Prior Anticoagulation in Patients with Ischemic Stroke and Atrial Fibrillation

Risk of stroke in patients with prior VKA or DOAC: A population-based real-world registry analysis

INTRODUCTION

To date, risk assessment of suffering ischemic and hemorrhagic stroke in individuals under oral anticoagulation (OAC) is limited to hospital-based cohorts and patients with atrial fibrillation.

PATIENTS AND METHODS

Through the combination of three individual datasets, (1) the population-based Tyrolean Stroke Pathway database, prospectively documenting all (unselected) stroke patients in the entire federal state of the Tyrol and (2) nation-wide prescription data, detailing each reimbursed prescription in Austria as well as (3) the Austrian Stroke Unit Registry, a nation-wide registry comprising data on all patients admitted to any of the 38 stroke units in Austria, we assessed risk of stroke in patients with prior oral anticoagulation and compared characteristics of patients taking direct oral anticoagulants and Vitamin-K-Antagonists.

RESULTS

In Austria, oral anticoagulant prescription reimbursements increased from 292,475 in 2015 to 389,407 in 2021. In the Tyrol, prior oral anticoagulation treatment was evident in 586 of 3861 (15.2%) patients with ischemic and 131 of 523 (25.0%) with hemorrhagic stroke, with 20% and 35% of those stroke patients respectively having prior oral anticoagulation due to other indications than non-valvular atrial fibrillation. Considering prescription rates, treatment with direct oral anticoagulants was associated with a reduced stroke risk compared to Vitamin-K-Antagonists, especially in ischemic (1.05% vs 0.62%; RR 0.59, p < 0.001) but also in hemorrhagic stroke, even if less pronounced (0.21% vs 0.14%; RR 0.68, p = 0.06). In Austria, prior intake of direct oral anticoagulants was associated with lower risk of suffering acute large vessel occlusion stroke (RR 0.79, p = 0.003).

DISCUSSION AND CONCLUSIONS

One in seven patients suffering ischemic and one in four suffering hemorrhagic stroke had prior oral anticoagulation treatment. Both ischemic and hemorrhagic strokes are less frequent in those with direct oral anticoagulant intake compared to those taking Vitamin-K-Antagonists. Establishment of clear standard operating procedures on how to best care for acute stroke patients with oral anticoagulation is essential.

Contemporary Outcomes of Acute Ischemic Stroke in Atrial Fibrillation Patients on Anticoagulation

BACKGROUND

Long-term anticoagulation (AC) therapy reduces the risk of stroke in patients with Atrial Fibrillation (AF). However, data on the impact of AC on in-hospital stroke outcomes is lacking.

METHODS

The National Inpatient Sample was used to identify adult inpatients with AF and a primary diagnosis of ischemic stroke between 2016 and 2020. Data was stratified between AC users and nonusers. A multivariate regression model was used to describe the in-hospital outcomes, adjusting for significant comorbidities.

RESULTS

A total of 655,540 hospitalizations with AF and a primary hospitalization diagnosis of ischemic stroke were included, of which 194,560 (29.7%) were on long-term AC. Patients on AC tended to be younger (mean age, 77 vs 78), had a higher average CHA2DS2VASc score (4.48 vs 4.20), higher rates of hypertension (91% vs 88%), hyperlipidemia (64% vs 59%), and heart failure (34% vs 30%) compared to patients not on long-term AC. Use of AC was associated with decreased in-hospital mortality (aOR [95% CI]: 0.62 [0.60 - 0.63]), decreased stroke severity (mean NIHSS, 8 vs 10), decreased use of tPA (aOR 0.42 [0.41 - 0.43]), mechanical thrombectomy (aOR 0.85 [0.83 - 0.87]), intracranial hemorrhage (aOR 0.69 [0.67 - 0.70]), gastrointestinal bleeding (aOR 0.74 [0.70 - 0.77]), and discharge to skilled nursing facilities (aOR 0.90 [0.89 - 0.91]), compared to patients not on AC (P<0.001 for all comparisons).

CONCLUSION

Among patients with AF admitted for acute ischemic stroke, AC use prior to stroke was associated with decreased in-hospital mortality, decreased stroke severity, decreased discharge to SNF, and fewer stroke-related and bleeding complications.

Intravenous thrombolysis in patients with recent intake of direct oral anticoagulants: A target trial analysis after the liberalization of institutional guidelines

INTRODUCTION

This study aimed to report the safety and efficacy of off-label intravenous thrombolysis (IVT) with alteplase after sequentially liberalizing our institutional guidelines allowing IVT for patients under direct oral anticoagulants (DOACs) regardless of plasma levels, time of last intake, and without prior anticoagulation reversal therapy.

PATIENTS AND METHODS

We utilized the target-trial methodology to emulate hypothetical criteria of a randomized controlled trial in our prospective stroke registry. Consecutive DOAC patients (06/2021-11/2023) otherwise qualifying for IVT were included. Safety and efficacy outcomes (symptomatic intracranial hemorrhage [ICH], any radiological ICH, major bleeding, 90-day mortality, 90-day good functional outcome [mRS 0-2 or return to baseline]) were assessed using inverse-probability-weighted regression-adjustment comparing patients with versus without IVT.

RESULTS

Ninety eight patients fulfilled the target-trial criteria. IVT was given in 49/98 (50%) patients at a median of 178 (interquartile range 134-285) min after symptom onset with median DOAC plasma level of 77 ng/ml (15 patients had plasma levels > 100 ng/ml; 25/49 [51%] were treated within 12 h after last DOAC ingestion). Endovascular therapy was more frequent in patients without IVT (73% vs 33%). Symptomatic ICH occurred in 0/49 patients receiving IVT and 2/49 patients without IVT (adjusted difference -2.5%; 95% CI -5.9 to 0.8). The rates of any radiological ICH were comparable. Patients receiving IVT were more likely to have good functional outcomes.

DISCUSSION AND CONCLUSION

After liberalizing our approach for IVT regardless of recent DOAC intake, we did not experience any safety concerns. The association of IVT with better functional outcomes warrants prospective randomized controlled trials.

Mechanical Thrombectomy in Anticoagulated Patients With Acute Ischemic Stroke: A Meta-Analysis

BACKGROUND

According to a previous studies, mechanical thrombectomy(MT) is safe for anticoagulated patients. However, the safety and prognosis of direct oral anticoagulants (DOACs) and vitamin K antagonists (VKA) have not been compared with those of MT.This meta-analysis aimed at determining the efficacy of DOACs or VKA for patients after MT.

REVIEW SUMMARY

We searched PubMed, Embase, Web of Science databases, and Cochrane from their inception to Aug 2022. Revman 5.3 served for the meta-analysis. The meta-analysis included 12 studies that covered 3571 patients, finding that after MT treatment, DOACs significantly decreased the symptomatic intracerebral hemorrhage [odd ratio (OR)=0.49, 95% CI 0.30-0.80, P =0.004] and mortality (OR=0.63, 95% CI 0.48-0.83, P =0.001) compared with VKA. Meanwhile, no obvious differences were found between DOACs and VKA after MT treatment in terms of in any hemorrhagic transformation (OR=1.07, 95% CI 0.84-1.37, P =0.59), good functional outcome (OR=1.06, 95% CI 0.88-1.27, P =0.53), and successful arterial recanalization (OR=1.24, 95% CI 1.00-1.53, P =0.05).

CONCLUSIONS

This meta-analysis demonstrates that the application of DOACs in MT treatment for anticoagulated patients with acute ischemic stroke is safer than that in the VKA group. However, further studies are necessary to confirm these results.

Secondary stroke prevention in people with atrial fibrillation: treatments and trials

Atrial fibrillation is one of the most common cardiac arrhythmias and is a major cause of ischaemic stroke. Recent findings indicate the importance of atrial fibrillation burden (device-detected, subclinical, or paroxysmal and persistent or permanent) and whether atrial fibrillation was known before stroke onset or diagnosed after stroke for the risk of recurrence. Secondary prevention in patients with atrial fibrillation and stroke aims to reduce the risk of recurrent ischaemic stroke. Findings from randomised controlled trials assessing the optimal timing to introduce direct oral anticoagulant therapy after a stroke show that early start (ie, within 48 h for minor to moderate strokes and within 4-5 days for large strokes) seems safe and could reduce the risk of early recurrence. Other promising developments regarding early rhythm control, left atrial appendage occlusion, and novel factor XI inhibitor oral anticoagulants suggest that these therapies have the potential to further reduce the risk of stroke. Secondary prevention strategies in patients with atrial fibrillation who have a stroke despite oral anticoagulation therapy is an unmet medical need. Research advances suggest a heterogeneous spectrum of causes, and ongoing trials are investigating new approaches for secondary prevention in this vulnerable patient group. In patients with atrial fibrillation and a history of intracerebral haemorrhage, the latest data from randomised controlled trials on stroke prevention shows that oral anticoagulation reduces the risk of ischaemic stroke but more data are needed to define the safety profile.

Longer and better lives for patients with atrial fibrillation: the 9th AFNET/EHRA consensus conference

AIMS

Recent trial data demonstrate beneficial effects of active rhythm management in patients with atrial fibrillation (AF) and support the concept that a low arrhythmia burden is associated with a low risk of AF-related complications. The aim of this document is to summarize the key outcomes of the 9th AFNET/EHRA Consensus Conference of the Atrial Fibrillation NETwork (AFNET) and the European Heart Rhythm Association (EHRA).

