Cognitive Impairment Before Atrial Fibrillation-Related Ischemic Events: Neuroimaging and Prognostic Associations

Association of Atrial Fibrillation and Cognitive Dysfunction: A Comprehensive Narrative Review of Current Understanding and Recent Updates

Atrial fibrillation (AF) is the most common sustained arrhythmia in adults. The prevalence of both AF and dementia is steadily rising and is expected to rise further in the coming decades. There is increasing evidence to suggest an association between AF and various degrees of cognitive dysfunction, from mild cognitive impairment to severe dementia. In this review, we aimed to discuss the epidemiological aspects, pathophysiological mechanisms, role of neuroimaging, impact of treatment modalities, and clinical and socioeconomic impact of this association. Numerous observational studies and meta-analyses have revealed this association to exist in AF patients with and without a history of stroke, and the association also persists after adjusting for shared risk factors such as hypertension and diabetes mellitus. Various pathophysiological mechanisms have been proposed for this association, including silent cerebral infarcts, cerebral microbleeds, cerebral hypoperfusion, inflammation, and atherosclerosis. While neuroimaging findings have been utilized to suggest some of these pathophysiological mechanisms, more studies are needed to further elucidate this and to determine the potential role of neuroimaging in altering anticoagulation and other treatment decisions. Anticoagulants have shown effectiveness in reducing the rate of cognitive decline in AF patients; however, their role in low-risk AF patients remains under investigation. Even though AF patients receiving catheter ablation may have post-operative cognitive dysfunction in the short term, long-term follow-up studies have shown an improvement in cognitive function following ablation. Cognitive decline in AF patients often occurs with greater functional decline and other psychosocial impairments such as depression and anxiety and future research on this association must incorporate aspects of social determinants of health and associated outcomes.

Prestroke Cognitive Impairment: Frequency and Association With Premorbid Neuropsychiatric, Functional, and Neuroimaging Features

BACKGROUND

Some patients with stroke have prestroke cognitive impairment (pre-SCI), but its etiology is not clear. The aim of this cross-sectional study was to assess the frequency of pre-SCI and its association with premorbid neuropsychiatric, functional, and neuroimaging features.

METHODS

Patients hospitalized in stroke unit with an informant who could complete IQCODE (Informant Questionnaire for Cognitive Decline in the Elderly) were included. Pre-SCI was diagnosed if the IQCODE score was >3.3. Prestroke assessment also included NPI-Q (Neuropsychiatric Inventory Questionnaire), the basic Activities of Daily Living and Instrumental Activities of Daily Living scales, and the Clinical Dementia Rating scale. A multivariate logistic regression model was used to evaluate the association of pre-SCI with age, sex, education, arterial hypertension, atrial fibrillation, white matter lesions, cerebral microbleeds, and pathological medial temporal lobe atrophy.

RESULTS

IQCODE was available in 474 of 520 patients (91.2%; 45% women; mean age 75.5±13.3 years). Pre-SCI had a prevalence of 32.5% and was associated with prestroke NPI-Q (pre-SCI absent versus present, 1.7±2.3 versus 5.5±4.9; P<0.001), Activities of Daily Living scale (0.3±0.8 versus 1.8±1.9; P<0.001), Instrumental Activities of Daily Living scale (0.6±1.3 versus 3.8±4.0; P<0.001), and Clinical Dementia Rating scale score (0.7±1.7 versus 7.2±6.2; P<0.001). In the 271 patients with a magnetic resonance imaging available, the multivariate logistic regression showed that age (odds ratio [OR], 1.05 [95% CI, 1.62-9.73]), white matter lesions (OR, 1.26 [95% CI, 1.003-1.58]), and a pathological medial temporal lobe atrophy score (OR, 3.97 [95% CI, 1.62-9.73]) were independently associated with pre-SCI. In the 218 patients with ischemic stroke, white matter lesions (OR, 1.34 [95% CI, 1.04-1.72]) and medial temporal lobe atrophy (OR, 3.56 [95% CI, 1.38-9.19]), but not age, were associated with pre-SCI.

