroke Volume and Prognosis between Warfarin and Four Non-Vitamin K Antagonist Oral Anticoagulants' Administration for Secondary Prevention of Stroke

Comparison between non-vitamin K oral antagonist versus warfarin in atrial fibrillation with and without valvular heart disease: a systematic review and meta-analysis

BACKGROUND

Atrial fibrillation (AF) poses a significant stroke risk in heart disease patients. This systematic review aims to evaluate the efficacy and safety of non-vitamin K oral antagonists (NOACs) versus vitamin K antagonists (VKAs) in AF patients with and without any valvular heart disease (VHD/N-VHD).

METHODS

A systematic search was conducted on PubMed, Scopus, and Google Scholar up to March 3, 2022. Efficacy and safety parameters were analyzed.

RESULTS

A total of 85,423 subjects from 10 studies were included in this meta-analysis. NOACs and VKAs showed similar effects on ischemic stroke in AF patients with VHD/N-VHD (RR 0.97; 95% CI 0.72-1.30; p = 0.83) and also on systemic embolic events (RR 1.02; 95% CI 0.83-1.25; p = 0.86). Similar effects were seen in VHD and N-VHD subgroups. Both treatments had similar effects on myocardial infarction in AF patients with VHD/N-VHD (RR 0.79; 95% CI 0.49-1.26; p = 0.32), VHD (RR 0.78; 95% CI 0.59-1.02; p = 0.07), and N-VHD subgroups (RR 0.82; 95% CI 0.30-2.21; p = 0.69). NOACs reduced the risk of intracranial bleeding in AF VHD/N-VHD (RR 0.64; 95% CI 0.54-0.77; p < 0.0001), VHD (RR 0.59; 95% CI 0.42-0.82; p = 0.002), and N-VHD subgroups (RR 0.70; 95% CI 0.57-0.85; p = 0.0003). Additionally, NOACs reduced the risk of gastrointestinal bleeding in AF VHD/N-VHD (RR 0.80; 95% CI 0.66-0.96; p = 0.02), specifically in the VHD subgroup (RR 0.69; 95% CI 0.54-0.89; p = 0.004). Moreover, NOACs were associated with a decreased risk for minor and non-fatal bleeding in AF patients with VHD/N-VHD (RR 0.86; 95% CI 0.75-0.99; p = 0.04).

CONCLUSION

NOACs are effective and safe for ischemic stroke, systemic embolic events, myocardial infarction, intracranial bleeding, and gastrointestinal bleeding in AF patients with VHD/N-VHD.

Acute Ischaemic Stroke in Patients Treated with Direct Oral Anticoagulants: Potential Causes, Clinical Characteristics, and Short-Term Outcomes

Introduction

Direct oral anticoagulants (DOAC) are the first-line treatment for primary and secondary acute ischaemic stroke (AIS) prevention in patients with nonvalvular atrial fibrillation (NVAF), but a significant percentage of patients develop AIS despite being treated with DOAC. As the number of DOAC-treated patients is growing, so is the number of patients with AIS on DOAC. The aim of the study was to assess the incidence of AIS with prestroke DOAC treatment among patients hospitalised in the University Hospital in Kraków, to analyse the clinical characteristics of AIS occurring in patients on DOAC, and to identify potential causes of treatment ineffectiveness in this group.

Materials and Methods

In the study, we included all patients hospitalised in the Department of Neurology of the University Hospital in Kraków within one year (July 2022 to June 2023) with the diagnosis of AIS. The group was divided into two subgroups of patients with and without prestroke DOAC treatment. Based on medical files, we retrospectively analysed the profile of cardiovascular risk factors, stroke severity (assessed with National Institutes of Health Stroke Scale, NIHSS), use of causative stroke treatment and short-term outcomes (defined as NIHSS score, modified Rankin scale (mRS) score at discharge, in-hospital mortality, and secondary intracerebral haemorrhage among patients treated with mechanical thrombectomy, MT). Within the DOAC-treated subgroup, we looked for potential causes of AIS occurring despite DOAC treatment (valvular AF, poor adherence to treatment, underdosing, other prothrombotic conditions, aetiology of stroke other than thromboembolic, and drug-drug interactions).

Results

In the study, we included 768 AIS patients. 109 (14.2%) had a history of prestroke DOAC treatment. A potential cause of DOAC treatment failure was identified in the majority of them (n = 63, 57.8%). Patients with prestroke DOAC treatment had worse functional condition before stroke and higher stroke severity on admission but similar short-term outcomes and similar short-term effects of treatment with MT. DOAC (+) and DOAC (-) patients had different profiles of cardiovascular risk factors and different factors associated with short-term outcome. Conclusions and Clinical Implications. A potential cause of AIS occurring in DOAC-treated patients can be identified in most cases and in many of them prevented.