METHODS AND RESULTS

Eighty-three international experts met in Münster for 2 days in September 2023. Key findings are as follows: (i) Active rhythm management should be part of the default initial treatment for all suitable patients with AF. (ii) Patients with device-detected AF have a low burden of AF and a low risk of stroke. Anticoagulation prevents some strokes and also increases major but non-lethal bleeding. (iii) More research is needed to improve stroke risk prediction in patients with AF, especially in those with a low AF burden. Biomolecules, genetics, and imaging can support this. (iv) The presence of AF should trigger systematic workup and comprehensive treatment of concomitant cardiovascular conditions. (v) Machine learning algorithms have been used to improve detection or likely development of AF. Cooperation between clinicians and data scientists is needed to leverage the potential of data science applications for patients with AF.

CONCLUSIONS

Patients with AF and a low arrhythmia burden have a lower risk of stroke and other cardiovascular events than those with a high arrhythmia burden. Combining active rhythm control, anticoagulation, rate control, and therapy of concomitant cardiovascular conditions can improve the lives of patients with AF.

Intracerebral haemorrhage in patients taking different types of oral anticoagulants: a pooled individual patient data analysis from two national stroke registries

BACKGROUND

We investigated outcomes in patients with intracerebral haemorrhage (ICH) according to prior anticoagulation treatment with Vitamin K antagonists (VKAs), direct oral anticoagulants (DOACs) or no anticoagulation.

METHODS

This is an individual patient data study combining two prospective national stroke registries from Switzerland and Norway (2013-2019). We included all consecutive patients with ICH from both registries. The main outcomes were favourable functional outcome (modified Rankin Scale 0-2) and mortality at 3 months.

RESULTS

Among 11 349 patients with ICH (mean age 73.6 years; 47.6% women), 1491 (13.1%) were taking VKAs and 1205 (10.6%) DOACs (95.2% factor Xa inhibitors). The median percentage of patients on prior anticoagulation was 23.7 (IQR 22.6-25.1) with VKAs decreasing (from 18.3% to 7.6%) and DOACs increasing (from 3.0% to 18.0%) over time. Prior VKA therapy (n=209 (22.3%); adjusted ORs (aOR), 0.64; 95% CI, 0.49 to 0.84) and prior DOAC therapy (n=184 (25.7%); aOR, 0.64; 95% CI, 0.47 to 0.87) were independently associated with lower odds of favourable outcome compared with patients without anticoagulation (n=2037 (38.8%)). Prior VKA therapy (n=720 (49.4%); aOR, 1.71; 95% CI, 1.41 to 2.08) and prior DOAC therapy (n=460 (39.7%); aOR, 1.28; 95% CI, 1.02 to 1.60) were independently associated with higher odds of mortality compared with patients without anticoagulation (n=2512 (30.2%)).

CONCLUSIONS

The spectrum of anticoagulation-associated ICH changed over time. Compared with patients without prior anticoagulation, prior VKA treatment and prior DOAC treatment were independently associated with lower odds of favourable outcome and higher odds of mortality at 3 months. Specific reversal agents unavailable during the study period might improve outcomes of DOAC-associated ICH in the future.

CADMUS: A Novel MRI-Based Classification of Spontaneous Intracerebral Hemorrhage Associated With Cerebral Small Vessel Disease

BACKGROUND AND OBJECTIVES

Cerebral small vessel disease (SVD) is the major cause of intracerebral hemorrhage (ICH). There is no comprehensive, easily applicable classification of ICH subtypes according to the presumed underlying SVD using MRI. We developed an MRI-based classification for SVD-related ICH.

METHODS

We performed a retrospective study in the prospectively collected Swiss Stroke Registry (SSR, 2013-2019) and the Stroke InvestiGation in North And central London (SIGNAL) cohort. Patients with nontraumatic, SVD-related ICH and available MRI within 3 months were classified as Cerebral Amyloid angiopathy (CAA), Deep perforator arteriopathy (DPA), Mixed CAA-DPA, or Undetermined SVD using hemorrhagic and nonhemorrhagic MRI markers (CADMUS classification). The primary outcome was inter-rater reliability using Gwet's AC1. Secondary outcomes were recurrent ICH/ischemic stroke at 3 months according to the CADMUS phenotype. We performed Firth penalized logistic regressions and competing risk analyses.

RESULTS

The SSR cohort included 1,180 patients (median age [interquartile range] 73 [62-80] years, baseline NIH Stroke Scale 6 [2-12], 45.6% lobar hematoma, systolic blood pressure on admission 166 [145-185] mm Hg). The CADMUS phenotypes were as follows: mixed CAA-DPA (n = 751 patients, 63.6%), undetermined SVD (n = 203, 17.2%), CAA (n = 154, 13.1%), and DPA (n = 72, 6.3%), with a similar distribution in the SIGNAL cohort (n = 313). Inter-rater reliability was good (Gwet's AC1 for SSR/SIGNAL 0.69/0.74). During follow-up, 56 patients had 57 events (28 ICH, 29 ischemic strokes). Three-month event rates were comparable between the CADMUS phenotypes.

DISCUSSION

CADMUS, a novel MRI-based classification for SVD-associated ICH, is feasible and reproducible and may improve the classification of ICH subtypes in clinical practice and research.

Acute ischemic stroke and measurement of apixaban and rivaroxaban: an observational cohort implementation study

Background

Treatment with intravenous thrombolysis for acute ischemic stroke is contraindicated with intake of apixaban/rivaroxaban in the last 48 hours. Recent European Stroke Organization guidelines suggest that thrombolysis can be considered if anti-factor Xa activity (AFXa) is <0.5 × 103 IU/L with low-molecular-weight (LMWH) or unfractionated heparin (UFH) calibrated assays. Some centers also use apixaban/rivaroxaban-calibrated AFXa assays to identify patients with low drug concentrations.

Objectives

To prospectively evaluate the first year of implementation of drug-calibrated AFXa assays at our center with 2500 yearly admittances with suspected stroke.

Methods

Samples were analyzed on Sysmex CS-5100 instruments with Innovance anti-Xa reagents. Thrombolysis could be considered with drug concentrations <25 μg/L. Patients were registered in an institutionally approved quality register. Outcomes included (1) the number of patients receiving thrombolysis after drug measurement, (2) turn-around time for drug concentration measurements, and (3) sensitivity of LMWH/UFH AFXa to apixaban and rivaroxaban.

Results

Apixaban or rivaroxaban was measured in 148 samples, and 4 patients who previously would have been ineligible for thrombolysis were treated with thrombolysis. In total, thrombolysis was administered in 123 patient episodes in the study period. The median turn-around time for the drug measurements was 38 minutes. Apixaban concentrations of 25 μg/L and 50 μg/L corresponded to LMWH/UFH AFXa of 0.13 and 0.27 × 103 IU/L, respectively. There were too few rivaroxaban results for regression analysis.

Conclusion

Implementation of apixaban and rivaroxaban measurements led to a small increase in the number of patients receiving thrombolysis. Excluding significant concentrations of apixaban or rivaroxaban using LMWH/UFH AFXa may be feasible.

Stroke Prevention in Atrial Fibrillation: Our Current Failures and Required Research

Nonvalvular atrial fibrillation is a common rhythm disorder of middle-aged to older adults that can cause ischemic strokes and systemic embolism. Lifelong use of oral anticoagulants reduces the risk of these ischemic events but increases the risk of major and clinically relevant hemorrhages. These medications also require strict compliance for efficacy, and they have nontrivial failure rates in higher-risk patients. Left atrial appendage closure is a nonpharmacological method to prevent ischemic strokes in atrial fibrillation without the need for lifelong anticoagulant use, but this procedure has the potential for complications and residual embolic events. This workshop of the Roundtable of Academia and Industry for Stroke Prevention discussed future research needed to further decrease the ischemic and hemorrhagic risks among patients with atrial fibrillation. A direct thrombin inhibitor, factor Xa inhibitors, and left atrial appendage closure are FDA-approved approaches whereas factor XIa inhibitors are currently being studied in phase 3 randomized controlled trials for stroke prevention. The benefits, risks, and shortcomings of these treatments and future research required in different high-risk patient populations are reviewed in this consensus statement.

Direct Oral Anticoagulants in Special Patient Populations

Anticoagulants are a cornerstone of treatment in atrial fibrillation. Nowadays, direct oral anticoagulants (DOACs) are extensively used for this condition in developed countries. However, DOAC treatment may be inappropriate in certain patient populations, such as: patients with chronic kidney disease in whom DOAC concentrations may be dangerously elevated; frail elderly patients with an increased risk of falls; patients with significant drug-drug interactions (DDI) affecting either DOAC concentration or effect; patients at the extremes of body mass in whom an "abnormal" volume of distribution may result in inappropriate drug concentrations; patients with recurrent stroke reflecting an unusually high thromboembolic tendency; and, lastly, patients who experience major hemorrhage on an anticoagulant and in whom continued anticoagulation is deemed necessary. Herein we provide a fictional case-based approach to review the recommendations for the use of DOACs in these special patient populations.

Meta-analysis of outcomes following intravenous thrombolysis in patients with ischemic stroke on direct oral anticoagulants

BACKGROUND

There has been debate on the use of intravenous thrombolysis (IVT) in patients with ischemic stroke and the recent use of direct oral anticoagulants (DOACs). Studies have compared these patients with non-DOAC groups in terms of outcomes. Herein, we aimed to systematically investigate the association between DOAC use and IVT's efficacy and safety outcomes.

