Phenotypes of Chronic Covert Brain Infarction in Patients With First-Ever Ischemic Stroke: A Cohort Study

Early vs Late Anticoagulation After Ischemic Stroke in Patients With Atrial Fibrillation and Covert Brain Infarcts

BACKGROUND AND OBJECTIVES

Covert brain infarcts (CBIs) in patients with first-ever ischemic stroke (IS) and atrial fibrillation (AF) are associated with an increased risk of stroke recurrence. We aimed to assess whether CBIs modify the treatment effect of early vs late initiation of direct oral anticoagulants (DOACs) in patients with IS and AF.

METHODS

We conducted a post hoc analysis of the international, multicenter, randomized-controlled ELAN trial, which compared early (<48 hours after ischemic stroke for minor and moderate stroke, 6-7 days for major stroke) vs late (>48 hours for minor, 3-4 days for moderate, 12-14 days for major stroke) initiation of DOACs in patients with IS and AF. The primary outcome was a composite of recurrent IS, symptomatic intracranial hemorrhage (sICH), major extracranial bleeding, systemic embolism, or vascular death within 30 days after stroke; secondary outcomes were the individual components. We estimated outcomes based on the presence of CBIs (any CBI vs no CBI) on prerandomization imaging (core-lab rating) using adjusted risk differences (aRDs) between treatment arms. Point estimates and 95% CIs are presented without reporting p values.

RESULTS

Of the 1,694 participants with first-ever IS included (median age: 77 years, 45.9% female), 678 (40.0%) had CBI. The imaging core-lab interrater reliability for the presence of CBI was 0.87 (0.81-0.94). The primary outcome occurred in 8 (2.3%; recurrent IS: 3/342) of 342 participants with CBI assigned to the early treatment arm vs 20 (6.0%; recurrent IS: 12/336) of 336 assigned to the late treatment arm (aRD: -3.6%, 95% CI -6.6 to -0.6) (p for interaction: 0.063). With early DOAC treatment, IS recurrence risk was lower in participants with CBI (aRD: -2.7%, 95% CI -5.0 to -0.4), but not in participants without CBI (aRD: -0.4, 95% CI -2.1 to 1.2). No sICH was observed in the early treatment group.

DISCUSSION

The presence of CBI may indicate a subgroup of patients with first-ever IS and AF who particularly benefits from early DOAC initiation to prevent ischemic event recurrence, without increasing harm. Our findings should be considered in clinical decision making regarding timely DOAC treatment in patients with stroke and AF.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that in patients with covert brain infarcts, atrial fibrillation, and first-ever ischemic stroke, early (vs late) initiation of DOACs is associated with lower risk of recurrent stroke with no increase in harm.

TRIAL REGISTRATION INFORMATION

URL: clinicaltrials.gov/study/NCT03148457; Unique identifier: NCT03148457; submitted: April 7, 2017; first patient enrolled: November 6, 2017.

The added value of b0-DWI analysis in the diagnosis of cavitating lacunes when T2-weighted spin-echo is unavailable

PURPOSE

Silent brain infarcts, sometimes appearing as incidental lacunes in patients with unknown history of vascular event, are linked to dementia, gait disturbances and depression. We observed that some cavitating lacunes were only visible on b0-diffusion-weighted-imaging (b0-DWI: T2-weighted without diffusion gradients) when T2-weighted-spin-echo (T2-SE) was unavailable. We aimed to evaluate the additional value of b0-DWI in detecting cavitating lacunes.

METHODS

We retrospectively included patients aged ≥ 65 years who underwent brain MRI (1.5 T or 3 T) for various indications, with FLAIR (Fluid Attenuated Inversion Recovery) and b0-DWI, without T2-SE. Patients with multiple sclerosis, lacking b0-DWI or with low-quality MRI were excluded. Vascular risk factors, white matter lesions (Fazekas scale) and mention of lacune in the radiology report were inquired. Two radiologists independently analyzed all b0-DWI sequences, followed by FLAIR.

