Insular Cortex Lesions, Cardiac Troponin, and Detection of Previously Unknown Atrial Fibrillation in Acute Ischemic Stroke

Isolated insular stroke: topography is the answer with respect to outcome and cardiac involvement

Background and purpose

Isolated insular strokes (IIS) are a rare occurrence due to the frequent concomitant involvement of adjacent territories, supplied by the M2 segment of the middle cerebral artery (MCA), and clinical aspects are sometimes contradictory. We aimed to describe clinical and radiological characteristics of a pure IIS case series, focusing on its functional outcome and cardiac involvement.

Methods

We identified 15 isolated insular ischemic strokes from a pool of 563 ischemic strokes occurred between January 2020 and December 2021. Data collection consisted of demographic and baseline clinical characteristics, comorbidities, electrocardiograms, echocardiograms, stroke topography and etiology, reperfusive treatments, and outcome measures. Descriptive statistical analysis was carried out.

Results

Newly detected cardiovascular alterations were the prevalent atypical presentation. Cardioembolism was the most frequent etiology. Most of patients had major neurological improvement at discharge and good outcome at 3-months follow-up.

Discussion and conclusion

IIS are extremely rare, representing according to our study about 2.6% ischemic strokes cases per year, and patients have peculiar clinical manifestations, such as dysautonomia and awareness deficits. Our data suggest the possibility for these patients to completely recover after acute ischemic stroke notwithstanding the pivotal role of the insula in cerebral connections and the frequent association with MCA occlusion. Moreover, given the central role of the insula in regulating autonomic functions, newly detected cardiac arrhythmias must be taken into consideration, as well as a full diagnostic work-up for the research of cardioembolic sources. To our knowledge, this is the largest monocentric case series of IIS and it might be useful for future systematic reviews.

Rising Cardiac Troponin: A Prognostic Biomarker for Mortality After Acute Ischemic Stroke

BACKGROUND

Elevated cardiac troponin (cTn) is detected in 10% to 30% of patients with acute ischemic stroke (AIS) and correlates with poor functional outcomes. Serial cTn measurements differentiate a dynamic cTn pattern (rise/fall >20%), specific for acute myocardial injury, from elevated but stable cTn levels (nondynamic), typically attributed to chronic cardiac/noncardiac conditions. We investigated if the direction of the cTn change (rising versus falling) affects mortality and outcome.

METHODS AND RESULTS

We retrospectively screened consecutive patients with AIS admitted to 5 stroke centers for elevated cTn at admission and at least 1 additional cTn measurement within 48 hours. The pattern of cTn was defined as rising if >20% increase from baseline, falling if >20% decrease, or nondynamic if ≤20% change in either direction. Logistic regression analyses were performed to assess the association of cTn patterns and 7-day mortality and unfavorable discharge disposition. Of 3789 patients with AIS screened, 300 were included. Seventy-two had a rising pattern, 66 falling, and 162 nondynamic. In patients with AIS with rising cTn, acute ischemic myocardial infarction was present in 54%, compared with 33% in those with falling cTn (P<0.01). Twenty-two percent of patients with a rising pattern had an isolated dynamic cTn in the absence of any ECG or echocardiogram changes, compared with 53% with falling cTn. A rising pattern was associated with higher risk of 7-day mortality (adjusted odds ratio [OR]=32 [95% CI, 2.5-415.0] rising versus aOR=1.3 [95% CI, 0.1-38.0] falling versus nondynamic as reference) and unfavorable discharge disposition (aOR=2.5 [95% CI, 1.2-5.2] rising versus aOR=0.6 [95% CI, 0.2-1.5] versus falling).

CONCLUSIONS

Rising cTn is independently associated with increased mortality and unfavorable discharge disposition in patients with AIS.

Insular cortex Hounsfield units predict postoperative neurocardiogenic injury in patients with aneurysmal subarachnoid hemorrhage

OBJECTIVE

Our study aims to investigate the association between the Hounsfield unit (Hu) value of the insular cortex (IC) during emergency admission and the subsequent occurrence of post-operative neurocardiogenic injury (NCI) among patients afflicted with aneurysmal subarachnoid hemorrhage (aSAH).

METHODS

Patients baseline characteristics were juxtaposed between those with and without NCI. The significant variables were incorporated into a multivariable stepwise logistic regression model. Receiver operating characteristic (ROC) curves were drafted for each significant variable, yielding cutoff values and the area under the curve (AUC). Subgroup and sensitivity analyses were performed to assess the predictive performance across various cohorts and ascertain result stability. Propensity score matching (PSM) was ultimately employed to redress any baseline characteristic disparities.

RESULTS

Patients displaying a right IC Hu value surpassing 28.65 exhibited an escalated risk of postoperative NCI upon confounder adjustment (p < 0.001). The ROC curve eloquently manifested the predictive capacity of right IC Hu in relation to NCI (AUC = 0.650, 95%CI, 0.591-0.709, p < 0.001). Further subgroup analysis revealed significant interactions between right IC Hu and factors such as age, history of heart disease, and Graeb 5-12 score. Sensitivity analysis further upheld the results' significant (p = 0.002). The discrepancy in NCI incidence between the two groups, both prior (p < 0.002) and post (p = 0.039) PSM, exhibited statistical significance. After PSM implementation, the likelihood of NCI displayed an ascending trend with increasing right IC Hu values, from the Hu1 cohort onward, receding post the Hu4 cohort.

CONCLUSION

This study definitively establishes an elevated right IC Hu value in the early stages of emergency admission as an autonomous predictor for ensuing NCI subsequent to aSAH.

Multiorgan talks in the presence of brain injury

PURPOSE OF REVIEW

The brain is the command center of the rest of the body organs. The normal multiorgan talks between the brain and the rest of the body organs are essential for the normal body homeostasis. In the presence of brain injury, the disturbed talks between the brain and the rest of body organs will result in several pathological conditions. The aim of this review is to present the most recent findings for the pathological conditions that would result from the impaired multiorgan talks in the presence of brain injury.

RECENT FINDINGS

The brain injury such as in acute ischemic stroke, subarachnoid hemorrhage and traumatic brain injury will result in cascade of pathological talks between the brain and the rest of body organs. These pathological talks could result in pathological conditions such as cardiomyopathy, acute lung and kidney injuries, impaired liver functions, and impaired gut barrier permeability as well.

SUMMARY

Better understanding of the pathological conditions that could result from the impaired multiorgan talks in the presence of brain injury will open the doors for precise targeted therapies in the future for myriad of pathological conditions.