RESULTS

A comprehensive systematic search was performed in PubMed, Embase, Scopus, and the Web of Science for the identification of relevant studies. After screening and data extraction, a random-effect meta-analysis was performed to calculate the odds ratio (OR) and 95% confidence interval (CI) for comparison of outcomes between patients on DOAC and controls. Six studies were included in the final review. They investigated a total of 254,742 patients, among which 3,499 had recent use of DOACs. The most commonly used DOACs were rivaroxaban and apixaban. The patients on DOAC had significantly higher rates of atrial fibrillation, hypertension, diabetes, and smoking. Good functional outcome defined by modified Rankin Scale (mRS) 0-2 was significantly lower in patients who received DOACs (OR 0.71, 95% CI 0.62 to 0.81, P < 0.01). However, in the subgroup analysis of 90-day mRS 0-2, there was no significant difference between groups (OR 0.71, 95% 0.46 to 1.11, P = 0.14). All-cause mortality was not different between the groups (OR 1.02, 95% CI 0.68 to 1.52, P = 0.93). Similarly, there was no significant difference in either of the in-hospital and 90-day mortality subgroups. Regarding symptomatic intracranial hemorrhage (sICH), the previous DOAC use was not associated with an increased risk of bleeding (OR 0.98, 95% CI 0.69 to 1.39, P = 0.92). A similar finding was observed for the meta-analysis of any ICH (OR 1.15, 95% CI 0.94 to 1.40, P = 0.18).

CONCLUSIONS

Based on our findings, IVT could be considered as a treatment option in ischemic stroke patients with recent use of DOACs since it was not associated with an increased risk of sICH, as suggested by earlier studies. Further larger studies are needed to confirm these findings and establish the safety of IVT in patients on DOAC.

Small vessel disease burden and risk of recurrent cerebrovascular events in patients with lacunar stroke and intracerebral haemorrhage attributable to deep perforator arteriolopathy

INTRODUCTION

Deep perforator arteriolopathy (DPA) causes intracerebral haemorrhage (ICH) and lacunar strokes (LS). We compare patient characteristics, MRI findings and clinical outcomes among patients with deep ICH and LS.

PATIENTS AND METHODS

We included patients with MRI-confirmed LS or ICH in the basal ganglia, thalamus, internal capsule or brainstem from the Bernese Stroke Registry. We assessed MRI small vessel disease (SVD) markers, SVD burden score, modified Rankin Scale (mRS) and ischaemic stroke or ICH at 3 months.

RESULTS

We included 716 patients, 117 patients (16.3%) with deep ICH (mean age (SD) 65.1 (±15.2) years, 37.1% female) and 599 patients (83.7%) with LS (mean age (SD) 69.7 (±13.6) years, 39.9% female). Compared to LS, deep ICH was associated with a higher SVD burden score (median (IQR) 2 (1-2) vs 1 (0-2)), aORshift 3.19, 95%CI 2.15-4.75). Deep ICH patients had more often cerebral microbleeds (deep ICH: 71.6% vs LS: 29.2%, p < 0.001, median count (IQR) 4(2-12) vs 2(1-6)) and a higher prevalence of lacunes (deep ICH: 60.5% vs LS: 27.4% p < 0.001). At 3 months, deep ICH was associated with higher mRS (aORshift 2.16, 95%CI 1.21-3.87). Occurrence of ischaemic stroke was numerically but not significantly higher in deep ICH (4.3% vs 2.9%; p = 0.51). One patient (1.1%) with ICH but none with LS suffered ICH recurrence.

DISCUSSION/CONCLUSION

DPA manifesting as ICH is associated with more severe MRI SVD burden and worse outcome compared to LS. The short-term risks of subsequent ischaemic stroke and recurrent ICH are similar in ICH and LS patients. This implies potential consequences for future secondary prevention strategies.

Characteristics and Mechanism of Acute Ischemic Stroke in NAVF Patients With Prior Oral Anticoagulant Therapy

OBJECTIVES

We aimed to analyze the characteristics and mechanisms of acute ischemic stroke (AIS) in patients with nonvalvular atrial fibrillation (NVAF) who received prior anticoagulant therapy.

METHODS

We retrospectively analyzed the data of patients with NVAF and AIS between January 2016 and December 2021. Patients were divided into non-anticoagulant, adequate anticoagulant, and insufficient anticoagulant groups according to their prior anticoagulant status. Patients with prior anticoagulant therapy were further divided into warfarin and direct oral anticoagulant groups.

RESULTS

A total of 749 patients (661 without anticoagulants, 33 with adequate anticoagulants, and 55 with insufficient anticoagulants) were included. Patients with adequate anticoagulant had a milder National Institute of Health Stroke Scale at presentation ( P =0.001) and discharge ( P =0.003), a higher proportion of Modified Rankin Scale (mRS) ≤2 at discharge ( P =0.011), and lower rates of massive infarction ( P =0.008) than patients without anticoagulant. Compared with the non-anticoagulant group, the proportion of intravenous thrombolysis was significantly lower in the adequate anticoagulant ( P <0.001) and insufficient anticoagulant ( P =0.009) groups. Patients in the adequate anticoagulant group had higher rates of responsible cerebral atherosclerotic stenosis ( P =0.001 and 0.006, respectively) and competing large artery atherosclerotic mechanisms ( P =0.006 and 0.009, respectively) than those in the other 2 groups. Compared with warfarin, direct oral anticoagulant was associated with higher rates of Modified Rankin Scale ≤2 at discharge ( P =0.003).

CONCLUSIONS

Adequate anticoagulant therapy may be associated with milder stroke severity and better outcomes at discharge in patients with NVAF. Competing large artery atherosclerotic mechanisms may be associated with anticoagulant failure in patients with NAVF with prior adequate anticoagulant therapy.

Functional outcomes of patients with ischaemic stroke with known atrial fibrillation not on therapeutic anticoagulation

BACKGROUND

Anticoagulation significantly reduces the risk of ischaemic stroke in patients with atrial fibrillation (AF). There are a proportion of patients with known AF who remain off anticoagulation. Aims This study aims to retrospectively compare the baseline characteristics, treatments and functional outcomes between patients with ischaemic stroke and known AF based on their anticoagulation status.

METHODS

A single-centre, retrospective review of consecutive patients with an ischaemic stroke and a known history of AF was conducted.

RESULTS

Two hundred four patients with an ischaemic stroke had documented AF prior to the index admission, of which 126 were anticoagulated. Median admission National Institutes of Health Stroke Scale score was lower for anticoagulated patients, though not statistically significant (5.1 vs 7.0, P = 0.09). Median baseline modified Rankin score (mRS) did not significantly differ. Nonanticoagulated patients were more likely to have large vessel occlusions (37.2% vs 23.8%, P = 0.04) and more likely to receive intravenous thrombolysis (15.4% vs 1.6%, P < 0.01). There was no difference in rates of endovascular clot retrieval between groups (P > 0.05). Unfavourable functional outcome at 90 days (mRS ≥ 3) did not significantly differ between groups (P = 0.51). A total of 38.5% of nonanticoagulated patients had no documented reason for this. Of the patients who survived the index admission, 81.5% of patients who were not anticoagulated on admission received anticoagulation.

CONCLUSIONS

Baseline anticoagulation was associated with milder stroke severity in ischaemic stroke patients with known AF. There was no significant difference in functional outcomes at 90 days between groups. Larger observational studies are required to further assess this cohort.

Oral Anticoagulant Therapy and Risk of Admission to Long-Term Care in patients With Atrial Fibrillation: A Nationwide Cohort Study

OBJECTIVES

The impact of oral anticoagulants (OACs) on the need of long-term care (LTC) in the aging and multimorbid population of patients with atrial fibrillation (AF) is unknown. We conducted a nationwide cohort study to evaluate the effect of OACs on the need of LTC.

DESIGN

Retrospective nationwide cohort study.

SETTING AND PARTICIPANTS

The registry-based FinACAF cohort study covers all patients with incident AF from all levels of care in Finland from 2007 to 2018, as well as all their OAC purchases, LTC admissions, and information on previous home care acuity.

METHODS

Incidence rate ratios (IRRs) of LTC admission were calculated using Poisson regression models with a Lexis-type data structure based on 3 time scales: follow-up time from AF diagnosis, calendar year, and age.

RESULTS

We identified 188,752 patients (49.0% female; mean age 71.4 years; mean follow-up 3.6 years) with incident AF without prior LTC, of whom 143,534 (76.0 %) initiated OAC therapy and 11,775 (6.2 %) were admitted to LTC. OAC therapy was associated with lower rates of LTC admission (adjusted IRR 0.79, 95% CI 0.76-0.82). When compared to warfarin, direct oral anticoagulants (DOACs) were associated with lower LTC admission rate (adjusted IRR 0.69, 95% CI 0.61-0.79). No significant disparities were observed between different DOACs.

CONCLUSIONS AND IMPLICATIONS

OAC therapy, particularly with DOACs, is associated with a substantially lower risk of admission to LTC in patients with AF. Increasing guideline-based OAC coverage among patients with AF may prevent the need of LTC, lengthen survival at home, and potentially decrease health care costs.