RESULTS

Among 306 subjects, at least one lacune was observed in 149 (48.7 %): 54 (36.2 %) supratentorial, 32 (21.5 %) infratentorial and 63 (42.3 %) both. Of these, 119 (79.9 %) had vascular risk factors and 135 (90.6 %) had white matter lesions. 33 (10.8 %) were exclusively detected on b0-DWI (b0-DWI-lacunes), of which 5 (1.6 %) without vascular factor, and 20 (6.5 %) were unmentioned in the report. Among b0-DWI-lacunes, 15 (45.5 %) were supratentorial, 9 (27.3 %) infratentorial and 9 (27.3 %) both, with 28 (84.8 %) associated with white matter lesions. Inter-rater reliability for b0-DWI-lacunes diagnosis was good (95.6 % agreement, kappa = 0.717, CI95% [0.568-0.869]).

CONCLUSION

In our study, 10.8% b0-DWI-lacunes were not visible on FLAIR, and 6.5% were unmentioned in the neuroradiology report. Examining FLAIR alongside b0-DWI improves diagnostic performance for cavitating lacune detection and contributes to vascular prevention.

Association of covert brain infarct phenotype with stroke recurrence in first-ever manifest ischemic stroke according to etiology

INTRODUCTION

Covert brain infarcts (CBI) are frequent incidental findings on MRI and associated with future stroke risk in patients without a history of clinically evident cerebrovascular events. However, the prognostic value of CBI in first-ever ischemic stroke patients is unclear and previous studies did not report on different etiological stroke subtypes. We aimed to test CBI phenotypes and their association with stroke recurrence in first-ever ischemic stroke patients according to stroke etiology.

PATIENTS AND METHODS

This study is a pooled data analysis of two prospectively collected cohorts of consecutive first-ever ischemic stroke patients admitted to the comprehensive stroke centers of Bern (Switzerland) and Graz (Austria). CBI phenotypes were identified on brain MRI within 72 h after admission. All patients underwent a routine follow-up (median: 12 months) to identify stroke recurrence.

RESULTS

Of 1577 consecutive ischemic stroke patients (median age: 71 years), 691 patients showed CBI on brain MRI (44%) and 88 patients had a recurrent ischemic stroke (6%). Baseline CBI were associated with stroke recurrence in multivariable analysis (HR 1.9, 95% CI 1.1-3.3). CBI phenotypes with the highest risk for stroke recurrence were cavitatory CBI in small vessel disease (SVD)-related stroke (HR 7.1, 95% CI 1.6-12.6) and cortical CBI in patients with atrial fibrillation (HR 3.0, 95% CI 1.1-8.1).

DISCUSSION AND CONCLUSION

This study reports a ≈ 2-fold increased risk for stroke recurrence in first-ever ischemic stroke patients with CBI. The risk of recurrent stroke was highest in patients with cavitatory CBI in SVD-related stroke and cortical CBI in patients with atrial fibrillation.Subject terms: Covert brain infarcts, stroke.

Chronic ischemic lesions and presence of patent foramen ovale in young adults with embolic stroke of undetermined source: Results of the young ESUS patient registry

BACKGROUND

Chronic ischemic lesions (CILs) are frequent findings in patients with acute ischemic stroke, but their phenotypes and relevance in young adults with embolic stroke of undetermined source (Y-ESUS) remains uncertain. We aimed to compare Y-ESUS patients with CIL to those without CIL and assessed the association of CIL and its phenotypes with the presence of patent foramen ovale (PFO).

METHODS

This prospective longitudinal, multicenter cohort study enrolled consecutive patients 50 years and younger with ESUS from October 2017 to October 2019 in 41 stroke research centers in 13 countries. Local investigators adjudicated presence and phenotypes of CIL on routine brain imaging (either magnetic resonance imaging (MRI) or computed tomography (CT)).