At the heart of the matter: how mental stress and negative emotions affect atrial fibrillation

Atrial fibrillation (AF) is the most common form of cardiac arrhythmia, affecting 2%-3% of the world's population. Mental and emotional stress, as well as some mental health conditions (e.g., depression) have been shown to significantly impact the heart and have been suggested to act both as independent risk factors and triggers in the onset of AF. In this paper, we review the current literature to examine the role that mental and emotional stress have in the onset of AF and summarise the current knowledge on the interaction between the brain and heart, and the cortical and subcortical pathways involved in the response to stress. Review of the evidence suggests that mental and emotional stress negatively affect the cardiac system, potentially increasing the risk for developing and/or triggering AF. Further studies are required to further understand the cortical and sub-cortical structures involved in the mental stress response and how these interact with the cardiac system, which may help in defining new strategies and interventions to prevent the development of, and improve the management of AF.

14-day Holter monitoring for atrial fibrillation after ischemic stroke: The yield of guideline-recommended monitoring duration

Introduction:

Current European Stroke Organisation (ESO) guidelines recommend >48 h of continuous electrocardiographic monitoring for atrial fibrillation (AF) in all patients with ischemic stroke or transient ischemic attack (TIA) with undetermined origin. We assessed the yield of the guideline-recommended monitoring for AF, as well as of extending monitoring up to 14 days.

Patients and methods:

We included consecutive patients with stroke/TIA without AF in an academic hospital in The Netherlands. We reported AF incidence and number needed to screen (NNS) in the overall sample after 48 h and 14 days of Holter monitoring.

Results:

Among 379 patients with median age 63 years (IQR 55–73), 58% male, Holter monitoring detected 10 cases of incident AF during a median of 13 (IQR 12–14) days of monitoring. Seven AF cases were detected within the first 48 hours (incidence 1.85%, 95% CI 0.74–3.81; NNS 54), and three additional AF cases were recorded among the 362 patients with >48 h of monitoring and without AF ⩽ 48 h (incidence 0.83%, 95% CI: 0.17–2.42; NNS 121). All AF cases were detected within the first 7 days of monitoring. Our sample was subject to sampling bias favoring inclusion of participants with low AF risk.

Discussion:

Strengths of this work were the broad inclusion criteria as recommended by ESO guidelines, and high Holter adherence among participants. The analysis was limited by inclusion of lower-risk cases and a relatively small sample size.

Conclusion:

In low-risk patients with recent stroke or TIA, ESO guideline-recommended screening for AF resulted in a low AF yield, with limited additional value of monitoring up to 14 days. Our results underline the need for a personalized approach in determining a patient’s optimum duration for post-stroke non-invasive ambulatory monitoring.

A nomogram for predicting atrial fibrillation detected after acute ischemic stroke

Background

Atrial fibrillation detected after stroke (AFDAS) is associated with an increased risk of ischemic stroke (IS) recurrence and death. Early diagnosis can help identify strategies for secondary prevention and improve prognosis. However, there are no validated predictive tools to assess the population at risk for AFDAS. Therefore, this study aimed to develop and validate a predictive model for assessing the incidence of AFDAS after acute ischemic stroke (AIS).

Methods

This study was a multicenter retrospective study. We collected clinical data from 5332 patients with AIS at two hospitals between 2014.01 and 2021.12 and divided the development and validation of clinical prediction models into a training cohort (n = 3173) and a validation cohort (n = 2159). Characteristic variables were selected from the training cohort using the least absolute shrinkage and selection operator (LASSO) algorithm and multivariable logistic regression analysis. A nomogram model was developed, and its performance was evaluated regarding calibration, discrimination, and clinical utility.

Results

We found the best subset of risk factors based on clinical characteristics and laboratory variables, including age, congestive heart failure (CHF), previous AIS/transient ischemia attack (TIA), national institutes of health stroke scale (NIHSS) score, C-reactive protein (CRP), and B-type natriuretic peptide (BNP). A predictive model was developed. The model showed good calibration and discrimination, with calibration values of Hosmer-Lemeshow χ² = 4.813, P = 0.732 and Hosmer-Lemeshow χ² = 4.248, P = 0.834 in the training and validation cohorts, respectively. The area under the ROC curve (AUC) was 0.815, 95% CI (0.777–0.853) and 0.808, 95% CI (0.770–0.847). The inclusion of neuroimaging variables significantly improved the performance of the integrated model in both the training cohort (AUC. 0.846 (0.811–0.882) vs. 0.815 (0.777–0.853), P = 0.001) and the validation cohort (AUC: 0.841 (0.804–0.877) vs. 0.808 (0.770–0.847), P = 0.001). The decision curves showed that the integrated model added more net benefit in predicting the incidence of AFDAS.

Conclusion

Predictive models based on clinical characteristics, laboratory variables, and neuroimaging variables showed good calibration and high net clinical benefit, informing clinical decision-making in diagnosing and treating patients with AFDAS.

Stroke-Heart Syndrome: Recent Advances and Challenges

After ischemic stroke, there is a significant burden of cardiovascular complications, both in the acute and chronic phase. Severe adverse cardiac events occur in 10% to 20% of patients within the first few days after stroke and comprise a continuum of cardiac changes ranging from acute myocardial injury and coronary syndromes to heart failure or arrhythmia. Recently, the term stroke–heart syndrome was introduced to provide an integrated conceptual framework that summarizes neurocardiogenic mechanisms that lead to these cardiac events after stroke. New findings from experimental and clinical studies have further refined our understanding of the clinical manifestations, pathophysiology, and potential long‐term consequences of the stroke–heart syndrome. Local cerebral and systemic mediators, which mainly involve autonomic dysfunction and increased inflammation, may lead to altered cardiomyocyte metabolism, dysregulation of (tissue‐resident) leukocyte populations, and (micro‐) vascular changes. However, at the individual patient level, it remains challenging to differentiate between comorbid cardiovascular conditions and stroke‐induced heart injury. Therefore, further research activities led by joint teams of basic and clinical researchers with backgrounds in both cardiology and neurology are needed to identify the most relevant therapeutic targets that can be tested in clinical trials.

Elevated troponin I levels on admission predict long-term mortality in patients with acute cerebral infarction following thrombolysis

Background/objective

Cardiac diseases are frequently accompanied by elevated levels of biomarkers, among which, troponin is commonly investigated. The levels of plasma cardiac troponin I (cTnI), which has been shown to predict short-term mortality, are elevated in patients with acute cerebral infarction (ACI). However, few studies have assessed the association between cTnI concentration and long-term mortality in patients with ACI following thrombolysis.

Methods

Patients with ACI admitted between January 1, 2014, and December 31, 2016, were registered. Data on demographics and outcomes with elevated cTnI levels were also collected.

Results

A total of 145 patients with ACI were recruited; 97 (66%), 30 (20%), and 18 (12%) patients had cTnI concentrations < 0.030 (group 1), 0.030–0.10 (group 2), and > 0.10 μg/L (group 3), respectively. cTnI elevation was associated with older age, atrial fibrillation, congestive heart failure, renal insufficiency, coronary artery disease, stroke severity (National Institutes of Health Stroke Scale score), and prior smoking history at admission. After adjusting for comorbidities and severity at 3 months after ACI, cTnI elevation on admission was significantly associated with ascending 5-year mortality (hazard ratio, 1.80; 95% confidence interval, 1.22–2.65).