Atrial Fibrillation and Ischemic Stroke despite Oral Anticoagulation

Patients with atrial fibrillation (AF) experiencing ischemic stroke despite oral anticoagulation (OAC), i.e., breakthrough strokes, are not uncommon, and represent an important clinical subgroup in view of the consistently high risk of stroke recurrence and mortality. The understanding of the heterogenous potential mechanism underlying OAC failure is essential in order to implement specific therapeutic measures aimed at reducing the risk of recurrent ischemic stroke. However, due to the incomplete comprehension of this phenomenon and the limited available data, secondary stroke prevention in such high-risk patients represents a clinical dilemma. There are several available strategies to prevent ischemic stroke recurrence in AF patients with breakthrough stroke in the absence of competing causes unrelated to AF, and these include continuation or change in the type of OAC, addition of antiplatelet therapy, left atrial appendage closure, or any combination of the above options. However, due to the limited available data, the latest guidelines do not provide any specific recommendations about which of the above strategies may be preferred. This review describes the incidence, the clinical impact and the potential mechanisms underlying OAC failure in AF patients. Furthermore, the evidence supporting each of the above therapeutic options for secondary stroke prevention and the potential future directions will be discussed.

Management and Prognosis of Acute Stroke in Atrial Fibrillation

Atrial fibrillation (AF) is an important risk factor for ischemic stroke (IS). Oral anticoagulation (OAC) significantly reduces the risk of IS in AF but also increases the risk of systemic bleeding, including intracerebral hemorrhage (ICH). AF-related strokes are associated with greater disability and mortality compared to non-AF strokes. The management of patients with AF-related strokes is challenging, and it involves weighing individual risks and benefits in the acute treatment and preventive strategies of these patients. This review summarizes the current knowledge of the acute management of ischemic and hemorrhagic stroke in patients with AF, and the prognosis and potential implications for management both in the acute and long-term setting.

Ischaemic stroke despite antiplatelet therapy: Causes and outcomes

BACKGROUND

Ischaemic stroke may occur despite antiplatelet therapy (APT). We aimed to investigate frequency, potential causes and outcomes in patients with ischaemic stroke despite APT.

METHODS

In this cohort study, we enrolled patients with imaging-confirmed ischaemic stroke from the Swiss Stroke Registry (01/2014-07/2022). We determined the frequency of prior APT, assessed stroke aetiology (modified TOAST classification) and determined the association of prior APT with unfavourable functional outcome (modified Rankin Scale score 3-6) and recurrent ischaemic stroke at 3 months using regression models.

RESULTS

Among 53,352 patients, 27,484 (51.5%) had no prior antithrombotic treatment, 17,760 (33.3%) were on APT, 7039 (13.2%) on anticoagulation and 1069 (2.0%) were on APT + anticoagulation. In patients with a history of ischaemic stroke/TIA (n = 11,948; 22.4%), 2401 (20.1%) had no prior antithrombotic therapy, 6594 (55.2%) were on APT, 2489 (20.8%) on anticoagulation and 464 (3.9%) on APT + anticoagulation. Amongst patients with ischaemic stroke despite APT, aetiology was large artery atherosclerosis in 19.8% (n = 3416), cardiac embolism in 23.6% (n = 4059), small vessel disease in 11.7% (n = 2011), other causes in 7.4% (n = 1267), more than one cause in 6.3% (n = 1078) and unknown cause in 31.3% (n = 5388). Prior APT was not independently associated with unfavourable outcome (aOR = 1.06; 95% CI: 0.98-1.14; p = 0.135) or death (aOR = 1.10; 95% CI: 0.99-1.21; p = 0.059) at 3-months but with increased odds of recurrent stroke (6.0% vs 4.3%; aOR 1.26; 95% CI: 1.11-1.44; p < 0.001).

CONCLUSIONS

One-third of ischaemic strokes occurred despite APT and 20% of patients with a history of ischaemic stroke had no antithrombotic therapy when having stroke recurrence. Aetiology of breakthrough strokes despite APT is heterogeneous and these patients are at increased risk of recurrent stroke.

Low-to-moderate dose statins improve the functional outcome of acute ischemic stroke with conventional medication treatment

Background

Low-to-moderate dose statins (LMDSs) are more commonly used among Asian acute ischemic stroke (AIS) patients in clinical practice. However, the correlation between the LMDS use and prognosis has not been evaluated in AIS patients with conventional medication treatment alone. This study aimed to investigate the influence of LMDS on the prognosis of AIS patients and how prognosis and potential prognostic factors interact with different statin doses.

Methods

This retrospective cohort study included AIS patients who were admitted within 7 days after symptom onset and received conventional medication treatment alone from November 2019 to November 2020 in the Neurology, Department of West China Hospital, Sichuan University. From a total of 782 initial patients, a final cohort of 327 patients was included in the study. These patients were divided into three groups based on statin doses: non-statin (48 patients), LMDS (152 patients), and high-dose statin (HDS) (127 patients). The follow-up period was 3 months after the onset of stroke and the primary outcome was defined as a modified Rankin scale (mRS) score of 0 to 2 at 3 months, secondary outcomes were hemorrhagic transformation (HT) and death within 3 months. Stratified analysis was also conducted to test the robustness of the relationship between the use of different statin doses and functional outcomes in various subgroups.

Results

Compared with non-statin therapy, both LMDS therapy and HDS therapy were associated with good functional outcomes [odds ratio (OR) =3.68, 95% confidence interval (CI): 1.13-12.01, P=0.0309; OR =3.45, 95% CI: 1.06-11.26, P=0.0402, respectively] and a lower risk of HT (OR =0.30, 95% CI: 0.11-0.86, P=0.0253; OR =0.36, 95% CI: 0.13-0.99, P=0.0488, respectively). However, there was no significant difference in all-cause death within 3 months among the three groups (OR =0.84, 95% CI: 0.29-2.46, P=0.7468; OR =0.76, 95% CI: 0.26-2.22, P=0.6104). Additionally, no significant differences were observed between LMDS therapy and HDS therapy regarding good functional outcomes at 3 months (OR =0.94, 95% CI: 0.50-1.77, P=0.8411) and the occurrence of HT (OR =1.19, 95% CI: 0.47-3.02, P=0.7093). The results of the relationship between different statin doses and 3-month good functional outcome were consistent after interaction tests.

Conclusions

Our findings provide evidence for the benefit and safety of LMDS therapy in AIS patients with medication treatment alone. LMDS therapy is associated with favorable impacts on 3-month functional outcomes and a reduced risk of HT compared to non-statin therapy. There were no significant differences in achieving 3-month good functional outcome, the risk of HT or death within 3 months were observed between LMDS and HDS therapy in our study. Further studies with prospective design and larger sample sizes are necessary to validate our results.

Safety of Mechanical Thrombectomy in Patients on Antiplatelet/Anticoagulation

BACKGROUND

Mechanical thrombectomy (MT) is performed in patients who are already on anticoagulation (AC)/antiplatelet therapy (AP). However, data are insufficient regarding MT's safety and efficacy profiles in these patients.

OBJECTIVE

Investigate the outcome of stroke patients already on anticoagulation/antiplatelet receiving MT.

METHODS

We included consecutive acute ischemic stroke patients treated with MT for 10 years (2012-2022) in a comprehensive stroke center. Baseline variables, efficacy (recanalization [Thrombolysis in Cerebral Infraction] ≥ 2b), good functional outcome (modified Ranking Scale ≤ 2 at 3 months), and safety (symptomatic intracranial hemorrhage [sICH], mortality rates) were evaluated. Additionally, we conducted a subgroup analysis of patients with prior single-AP versus DAPT.

RESULTS

Six hundred forty-six patients were included (54.5% women, median age 71 years), 84 (13%) were on AC, 196 (30.3%) on AP, and 366 (56.7%) in the control group. The AC and AP groups were older and had more comorbidities. sICH occurred in 7.3% of cases. There was no significant difference in sICH incidence across the groups. The AC group had a lower rate of intravenous thrombolysis (15.9%; P < 0.001), a higher rate of sICH (11.9% vs. AP 7.7% and control 6%; P = 0.172), and higher mortality at discharge (17.9% vs. AP 8.7% and control 10.4%; P = 0.07). However, the groups had similar functional outcomes and mortality rates at 3 months. Successful recanalization was achieved in 92.7% and was similar across groups. Multivariable logistic regression and the subgroup analysis (single-AP vs. dual AP) did not reveal statistically significant associations.

CONCLUSIONS

MT in patients with prior anticoagulation and AP presenting with acute ischemic strokeis feasible, effective, and safe.

Warfarin vs doac: Comparative outcomes of mechanical thrombectomy for acute ischemic stroke in atrial fibrillation patients

PURPOSE

To compare outcomes of mechanical thrombectomy (MT) for acute ischemic stroke (AIS) in patients with atrial fibrillation (AF) taking warfarin or direct oral anticoagulants (DOACs).

METHODS

A total of 71 consecutive patients with AF who underwent MT due to AIS between January 2018 and December 2021 were retrospectively analyzed. Patients were grouped as warfarin versus DOAC group. CHA₂DS₂-VASc, HAS-BLED, The National Institutes of Health Stroke Scale (NIHSS) at the time of admission and at 24 h, successful recanalization, post- MT complications and technical properties of MT were evaluated. Patients were divided into a good prognosis group, and a mortality group according to the 90th day mRS.

RESULTS

HAS-BLED score was significantly higher in DOAC group (p = 0.006) There were no significant differences in stroke severity, successful recanalization rates, post-procedural complications and mRS 90th day scores between patients with warfarin and DOACs. CHA₂DS₂-VASc, NIHSS at admission and NIHSS on the 24th hour scores were significantly lower in the good mRS group (p = 0.012, p = 0.002, p < 0.001, respectively).

CONCLUSION

MT is safe and effective in patients receiving warfarin or DOACs. HASBLED and CHA₂DS₂-VASc scores can help to predict functional outcome after MT.