Ischemic stroke in oral anticoagulated patients with atrial fibrillation

BACKGROUND

Ischemic strokes in orally anticoagulated patients pose challenges for acute management and secondary prevention but the characteristics of these strokes are poorly understood. We examined the clinical and imaging features, the presumed underlying etiology and the subsequent antithrombotic management.

METHODS

We analyzed a consecutive series of patients enrolled into the EIDASAF study, a single center, observational study of ischemic stroke patients with a diagnosis atrial fibrillation (AF) prior to the index event who had been admitted to the Hyperacute Stroke Unit of Imperial College London between 2010 and 2017. We compared patients with oral anticoagulation therapy prior admission (OAC_prior ) with those without anticoagulation (OAC_naive ). Brain imaging was analyzed centrally.

RESULTS

763 patients were included in the analysis. 481 (63%) were OAC_naive while 282 (37%) were OAC_prior . Patients with OAC_prior were younger, more often had a previous history of stroke or transient ischemic attack (TIA), and more often suffered from hypertension and diabetes. In OAC_naive, patients, large and deep middle cerebral artery infarcts occurred more often than in OAC_prior patients. The groups differed significantly in the distribution of competing etiologies underlying their stroke. At discharge, OAC_prior more frequently were (re)-anticoagulated compared to OAC_naive patients. Within the OAC_prior group, patients with recurrent strokes did not differ from those with a first stroke regarding clinical characteristics and pattern of cerebral infarction but they were less frequently anticoagulated.

CONCLUSIONS

Ischemic strokes on OAC represent a significant proportion of AF-related strokes. There is an unmet need to better understand the causes underlying these strokes and to optimize the medical management.

Treatment standards for direct oral anticoagulants in patients with acute ischemic stroke and non-valvular atrial fibrillation: A survey among German stroke units

BACKGROUND

Acute ischemic stroke (AIS) in patients with non-valvular atrial fibrillation (AF) despite oral anticoagulation (OAC) is a complex and insufficiently investigated setting. Potential strategies range from maintaining the current OAC to changing the substance class. We have queried the specific treatment standards on German stroke units (SUs).

METHODS

By means of a standardized online questionnaire via SurveyMonkey™ (San Mateo, CA, USA), all clinical heads of German SUs were asked about their treatment standards in the following clinical situations: first AIS of an OAC-naïve AF patient, AF patient with AIS despite administration of a vitamin K antagonist (VKA), AF patient with AIS despite administration of direct OAC (DOAC). In addition, the performance of specific coagulation tests in AF patients with AIS despite OAC was queried.

RESULTS

160 (48%) clinical heads of German SU responded. Data from pivotal trials (84%), own experience with substances (71%), and side-effect profiles (66%) determine the initial DOAC prescription. In case of an AIS despite OAC, 83 and 18% would switch from VKA to DOAC under certain conditions and always, respectively. Half of respondents would switch from DOAC to VKA under certain conditions, while the other half would decline. 96% would switch to an alternative DOAC. The vast majority of those who made preconditions considered concomitant diseases (92, 90, and 81%, respectively). Few would consider infarct pattern (<35%). 61% perform initial coagulation tests (only one-third substance-specific assessments); however, the majority do not use these to make further decisions.

CONCLUSIONS

In the setting of an OAC-naïve AF patient with AIS, established pivotal data are most respected. In the unclear setting of an AIS despite OAC, most respondents consider concomitant diseases and give preference to switching to a (different) DOAC.

Infarct Volumes of Patients with Acute Ischemic Stroke Receiving Direct Oral Anticoagulants due to Non-Valvular Atrial Fibrillation

Direct oral anticoagulants (DOACs) have been shown to decrease the risk of ischemic stroke in non-valvular atrial fibrillation (NVAF). This study aims to investigate whether DOACs result in a significant change in lesion volume and the severity of the subsequent disability in patients who have experienced a stroke.

MRI characteristics in acute ischemic stroke patients with preceding direct oral anticoagulant therapy as compared to vitamin K antagonists

Background

Despite the utility of neuroimaging in the diagnostic and therapeutic management of patients with acute ischemic stroke (AIS), imaging characteristics in patients with preceding direct oral anticoagulants (DOAC) compared to vitamin K antagonists (VKA) have hardly been described. We aimed to determine presence of large vessel occlusion (LVO), thrombus length, infarction diameter, and occurrence of hemorrhagic transformation in AIS patients with preceding DOAC as compared to VKA therapy.

Methods

Using a prospectively collected cohort of AIS patients, we performed univariate and multivariable regression analyses regarding imaging outcomes. Additionally, we provide a sensitivity analysis for the subgroup of patients with confirmed therapeutic anticoagulation.