Conclusions

Even after adjusting for several possible confounders, cTnI elevation in patients with ACI treated with rt-PA was associated with a 1.80-fold increased risk of 5-year mortality.

European Stroke Organisation (ESO) guideline on screening for subclinical atrial fibrillation after stroke or transient ischaemic attack of undetermined origin

We aimed to provide practical recommendations for the screening of subclinical atrial fibrillation (AF) in patients with ischaemic stroke or transient ischaemic attack (TIA) of undetermined origin. These guidelines are based on the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) methodology. Five relevant Population, Intervention, Comparator, Outcome questions were defined by a multidisciplinary module working group (MWG).

Longer duration of cardiac rhythm monitoring increases the detection of subclinical AF, but the optimal monitoring length is yet to be defined. We advise longer monitoring to increase the rate of anticoagulation, but whether longer monitoring improves clinical outcomes needs to be addressed. AF detection does not differ from in- or out-patient ECG-monitoring with similar monitoring duration, so we consider it reasonable to initiate in-hospital monitoring as soon as possible and continue with outpatient monitoring for more than 48h. Although insertable loop recorders (ILR) increase AF detection based on their longer monitoring duration, comparison with non-implantable ECG devices for similar monitoring time is lacking. We suggest the use of implantable devices, if feasible, for AF detection instead of non- implantable devices to increase the detection of subclinical AF. There is weak evidence of a useful role for blood, ECG, and brain imaging biomarkers for the identification of patients at high risk of AF. In patients with patent foramen ovale, we found insufficient evidence from RCT, but prolonged cardiac monitoring in patients >55 years is advisable for subclinical AF detection. To conclude, in adult patients with ischaemic stroke or TIA of undetermined origin, we recommend longer duration of cardiac rhythm monitoring of more than 48h and if feasible with IRL to increase the detection of subclinical AF.

Acute care and secondary prevention of stroke with newly detected versus known atrial fibrillation

BACKGROUND

Atrial fibrillation (AF) in stroke patients can be classified as either "known AF (KAF)", which was confirmed before stroke-onset, or "AF detected after stroke (AFDAS)", which was diagnosed after stroke-onset. While KAF is considered primarily cardiogenic, AFDAS includes patients with stroke-triggered neurogenic arrhythmias. This study aimed to investigate the clinical course of stroke, functional outcome and the value of oral anticoagulation for secondary prevention according to AF subtype.

METHODS

Acute ischemic stroke patients were consecutively enrolled, AF was classified as AFDAS or KAF. Stroke severity was assessed using the National Institutes of Health Stroke Scale (NIHSS) and the three-month functional outcome was measured on the modified Rankin scale. Inverse probability weighting was applied to adjust baseline confounders in patients with AFDAS and KAF. Multivariate logistic regression models were calculated to investigate the value of oral anticoagulation for secondary prevention.

RESULTS

822 stroke patients with AF were included, 234 patients (28.5%) had AFDAS. AFDAS patients had lower prevalence of coronary artery disease, heart failure, and sustained AF, but higher rates of large-vessel occlusion compared to KAF patients. NIHSS-scores were lower in patients on pre-stroke anticoagulation. Oral anticoagulation for secondary prevention was associated with a favorable three-month functional outcome (odds ratio 7.60, 95% confidence interval 3.42-16.88) independently from AF subtype. The rate of stroke recurrence did not differ significantly.

CONCLUSIONS

Clinical characteristics suggest that AFDAS might comprise a distinct pathophysiologic and clinical entity among stroke patients with AF. The benefit of anticoagulation for secondary prevention was not affected by AF subtype.

Using machine learning to predict atrial fibrillation diagnosed after ischemic stroke

BACKGROUND

Selecting best candidates for prolonged poststroke cardiac monitoring in acute ischemic stroke (AIS) patients is still challenging. We aimed to develop a machine learning (ML) model to select AIS patients at high risk of poststroke atrial fibrillation (AF) for prolonged cardiac monitoring and then to compare ML model with traditional risk scores and classic statistical logistic regression (classic-LR) model.

METHODS

AIS patients from July 2012 to September 2020 across Nanjing First Hospital were collected. We performed the LASSO regression for selecting the critical features and built five ML models to assess the risk of poststroke AF. The SHAP and partial dependence plot (PDP) method were introduced to interpret the optimal model. We also compared ML model with CHADS₂ score, CHA₂DS₂-VASc score, AS5F score, HAVOC score, and classic-LR model.

RESULTS

A total of 3929 AIS patients were included. Among the five ML models, deep neural network (DNN) was the model with best performance. It also exhibited superior performance compared with CHADS₂ score, CHA₂DS₂-VASc score, AS5F score, HAVOC score and classic-LR model. The results of SHAP and PDP method revealed age, cardioembolic stroke, large-artery atherosclerosis stroke, and NIHSS score at admission were the top four important features and revealed the DNN model had good interpretability and reliability.

CONCLUSION

The DNN model achieved best performance and improved prediction performance compared with traditional risk scores and classic-LR model. The DNN model can be applied to identify AIS patients at high risk of poststroke AF as best candidates for prolonged poststroke cardiac monitoring.

Sex Hormone-Specific Neuroanatomy of Takotsubo Syndrome: Is the Insular Cortex a Moderator?

Takotsubo syndrome (TTS), a transient form of dysfunction in the heart’s left ventricle, occurs predominantly in postmenopausal women who have emotional stress. Earlier studies support the concept that the human circulatory system is modulated by a cortical network (consisting of the anterior cingulate gyrus, amygdala, and insular cortex (Ic)) that plays a pivotal role in the central autonomic nervous system in relation to emotional stressors. The Ic plays a crucial role in the sympathovagal balance, and decreased levels of female sex hormones have been speculated to change functional cerebral asymmetry, with a possible link to autonomic instability. In this review, we focus on the Ic as an important moderator of the human brain–heart axis in association with sex hormones. We also summarize the current knowledge regarding the sex-specific neuroanatomy in TTS.