CONCLUSIONS

One-third of patients admitted to a stroke unit have pre-SCI that is associated with preexisting neuropsychiatric symptoms and functional performance. White matter lesions and medial temporal lobe atrophy are associated with pre-SCI, suggesting that both small vessel disease and neurodegeneration might be involved in its etiology.

Associations of cognitive impairment and longitudinal change in cognitive function with the risk of fatal stroke in middle-aged to older Chinese

It is unclear whether cognitive impairment and the longitudinal change in cognition are associated with the risk of fatal stroke in aging populations. Based on the Guangzhou Biobank Cohort Study data a sum of 26,064 participants at baseline and all deaths caused by stroke in a mean follow-up of 14.3 years (standard deviation = 3.2) were included, and the Cox proportional hazard regression was used in this prospective cohort study. Cognitive impairment was respectively associated with an increased risk of fatal strokes (the adjusted hazard ratio (aHR) = 1.38, 95% CI1.16-1.64, P < 0.001) and fatal ischaemic stroke (aHR = 1.39, 95% CI1.10-1.77, P = 0.007), compared to median cognition; the Delayed Word Recall Test (DWRT) score was associated with a decreasing trend for the risk of fatal strokes in a restricted cubic spline analysis; the longitudinal DWRT score decline was associated with the increased risks of fatal strokes (aHR = 1.42, 95% CI 1.11-1.82, P = 0.006) and fatal haemorrhagic stroke (aHR = 1.75, 95% CI 1.10-2.78, P = 0.02), compared to the longitudinal DWRT score rise. In summary, cognitive impairment and the longitudinal decline in DWRT scores were associated with the increased risk of fatal strokes; early screening of cognitive function should be conducive to predictive intervention in fatal stroke among relatively healthy middle-aged to older populations.

Genetic Evidence for Causal Association Between Atrial Fibrillation and Dementia: A Mendelian Randomization Study

Background The knowledge gap regarding whether the correlation between atrial fibrillation (AF) and dementia in observational studies is causation or driven by other shared risk factors remains substantially unfilled. Methods and Results We performed a comprehensive 2-sample Mendelian randomization study to evaluate the causal effect of AF on overall dementia and its subtypes, including vascular dementia, Alzheimer dementia, Lewy body dementia, and frontotemporal dementia. The primary results in inverse variance-weighted analyses were further validated by various Mendelian randomization sensitivity analyses. Additionally, we conducted multivariable Mendelian randomization to examine 10 candidate mediators of the causal association of AF and dementia. Genetic predisposition to AF was modestly associated with an increased risk of overall dementia (odds ratio, 1.140 [95% CI, 1.023-1.271]; P=0.018) and strongly associated with vascular dementia (odds ratio, 1.350 [95% CI, 1.076-1.695]; P=0.010). Genetically predicted AF indicated neutral effects on Alzheimer dementia, Lewy body dementia, and frontotemporal dementia. In multivariable Mendelian randomization analysis, the total effect of AF on overall dementia was remarkably attenuated by adjusting for genetic effect for ischemic stroke (odds ratio, 1.068 [95% CI, 0.953-1.197]; P=0.259) and low cardiac output (odds ratio, 1.046 [95% CI, 0.926-1.181]; P=0.475), indicating that the causal association of genetically predicted AF with dementia was potentially mediated by ischemic stroke and low cardiac output. The causal effect of genetically predicted AF on dementia was independent of cerebral small-vessel disease and brain volume phenotypes. Conclusions Our findings provided novel evidence supporting the causal effect of genetically predicted AF on dementia mediated by ischemic stroke and low cardiac output. Future clinical trials are warranted to evaluate the potential role of appropriate AF management in dementia prevention.

Thrombolysis Outcomes in Acute Ischaemic Stroke Patients with Pre-Existing Cognitive Impairment

BACKGROUND

Thrombolysis treatment for ischaemic stroke in patients with pre-existing disabilities, including cognitive impairment, remains controversial. Previous studies have suggested functional outcomes post-thrombolysis are worse in patients with cognitive impairment. This study aimed to compare and explore factors contributing to thrombolysis outcomes, including haemorrhagic complications, in cognitively and non-cognitively impaired patients with ischaemic stroke.