RESULTS

Overall, 535 patients were enrolled (mean age = 40.4 (standard deviation (SD) = 7.3) years, 238 (44%) female). CILs were present in 76/534 (14.2%) patients with a median count CIL count of 1.0 (interquartile range (IQR) = 1-2), 42/76 (55%) had at least one cortical phenotype and 38/76 (50%) at least one non-cortical phenotype. Y-ESUS with CIL were less often female (32% vs 47% in non-CIL Y-ESUS), were older (mean 43 vs 40 years), had more often hypertension (42% vs 19%), diabetes (17% vs 7%), and hyperlipidemia (34% vs 18%). CIL Y-ESUS were independently associated with lower stroke recurrence (relative risk (RR) = 0.17 (0.05-0.61)). In Y-ESUS with PFO, CILs were less frequent in probable pathogenic PFO than with probable non-pathogenic PFO (6.1% vs 30% p< 0.001).

CONCLUSION

One in seven Y-ESUS patients has additional CIL. CILs were associated with several vascular risk factors, lower probability of a pathogenic PFO, and lower stroke recurrence.

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.

Endovascular Treatment for Acute Large Vessel Occlusion Due to Underlying Intracranial Atherosclerotic Disease

Intracranial atherosclerotic disease (ICAD) is one of the most common causes of acute ischemic stroke worldwide. Patients with acute large vessel occlusion due to underlying ICAD (ICAD-LVO) often do not achieve successful recanalization when undergoing mechanical thrombectomy (MT) alone, requiring rescue treatment, including intra-arterial thrombolysis, balloon angioplasty, and stenting. Therefore, early detection of ICAD-LVO before the procedure is important to enable physicians to select the optimal treatment strategy for ICAD-LVO to improve clinical outcomes. Early diagnosis of ICAD-LVO is challenging in the absence of consensus diagnostic criteria on noninvasive imaging and early digital subtraction angiography. In this review, we summarize the clinical and diagnostic criteria, prediction of ICAD-LVO prior to the procedure, and EVT strategy of ICAD-LVO and provide recommendations according to the current literature.

Covert Brain Infarction as a Risk Factor for Stroke Recurrence in Patients With Atrial Fibrillation

BACKGROUND

We aimed to evaluate covert brain infarction (CBI), frequently encountered during the diagnostic work-up of acute ischemic stroke, as a risk factor for stroke recurrence in patients with atrial fibrillation (AF).

METHODS

For this prospective cohort study, from patients with acute ischemic stroke hospitalized at 14 centers between 2017 and 2019, we enrolled AF patients without history of stroke or transient ischemic attack and divided them into the CBI (+) and CBI (-) groups. The 2 groups were compared regarding the 1-year cumulative incidence of recurrent ischemic stroke and all-cause mortality using the Fine and Gray subdistribution hazard model with nonstroke death as a competing risk and the Cox frailty model, respectively. Each CBI lesion was also categorized into either embolic-appearing (EA) or non-EA pattern CBI. Adjusted hazard ratios and 95% CIs of any CBI, EA pattern CBI only, non-EA pattern CBI only, and both CBIs were estimated.

RESULTS

Among 1383 first-ever stroke patients with AF, 578 patients (41.8%) had CBI. Of these 578 with CBI, EA pattern CBI only, non-EA pattern CBI only, and both CBIs were 61.8% (n=357), 21.8% (n=126), and 16.4% (n=95), respectively. The estimated 1-year cumulative incidence of recurrent ischemic stroke was 5.2% and 1.9% in the CBI (+) and CBI (-) groups, respectively (P=0.001 by Gray test). CBI increased the risk of recurrent ischemic stroke (adjusted hazard ratio [95% CI], 2.91 [1.44-5.88]) but did not the risk of all-cause mortality (1.32 [0.97-1.80]). The EA pattern CBI only and both CBIs elevated the risk of recurrent ischemic stroke (2.76 [1.32-5.77] and 5.39 [2.25-12.91], respectively), while the non-EA pattern only did not (1.44 [0.40-5.16]).

CONCLUSIONS

Our study suggests that AF patients with CBI might have increased risk of recurrent stroke. CBI could be considered when estimating the stroke risk in patients with AF.