Atrial Fibrillation Detected After Stroke and Transient Ischemic Attack: A Novel Clinical Concept Challenging Current Views

Atrial fibrillation (AF) can be newly detected in approximately one-fourth of patients with ischemic stroke and transient ischemic attack without previously recognized AF. We present updated evidence supporting that AF detected after stroke or transient ischemic attack (AFDAS) may be a distinct clinical entity from AF known before stroke occurrence (known atrial fibrillation). Data suggest that AFDAS can arise from the interplay of cardiogenic and neurogenic forces. The embolic risk of AFDAS can be understood as a gradient defined by the prevalence of vascular comorbidities, the burden of AF, neurogenic autonomic changes, and the severity of atrial cardiopathy. The balance of existing data indicates that AFDAS has a lower prevalence of cardiovascular comorbidities, a lower degree of cardiac abnormalities than known atrial fibrillation, a high proportion (52%) of very brief (<30 seconds) AF paroxysms, and is more frequently associated with insular brain infarction. These distinctive features of AFDAS may explain its recently observed lower associated risk of stroke than known atrial fibrillation. We present an updated ad-hoc meta-analysis of randomized clinical trials in which the association between prolonged cardiac monitoring and reduced risk of ischemic stroke was nonsignificant (incidence rate ratio, 0.90 [95% CI, 0.71-1.15]). These findings highlight that larger and sufficiently powered randomized controlled trials of prolonged cardiac monitoring assessing the risk of stroke recurrence are needed. Meanwhile, we call for further research on AFDAS and stroke recurrence, and a tailored approach when using prolonged cardiac monitoring after ischemic stroke or transient ischemic attack, focusing on patients at higher risk of AFDAS and, more importantly, at higher risk of cardiac embolism.

A Comprehensive Model to Predict Atrial Fibrillation in Cryptogenic Stroke: The Decryptoring Score

OBJETIVE

Cryptogenic stroke (CS) represents up to 30% of ischemic strokes (IS). Since atrial fibrillation (AF) can be detected in up to 30% of CS, there is a clinical need for estimating the probability of underlying AF in CS to guide the optimal secondary prevention strategy. The aim of the study was to develop the first comprehensive predictive score including clinical conditions, biomarkers, and left atrial strain (LAS), to predict AF detection in this setting.

METHODS

Sixty-three consecutive patients with IS or transient ischemic attack with ABCD2 scale ≥ 4 of unknown etiology were prospectively recruited. Clinical, laboratory, and echocardiographic variables were collected. All patients underwent 15 days wearable Holter-ECG monitoring. Main objective was the Decryptoring score creation to predict AF in CS. Score variables were selected by a univariate analysis and, thereafter, score points were derived according to a multivariant analysis.

RESULTS

AF was detected in 15 patients (24%). Age > 75 (9 points), hypertension (1 point), Troponin T > 40 ng/L (8.5 points), NTproBNP > 200 pg/ml (0.5 points), LAS reservoir < 25.3% (24.5 points) and LAS conduct < 10.4% (0.5 points) were included in the score. The rate of AF detection was 0% among patients with a score of < 10 and 80% among patients with a score > 35. The comparison of the predictive validity between the proposed score and AF-ESUS score resulted in an AUC of 0.94 for Decryptoring score and of 0.65 for the AF-ESUS score(p < 0.001).

CONCLUSION

This novel score offers an accurate AF prediction in patients with CS; however these results will require validation in an independent cohort using this model before they may be translated into clinical practice.

Cerebral-Cardiac Syndrome and Diabetes: Cardiac Damage After Ischemic Stroke in Diabetic State

Cerebral-cardiac syndrome (CCS) refers to cardiac dysfunction following varying brain injuries. Ischemic stroke is strongly evidenced to induce CCS characterizing as arrhythmia, myocardial damage, and heart failure. CCS is attributed to be the second leading cause of death in the post-stroke stage; however, the responsible mechanisms are obscure. Studies indicated the possible mechanisms including insular cortex injury, autonomic imbalance, catecholamine surge, immune response, and systemic inflammation. Of note, the characteristics of the stroke population reveal a common comorbidity with diabetes. The close and causative correlation of diabetes and stroke directs the involvement of diabetes in CCS. Nevertheless, the role of diabetes and its corresponding molecular mechanisms in CCS have not been clarified. Here we conclude the features of CCS and the potential role of diabetes in CCS. Diabetes drives establish a “primed” inflammatory microenvironment and further induces severe systemic inflammation after stroke. The boosted inflammation is suspected to provoke cardiac pathological changes and hence exacerbate CCS. Importantly, as the key element of inflammation, NOD-like receptor pyrin domain containing 3 (NLRP3) inflammasome is indicated to play an important role in diabetes, stroke, and the sequential CCS. Overall, we characterize the corresponding role of diabetes in CCS and speculate a link of NLRP3 inflammasome between them.

Alamandine but not angiotensin-(1-7) produces cardiovascular effects at the rostral insular cortex

Experiments aimed to evaluate the tissue distribution of Mas-related G protein-coupled receptor D (MrgD) revealed the presence of immunoreactivity for the MrgD protein in the rostral insular cortex (rIC), an important area for autonomic and cardiovascular control. To investigate the relevance of this finding, we evaluated the cardiovascular effects produced by the endogenous ligand of MrgD, alamandine, in this brain region. Mean arterial pressure (MAP), heart rate (HR), and renal sympathetic nerve activity (RSNA) were recorded in urethane anesthetized rats. Unilateral microinjection of equimolar doses of alamandine (40 pmol/100 nL), angiotensin-(1-7), angiotensin II, angiotensin A, and Mas/MrgD antagonist d-Pro7-Ang-1-7 (50 pmol/100 nL), Mas antagonist A779 (100 pmol/100 nL), or vehicle (0.9% NaCl) were made in different rats (n = 4-6/group) into rIC. To verify the specificity of the region, a microinjection of alamandine was also performed into intermediate insular cortex (iIC). Microinjection of alamandine in rIC produced an increase in MAP (Δ = 15 ± 2 mmHg), HR (Δ = 36 ± 4 beats/min), and RSNA (Δ = 31 ± 4%), but was without effects at iIC. Strikingly, an equimolar dose of angiotensin-(1-7) at rIC did not produce any change in MAP, HR, and RSNA. Angiotensin II and angiotensin A produced only minor effects. Alamandine effects were not altered by A-779, a Mas antagonist, but were completely blocked by the Mas/MrgD antagonist d-Pro7-Ang-(1-7). Therefore, we have identified a brain region in which alamandine/MrgD receptor but not angiotensin-(1-7)/Mas could be involved in the modulation of cardiovascular-related neuronal activity. This observation also suggests that alamandine might possess unique effects unrelated to angiotensin-(1-7) in the brain.

Atrial fibrillation: is there a role for cardiac troponin?

Atrial fibrillation (AF) is the most common sustained arrhythmia, and its prevalence rate is expected to be doubled over the next decades. Despite the wide use of biomarkers in the management of different cardiac diseases such as myocardial infarction and heart failure, utilization of biomarkers in AF management is not routinely recommended by current guidelines. There is also growing evidence that higher levels of cardiac-specific troponin, as an intracellular protein involved in cardiomyocyte contraction, may be associated with the risk of incident and recurrent AF and its complications. In the present paper, we review the association between troponin and AF and propose clinical suggestions for use of troponin in the management of AF patients.