Endovascular therapy outcome in isolated posterior cerebral artery occlusion strokes: A multicenter analysis of the Swiss Stroke Registry

PURPOSE

There is little data on the safety and efficacy of endovascular treatment (EVT) in comparison with intravenous thrombolysis (IVT) in acute ischemic stroke due to isolated posterior cerebral artery occlusion (IPCAO). We aimed to investigate the functional and safety outcomes of stroke patients with acute IPCAO treated with EVT (with or without prior bridging IVT) compared to IVT alone.

METHODS

We did a multicenter retrospective analysis of data from the Swiss Stroke Registry. The primary endpoint was overall functional outcome at 3 months in patients undergoing EVT alone or as part of bridging, compared with IVT alone (shift analysis). Safety endpoints were mortality and symptomatic intracranial hemorrhage. EVT and IVT patients were matched 1:1 using propensity scores. Differences in outcomes were examined using ordinal and logistic regression models.

FINDINGS

Out of 17,968 patients, 268 met the inclusion criteria and 136 were matched by propensity scores. The overall functional outcome at 3 months was comparable between the two groups (EVT vs IVT as reference category: OR = 1.42 for higher mRS, 95% CI = 0.78-2.57, p = 0.254). The proportion of patients independent at 3 months was 63.2% in EVT and 72.1% in IVT (OR = 0.67, 95% CI = 0.32-1.37, p = 0.272). Symptomatic intracranial hemorrhages were overall rare and present only in the IVT group (IVT = 5.9% vs EVT = 0%). Mortality at 3 months was also similar between the two groups (IVT = 0% vs EVT = 1.5%).

CONCLUSION

In this multicenter nested analysis, EVT and IVT in patients with acute ischemic stroke due to IPCAO were associated with similar overall good functional outcome and safety. Randomized studies are warranted.

[Intravenous thrombolysis of ischemic stroke-Current status]

Intravenous thrombolysis (IVT) treatment with alteplase (rtPA) is an essential part of the routine treatment of patients with ischemic stroke since its introduction in the late 1990s. Rapid treatment is of essential importance. For patients with an unclear time window, various mismatch concepts have been established to identify salvageable brain tissue prior to IVT. Numerous official contraindications for rtPA are not evidence-based; for example, current data from observational studies show that systemic thrombolytic treatment is possible even in patients receiving direct oral anticoagulant (DOAC) treatment. Tenecteplase (TNK) is an alternative thrombolytic agent with some pharmacologic advantages. The most recent guidelines indicate that TNK is particularly advantageous over rtPA in patients treated in combination with endovascular stroke therapy (EST). The combination of IVT and EST should primarily be performed in the 4.5‑h time window in patients without contraindications; in the later time window EST alone is conceivable if it can be performed without delay.

Effect of prior anticoagulation therapy on stroke severity and in-hospital outcomes in patients with acute ischemic stroke and atrial fibrillation

BACKGROUND

We aimed to assess the prevalence of prior anticoagulation therapy (warfarin or non-vitamin K antagonist oral anticoagulants [NOACs]) among patients with acute ischemic stroke (AIS) and atrial fibrillation (AF) in China and investigate the associations between prior anticoagulation therapy and initial stroke severity and in-hospital outcomes.

METHODS

We included consecutive patients with AIS and known history of AF admitted to hospitals in the China Stroke Center Alliance (CSCA) program from January 2019 to July 2019. Multivariate logistic regression analyses were performed to determine the associations between prior anticoagulation therapy and initial stroke severity and in-hospital outcomes.

RESULTS

Of 7181 patients (median [IQR] age, 75.0 [68.0-81.0] years; 48.7% men), 700 (9.7%), 129 (1.8%), and 255 (3.6%) patients received prior subtherapeutic warfarin (international normalized ratio [INR] <2.0), therapeutic warfarin (INR ≥2.0), and NOACs therapy, respectively. A total of 6499 patients had a preadmission CHA₂DS₂-VASc score ≥ 2, among whom 94.6% were not adequately anticoagulated. Compared with no prior anticoagulation therapy, prior NOACs therapy was associated with reduced risk of moderate or severe stroke at admission (odds ratio [95% CI], 0.64 [0.43-0.94], P = 0.023) and in-hospital mortality or discharge against medical advice (DAMA) (0.46 [0.24-0.86], P = 0.015). However, no significant association was observed between prior therapeutic warfarin therapy and stroke severity or in-hospital mortality or DAMA.

CONCLUSIONS

Among patients with AIS and AF in China, the proportion of patients with inadequate anticoagulation prior to stroke remained substantially high. Prior NOACs therapy was associated with reduced stroke severity and less in-hospital mortality or DAMA.

Outcomes of patients with atrial fibrillation and ischemic stroke while on oral anticoagulation

AIMS

The prognosis of patients with atrial fibrillation (AF) and ischemic stroke while taking oral anticoagulation is poorly understood. This study aimed to characterize the outcomes of patients following a stroke event while on oral anticoagulation.

METHODS AND RESULTS

Individual participant data from five pivotal randomized trials of antithrombotic therapy in AF were used to assess the outcomes of patients with a post-randomization ischemic stroke while on study medication (warfarin, standard-, or lower-dose direct oral anticoagulant regimen) during trial follow-up. The primary outcome was recurrent ischemic stroke after the first post-randomization ischemic stroke. The primary analysis included 1163 patients with a first post-randomization ischemic stroke while on study medication (median age 73 years, 39.3% female, 35.4% history of stroke before trial enrollment). During a median continued follow-up of 337 days, 74 patients had a recurrent ischemic stroke [cumulative incidence at 1 year: 7.0%, 95% confidence interval (CI) 5.2%-8.7%]. The cumulative incidence of mortality at 3 months after stroke was 12.4% (95% CI 10.5%-14.4%). Consistent results for the incidence of recurrent ischemic stroke at 1 year were obtained in an analysis accounting for the competing risk of death (6.2%, 95% CI 4.8%-7.9%) and in a landmark analysis excluding the first 2 weeks after the index stroke and only including patients without permanent study drug discontinuation since then (6.8%, 95% CI 4.6%-8.9%).

CONCLUSION

Patients with AF and ischemic stroke while on oral anticoagulation are at increased risk of recurrent ischemic stroke and death. These patients currently have an unmet medical need.

Anticoagulation under-utilization in atrial fibrillation patients is responsible for a large proportion of strokes requiring endovascular therapy

OBJECTIVES

Atrial fibrillation (AF) is responsible for 30-50% of large strokes requiring endovascular thrombectomy (EVT). Anticoagulation (AC) underutilization is a common source of AF-related stroke. We compared antithrombotic medications among stroke patients with AF that did or did not undergo EVT to determine if AC underutilization disproportionately results in strokes requiring EVT, while quantifying the proportion of likely preventable thrombectomies.

METHODS

This retrospective single-center cohort included consecutive patients admitted with acute ischemic stroke between 2016 and 2021. Patients were categorized based on the presence of AF, and pre-admission antithrombotic medications were compared between those who underwent EVT and those who didn't. The reason for not being on AC was abstracted from the medical record, and patients were categorized as either AC eligible or AC contraindicated.

RESULTS

Of 3092 acute ischemic stroke patients, 644 had a history of AF, 213 of whom underwent EVT. Patients who required EVT were more likely to not be taking any antithrombotics prior to admission (34% vs 24%, p=0.007) or have subtherapeutic INR on admission if taking warfarin (83% vs 63%; p = 0.046). Among the AF-EVT patients, 44% were taking AC, and only 31% were adequately anticoagulated. Only 8% of AF-EVT patients who were not on pre-admission AC had a clear contraindication, and 94% were ultimately discharged on AC.

CONCLUSIONS

Lack of antithrombotic therapy in AF patients disproportionately contributes to strokes requiring EVT. A small minority of AF patients have contraindications to AC, so adequate anticoagulation can prevent a remarkable number of strokes requiring EVT.

Intravenous thrombolysis in acute ischemic stroke after antagonization of unfractionated heparin with protamine: case series and systematic review of literature

Background and aims

Intravenous thrombolysis (IVT) is standard of care for disabling acute ischemic stroke (AIS) within a time window of ⩽ 4.5 h. Some AIS patients cannot be treated with IVT due to limiting contraindications, including heparin usage in an anticoagulating dose within the past 24 h or an elevated activated prothrombin time (aPTT) > 15 s. Protamine is a potent antidote to unfractionated heparin.

Objectives

The objective of this study was to investigate the safety and efficacy of IVT in AIS patients after antagonization of unfractionated heparin with protamine.

Methods

Patients from our stroke center (between January 2015 and September 2021) treated with IVT after heparin antagonization with protamine were analyzed. National Institutes of Health Stroke Scale (NIHSS) was used for stroke severity and modified Rankin Scale (mRS) for outcome assessment. Substantial neurological improvement was defined as the difference between admission and discharge NIHSS of ⩾8 or discharge NIHSS of ⩽1. Good outcome at follow-up after 3 months was defined as mRS 0-2. Safety data were obtained for mortality, symptomatic intracerebral hemorrhage (sICH), and for adverse events due to protamine. Second, a systematic review was performed searching PubMed and Scopus for studies and case reviews presenting AIS patients treated with IVT after heparin antagonization with protamine. The search was limited from January 1, 2011 to September 29, 2021. Furthermore, we conducted a propensity score matching comparing protamine-treated patients to a control IVT group without protamine (ratio 2:1, match tolerance 0.2).

