Oral Anticoagulation and Risk of Symptomatic Hemorrhagic Transformation in Stroke Patients Treated With Mechanical Thrombectomy: Data From the Nordictus Registry

CHA2DS2-VASc score and prior oral anticoagulant use on endovascular treatment for acute ischemic stroke

OBJECTIVE

We evaluated the effect of CHA2DS2-VASc score and prior use of oral anticoagulants (OACs) on endovascular treatment (EVT) in patients with acute ischemic stroke and atrial fibrillation (AF).

METHODS

Patients with AF who received EVT in 353 centers in Japan (2018-2020) were included. The outcomes were symptomatic intracerebral hemorrhage (sICH), in-hospital mortality, functional independence, and successful and complete reperfusion. The effects of CHA2DS2-VASc score, its components, and prior use of OACs were assessed via a multiple logistic regression model.

RESULTS

Of the 6984 patients, 780 (11.2%) used warfarin and 1168 (16.7%) used direct oral anticoagulants (DOACs) before EVT. Based on the CHA2DS2-VASc score, 6046 (86.6%) presented a high risk (≥2 for males and ≥3 for females) while 938 (13.4%) had intermediate to low risks. Higher CHA2DS2-VASc scores were associated with increased sICH, in-hospital mortality, and decreased functional independence, regardless of prior OACs. For patients with a high-risk category, prior DOACs increased the odds of successful and complete reperfusion (adjusted odds ratio [95% confidence interval (CI)], 1.27 [1.00-1.61] and 1.30 [1.10-1.53]). For those with integrated intermediate to low risks, neither prior warfarin nor DOAC affected the outcomes. Regardless of total CHA2DS2-VASc scores, patients with congestive heart failure or left ventricular dysfunction, hypertension, age >75 years, or female benefited similarly from prior DOAC use.

INTERPRETATION

Prior DOAC use for patients with high- and selected intermediate-risk CHA2DS2-VASc scores increased prevalence of successful and complete reperfusion. These findings may provide supplemental evidence to introduce preventive DOAC for patients with AF.

Building evidence on safety of endovascular thrombectomy for patients under anticoagulation with vitamin K antagonists

A recent study by Brian Mac Grory and colleagues investigated the safety of endovascular thrombectomy (EVT) among patients under vitamin K antagonists (VKAs) use within 7 days prior to hospital admission. Through this retrospective, observational cohort study, they found prior VKA use did not increase the risk of symptomatic intracranial hemorrhage (sICH) overall. However, recent VKA use with a presenting international normalized ratio (INR) > 1.7 was associated with a significantly increased risk of sICH. Future large-scale randomized controlled trials should be conducted to further clarify the effects and feasibility of EVT therapy in ischemic stroke patients under anticoagulation.

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.

Update of Anticoagulation Use in Cardioembolic Stroke With a Special Reference to Endovascular Treatment

Cardioembolic stroke is a major cause of morbidity, with a high risk of recurrence, and anticoagulation represents the mainstay of secondary stroke prevention in most patients. The implementation of endovascular treatment in routine clinical practice complicates the decision to initiate anticoagulation, especially in patients with early hemorrhagic transformation who are considered at higher risk of hematoma expansion. Late hemorrhagic transformation in the days and weeks following stroke remains a potentially serious complication for which we still do not have any established clinical or radiological prediction tools. The optimal time to initiate therapy is challenging to define since delaying effective secondary prevention treatment exposes patients to the risk of recurrent embolism. Consequently, there is clinical equipoise to define and individualize the optimal timepoint to initiate anticoagulation combining the lowest risk of hemorrhagic transformation and ischemic recurrence in cardioembolic stroke patients. In this narrative review, we will highlight and critically outline recent observational and randomized relevant evidence in different subtypes of cardioembolic stroke with a special focus on anticoagulation initiation following endovascular treatment. We will refer mainly to the commonest cause of cardioembolism, non-valvular atrial fibrillation, and examine the possible risk and benefit of anticoagulation before, during, and shortly after the acute phase of stroke. Other indications of anticoagulation after ischemic stroke will be briefly discussed. We provide a synthesis of available data to help clinicians individualize the timing of initiation of oral anticoagulation based on the presence and extent of hemorrhagic transformation as well as stroke severity.

Outcomes of mechanical thrombectomy in orally anticoagulated patients with anterior circulation large vessel occlusion: a propensity-matched analysis of the Imperial College Thrombectomy Registry

BACKGROUND

Mechanical thrombectomy (MT) remains an effective treatment for patients with acute ischemic stroke receiving oral anticoagulation (OAC) and large vessel occlusion (LVO). However, to date, it remains unclear whether MT is safe in patients on treatment with OAC.

AIMS

In our study, we performed a propensity-matched analysis to investigate the safety and efficacy of MT in patients with acute ischemic stroke receiving anticoagulants. A propensity score method was used to target the causal inference of the observational study design.