Myocardial injury in acute ischemic stroke

Since antiquity, the interaction of brain and heart has inspired physicians and philosophers. Today, our knowledge has vastly improved, but the exact way of their interaction still holds many secrets to reveal. The interaction between brain and heart merits particular attention in the aftermath of a sudden injury to the brain-like acute ischemic stroke (AIS). This narrative review gives an overview of current knowledge on frequency, prognosis, and potential pathophysiological mechanisms of myocardial injury following AIS.

Systematic monitoring for detection of atrial fibrillation in patients with acute ischaemic stroke (MonDAFIS): a randomised, open-label, multicentre study

BACKGROUND

Systematic electrocardiogram (ECG) monitoring improves detection of covert atrial fibrillation in stroke survivors but the effect on secondary prevention is unknown. We aimed to assess the effect of systematic ECG monitoring of patients in hospital on the rate of oral anticoagulant use after 12 months.

METHODS

In this investigator-initiated, randomised, open-label, parallel-group multicentre study with masked endpoint adjudication, we recruited patients aged at least 18 years with acute ischaemic stroke or transient ischaemic attack without known atrial fibrillation in 38 certified stroke units in Germany. Patients were randomly assigned (1:1) to usual diagnostic procedures for atrial fibrillation detection (control group) or additional Holter-ECG recording for up to 7 days in hospital (intervention group). Patients were stratified by centre using a random permuted block design. The primary outcome was the proportion of patients on oral anticoagulants at 12 months after the index event in the intention-to-treat population. Secondary outcomes included the number of patients with newly diagnosed atrial fibrillation in hospital and the composite of recurrent stroke, major bleeding, myocardial infarction, or death after 6 months, 12 months, and 24 months. This trial was registered with ClinicalTrials.gov, NCT02204267, and is completed and closed for participants.

FINDINGS

Between Dec 9, 2014, and Sept 11, 2017, 3465 patients were randomly assigned, 1735 (50·1%) to the intervention group and 1730 (49·9%) to the control group. Oral anticoagulation status was available in 2920 (84·3%) patients at 12 months (1484 [50·8%] in the intervention group and 1436 [49·2%] in the control group). For the primary outcome, at 12 months, 203 (13·7%) of 1484 patients in the intervention group versus 169 (11·8%) of 1436 in the control group were on oral anticoagulants (odds ratio [OR] 1·2 [95% CI 0·9-1·5]; p=0·13). Atrial fibrillation was newly detected in patients in hospital in 97 (5·8%) of 1714 in the intervention group versus 68 (4·0%) of 1717 in the control group (hazard ratio [HR] 1·4 [95% CI 1·0-2·0]; p=0·024). The composite of cardiovascular outcomes and death did not differ between patients randomly assigned to the intervention group versus the control group at 24 months (232 [13·5%] of 1714 vs 249 [14·5%] of 1717; HR 0·9 [0·8-1·1]; p=0·43). Skin reactions due to study ECG electrodes were reported in 56 (3·3%) patients in the intervention group. All-cause death occured in 73 (4·3%) patients in the intervention group and in 103 (6·0%) patients in the control group (OR 0·7 [0·5-0·9]).

INTERPRETATION

Systematic core centrally reviewed ECG monitoring is feasible and increases the detection rate of atrial fibrillation in unselected patients hospitalised with acute ischaemic stroke or transient ischaemic attack, if added to usual diagnostic care in certified German stroke units. However, we found no effect of systematic ECG monitoring on the rate of oral anticoagulant use after 12 months and further efforts are needed to improve secondary stroke prevention.

FUNDING

Bayer Vital.

TRANSLATION

For the German translation of the abstract see Supplementary Materials section.

High-Sensitivity Cardiac Troponin T and Recurrent Vascular Events After First Ischemic Stroke

Background Recent evidence suggests cardiac troponin levels to be a marker of increased vascular risk. We aimed to assess whether levels of high-sensitivity cardiac troponin T (hs-cTnT) are associated with recurrent vascular events and death in patients with first-ever, mild to moderate ischemic stroke. Methods and Results We used data from the PROSCIS-B (Prospective Cohort With Incident Stroke Berlin) study. We computed Cox proportional hazards regression analyses to assess the association between hs-cTnT levels upon study entry (Roche Elecsys, upper reference limit, 14 ng/L) and the primary outcome (composite of recurrent stroke, myocardial infarction, and all-cause death). A total of 562 patients were analyzed (mean age, 67 years [SD 13]; 38.6% women; median National Institutes of Health Stroke Scale=2; hs-cTnT above upper reference limit, 39.2%). During a mean follow-up of 3 years, the primary outcome occurred in 89 patients (15.8%), including 40 (7.1%) recurrent strokes, 4 (0.7%) myocardial infarctions, and 51 (9.1%) events of all-cause death. The primary outcome occurred more often in patients with hs-cTnT above the upper reference limit (27.3% versus 10.2%; adjusted hazard ratio, 2.0; 95% CI, 1.3-3.3), with a dose-response relationship when the highest and lowest hs-cTnT quartiles were compared (15.2 versus 1.8 events per 100 person-years; adjusted hazard ratio, 4.8; 95% CI, 1.9-11.8). This association remained consistent in sensitivity analyses, which included age matching and stratification for sex. Conclusions Hs-cTnT is dose-dependently associated with an increased risk of recurrent vascular events and death within 3 years after first-ever, mild to moderate ischemic stroke. These findings support further studies of the utility of hs-cTnT for individualized risk stratification after stroke. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT01363856.

Laboratory predictors of clinical outcomes in patients with atrial fibrillation

Atrial fibrillation (AF) is the most common cardiac arrhythmia in clinical practice that affects intracardiac hemodynamics and is accompanied by increased mortality due to the risk of stroke and systemic thromboembolism. In recent years, numerous studies, evaluating the use of biomarkers in AF patients, have been conducted to expand the possibility of stratification the complications risks.

The aim of the review is to evaluate the possible isolated and combined predictive significance of NT-proBNP, troponin T (TnT) and D-dimer levels in the development and progression of AF and its thromboembolic complications according to published data. Determining the level of NT-proBNP can be used to diagnose cardioembolic stroke in latent forms of AF. Patients with a cardioembolic stroke have been shown to have higher BNP/NT-proBNP levels than patients with an atherothrombotic stroke and venous thromboembolism. Elevated TnT level is independently associated with AF detection as a cause of stroke. The assessment on the CHADS2 scale significantly correlates with the level of troponin I (TnI). However, it is equally important to take into account TnI level even with a low score of CHADS2. Patients with the level of TnI ≥ 0.040 pg/L are considered to be prescribed anticoagulants in the same way as the patients with high CHADS2 score. Similar results were obtained analyzing high-sensitivity cardiac troponin T (hs-cTnT) data. The level of D-dimer 0.315 mg/L was determined to be the optimal limit level for predicting the adverse functional outcome of stroke owing to AF. Patients with a high level of D-dimer have shown a high risk of developing thromboembolic and cardiovascular complications despite their taking anticoagulant drugs. D-dimer levels positively correlate with the CHA2DS2 and CHA2DS2-VASC scales of stroke risk stratification. The analysis of the biomarkers combination has revealed the increase of hs-cTnT and BNP associated with stroke in AF patients (p<0.05). However, ABC scale, including hs-cTnT and NT- pro BNP, hasn't given more accurate result in stroke predicting than CHA2DS2-VASc scale. The integration of biomarkers in predicting the risk of AF occurrence, progression and appearance of thromboembolic complications is a promising direction. An isolated level of biomarkers (hs-cTnT, NT-proBNP, D-dimer) and their combination with clinical risk factors can improve the quality of cardioembolic strokes prognosis.