MATERIALS AND METHODS

A retrospective analysis of 428 ischaemic stroke patients who were thrombolysed between January 2016 and February 2021 was performed. Cognitive impairment was defined as a diagnosis of dementia, mild cognitive impairment, or clinical evidence of the condition. The outcome measures included morbidity (using NIHSS and mRS), haemorrhagic complications, and mortality, and were analysed using multivariable logistic regression models.

RESULTS

The analysis of the cohort revealed that 62 patients were cognitively impaired. When compared to those without cognitive impairment, this group showed worse functional status at discharge (mRS 4 vs. 3, p < 0.001) and a higher probability of dying within 90 days (OR 3.34, 95% CI 1.85-6.01, p < 0.001). A higher risk of a fatal ICH post-thrombolysis was observed in the cognitively impaired patients, and, after controlling for covariates, cognitive impairment remained a significant predictor of a fatal haemorrhage (OR 4.79, 95% CI 1.24-18.45, p = 0.023).

CONCLUSIONS

Cognitively impaired ischaemic stroke patients experience increased morbidity, mortality, and haemorrhagic complications following thrombolytic therapy. However cognitive status is not independently predictive of most outcome measures. Further work is required to elucidate contributing factors to the poor outcomes observed in these patients and help guide thrombolysis decision-making in clinical practice.

[Impairment of cognitive functions in patients with chronic thromboembolic pulmonary hypertension before and after surgical treatment]

OBJECTIVE

To study cognitive functions in patients with chronic thromboembolic pulmonary hypertension (CTEPH) before and in the long-term after pulmonary thromboendarterectomy and to study factors that negatively affect cognitive status.

MATERIAL AND METHODS

One hundred and twenty-four patients with CTEPH were examined before and 6 months after surgery with an assessment of cognitive impairment using the Mini-Mental State Examination (MMSE). Multivariate regression analysis was used to identify factors affecting the MMSE indicators before and in the long-term postoperative periods.

RESULTS

Initially, patients with CTEPH had a total MMSE score 23.8±1.1. Six months after surgery, the score was 26.1±1.9 (p<0.001). A history of stroke, disability, stress (loss of spouse), and a high Charleson comorbidity index were independent factors affecting MMSE score before surgery. After surgery, the total MMSE score was influenced by a history of stroke, stress (loss of spouse), residual pulmonary hypertension and atrial fibrillation in the early postoperative period.

CONCLUSION

Cognitive impairment in the form of mild dementia was observed in patients with CTEPH before surgery. Six months after the operation, an improvement in cognitive status was revealed, which corresponded to moderate cognitive impairment. At the same time, no complete recovery of cognitive functions was recorded. Patients with CTEPH still experienced the greatest difficulties in the following areas: concentration and counting, memory. A history of stroke, disability, stress (loss of spouse), and a high comorbidity index are associated with a decrease in MMSE scores before surgery. Six months after surgery, MMSE score was affected by a history of stroke, stress (loss of spouse), residual pulmonary hypertension and atrial fibrillation in the early postoperative period.

Impact of cognitive impairment on clinical outcomes in elderly patients with atrial fibrillation: ANAFIE Registry

Background

This subcohort study of All Nippon AF In the Elderly (ANAFIE) Registry based on 33 275 elderly patients (aged ≥75 years) with non-valvular atrial fibrillation (NVAF) investigated the relationship between cognitive function and 2-year clinical outcomes.

Methods

A total of 2963 (mean age, 81.4 years) patients participated in this subcohort study and were classified as having normal cognition (Mini-Mental State Examination (MMSE) score ≥24/30) or cognitive impairment (score ≤23/30) at baseline. Patients with a decrease of >2 points after 24 months were classified as having cognitive decline.