Association of Chronic Covert Cerebral Infarctions and White Matter Hyperintensities With Atrial Fibrillation Detection on Post-Stroke Cardiac Rhythm Monitoring: A Cohort Study

Background This study was conducted to explore the association of different phenotypes, count, and location of chronic covert brain infarctions (CBIs) with detection of atrial fibrillation (AF) on prolonged post-stroke cardiac rhythm monitoring (PCM). Methods and Results We conducted a cohort single-center study of consecutive first-ever ischemic stroke or transient ischemic attack patients undergoing PCM between January 2015 and December 2017. We blindly rated CBI phenotypes according to established definitions and white matter hyperintensities (WMHs) according to the age-related white matter changes rating scale. We used (multiple) regression models to assess the association of the imaging biomarkers and incident AF on PCM. A total of 795 patients (median [interquartile range]) aged 69 (57-78) years, 41% women, median National Institutes of Health Stroke Scale score 2 (0-5), median PCM duration 14 (7-14) days, and AF detection in 61 patients (7.7%) were included. On univariate analysis, WMHs (per point odds ratio, 1.35 [95% CI, 1.03-1.78]) but not CBIs (odds ratio, 0.90 [95% CI, 0.52-1.56]) were associated with AF detection. Neither CBI phenotype, count, nor location were associated with AF detection. After adjustment for age, hypertension, and stroke severity, neither increasing WMHs (per point adjusted odds ratio, 0.85 [95% CI, 0.60-1.20]) nor CBIs (adjusted odds ratio, 0.60 [95% CI, 0.33-1.09]) were independently associated with AF detection. Conclusions Although WMHs and CBIs represent surrogate biomarkers of vascular risk factors, neither WMHs nor CBIs, including their phenotypes, count, and location, were independently associated with AF detection on PCM. In patients with manifest ischemic stroke or transient ischemic attack, the presence of imaging biomarkers of chronic ischemic injury does not seem promising to further refine prediction tools for AF detection on PCM.

Population-Based Prevalence of Infarctions on 3D Fluid-Attenuated Inversion Recovery (FLAIR) Imaging

OBJECTIVES

To report population-based, age-specific prevalence of infarctions as identified via 3D fluid-attenuated inversion recovery (FLAIR) imaging.

MATERIALS AND METHODS

Participants without dementia in the Mayo Clinic Study of Aging (MCSA), a population-based study in Olmsted County, MN, age 50-89 who underwent 3D FLAIR imaging between 2017 and 2020 were included. Infarctions per participant were determined via visual interpretation. Inter- and intra-reader reliability were calculated. Infarction prevalence on 3D FLAIR was derived by standardization to the Olmsted County population and was compared to that previously reported on 2D FLAIR imaging.

RESULTS

Among 580 participants (mean age 71 years, 46% female) the prevalence (95% confidence interval) of any infarction was 5.0% (0.0%-9.9%) at age 50-59 years and 38.8% (28.6%-49.0%) at 80-89 years. In addition to increasing with age, the prevalence varied by sex and type of infarction. Prevalence estimates of cortical infarcts were 0.9% (0.0%-2.7%) at age 50-59 years and 20.2% (10.7%-29.7%) at 80-89 years and lacunar infarcts 4.1% (0.0%-8.8%) at age 50-59 years and 31.2% (21.5%-41.0%) at 80-89 years. Prevalence estimates of any infarction by sex were: men, 8.7% (0.0%-18.7%) at 50-59 years and 54.9% (41.0%-68.8%) at 80-89 years and women, 2.4% (0.0%-7.3%) at age 50-59 years and 27.3% (12.9%-41.7%) at 80-89 years. Intra- and inter- reader reliability were very good (kappa = 0.85 and 0.82, respectively). After adjusting for age, sex and education, individuals imaged with 3D FLAIR were 1.5 times (95% CI 1.2-1.8, p<0.001) more likely to be identified as positive for infarction compared to those imaged with 2D FLAIR.

CONCLUSIONS

Infarction prevalence increases with age and is greater in men than women. Infarction prevalence on 3D FLAIR imaging, which has become more widely implemented as an alternative to 2D FLAIR over the past several years, will be a useful reference in future work.