Trauma, a Matter of the Heart-Molecular Mechanism of Post-Traumatic Cardiac Dysfunction

Trauma remains a leading global cause of mortality, particularly in the young population. In the United States, approximately 30,000 patients with blunt cardiac trauma were recorded annually. Cardiac damage is a predictor for poor outcome after multiple trauma, with a poor prognosis and prolonged in-hospitalization. Systemic elevation of cardiac troponins was correlated with survival, injury severity score, and catecholamine consumption of patients after multiple trauma. The clinical features of the so-called "commotio cordis" are dysrhythmias, including ventricular fibrillation and sudden cardiac arrest as well as wall motion disorders. In trauma patients with inappropriate hypotension and inadequate response to fluid resuscitation, cardiac injury should be considered. Therefore, a combination of echocardiography (ECG) measurements, echocardiography, and systemic appearance of cardiomyocyte damage markers such as troponin appears to be an appropriate diagnostic approach to detect cardiac dysfunction after trauma. However, the mechanisms of post-traumatic cardiac dysfunction are still actively being investigated. This review aims to discuss cardiac damage following trauma, focusing on mechanisms of post-traumatic cardiac dysfunction associated with inflammation and complement activation. Herein, a causal relationship of cardiac dysfunction to traumatic brain injury, blunt chest trauma, multiple trauma, burn injury, psychosocial stress, fracture, and hemorrhagic shock are illustrated and therapeutic options are discussed.

Patterns of Infarction on MRI in Patients With Acute Ischemic Stroke and Cardio-Embolism: A Systematic Review and Meta-Analysis

Background: Cardioembolic strokes are common however atrial fibrillation, the most common cause, is often asymptomatic and difficult to detect. There is evidence that infarct topography and volume on magnetic resonance imaging may be associated with specific stroke etiologies.

Aim: A systematic review and meta-analysis were undertaken to summarize the available evidence on the association between stroke etiology, infarct topography, and volume.

Methods: A systematic review was conducted using Medline (OVID), Embase (OVID), and PubMed databases. Hand searches of the gray literature and of reference lists in relevant articles were also performed. A quality assessment was undertaken, based on the STROBE checklist. For each study, the number of patients with and without a CE source of stroke and infarct topography was collected and outcomes presented as odds ratios (OR) with 95% CI and p-values.

Results: Four thousand eight hundred and seventy-three patients with ischemic stroke were included, of whom 1,559 were determined to have a CE source. Bilateral infarcts (OR 3.41; 95% CI 2.20–5.29; p < 0.0001) and multiple territory infarcts (OR 1.57; 95% CI 1.12–2.21; p = 0.009) were more common in patients with a CE source of stroke, than patients without a CE source. Lacunar infarcts (OR 0.49; 95% CI 0.31–0.80; p = 0.004) were more likely to occur in patients without a CE source. No significant difference between the frequency of multiple infarcts (OR 0.96; 95% CI 0.57–1.61; p = 0.87) anterior circulation (OR 1.45; 95% CI 0.83–2.53; p = 0.19) or posterior circulation infarcts (OR 1.06; 95% CI 0.72–1.57; p = 0.75), between the two groups were identified. Three out of four studies examining volume, found a significant association between increased infarct volume and CE source of stroke. A sensitivity analysis with cryptogenic and undetermined stroke sources assumed to be cardioembolic, did not alter the associations observed.

Conclusion: The findings of this systematic review and meta-analysis are broadly consistent with previous literature and provide more robust evidence on the association between infarct topography, volume and stroke etiology. Our findings may assist with refining cardiac investigations for patients with cryptogenic stroke, based on infarct topography.

High-Sensitivity Cardiac Troponin T for Risk Stratification in Patients With Embolic Stroke of Undetermined Source

Background and Purpose:

Optimal secondary prevention for patients with embolic stroke of undetermined source (ESUS) remains unknown. We aimed to assess whether high-sensitivity cardiac troponin T (hs-cTnT) levels are associated with major vascular events and whether hs-cTnT may identify patients who benefit from anticoagulation following ESUS.

Methods:

Data were obtained from the biomarker substudy of the NAVIGATE ESUS trial, a randomized controlled trial testing the efficacy of rivaroxaban versus aspirin for secondary stroke prevention in ESUS. Patients were dichotomized at the hs-cTnT upper reference limit (14 ng/L, Gen V, Roche Diagnostics). Cox proportional hazard models were computed to explore the association between hs-cTnT, the combined cardiovascular end point (recurrent stroke, myocardial infarction, systemic embolism, cardiovascular death), and recurrent ischemic stroke.

Results:

Among 1337 patients enrolled at 111 participating centers in 18 countries (mean age 67±9 years, 61% male), hs-cTnT was detectable in 95% and at/above the upper reference limit in 21%. During a median follow-up of 11 months, the combined cardiovascular end point occurred in 68 patients (5.0%/y, rivaroxaban 28 events, aspirin 40 events; hazard ratio, 0.67 [95% CI, 0.41–1.1]), and recurrent ischemic stroke occurred in 50 patients (4.0%/y, rivaroxaban 16 events, aspirin 34 events, hazard ratio 0.45 [95% CI, 0.25–0.81]). Annualized combined cardiovascular end point rates were 8.2% (9.5% rivaroxaban, 7.0% aspirin) for those above hs-cTnT upper reference limit and 4.8% (3.1% rivaroxaban, 6.6% aspirin) below with a significant treatment modification ( P =0.04). Annualized ischemic stroke rates were 4.7% above hs-cTnT upper reference limit and 3.9% below, with no suggestion of an interaction between hs-cTnT and treatment ( P =0.3).

Conclusions:

In patients with ESUS, hs-cTnT was associated with increased cardiovascular event rates. While fewer recurrent strokes occurred in patients receiving rivaroxaban, outcomes were not stratified by hs-cTn results. Our findings support using hs-cTnT for cardiovascular risk stratification but not for decision-making regarding anticoagulation therapy in patients with ESUS.