Results

At baseline, 586 (19.8%) patients had cognitive impairment. These patients tended to be older and had poorer general conditions than patients with normal cognition. The 2-year probability of stroke/systemic embolic events (SEEs), major bleeding and intracranial haemorrhage was numerically higher; those of cardiovascular death, all-cause death and net clinical outcome (composite of stroke/SEE, major bleeding and all-cause death) were significantly higher (all p<0.001) in patients with cognitive impairment versus normal cognition. In multivariate analysis, the risks of cardiovascular death (p=0.021), all-cause death (p<0.001) and net clinical outcome (p<0.001) were higher in patients with cognitive impairment versus those with normal cognition. After 24 months, 642 of 1915 (33.5%) patients with repeated MMSE determination had cognitive decline. Educational background <9 years, older age and concomitant cerebrovascular disorders were significant risk factors of cognitive decline at the 2-year follow-up.

Conclusions

Elderly patients with NVAF with cognitive impairment have a higher mortality risk than those with normal cognition. Several significant risk factors of cognitive decline were identified at 2-year follow-up.

Trial registration number

UMIN000024006 (http://www.umin.ac.jp/).

Relationships between cerebral small vessel diseases markers and cognitive performance in stroke-free patients with atrial fibrillation

Background

Atrial fibrillation (AF) is related to an increased risk of cognitive dysfunction. Besides clinically overt stroke, AF can damage the brain via several pathophysiological mechanisms. We aimed to assess the potential mediating role of cerebral small vessel disease (SVD) and cognitive performance in individuals with AF.

Methods

Stroke-free individuals with AF from the cardiological outpatient clinic at West China Hospital of Sichuan University were recruited. Extensive neuropsychological testing tools were assessed including global function, domains of attention, executive functions, learning, and memory. 3 T magnetic resonance imaging (MRI) was used for SVD markers assessment of white matter hyperintensities (WMH), lacunes, cerebral microbleeds (CMBs), and enlarged perivascular spaces (EPVS). The correlation between SVD markers and cognitive measures was analyzed by multivariate linear regression models.

Results

We finally enrolled 158 participants, of whom 95 (60.1%) were males. In multivariate models, the presence of lacunes independently associated with Montreal Cognitive Assessment (Model 1: ß = 0.52, Model 2: ß = 0.55), Rey Auditory Verbal Learning Test-immediate and delayed recall (Model 1: ß = 0.49; ß = 0.69; Model 2: ß = 0.53; ß = 0.73) as well as Stroop-A_correct (Model 1: ß = 0.12; Model 2: ß = 0.13), while total WMH severity independently associated with Stroop_time-A (Model 1: ß = 0.24; Model 3: ß = 0.27), Stroop_time-B (Model 1: ß = 0.17; Model 3: ß = 0.17), Stroop_time-C (Model 1: ß = 0.22; Model 3: ß = 0.21) and Shape Trail Test-A (Model 1: ß = 0.17; Model 3: ß = 0.16).

Conclusion

In our cohort of stroke-free individuals with AF, lacunes, and WMHs were independently associated with cognitive decline while EPVS and CMBs did not show significance. Assessment of SVD MRI markers might be valuable for cognition risk stratification and facilitate optimal management of patients with AF.

[Cognitive impairment in patients with atrial fibrillation]

Atrial fibrillation (AF) is a serious medical and social problem, being a common cause of ischemic stroke (IS) and cognitive impairment (CI), often reaching the degree of dementia. The most common cause of CI in patients with AF is transferred IS or repeated IS. In a significant part of patients with AF who have undergone IS, CI is detected directly in the acute period of the disease and progresses subsequently. In addition, the risk of developing CI is increased even in patients with AF who have not experienced IS before. The review discusses the data on the relationship between CI and AF, provides information on the possible causes of the development of CI in the considered group of patients. The main difficulties of managing a patient with AF and CI are considered.

Echocardiographic correlates of MRI imaging markers of cerebral small-vessel disease in patients with atrial-fibrillation-related ischemic stroke

Background and objectives

Atrial fibrillation (AF) has been linked to dementia risk, partly explained by cerebral small vessel disease (CSVD). Since AF and cardiovascular comorbidities were associated with cardiac dysfunction, we aimed to determine the association between echocardiographic parameters and neuroimaging markers of CSVD in patients with AF-related ischemic stroke.