Results

A total of 16 patients, 5 treated in our hospital and 11 from literature, [65.2 ± 13.1 years, 37.5% female, median premorbid mRS (pmRS) 1 (IQR 1, 4)] treated with IVT after heparin antagonization using protamine were included and compared to 31 IVT patients [76.2 ± 10.9 years, 45% female, median pmRS 1 (IQR 0, 2)]. Substantial neurological improvement was evident in 68.8% of protamine-treated patients versus 38.7% of control patients (p = 0.028). Good clinical outcome at follow-up was observed in 56.3% versus 58.1% of patients (p = 0.576). No adverse events due to protamine were reported, one patient suffered sICH after secondary endovascular thrombectomy of large vessel occlusion. Mortality was 6.3% versus 22.6% (p = 0.236).

Conclusion

IVT after heparin antagonization with protamine seems to be safe and, prospectively, may extend the number of AIS patients who can benefit from reperfusion treatment using IVT. Further prospective registry trials would be helpful to further investigate the clinical applicability of heparin antagonization.

Practical Nomogram Predicting Apixaban or Rivaroxaban Concentrations from Low-Molecular-Weight Heparin Anti-Xa Values: Special Interest in Acute Ischemic Stroke Patients

BACKGROUND AND PURPOSE

In patients with acute ischemic stroke (AIS) using a direct oral factor-Xa anticoagulant (DOAC) during the last 48 hours, a fixed plasma heparin-calibrated anti-Xa activity (0.5 IU/mL) was proposed as a threshold below which patients could be eligible for thrombolysis and/or thrombectomy. Besides, specific DOAC-calibrated anti-Xa thresholds up to 50 ng/mL have been proposed. However, specific DOAC assays are not widely available contrarily to low-molecularweight heparin (LMWH) anti-Xa activity. We developed and validated a nomogram for predicting apixaban and rivaroxaban concentrations based on LMWH anti-Xa assay.

METHODS

Our prospective study included apixaban (n=325) and rivaroxaban (n=276) patients. On the same sample, we systematically measured specific DOAC concentration and LMWH anti-Xa activity, using STA®-Liquid-Anti-Xa (Stago) and specific DOAC- or LMWH-calibrators, respectively. The nomogram was built using quantifiable values for both assays on the derivation cohorts with a log-linear regression model. Model performances including sensitivity, specificity, and true positive rate for different thresholds were checked on the validation cohorts.

RESULTS

The models built from the derivation cohorts predicted that values <30 ng/mL and <50 ng/ mL DOAC thresholds corresponded to LMWH-anti-Xa values <0.10 IU/mL and <0.64 IU/mL for apixaban; <0.10 IU/mL and <0.71 IU/mL for rivaroxaban. The model accurately predicted apixaban/ rivaroxaban concentrations in the validation cohort.

CONCLUSIONS

This easy-to-use nomogram, developed with our reagent, allowed accurately predicting DOAC concentrations based on LMWH-anti-Xa results in emergency situations such as AIS when drug-specific assessments are not rapidly available. Using DOAC <50 ng/mL equivalent threshold, instead of the fixed LMWH <0.5 IU/mL one, would allow proposing thrombolysis to more patients.

Atrial fibrillation and stroke

INTRODUCTION

Stroke is one of the leading causes of mortality and morbidity globally. Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia. It is set to reach epidemic proportions. AF is associated with a five-fold increase in risk of stroke. Strokes caused by AF more often are fatal or result in severe disability. Even though the incidence of stroke has been significantly reduced by oral anticoagulation, AF is thought to account for a significant proportion of cryptogenic strokes where no etiology is identified.

AREAS COVERED

This article reviews the literature related to AF and stroke, pathophysiological insights, diagnosis of AF in stroke patients, and its management (Graphical Abstract).

EXPERT OPINION

The pathophysiology of thrombogenesis that links AF and stroke is not well understood and is an area of active research to identify new therapeutic targets to prevent AF and stroke. As the nature of AF and stroke is multifaceted, an integrated care approach to managing AF and stroke is increasingly essential.

Cost-effectiveness of population screening for atrial fibrillation: the STROKESTOP study

AIMS

Previous studies on the cost-effectiveness of screening for atrial fibrillation (AF) are based on assumptions of long-term clinical effects. The STROKESTOP study, which randomised 27 975 persons aged 75/76 years into a screening invitation group and a control group, has a median follow-up time of 6.9 years. The aim of this study was to estimate the cost-effectiveness of population-based screening for AF using clinical outcomes.

METHODS AND RESULTS

The analysis is based on a Markov cohort model. The prevalence of AF, the use of oral anticoagulation, clinical event data, and all-cause mortality were taken from the STROKESTOP study. The cost for clinical events, age-specific utilities, utility decrement due to stroke, and stroke death was taken from the literature. Uncertainty in the model was considered in a probabilistic sensitivity analysis. Per 1000 individuals invited to the screening, there were 77 gained life years and 65 gained quality-adjusted life years. The incremental cost was €1.77 million lower in the screening invitation group. Gained quality-adjusted life years to a lower cost means that the screening strategy was dominant. The result from 10 000 Monte Carlo simulations showed that the AF screening strategy was cost-effective in 99.2% and cost-saving in 92.7% of the simulations. In the base-case scenario, screening of 1000 individuals resulted in 10.6 [95% confidence interval (CI): -22.5 to 1.4] fewer strokes (8.4 ischaemic and 2.2 haemorrhagic strokes), 1.0 (95% CI: -1.9 to 4.1) more cases of systemic embolism, and 2.9 (95% CI: -18.2 to 13.1) fewer bleedings associated with hospitalization.

CONCLUSION

Based on the STROKESTOP study, this analysis shows that a broad AF screening strategy in an elderly population is cost-effective. Efforts should be made to increase screening participation.

Safety of Recanalization Therapy in Acute Ischemic Stroke Patients on Direct Oral Anticoagulant Therapy: An Updated Systematic Review and Meta-Analysis

This review provides an updated assessment of the safety of recanalization therapy for Acute Ischemic Stroke (AIS) patients receiving direct oral anticoagulants (DOAC) therapy. We checked the literature for published observational from 1st January 1950 to 31st March 2021. The rate of symptomatic intracerebral hemorrhage (sICH), arterial recanalization rate, good functional recovery, and mortality at 3 months were investigated, and data were expressed as Risk ratio (RR) with a 95% confidence interval (CI). Publication bias, sensitivity analysis, and meta-regression analyses were conducted utilizing STATA software. 17 articles [14 for endovascular therapy (EVT) and 3 intravenous thrombolysis for (IVT)] were finally included in the review. AIS patients with DOAC therapy showed a decreased rate of sICH (RR = 0.85, 95% CI = 0.72 to 1.00, P = 0.04), and lower probability of good functional recovery at three months (RR = 0.79, 95% CI = 0.73 to 0.85, P < 0.001) than patients without anticoagulation therapy post EVT. However, no significant differences in sICH rates in AIS patients with DOAC therapy after IVT (RR = 0.87, 95% CI = 0.48 to 1.58, P = 0.64) were observed. AIS patients not prescribed DOAC after EVT had a higher mortality risk (RR = 1.29, 95% CI = 1.15-1.44, P < 0.001). Patients with AIS on DOAC therapy were found to have a lower incidence of sICH following EVT. However, no evidence of an increased bleeding risk in patients previously treated with DOAC after IVT was observed. Therefore, more detailed studies with biological data to monitor compliance and details on the size and etiology/severity of the incident ischemic lesion is needed.

Bridging intravenous thrombolysis in patients with atrial fibrillation

Background and purpose

40% of acute ischemic stroke patients treated by mechanical thrombectomy (MT) have a clinical history of atrial fibrillation (AF). The safety of bridging intravenous thrombolysis (IVT) (MT + IVT) is currently being discussed. We aimed to analyze the interaction between oral anticoagulation (OAC) status or AF with bridging IVT, regarding the occurrence of symptomatic intracranial hemorrhage (sICH) and functional outcome.

Materials and Methods

Multicentric observational cohort study (BEYOND-SWIFT registry) of consecutive patients undergoing MT between 2010 and 2018 (n = 2,941). Multinomial regression models were adjusted for prespecified baseline and plausible pathophysiological covariates identified on a univariate analysis to assess the association of AF and OAC status with sICH and good outcomes (90-day modified Rankin Scale score 0–2).

Results

In the total cohort (median age 74, 50.6% women), 1,347 (45.8%) patients had AF. Higher admission National Institutes of Health Stroke Scale (NIHSS) score (aOR 1.04 [95% 1.02–1.06], per point of increase) and prior medication with Vitamin K antagonists (VKA) (aOR 2.19 [95% 1.27–3.66]) were associated with sICH. Neither AF itself (aOR 0.71 [95% 0.41–1.24]) nor bridging IVT (aOR 1.08 [0.67–1.75]) were significantly associated with increased sICH. Receiving bridging IVT (aOR 1.61 [95% 1.24–2.11]) was associated with good 90-day outcome, with no interaction between AF and IVT (p = 0.92).

Conclusion

Bridging IVT appears to be a reasonable clinical option in selected patients with AF. Given the increased sICH risk in patients with VKA, subgroup analysis of the randomized controlled trials should analyze whether patients with VKA might benefit from withholding bridging IVT.

Registration

clinicaltrials.gov; Unique identifier: NCT03496064.