METHODS

This observational, prospective, single-centre study included consecutive patients with acute LVO ischemic stroke of the anterior circulation. Demographic, neuro-imaging and clinical data were collected and compared according to the anticoagulation status at baseline, patients on OAC vs those not on OAC. The primary study outcomes were the occurrence of any intracerebral haemorrhage (ICH) and symptomatic ICH. The secondary study outcomes were functional independence at 90 days after stroke (defined as modified Rankin Scale (mRS) scores of 0 through 2), mortality at 3 months and successful reperfusion rate according to the modified treatment in cerebral infarction (mTICI) score.

RESULTS

Overall, our cohort included 573 patients with acute ischemic stroke and LVO treated with MT. After propensity score matching, 495 patients were matched (99 OAC group vs 396 no OAC group). There were no differences in terms of clinical characteristics between the two groups, except for the rate of intravenous thrombolysis less frequently given in the OAC group. There was no significant difference in terms of the rate of any ICH and symptomatic ICH between the two groups. With regards to the secondary study outcome, there was no significant difference in terms of the rate of successful recanalization post-procedure and functional independence at 3 months between the two groups. Patients in the OAC group showed a reduced mortality rate at 90 days compared to the patients with no previous use of anticoagulation (20.2% vs 21.2%, p = 0.031). Logistic regression analysis did not reveal a statistically significant influence of the anticoagulation status on the likelihood of any ICH (OR = 0.95, 95% CI = 0.46-1.97, p = 0.900) and symptomatic ICH (OR = 4.87, 95% CI = 0.64-37.1, p = 0.127). Our analysis showed also that pre-admission anticoagulant use was not associated with functional independence at 90 days after stroke (OR = 0.76, 95% CI = 0.39-1.48, p = 0.422) and rate of successful reperfusion (OR = 0.81, 95% CI = 0.38-1.72, p = 0.582).

CONCLUSION

According to our findings anticoagulation status at baseline did not raise any suggestion of safety and efficacy concerns when MT treatment is provided according to the standard guidelines. Confirmation of these results in larger controlled prospective cohorts is necessary.

Mildly elevated INR is associated with worse outcomes following mechanical thrombectomy for acute ischemic stroke

BACKGROUND

Elevated International Normalized Ratio (INR) is a marker of coagulopathy, but its impact on outcomes following mechanical thrombectomy (MT) in patients with stroke is unclear. This study investigates the impact of mild INR elevations on clinical outcomes following MT.

METHODS

In this retrospective cohort study, consecutive patients with stroke treated with MT were identified from 2015 to 2020 at a Comprehensive Stroke Center. Demographic information, past medical history, INR, National Institutes of Health Stroke Scale score, use of tissue plasminogen activator, and last known normal to arteriotomy time were recorded. Outcome measures included modified Thrombolysis in Cerebral Infarction (mTICI) score, modified Rankin Scale (mRS) score at 90 days, and intracerebral hemorrhage (ICH). Patients were divided into two groups: normal INR (0.8-1.1) and mildly elevated INR (1.2-1.7).

RESULTS

A total of 489 patients were included for analysis, of which 349 had normal INR and 140 had mildly elevated INR. After multivariable adjustments, mildly elevated INR was associated with lower odds of excellent outcomes (mRS 0-1, OR 0.24, p=0.009), lower odds of functional independence (mRS 0-2, OR 0.38, p=0.038), and higher odds of 90-day mortality (OR 3.45, p=0.018). Elevated INR was not associated with a higher likelihood of ICH, and there were no differences in rates of HI1, HI2, PH1, or PH2 hemorrhagic transformations; however, elevated INR was associated with significantly higher odds of 90-day mortality in patients with ICH (OR 6.22, p=0.024). This effect size was larger than in patients without ICH (OR 3.38, p<0.001).

CONCLUSION

In patients with stroke treated with MT, mildly elevated INR is associated with worse clinical outcomes after recanalization and may worsen the mortality risk of hemorrhagic transformations.

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.

Recent Vitamin K Antagonist Use and Intracranial Hemorrhage After Endovascular Thrombectomy for Acute Ischemic Stroke

Importance

Use of oral vitamin K antagonists (VKAs) may place patients undergoing endovascular thrombectomy (EVT) for acute ischemic stroke caused by large vessel occlusion at increased risk of complications.

Objective

To determine the association between recent use of a VKA and outcomes among patients selected to undergo EVT in clinical practice.

Design, Setting, and Participants

Retrospective, observational cohort study based on the American Heart Association's Get With the Guidelines-Stroke Program between October 2015 and March 2020. From 594 participating hospitals in the US, 32 715 patients with acute ischemic stroke selected to undergo EVT within 6 hours of time last known to be well were included.

Exposure

VKA use within the 7 days prior to hospital arrival.