Methods

This cross-sectional study enrolled patients with AF-related ischemic stroke from March 2013 to December 2019 who underwent transthoracic echocardiography and brain 3T MRI, including T1, T2, Flair, and SWI imaging sequences. We assessed the presence of lacunes and cerebellar microbleeds (CMBs), the severity of white matter hyperintensity (WMH) scored by the Fazekas scale (0-6), and the severity of enlarged perivascular spaces (EPVS) in basal ganglia (BG) and centrum semiovale (CSO) classified into three categories (0-10, 10-25, and >25). CSVD burden was rated on a 0-to-4 ordinal scale. Generalized linear regression analysis and post hoc comparisons with Bonferroni correction were performed to assess the association between various echocardiographic parameters and these lesions, adjusted for demographics and potential confounders.

Results

119 patients (68.38 ± 12.692 years; male 45.4 %) were included for analysis, of whom 55 (46.2%) had lacunes, 40 (33.6%) had CMBs, and median severity for WMH, BG-EPVS, CSO-EPVS, and CSVD burden were 2 (IQR: 1-3), 1 (IQR: 1-2), 1 (IQR: 0-1), and 1 (IQR: 1-2) respectively. In multivariable, fully adjusted models, left ventricular posterior wall thickness (LVPW) was associated with a higher risk of lacunes (RR 1.899, 95% CI: 1.342-2.686) and CSVD burden (RR = 2.081, 95%CI: 1.562-2.070). Right atrial diameter (RAD) was associated with greater CSO-EPVS (RR = 2.243, 95%CI: 1.234-4.075). No echocardiographic parameters were revealed to be associated with CMBs and WMH.

Conclusion

In patients with AF-related ischemic stroke, LVPW is associated with a higher risk of lacunes and CSVD burden, while RAD was associated with greater CSO-EPVS. Larger studies are required to determine these associations and to elucidate if these associations can help facilitate cognitive evaluation and brain MRI screening.

Comparative validity of informant tools for assessing pre-stroke cognitive impairment

OBJECTIVES

Various informant-based questionnaires are used in clinical practice to screen for pre-stroke cognitive problems. However, there is no guidance on which tool should be preferred. We compared the validity of the two most commonly used informant-based tools.

METHODS

We recruited consecutively admitted stroke patients. Patients' informants completed the Informant Questionnaire for Cognitive Decline in the Elderly Short Form (IQCODE-SF, 16-item) and Ascertain Dementia 8 (AD8). We assessed construct validity (accuracy) against a semi-structured clinical interview for dementia or mild cognitive impairment (MCI), describing test accuracy metrics and comparing area under ROC curves (AUROC). We described criterion validity by evaluating associations between test scores and neuroimaging markers of dementia and overall 'brain frailty'. Finally, we described prognostic validity comparing ROC curves for 18-month clinical outcomes of dementia, death, stroke, and disability.

RESULTS

One-hundred-thirty-seven patient-informant dyads were recruited. At usual clinical cut-points, the IQCODE-SF had comparable sensitivity to the AD8 (both = 92%) for pre-stroke dementia, but superior specificity (IQCODE-SF: 82% vs. AD8: 58%). Youden index suggested that the optimal AD8 threshold for diagnosis of dementia is ≥4. The IQCODE-SF demonstrated stronger associations with markers of generalised and medial-temporal lobe atrophy, neurovascular disease, and overall brain frailty. IQCODE-SF also demonstrated greater accuracy for predicting future dementia (IQCODE-SF AUROC = 0.903, 95% CI = 0.798-1.00; AD8 AUROC = 0.821, 95% CI = 0.664-0.977).

CONCLUSIONS

Both IQCODE-SF and AD8 are valid measures of pre-stroke dementia. Higher cut points for AD8 may improve performance in the acute stroke setting. Based on consistent superiority across a range of validity analyses, IQCODE-SF may be preferable to AD8 for pre-stroke dementia screening.