Pre-admission antithrombotic use is associated with 3-month mRS score after thrombectomy for acute ischemic stroke

In patients who undergo thrombectomy for acute ischemic stroke, the relationship between pre-admission antithrombotic (anticoagulation or antiplatelet) use and both radiographic and functional outcome is not well understood. We sought to explore the relationship between pre-admission antithrombotic use in patients who underwent thrombectomy for acute ischemic stroke at two medical centers in New York City between December 2018 and November 2020. Analyses were performed using analysis of variance and Pearson's chi-squared tests. Of 234 patients in the analysis cohort, 65 (28%) were on anticoagulation, 64 (27%) were on antiplatelet, and 105 (45%) with no antithrombotic use pre-admission. 3-month Modified Rankin Scale (mRS) score of 3-6 was associated with pre-admission antithrombotic use (71% anticoagulation vs. 77% antiplatelet vs. 56% no antithrombotic, p = 0.04). There was no relationship between pre-admission antithrombotic use and Thrombolysis in Cerebral Iinfarction (TICI) score, post-procedure Alberta Stroke Program Early CT Score (ASPECTS) score, rate of hemorrhagic conversion, length of hospital admission, discharge NIH Stroke Scale (NIHSS), discharge mRS score, or mortality. When initial NIHSS score, post-procedure ASPECTS score, and age at admission were included in multivariate analysis, pre-admission antithrombotic use was still significantly associated with a 3-month mRS score of 3-6 (OR 2.36, 95% CI 1.03-5.54, p = 0.04). In this cohort of patients with acute ischemic stroke who underwent thrombectomy, pre-admission antithrombotic use was associated with 3-month mRS score, but no other measures of radiographic or functional outcome. Further research is needed on the relationship between use of specific anticoagulation or antiplatelet agents and outcome after acute ischemic stroke, but moreover, improve stroke prevention.

Antithrombotic dilemmas in stroke medicine: new data, unsolved challenges

Antithrombotic therapy is a key element of secondary prevention in patients who have had an ischaemic stroke or transient ischaemic attack. However, its use in clinical practice is not always straightforward. This review provides an update on certain difficult scenarios in antithrombotic management, with a focus on recent clinical trials and large observational studies. We discuss the approach to patients with an indication for antithrombotic treatment who also have clinical or radiological evidence of previous intracranial bleeding, patients with indications for both anticoagulant and antiplatelet treatment, and patients in whom antithrombotic treatment fails to prevent stroke. We also review the timing of anticoagulation initiation after cardioembolic stroke, and the use of antithrombotics in patients with asymptomatic cerebrovascular disease. Despite a wealth of new evidence, numerous uncertainties remain and we highlight ongoing trials addressing these.

Admission Severity of Atrial-Fibrillation-Related Acute Ischemic Stroke in Patients under Anticoagulation Treatment: A Systematic Review and Meta-Analysis

Background: In non-valvular-associated atrial fibrillation (AF), direct oral anticoagulants (DOAC) are as effective as vitamin K antagonists (VKA) for the prevention of acute ischemic stroke (AIS). DOAC are associated with decreased risk and severity of intracranial hemorrhage. It is unknown if different pre-admission anticoagulants impact the prognosis of AF related AIS (AF-AIS). We sought to analyze the literature to assess the association between pre-admission anticoagulation (VKA or DOAC) and admission severity of AF-AIS. Methods: A Systematic literature search (PubMed and ScienceDirect) between January 2011 to April 2021 was undertaken to identify studies describing the outcome of AF-AIS. Results: A total of 128 articles were identified. Of 9493 patients, 1767 were on DOAC, 919 were on therapeutical VKA, 792 were on non-therapeutical VKA and 6015 were not anticoagulated. In comparison to patients without anticoagulation, patients with therapeutical VKA and under DOAC presented with less severe stroke (MD −1.69; 95% CI [−2.71, −0.66], p = 0.001 and MD −2.96; 95% Cl [−3.75, −2.18], p < 0.00001, respectively). Patients with non-therapeutical VKA presented with more severe stroke (MD 1.28; 95% Cl [0.45, 2.12], p = 0.003). Conclusions: In AF-AIS, patients under therapeutical VKA or DOAC have reduced stroke severity on admission in comparison to patients without any anticoagulation, with higher magnitude of protection for DOAC.

Aetiology, secondary prevention strategies and outcomes of ischaemic stroke despite oral anticoagulant therapy in patients with atrial fibrillation

OBJECTIVE

To investigate the aetiology, subsequent preventive strategies and outcomes of stroke despite anticoagulation in patients with atrial fibrillation (AF).

METHODS

We analysed consecutive patients with AF with an index imaging-proven ischaemic stroke despite vitamin K-antagonist (VKA) or direct oral anticoagulant (DOAC) treatment across 11 stroke centres. We classified stroke aetiology as: (i) competing stroke mechanism other than AF-related cardioembolism; (ii) insufficient anticoagulation (non-adherence or low anticoagulant activity measured with drug-specific assays); or, (iii) AF-related cardioembolism despite sufficient anticoagulation. We investigated subsequent preventive strategies with regard to the primary (composite of recurrent ischaemic stroke, intracranial haemorrhage, death) and secondary endpoint (recurrent ischaemic stroke) within 3 months after index stroke.

RESULTS

Among 2946 patients (median age 81 years; 48% women; 43% VKA, 57% DOAC), stroke aetiology was competing mechanism in 713 patients (24%), insufficient anticoagulation in 934 (32%) and cardioembolism despite sufficient anticoagulation in 1299 (44%). We found high rates of the primary (27% of patients; completeness 91.6%) and secondary endpoint (4.6%; completeness 88.5%). Only DOAC (vs VKA) treatment after index stroke showed lower odds for both endpoints (primary: adjusted OR (aOR) (95% CI) 0.49 (0.32 to 0.73); secondary: 0.44 (0.24 to 0.80)), but not switching between different DOAC types. Adding antiplatelets showed higher odds for both endpoints (primary: aOR (95% CI) 1.99 (1.25 to 3.15); secondary: 2.66 (1.40 to 5.04)). Only few patients (1%) received left atrial appendage occlusion as additional preventive strategy.

CONCLUSIONS

Stroke despite anticoagulation comprises heterogeneous aetiologies and cardioembolism despite sufficient anticoagulation is most common. While DOAC were associated with better outcomes than VKA, adding antiplatelets was linked to worse outcomes in these high-risk patients. Our findings indicate that individualised and novel preventive strategies beyond the currently available anticoagulants are needed.

TRIAL REGISTRATION NUMBER

ISRCTN48292829.

Etiology, 3-Month Functional Outcome and Recurrent Events in Non-Traumatic Intracerebral Hemorrhage

Background and Purpose Knowledge about different etiologies of non-traumatic intracerebral hemorrhage (ICH) and their outcomes is scarce.Methods We assessed prevalence of pre-specified ICH etiologies and their association with outcomes in consecutive ICH patients enrolled in the prospective Swiss Stroke Registry (2014 to 2019). Results We included 2,650 patients (mean±standard deviation age 72±14 years, 46.5% female, median National Institutes of Health Stroke Scale 8 [interquartile range, 3 to 15]). Etiology was as follows: hypertension, 1,238 (46.7%); unknown, 566 (21.4%); antithrombotic therapy, 227 (8.6%); cerebral amyloid angiopathy (CAA), 217 (8.2%); macrovascular cause, 128 (4.8%); other determined etiology, 274 patients (10.3%). At 3 months, 880 patients (33.2%) were functionally independent and 664 had died (25.1%). ICH due to hypertension had a higher odds of functional independence (adjusted odds ratio [aOR], 1.33; 95% confidence interval [CI], 1.00 to 1.77; <i>P</i>=0.05) and lower mortality (aOR, 0.64; 95% CI, 0.47 to 0.86; <i>P</i>=0.003). ICH due to antithrombotic therapy had higher mortality (aOR, 1.62; 95% CI, 1.01 to 2.61; <i>P</i>=0.045). Within 3 months, 4.2% of patients had cerebrovascular events. The rate of ischemic stroke was higher than that of recurrent ICH in all etiologies but CAA and unknown etiology. CAA had high odds of recurrent ICH (aOR, 3.38; 95% CI, 1.48 to 7.69; <i>P</i>=0.004) while the odds was lower in ICH due to hypertension (aOR, 0.42; 95% CI, 0.19 to 0.93; <i>P</i>=0.031).Conclusions Although hypertension is the leading etiology of ICH, other etiologies are frequent. One-third of ICH patients are functionally independent at 3 months. Except for patients with presumed CAA, the risk of ischemic stroke within 3 months of ICH was higher than the risk of recurrent hemorrhage.

Effect of admission time on provision of acute stroke treatment at stroke units and stroke centers—An analysis of the Swiss Stroke Registry

Introduction:

Rapid treatment of acute ischemic stroke (AIS) depends on sufficient staffing which differs between Stroke Centers and Stroke Units in Switzerland. We studied the effect of admission time on performance measures of AIS treatment and related temporal trends over time.

Patients and methods:

We compared treatment rates, door-to-image-time, door-to-needle-time, and door-to-groin-puncture-time in stroke patients admitted during office hours (Monday–Friday 8:00–17:59) and non-office hours at all certified Stroke Centers and Stroke Units in Switzerland, as well as secular trends thereof between 2014 and 2019, using data from the Swiss Stroke Registry. Secondary outcomes were modified Rankin Scale and mortality at 3 months.