Chronic Covert Brain Infarctions and White Matter Hyperintensities in Patients With Stroke, Transient Ischemic Attack, and Stroke Mimic

Background

This study was conducted to compare frequencies of chronic brain infarctions (CBIs) and white matter hyperintensities (WMHs) as well as their associations with established early recurrence risk scores in patients with transient ischemic attack (TIA) and stroke mimics compared with ischemic stroke.

Methods and Results

Single‐center cohort study including consecutive patients with TIA, stroke mimics, and acute ischemic stroke, with available magnetic resonance imaging from January 2015 to December 2017. Blinded raters adjudicated WMH (age‐related white matter changes score) and CBI according to established definitions. A total of 2112 patients (median [Q1–Q3] age 71 [59–80] years, 43% women, National Institutes of Health Stroke Scale score of 2 [1–7], 80% ischemic stroke, 18% TIA, 2% stroke mimics) were included. While CBIs were present in only 10% of patients with stroke mimic, they were detected in 28% of TIAs and 38% of ischemic strokes (P<0.001). WMHs were less pronounced (0, 0–1) in patients with stroke mimic, but there was no difference between TIA (1, 1–2) and ischemic stroke (0, 1–2) patients. CBIs (adjusted odds ratio, 0.3; 95% CI, 0.1–0.9) were associated with a lower rate of stroke mimic as the final diagnosis, while WMHs were not (adjusted odds ratio per point, 1.3; 95% CI, 0.7–2.2). WMH (β per point, 0.4; 95% CI, 0.3–0.6) and presence of CBI (β, 0.6; 95% CI, 0.3–0.9) were associated with a higher cardiovascular risk profile according to the ABCD3‐I score. The accuracy of prediction was good for high‐risk TIA (cross‐validated area under the receiver operating characteristic curve, 0.89; 95% CI, 0.79–0.93) on the basis of brain imaging, age, and sex.

Conclusions

CBI and WMH differ between patients with stroke mimic and patients with TIA/ischemic stroke and are closely associated with established recurrence risk scores. Prospective studies need to clarify whether including brain frailty markers may contribute to the refinement of current management algorithms and risk stratifications.

Chronic cerebral infarctions and white matter lesions link to long-term survival after a first ischemic event: A cohort study

BACKGROUND AND PURPOSE

To investigate the association of different phenotypes, count, and locations of chronic covert brain infarctions (CBI) with long-term mortality in patients with first-ever manifest acute ischemic stroke (AIS) or transient ischemic attack (TIA). Additionally, to analyze their potential interaction with white matter hyperintensities (WMH) and predictive value in addition to established mortality scores.

METHODS

Single-center cohort study including consecutive patients with first-ever AIS or TIA with available MRI imaging from January 2015 to December 2017. Blinded raters adjudicated CBI phenotypes and WMH (age-related white matter changes score) according to established definitions. We compared Cox regression models including prespecified established predictors of mortality using Harrell's C and likelihood ratio tests.

RESULTS

A total of 2236 patients (median [interquartile range] age: 71 [59-80] years, 43% female, National Institutes of Health Stroke Scale: 2 [1-6], median follow-up: 1436 days, 21% death during follow-up) were included. Increasing WMH (per point adjusted Hazard Ratio [aHR] = 1.29 [1.14-1.45]), but not CBI (aHR = 1.21 [0.99-1.49]), were independently associated with mortality. Neither CBI phenotype, count, nor location was associated with mortality and there was no multiplicative interaction between CBI and WMH (p &gt; .1). As compared to patients without CBI or WMH, patients with moderate or severe WMH and additional CBI had the highest hazards of death (aHR = 1.62 [1.23-2.13]). The Cox regression model including CBI and WMH had a small but significant increment in Harrell's C when compared to the model including 14 clinical variables (0.831 vs. 0.827, p &lt; .001).

DISCUSSION

WMH represent a strong surrogate biomarker of long-term mortality in first-ever manifest AIS or TIA patients. CBI phenotypes, count, and location seem less relevant. Incorporation of CBI and WMH slightly improves predictive capacity of established risk scores.