Research progress in atrial fibrillation with cerebral small vessel disease

Non-valvular atrial fibrillation is a common arrhythmia and a major risk factor for cardioembolic stroke. Small cerebral vascular disease is a syndrome of clinical, cognitive, imaging, and pathological manifestations caused by intracranial small vascular lesions. The imaging findings on cranial magnetic resonance usually shows recent subcortical small infarction, vascularised lacunae, white matter hypersignal, perivascular space enlargement, cerebral microhemorrhage, and brain atrophy. It is a major cause of neurological loss and cognitive function decline in the elderly. Current studies suggest that atrial fibrillation may increase the imaging load of cerebral small vessel disease through a series of mechanisms such as microembolization, hypoperfusion, inflammation, endothelial dysfunction, and lymphoid system dysfunction. The imaging of cerebral small vessel disease with atrial fibrillation has a potential relationship with cognitive function decline and is related to the occurrence and prognosis of stroke, even more has a potential role in suggesting the etiology and secondary prevention strategies of ischemic stroke.

Atrial Fibrillation and Dementia: A Report From the AF-SCREEN International Collaboration

Growing evidence suggests a consistent association between atrial fibrillation (AF) and cognitive impairment and dementia that is independent of clinical stroke. This report from the AF-SCREEN International Collaboration summarizes the evidence linking AF to cognitive impairment and dementia. It provides guidance on the investigation and management of dementia in patients with AF on the basis of best available evidence. The document also addresses suspected pathophysiologic mechanisms and identifies knowledge gaps for future research. Whereas AF and dementia share numerous risk factors, the association appears to be independent of these variables. Nevertheless, the evidence remains inconclusive regarding a direct causal effect. Several pathophysiologic mechanisms have been proposed, some of which are potentially amenable to early intervention, including cerebral microinfarction, AF-related cerebral hypoperfusion, inflammation, microhemorrhage, brain atrophy, and systemic atherosclerotic vascular disease. The mitigating role of oral anticoagulation in specific subgroups (eg, low stroke risk, short duration or silent AF, after successful AF ablation, or atrial cardiopathy) and the effect of rhythm versus rate control strategies remain unknown. Likewise, screening for AF (in cognitively normal or cognitively impaired patients) and screening for cognitive impairment in patients with AF are debated. The pathophysiology of dementia and therapeutic strategies to reduce cognitive impairment warrant further investigation in individuals with AF. Cognition should be evaluated in future AF studies and integrated with patient-specific outcome priorities and patient preferences. Further large-scale prospective studies and randomized trials are needed to establish whether AF is a risk factor for cognitive impairment, to investigate strategies to prevent dementia, and to determine whether screening for unknown AF followed by targeted therapy might prevent or reduce cognitive impairment and dementia.

[Cerebrovascular disease with neurocognitive impairment]

In the International Classification of Diseases 11th revision in the section «Diseases of the nervous system», it is proposed to distinguish «Cerebrovascular disorder with neurocognitive impairment», which corresponds to both discirculatory encephalopathy (DEP) or chronic cerebral ischemia (CCI) accepted in our country, and also vascular cognitive impairments. The terminology, prevalence, risk factors and pathological basis of the disease are discussed, in particular multiple infarctions, strategic infarctions, cerebral small vessel disease, specific microangiopathies, intracerebral hemorrhage and global hypoperfusion. Post-stroke cognitive impairments are discussed in detail. The article presents relevant data on the pathogenesis of the disease, highlights the issues of clinical and neuroimaging diagnostics. Based on the data presented in the article, we can conclude that the diagnosis of DEP, CCI should be based on the presence of cerebrovascular disease with neurocognitive impairment, which implies the verification of vascular cognitive impairments and reliable neuroimaging signs of cerebrovascular pathology while excluding other causes. Early diagnosis and effective treatment of cerebrovascular disease with neurocognitive impairment (DEP, CCI) is becoming increasingly important, since treatment can slow the progression of the disease and lead to a decrease in the incidence of stroke and dementia.