Results

We included AIS in patients with preceding DOAC (N = 75) and VKA (N = 61) therapy, median age 79 (IQR 70–83), 39% female. Presence of any LVO between DOAC and VKA patients (29.3% versus 37.7%, P = 0.361), and target LVO for endovascular therapy (26.7% versus 27.9%, P = 1.0) was equal with a similar occlusion pattern. DOAC as compared to VKA were associated with a similar rate of target LVO for EVT (aOR 0.835, 95% CI 0.368–1.898). The presence of multiple lesions and characteristics of the thrombus were similar in DOAC and VKA patients. Acute ischemic lesion diameter in real world patients was equal in patients taking DOAC as compared to VKA. Lesion diameter in VKA patients (median 13 mm, IQR 6–26 versus median 20 mm, IQR 7–36, P = 0.001), but not DOAC patients was smaller in the setting of confirmed therapeutic VKA. The frequency of radiological hemorrhagic transformation and symptomatic intracranial hemorrhage in OAC patients was low. Sensitivity analysis considering only patients with confirmed therapeutic anticoagulation did not change any of the results.

Conclusion

Preceding DOAC treatment showed equal rates of LVO and infarct size as compared to VKA in AIS patients. This study adds to the knowledge of imaging findings in AIS patients with preceding anticoagulation.

Clinical presentation, diagnostic findings and management of cerebral ischemic events in patients on treatment with non-vitamin K antagonist oral anticoagulants - A systematic review

Background

Non-vitamin K antagonist oral anticoagulants (NOAC) are equally or potentially superior in terms of effectiveness in the prevention of ischemic stroke and carry a lower associated risk of intracranial hemorrhage compared to Vitamin K antagonists. Nevertheless, ischemic strokes also occur in patients who are being treated with NOAC. In those particular patients, knowledge about the underlying stroke etiology, clinical presentation, acute management, and complication rates is scarce.

Objective

Systematic literature review to provide a comprehensive clinical overview in terms of presentation, laboratory, imaging parameters and outcomes of patients suffering from acute cerebral ischemic events (i.e. TIA and acute ischemic stroke) while on treatment with a NOAC. Only if available, comparison to VKA is presented which was not the primary focus of this analysis.

Data sources

PubMed/MEDLINE, Scopus and EMBASE from January 1, 2006, to November 20, 2018.

Study eligibility criteria

52 studies providing detailed information on a total of 12247 patients were included. We excluded case reports and case series with less than five patients.

Study appraisal and synthesis method

We systematically assessed study quality using a bias tool and pooled consistent data.

Results

Existing data indicates milder stroke severity and smaller infarct size of acute ischemic stroke on treatment with NOAC compared to stroke occurrence on Vitamin K antagonists (VKA). Established risk factors for ischemic events also play a role in stroke while on NOACs, albeit the underlying etiology remains poorly understood. Intravenous thrombolysis and endovascular therapy seem to be safe and effective, but patient selection for recanalization therapies is challenging.

Limitations

Limited quality of published data, duplicate cases, statistical issues of data pooling, possible incomplete retrieval of identified research and reporting bias might have limited our findings.

Conclusions

Acute ischemic events despite treatment with NOAC therapy are insufficiently investigated.

Systematic review registration number

PROSPERO: CRD42018074853.

Dabigatran Versus Rivaroxaban for Secondary Stroke Prevention in Patients with Atrial Fibrillation Rehabilitated in Skilled Nursing Facilities

BACKGROUND

Thromboembolic and bleeding risk are elevated in older patients with atrial fibrillation and prior stroke. We compared dabigatran with rivaroxaban for secondary prevention in a national population after skilled nursing facility (SNF) discharge.

METHODS

Medicare fee-for-service beneficiaries aged ≥ 65 years with atrial fibrillation hospitalized for ischemic stroke (November 2011-October 2013) and subsequently admitted to an SNF were studied. Dabigatran (n = 332) and rivaroxaban users (n = 378) were compared in a retrospective, active comparator, new-user cohort. The index medication claim occurred within 120 days after hospital discharge and exposure continued until a 14-day treatment gap ('as treated'). The primary net clinical benefit outcome was the time to recurrent stroke, transient ischemic attack, intracranial hemorrhage, extracranial bleed, myocardial infarction, venous thromboembolism, or death. All-cause mortality was evaluated separately as a secondary outcome. Multivariable adjusted Cox models stratified by dosage estimated hazard ratios (aHR).

RESULTS

Among those receiving low dosages, the crude composite event rate was 40.4/100 person-years among dabigatran users and 33.7/100 person-years among rivaroxaban users. The composite outcome [aHR 1.48; 95% confidence interval (CI) 0.87-2.51] and all-cause mortality (aHR 1.67; 95% CI 0.84-3.31) rates were higher among low-dose dabigatran users. For those receiving standard doses, the crude composite event rates were 19.5/100 person-years for dabigatran users and 37.1/100 person-years for rivaroxaban users. Although no difference in mortality was observed, the composite outcome rate was lower among standard-dose dabigatran users (aHR 0.65; 95% CI 0.36-1.15).

CONCLUSIONS

In older adults treated with direct-acting oral anticoagulants after ischemic stroke, outcome rates varied considerably by drug and dosage.