Registration:

URL: https://www.clinicaltrials.gov . Unique identifier: NCT02313909.

Exploring the causal pathway from ischemic stroke to atrial fibrillation: a network Mendelian randomization study

BACKGROUND AND PURPOSE

Previous studies have found ischemic stroke is associated with atrial fibrillation. However, the causal association between ischemic stroke and atrial fibrillation is not clear. Furthermore, the network relationship among ischemic stroke, atrial fibrillation and its risk factors need further attention. This study aims to examine the potential causal association between ischemic stroke and atrial fibrillation and further to explore potential mediators in the causal pathway from ischemic stroke to atrial fibrillation.

METHODS

Summary statistics from the ISGC (case = 10,307 and control = 19,326) were used as ischemic stroke genetic instruments, AFGen Consortium data (case = 65,446 and control = 522,744) were used for atrial fibrillation, and other consortia data were used for potential mediators (fasting insulin, white blood cell count, procalcitonin, systolic and diastolic blood pressure, body mass index, waist circumference, and height). Under the framework of network Mendelian randomization, two-sample Mendelian randomization study was performed using summary statistics from several genome-wide association studies. Inverse-variance weighted method was performed to estimate causal effect.

RESULTS

Blood pressure mediates the causal pathways from ischemic stroke to atrial fibrillation. The total odds ratio of ischemic stroke on atrial fibrillation was 1.05 (95% confidence interval [CI], 1.02 to 1.07; P = 1.3 × 10-5). One-unit increase of genetically determined ischemic stroke was associated with 0.02 (DBP: 95% CI, 0.001 to 0.034, P = 0.029; SBP: 95% CI, 0.006 to 0.034, P = 0.003) upper systolic and diastolic blood pressure levels. Higher genetically determined systolic and diastolic blood pressure levels were associated with higher atrial fibrillation risk (DBP: RR, 1.18; 95% CI, 1.03 to 1.35; P = 0.012. SBP: RR, 1.18; 95% CI, 1.01 to 1.38; P = 0.04). Specially, we also found the bidirectional causality between blood pressure and ischemic stroke.

CONCLUSIONS

Our study provided a strong evidence that raised blood pressure in stroke patients increases the risk of atrial fibrillation and active acute blood pressure lowering can improve the outcome in ischemic stroke patients.

Atrial Fibrillation Known Before or Detected After Stroke Share Similar Risk of Ischemic Stroke Recurrence and Death

Background and Purpose- We aim to compare the risk of 1-year ischemic stroke recurrence and death for atrial fibrillation diagnosed after stroke (AFDAS), atrial fibrillation known before stroke (KAF), and sinus rhythm (SR). Methods- From June 2012 to January 2013, 19 604 patients with acute ischemic stroke were admitted to 219 urban hospitals in the China National Stroke Registry II. Based on heart rhythm assessed during admission, we classified patients as AFDAS, KAF, or SR. We explored the relationship between heart rhythm groups and 1-year ischemic stroke recurrence or death by using Cox regression adjusted for multiple covariates. Considering that death is a competing risk for stroke recurrence, we used the competing risks analysis of Fine and Gray and subdistribution Cox proportional hazards to test the association between heart rhythm and 1-year outcomes. Results- Among 19 604 ischemic stroke patients, 17 727 had SR, 495 AFDAS, and 1382 KAF. At 1 year, 54 (10.9%) patients with AFDAS, 182 (13.2%) with KAF, and 1008 (5.7%) with SR had recurrent ischemic strokes ( P<0.0001). Mortality was 22.0% in patients with AFDAS, 22.1% in patients with KAF, and 7.0% in patients with SR ( P<0.0001). AFDAS-related ischemic stroke recurrence adjusted risk was higher than that of SR (adjusted subdistribution hazard ratios, 1.61; 95% CI, 1.29-2.01) but not different from that of KAF (adjusted subdistribution hazard ratio, 1.12; 95% CI, 0.87-1.45]). The adjusted risk of 1-year death for AFDAS was also higher than that of SR (hazard ratio, 1.70; 95% CI, 1.37-2.12) and not different from that of KAF (hazard ratio, 1.10; 95% CI, 0.86-1.41). Conclusions- This study showed that AFDAS had similar risk of 1-year ischemic stroke recurrence and mortality when compared with KAF and higher risk when compared with SR. The potential risk of AFDAS should be given more emphasis, and appropriate treatment is needed to achieve reduction in the incidence of stroke recurrence and mortality.

Association of Serum Troponin Obtained During Stroke Codes with Cardioembolic Strokes

BACKGROUND

Troponin is a marker of cardiac ischemia and is elevated in about 30% of stroke patients. We investigated if the elevation of troponin during an acute stroke code is associated with a cardioembolic source.

METHODS

We performed a retrospective chart review of patients evaluated for acute strokes from July 2014 to March 2018. Patients included in the study were all given intravenous alteplase, had blood drawn for troponins during the acute stroke code and had confirmation of a new stroke on neuroimaging during hospitalization. Patients who were on dialysis or had a glomerular filtration rate of less than or equal to 40 ml/minutes on initial laboratory evaluation were excluded. Stroke etiology was classified into noncardioembolic (NCE) and cardioembolic (CE), according to Trial of Org 10172 in Acute Stroke Treatment criteria. The NCE group was compared with the CE group with respect to troponin levels. Troponin was considered as a dichotomous categorical variable, with a cut-off point at greater than or equal to.05 ng/ml.

RESULTS

144 patients met the inclusion criteria. In our cohort, 40.74% of patients in the CE group had troponin levels of greater than or equal to .05 ng/mL compared to 12.22% in NCE group. A troponin level of greater than or equal to.05 ng/ml obtained during a stroke code showed a significant difference between cardioembolic and noncardioembolic strokes (OR, 4.94; 95% CI, 2.15-11.35; P < .001), with high specificity (87.78%) but low sensitivity (40.74%) to exclude noncardioembolic stroke.

CONCLUSIONS

A troponin level of greater than or equal to .05 ng/ml obtained during a stroke code showed a significant difference between CE and NCE strokes. This finding may have implications for clinical workup, and patients with admission troponin levels of greater than or equal to .05 ng/mL may need further clinical investigations to look for a cardioembolic source. A troponin level of greater than or equal to .05 ng/ml may prompt a more thorough search for a cardioembolic source in cases in which such a source is not identified on initial evaluation.

Troponin T Predicts Cardioembolic Aetiology and Clinical Outcome in Undetermined Ischaemic Stroke in Hyperacute Phase

BACKGROUND

Elevated high-sensitivity cardiac troponin T (hs-cTnT) levels have been related to clinical outcome in stroke patients. However, the role of hs-cTnT and its potential as a biomarker in ischaemic stroke (IS) has not been well established. This study aims to determine whether basal hs-cTnT determination in the hyperacute phase of undetermined IS and transient ischaemic attack (TIA) can predict the cardioembolic aetiology and clinical outcome.