High-Mobility Group Box-1 and Its Potential Role in Perioperative Neurocognitive Disorders

Aseptic surgical trauma provokes the release of HMGB1, which engages the innate immune response after binding to pattern-recognition receptors on circulating bone marrow-derived monocytes (BM-DM). The initial systemic inflammation, together with HMGB1, disrupts the blood-brain barrier allowing penetration of CCR2-expressing BM-DMs into the hippocampus, attracted by the chemokine MCP-1 that is upregulated by HMGB1. Within the brain parenchyma quiescent microglia are activated and, together with the translocated BM-DMs, release proinflammatory cytokines that disrupt synaptic plasticity and hence memory formation and retention, resulting in postoperative cognitive decline (PCD). Neutralizing antibodies to HMGB1 prevents the inflammatory response to trauma and PCD.

Stroke prevention strategies in high-risk patients with atrial fibrillation

Effective stroke prevention with oral anticoagulation (OAC) is the cornerstone of the management of patients with atrial fibrillation. The use of OAC reduces the risk of stroke and death. For most patients with atrial fibrillation without moderate or severe mitral valve stenosis or prosthetic mechanical heart valves, treatment options include vitamin K antagonists, such as warfarin, and non-vitamin K antagonist oral anticoagulants (NOACs). Although most guidelines generally recommend NOACs as the first-line OAC, caution is required in some groups of patients with atrial fibrillation at high risk of stroke and bleeding who have been under-represented or not studied in the randomized clinical trials on NOACs for stroke prevention. In addition to OAC, non-pharmacological, percutaneous therapies, including left atrial appendage occlusion, for stroke prevention have emerged, sometimes used in combination with catheter ablation for the treatment of the atrial fibrillation. High-risk groups of patients with atrial fibrillation include patients with end-stage renal failure (including those receiving dialysis), extremely old patients (such as those aged >80 years with multiple risk factors for bleeding), patients with dementia or those living in a long-term care home, patients with previous intracranial bleeding or recent acute bleeding (such as gastrointestinal bleeding), patients with acute ischaemic stroke and patients with an intracardiac thrombus. This Review provides an overview of stroke prevention strategies, including left atrial appendage occlusion, in patients with atrial fibrillation at high risk of stroke and bleeding.

Cognitive Impairment Before Atrial Fibrillation-Related Ischemic Events: Neuroimaging and Prognostic Associations

Background

It is likely that a proportion of poststroke cognitive impairment is sometimes attributable to unidentified prestroke decline; prestroke cognitive function is also clinically relevant because it is associated with poor functional outcomes, including death. We investigated the radiological and prognostic associations of preexisting cognitive impairment in patients with ischemic stroke or transient ischemic attack associated with atrial fibrillation.

Methods and Results

We included 1102 patients from the prospective multicenter observational CROMIS‐2 (Clinical Relevance of Microbleeds in Stroke 2) atrial fibrillation study. Preexisting cognitive impairment was identified using the 16‐item Informant Questionnaire for Cognitive Decline in the Elderly. Functional outcome was measured using the modified Rankin scale. Preexisting cognitive impairment was common (n=271; 24.6%). The presence of lacunes (odds ratio [OR], 1.50; 95% CI, 1.03–1.05; P=0.034), increasing periventricular white matter hyperintensity grade (per grade increase, OR, 1.38; 95% CI, 1.17–1.63; P<0.0001), deep white matter hyperintensity grade (per grade increase, OR, 1.26; 95% CI, 1.05–1.51; P=0.011), and medial temporal atrophy grade (per grade increase, OR, 1.61; 95% CI, 1.34–1.95; P<0.0001) were independently associated with preexisting cognitive impairment. Preexisting cognitive impairment was associated with poorer functional outcome at 24 months (mRS >2; adjusted OR, 2.43; 95% CI, 1.42–4.20; P=0.001).

Conclusions

Preexisting cognitive impairment in patients with atrial fibrillation–associated ischemic stroke or transient ischemic attack is common, and associated with imaging markers of cerebral small vessel disease and neurodegeneration, as well as with longer‐term functional outcome.

Clinical Trial Registration

URL: http://www.clinicaltrials.gov. Unique identifier: NCT02513316.