Main Outcome and Measures

The primary end point was symptomatic intracranial hemorrhage (sICH). Secondary end points included life-threatening systemic hemorrhage, another serious complication, any complications of reperfusion therapy, in-hospital mortality, and in-hospital mortality or discharge to hospice.

Results

Of 32 715 patients (median age, 72 years; 50.7% female), 3087 (9.4%) had used a VKA (median international normalized ratio [INR], 1.5 [IQR, 1.2-1.9]) and 29 628 had not used a VKA prior to hospital presentation. Overall, prior VKA use was not significantly associated with an increased risk of sICH (211/3087 patients [6.8%] taking a VKA compared with 1904/29 628 patients [6.4%] not taking a VKA; adjusted odds ratio [OR], 1.12 [95% CI, 0.94-1.35]; adjusted risk difference, 0.69% [95% CI, -0.39% to 1.77%]). Among 830 patients taking a VKA with an INR greater than 1.7, sICH risk was significantly higher than in those not taking a VKA (8.3% vs 6.4%; adjusted OR, 1.88 [95% CI, 1.33-2.65]; adjusted risk difference, 4.03% [95% CI, 1.53%-6.53%]), while those with an INR of 1.7 or lower (n = 1585) had no significant difference in the risk of sICH (6.7% vs 6.4%; adjusted OR, 1.24 [95% CI, 0.87-1.76]; adjusted risk difference, 1.13% [95% CI, -0.79% to 3.04%]). Of 5 prespecified secondary end points, none showed a significant difference across VKA-exposed vs VKA-unexposed groups.

Conclusions and Relevance

Among patients with acute ischemic stroke selected to receive EVT, VKA use within the preceding 7 days was not associated with a significantly increased risk of sICH overall. However, recent VKA use with a presenting INR greater than 1.7 was associated with a significantly increased risk of sICH compared with no use of anticoagulants.

Predictive Factors for Hemorrhagic Transformation in Acute Ischemic Stroke in the REAL-World Clinical Practice

BACKGROUND

Few data exists on predictive factors of hemorrhagic transformation (HT) in real-world acute ischemic stroke patients. The aims of this study were: (i) to identify predictive variables of HT (ii) to develop a score for predicting HT.

METHODS

We retrospectively analyzed the clinical, radiographic, and laboratory data of patients with acute ischemic stroke consecutively admitted to our Stroke Unit along two years. Patients with HT were compared with those without HT. A multivariate logistic regression analysis was performed to identify independent predictors of HT on CT scan at 24 hours to develop a practical score.

RESULTS

The study population consisted of 564 patients with mean age 77.5±11.8 years. Fifty-two patients (9.2%) showed HT on brain CT at 24 hours (4.9% symptomatic). NIHSS score ≥8 at Stroke Unit admission (3 points), cardioembolic etiology (2 points), acute revascularization by systemic thrombolysis and/or mechanical thrombectomy (1 point), history of previous TIA/stroke (1 point), and major vessel occlusion (1 point) were found independent risk factors of HT and were included in the score (Hemorrhagic Transformation Empoli score (HTE)). The predictive power of HTE score was good with an AUC of 0.785 (95% CI: 0.749-0.818). Compared with 5 HT predictive scores proposed in the literature (THRIVE, SPAN-100, MSS, GRASPS, SITS-SIC), the HTE score significantly better predicted HT.

CONCLUSIONS

NIHSS score ≥8 at Stroke Unit admission, cardioembolism, urgent revascularization, previous TIA/stroke, and major vessel occlusion were independent predictors of HT. The HTE score has a good predictive power for HT. Prospective studies are warranted.

Risk factors of hemorrhagic transformation in acute ischaemic stroke: A systematic review and meta-analysis

Background

Hemorrhagic transformation (HT) following reperfusion therapies for acute ischaemic stroke often predicts a poor prognosis. This systematic review and meta-analysis aims to identify risk factors for HT, and how these vary with hyperacute treatment [intravenous thrombolysis (IVT) and endovascular thrombectomy (EVT)].

Methods

Electronic databases PubMed and EMBASE were used to search relevant studies. Pooled odds ratio (OR) with 95% confidence interval (CI) were estimated.

Results

A total of 120 studies were included. Atrial fibrillation and NIHSS score were common predictors for any intracerebral hemorrhage (ICH) after reperfusion therapies (both IVT and EVT), while a hyperdense artery sign (OR = 2.605, 95% CI 1.212-5.599, I ² = 0.0%) and number of thrombectomy passes (OR = 1.151, 95% CI 1.041-1.272, I ² = 54.3%) were predictors of any ICH after IVT and EVT, respectively. Common predictors for symptomatic ICH (sICH) after reperfusion therapies were age and serum glucose level. Atrial fibrillation (OR = 3.867, 95% CI 1.970-7.591, I ² = 29.1%), NIHSS score (OR = 1.082, 95% CI 1.060-1.105, I ² = 54.5%) and onset-to-treatment time (OR = 1.003, 95% CI 1.001-1.005, I ² = 0.0%) were predictors of sICH after IVT. Alberta Stroke Program Early CT score (ASPECTS) (OR = 0.686, 95% CI 0.565-0.833, I ² =77.6%) and number of thrombectomy passes (OR = 1.374, 95% CI 1.012-1.866, I ² = 86.4%) were predictors of sICH after EVT.