Results:

Data were eligible for analysis in 31,788 (90.2%) of 35,261 patients. Treatment rates for IVT/EVT were higher during non-office hours compared with office hours in Stroke Centers (40.8 vs 36.5%) and Stroke Units (21.8 vs 18.5%). Door-to-image-time and door-to-needle-time increased significantly during non-office hours. Median (IQR) door-to-groin-puncture-time at Stroke Centers was longer during non-office hours compared to office hours (84 (59–116) vs 95 (66–130) minutes). Admission during non-office hours was independently associated with worse functional outcome (1.11 [95%CI: 1.04–1.18]) and increased mortality (1.13 [95%CI: 1.01–1.27]). From 2014 to 2019, median door-to-groin-puncture-time improved and the treatment rate for wake-up strokes increased.

Discussion and Conclusion:

Despite differences in staffing, patient admission during non-office hours delayed IVT to a similar, modest degree at Stroke Centers and Stroke Units. A larger delay of EVT was observed during non-office hours, but Stroke Centers sped up delivery of EVT over time. Patients admitted during non-office hours had worse functional outcomes, which was not explained by treatment delays.

Yield of Echocardiography in Ischemic Stroke and Patients With Transient Ischemic Attack With Established Indications for Long-Term Direct Oral Anticoagulant Therapy: A Cross-Sectional Diagnostic Cohort Study

Background

We aimed to determine the diagnostic yield of transthoracic (TTE) and transesophageal echocardiography (TEE) in patients with ischemic stroke and transient ischemic attack with established indications for direct oral anticoagulants before the index event.

Methods and Results

This was a retrospective cohort study of consecutive patients with preceding established indications for long‐term therapeutic direct oral anticoagulants presenting to a single comprehensive stroke center with ischemic stroke or transient ischemic attack. Choice of echocardiography modality was based on expert recommendations. The primary outcome was a composite of prespecified management‐relevant high‐risk findings adjudicated by an expert panel, based on TTE and TEE reports according to evidence‐based recommendations. Explorative analyses were performed to identify biomarkers associated with the primary outcome. Of 424 patients included (median [interquartile range] age, 78 [70–84] years; 175 [41%] women; National Institutes of Health Stroke Scale, 4 [1–12]; 67% atrial fibrillation), 292 (69%) underwent echocardiography, while 132 (31%) did not. Modality was TTE in 191 (45%) and TEE in 101 (24%). Median time from index event to echocardiography was 2 (1–3) days. TTE identified 26 of 191 (14%) patients with 35 management‐relevant pathologies. TEE identified 16 of 101(16%) patients with 20 management‐relevant pathologies. Most management‐relevant findings represented indicated coronary artery disease and valvular pathologies. In a further 3 of 191 (2%) patients with TTE and 4 of 101 (4%) patients with TEE, other relevant findings were identified. Variables associated with management‐relevant high‐risk pathologies included more severe stroke, diabetes, and laboratory biomarkers (NT‐proBNP [N‐terminal pro‐B‐type natriuretic peptide], C‐reactive protein, d‐dimer, and troponin levels).

Conclusions

In patients with established indications for long‐term direct oral anticoagulant therapy and stroke who received echocardiography, both TTE and TEE identified a relevant and similar proportion of management‐relevant high‐risk pathologies and predictive biomarkers could help to guide diagnostic workup in such patients.

Undertreatment of Anticoagulant Therapy in Hospitalized Acute Ischemic Stroke Patients With Atrial Fibrillation

Background

This study aimed to investigate the prevalence and factors associated with the initiation of oral anticoagulation among patients with acute ischemic stroke (AIS) and concurrent atrial fibrillation (AF) at discharge in China.

Methods

We continuously included hospitalized patients with AIS with an AF diagnosis registered in the computer-based Online Database of Acute Stroke Patients for Stroke Management Quality Evaluation (CASE II) from January 2016 to December 2020 and divided them into a and non-anticoagulant groups according to the medications at discharge. Binary logistic regression was used to determine the factors associated with the prescription of anticoagulants in patients with AF.

Results

A total of 16,162 patients were enrolled. The mean age was 77 ± 9 years, 8,596 (53.2%) were males, and the median baseline National Institute of Health Stroke Scale score was 5 (2–12). Of the 14,838 patients without contraindications of antithrombotic therapy, 6,335 (42.7%) patients were initiated with anticoagulation treatment at discharge. Prior history of hemorrhagic stroke (OR 0.647, p < 0.001) and gastrointestinal bleeding (OR 0.607, p = 0.003) were associated with a lower rate of anticoagulation at discharge. Patients with any intracranial hemorrhage (OR 0.268, p < 0.001), gastrointestinal bleeding (OR 0.353, p < 0.001), or pneumonia during hospitalization (OR 0.601, p < 0.001) were less likely to receive anticoagulants at discharge. Among 7,807 patients with previously diagnosed AF and high risk of stroke (CHA₂DS₂-VASc ≥2), only 1,585 (20.3%) had been receiving anticoagulation treatment prior to the onset of stroke. However, the mean international normalized ratio (INR) was 1.5 on the first test during hospitalization in patients receiving warfarin. Patients complicated with a previous history of ischemic stroke/transient ischemic attack (TIA; OR 2.303, p < 0.001) and peripheral artery disease (OR 1.456, p = 0.003) were more common to start anticoagulants.

Conclusions

Less than half of patients with AIS and concurrent AF initiated guideline-recommended oral anticoagulation at discharge, while only 20% of patients with previously diagnosed AF with a high risk of stroke had been using anticoagulants prior to the onset of stroke, which highlights a large care gap in hospitalized stroke patients and the importance of AF management.

Failure of Therapeutic Anticoagulation in COVID-19 Patients With Acute Ischemic Stroke. A Retrospective Multicenter Study

Background

Acute ischemic stroke (AIS) is a possible complication of coronavirus disease 2019 (COVID-19) infection. Although peculiar clinical features and underlying specific mechanisms of thrombogenesis have been suggested so far, there is no consensus on the appropriate vascular preventive drug regimen in patients with COVID-19.

Aim and Methods

From a larger clinical series of consecutive acute ischemic strokes related to COVID-19 admitted to three cerebrovascular units in Northern Italy, herein, we describe the clinical features of a subgroup of patients in whom stroke occurred despite therapeutic anticoagulation.

Results

A total of seventeen/80 AIS related to COVID-19 (21.2%) occurred in anticoagulated patients. Although no blood level was available for Direct Oral AntiCoagulant, the drug dosage was appropriate according to guidelines. Their National Institute of Health Stroke Scale (NIHSS) at admission was 12.0 (SD = 7.4) and 58.8% of them had evidence of large vessel occlusion. The case fatality rate was as high as 64.7%.

Discussion and Conclusions

The occurrence of an anticoagulation failure seems to be increased in the setting of COVID-19 infection, with worse clinical outcomes if compared to non-COVID-19 related ischemic strokes. We discuss the diagnostic and therapeutic implications of such evidence, suggesting that some arterial thrombotic complications might be either resistant to or independent of the anticoagulation effect.

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.

Anticoagulation after stroke: persistent uncertainties

PURPOSE OF REVIEW

Direct oral anticoagulants (DOAC) are the mainstay of anticoagulant therapy for stroke prevention in patients with nonvalvular atrial fibrillation. Persistent uncertainties remain in different areas, and this review discusses current dilemmas based on selected studies.

RECENT FINDINGS

Optimal timing of DOAC initiation after a recent ischaemic stroke in patients with atrial fibrillation is currently unknown and subject of ongoing randomized controlled trials. Ischaemic stroke despite anticoagulant therapy in patients with atrial fibrillation is frequent, constitutes heterogeneous causes (competing stroke cause, medication error and cardioembolism despite anticoagulation) and optimal treatment is currently unknown. Thorough etiological work-up is justified. Recent randomized controlled trials found no beneficial effect of DOAC therapy in unselected patients with embolic stroke of undetermined source (ESUS). Currently ongoing trials targeting subgroup of ESUS patients with additional atrial cardiopathy will provide novel data. Cerebral mircobleeds combined in a novel risk score (MICON score) provide good predictive value to stratify the risk of intracranial haemorrhage in patients taking anticoagulants. Use of DOAC after intracerebral haemorrhage in patients with atrial fibrillation is subject of ongoing trials.

SUMMARY

There are still significant uncertainties in anticoagulant management in patients with stroke. Ongoing trials will soon provide novel data to improve management of these patients.

Ischaemic stroke in anticoagulated patients with atrial fibrillation

Anticoagulation substantially reduces the risk of stroke in patients with atrial fibrillation (AF). However, recent studies have shown that up to 22%-36% of patients on anticoagulation will suffer an ischaemic stroke (IS). In this narrative review, we provide an overview of risk factors, mechanisms, management of acute IS and strategies for secondary prevention for patients with AF with stroke despite oral anticoagulation. For this paper, we reviewed available literature from important studies (randomised clinical trials, meta-analyses, reviews and case series) on patients with IS despite anticoagulation. We focused on recent studies that examined safety and efficacy of acute stroke treatments and evaluation and management strategies for secondary prevention. The literature review suggests that patients with AF with IS despite anticoagulation are a heterogeneous group with several possible mechanisms, which may include reduced or non-adherence to anticoagulation, competing non-cardioembolic stroke aetiologies or cardioembolic mechanisms separate from AF. The identification of one or more possible mechanisms of stroke despite anticoagulation may allow for a more targeted and individualised approach for secondary prevention. There are limited data to guide management in such patients, and strategies to prevent recurrent strokes include strict risk factor control and therapies targeting the most likely stroke mechanism. In cases where AF is suspected to be the culprit, clinical trials are needed to test the safety and efficacy of left atrial appendage occlusion plus anticoagulation versus continued anticoagulation alone.