Conclusion

Several predictors of ICH were identified, which varied by treatment type. Studies based on larger and multi-center data sets should be prioritized to confirm the results.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=268927, identifier: CRD42021268927.

Predictors of Symptomatic Intracranial Hemorrhage after Endovascular Thrombectomy in Acute Ischemic Stroke: A Systematic Review and Meta-Analysis

INTRODUCTION

This meta-analysis assessed the predictors of symptomatic intracranial hemorrhage (sICH) after endovascular thrombectomy (EVT) for patients with acute ischemic stroke.

METHODS

PubMed, Embase, the Cochrane Central Register of Controlled Trials, and Web of Science were searched for studies published from inception to February 16, 2021. We included studies that evaluated the predictors of sICH after EVT. The random-effect model or fixed-effect model was used to pool the estimates according to the heterogeneity.

RESULTS

A total of 25 cohort studies, involving 15,324 patients, were included in this meta-analysis. The total incidence of sICH was 6.72 percent. Age (MD = 2.57, 95% CI: 1.53-3.61; p < 0.00001), higher initial NIHSS score (MD = 1.71, 95% CI: 1.35-2.08, p < 0.00001), higher initial systolic blood pressure (MD = 7.40, 95% CI: 5.11-9.69, p < 0.00001), diabetes mellitus (OR = 1.36, 95% CI: 1.10-1.69, p = 0.005), poor collaterals (OR = 3.26, 95% CI: 2.35-4.51; p < 0.0001), internal carotid artery occlusion (OR = 1.55, 95% CI: 1.26-1.90; p < 0.0001), longer procedure time (MD = 18.92, 95% CI: 11.49-26.35; p < 0.0001), and passes of retriever >3 (OR = 3.39, 95% CI: 2.45-4.71; p < 0.0001) were predictors of sICH, while modified thrombolysis in cerebral infarction score ≥2b (OR = 0.61, 95% CI: 0.46-0.79; p = 0.0002) was associated with a decreased risk of sICH. There were no significant differences in the female gender, initial serum glucose, initial ASPECT score, atrial fibrillation, oral anticoagulants, antiplatelet therapy, intravenous thrombolysis, general anesthesia, neutrophil-to-lymphocyte ratio, and emergent stenting.

CONCLUSIONS

This study identified many predictors of sICH. Some of the results lack robust evidence given the limitations of the study. Therefore, larger cohort studies are needed to confirm these predictors.

Safety and efficacy of endovascular thrombectomy in acute ischemic stroke treated with anticoagulants: a systematic review and meta-analysis

Background

Endovascular thrombectomy (EVT) is an effective therapy in acute ischemic stroke (AIS) with large vessel occlusion, especially for those who are unsuitable for intravenous thrombolysis. However, the safety and efficacy of EVT in AIS patients who receiving oral anticoagulants (OACs) is unclear, especially for the risk of symptomatic intracranial hemorrhage (sICH). 

Methods

Database of PubMed, Embase, and Cochrane Library were searched from Jan 1, 2000, through the final search date of Jun 2, 2021. Eligible studies for enrollment required outcomes reported for events of sICH, mortality, functional status, and successful reperfusion. Meta-analysis was conducted to compare the outcomes difference after EVT between AIS patients with or without OACs use. The primary safety outcome was sICH after EVT, and the primary efficacy outcome was functional status at 3 months. 

Results

One thousand nine hundred forty studies were screened for eligibility and 15 of them were included in the meta-analysis. Compared the OACs group to control arm, vitamin K antagonists (VKAs) was associated with higher risk of sICH (OR 1.49, 95% CI 1.10–2.02) and mortality (OR 1.67, 95% CI 1.35–2.06). Poor functional outcomes were noted both in the VKAs and direct oral anticoagulants (DOACs) groups (OR 0.62, 95% CI 0.54–0.71 and OR 0.61, 95% CI 0.53–0.71, respectively). No differences in successful reperfusion were observed.

Conclusions

Comparing with DOACs, VKAs use was associated with a higher risk of sICH and mortality after EVT. Patients who did not receive OACs exhibited more favorable outcomes. The successful reperfusion did not differ between groups. However, results for mortality and functional outcomes have to be interpreted with caution since they are based on non-randomized data and unadjusted proportions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12959-022-00394-y.

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.