METHODS

We prospectively studied 110 consecutive patients with undetermined acute IS and TIA. hs-cTnT levels were determined at hospital arrival. Large vessel stenosis/occlusion and previously known aetiologies at admission were exclusion criteria for this study. All patients were subjected to a complete aetiological evaluation. A 12-month follow-up was performed in all patients. The subtype of IS was evaluated following the SSS-TOAST criteria. We established two groups at admission: cardioembolic aetiology (group A) and noncardioembolic aetiologies (group B).

RESULTS

The number of patients in each group was similar (group A: 52, 47.27%; group B, 58, 52.73%). Patients in group A had elevated hs-cTnT more frequently (61.54% versus 17.24%; P < .001). Group A patients had significantly higher mortality at 3 months (14.29% versus 1.82%, P = .025). In the multivariate analysis, elevated hs-cTnT was the only independent predictor of cardioembolic aetiology (odds ratio: 14.821; 95% confidence interval: 3.717-59.102, P < .001).

CONCLUSION

Baseline hs-cTnT assessment in undetermined strokes and TIA during the hyperacute phase is independently associated with cardioembolic aetiology.

Insula stroke: the weird and the worrisome

Infarction of the insula is a common scenario with large tissue-volume strokes in the middle cerebral artery territory. Considered to be part of the central autonomic network, infarction of this region is associated with autonomic disturbances, in particular cardiovascular dysregulation. Risk of aspiration following stroke is also associated with involvement of the insula, consistent with its purported participation in complex functions of the mouth and pharynx. Strokes restricted to the insula are rare and present with a broad range of symptoms that offer a window of insight into the diverse functionality of the insular cortex. Chemosensory, autonomic, vestibular, auditory, somatosensory, language and oropharyngeal functional deficits are all recognised, among others. Long-term sequelae are unknown but profound symptoms, such as hemiparesis, are usually transient. Understanding the patterns of dysfunction highlighted provides the basis for future strategies to optimise stroke management on the discovery of insula involvement.

Atrial fibrillation and stroke: a practical guide

Neurologists and stroke physicians will be familiar with atrial fibrillation as a major cause of ischaemic stroke, and the role of anticoagulation in preventing cardioembolic stroke. However, making decisions about anticoagulation for individual patients remains a difficult area of clinical practice, balancing the serious risk of ischaemic stroke against that of major bleeding, particularly intracranial haemorrhage. Atrial fibrillation management requires interdisciplinary collaboration with colleagues in cardiology and haematology. Recent advances, especially the now-widespread availability of direct oral anticoagulants, have brought opportunities to improve stroke care while posing new challenges. This article gives an overview of the contemporary diagnosis and management of atrial fibrillation, and the associated evidence base. Where there is uncertainty, we describe our own approach to these areas, while highlighting ongoing research that will likely guide future practice.

[A role of the autonomic nervous system in cerebro-cardiac disorders]

The authors consider anatomical/physiological characteristics and a role of different autonomic CNS regions, including insula cortex, amygdala complex, anterior cingulate cortex, ventral medial prefrontal cortex, hypothalamus and epiphysis, involved in the regulation of cardiovascular activity. The damage of these structures, e.g., due to the acute disturbance of cerebral blood circulation, led to arrhythmia, including fatal arrhythmia, in previously intact myocardium; systolic and diastolic dysfunction, ischemic changes considered in the frames of cerebro-cardial syndrome. On the cellular level, the disturbance of autonomic regulation resulted in catechol amine excitotoxicity, oxidative stress and free radical myocardium injury.

Occult paroxysmal atrial fibrillation in non-cryptogenic ischemic stroke

OBJECTIVE

To determine the prevalence and risk factors for paroxysmal atrial fibrillation (PAF) diagnosis in non- cryptogenic ischemic stroke (CIS) patients.

METHODS

In this pilot-prospective cohort study of non-CIS patients from September 2014 to September 2017, 53 patients were enrolled. 51/53 patients were implanted within 10 days of stroke onset with the Reveal LINQ insertable cardiac monitor and monitored until PAF detection or a minimum of 12 months. Inclusion required diagnosis of a non-AF stroke etiology, age ≥ 40, and either a virtual CHADS₂ score ≥ 3 or ≥ 2 PAF-related comorbidities.

RESULTS

Over a median monitoring period of 398 days, PAF was detected in 6/51 (11.8%) patients and anticoagulation was initiated in 5/6 (83.3%). Median time to PAF detection was 87 days (range 0-356 days). Median longest PAF episode was 96 min (range 1 to 1122 min), and 4/6 had multiple PAF recordings. Mean left atrial volume index was significantly higher in PAF patients (31.0 vs. 23.2 cc/m²; p = 0.04).

CONCLUSION

Long-term monitoring of non-CIS patients detected PAF in a clinically relevant proportion of patients, resulting in stroke prevention therapy optimization. Further study to confirm these findings and refine the subset that would benefit from long-term cardiac monitoring is warranted.

Prognostic Significance of Infarct Size and Location: The Case of Insular Stroke

The prognostic relevance of strokes in different locations is debated. For example, insular strokes have been associated with increased mortality, but this association could reflect their greater severity. In two independent cohorts of patients with supratentorial ischemic stroke (n = 90 and 105), we studied the prognostic consequences of lesion size and location using voxel-based lesion-symptom mapping before and after volume control, which better accounts for total lesion volume. Strokes affecting the insula were larger than non-insular strokes (28 vs 2cc and 25 vs 3cc, p < 0.001 in both cohorts). A number of supratentorial areas (mainly in the left hemisphere), including the insula, were associated with poor functional outcome in both cohorts before (4014 voxels) and after volume control (1378 voxels), while the associations with death were greatly reduced after volume control (from 8716 to 325 voxels). Exploratory analyses suggested that the method of lesion volume quantification, the National Institutes of Health Stroke Scale hemispheric bias and patient selection can result in false associations between specific brain lesions and outcomes. In conclusion, death in the first months after stroke is mainly explained by large infarct volumes, whereas lesions of specific supratentorial structures, mostly in the left hemisphere, also contribute to poor functional outcomes.

Contribution of routine cardiac biological markers to the etiological workup of ischemic stroke

BACKGROUND

Optimization of the detection of atrial fibrillation following stroke is mandatory. Unfortunately, access to long-term cardiac monitoring is limited in many centers. The aim of this study was to assess the potential usefulness of three routine biological markers, troponin, D-dimers and BNP, measured in acute stroke phase in the selection of patients at risk of cardio-embolic stroke.

METHODS

Troponin, D-Dimers and BNP were measured within 48 h after admission for ischemic stroke in 634 patients. Stroke mechanism was defined at the 3 months follow-up visit using ASCOD classification using a standardized work-up. Association between clinical, radiological and biological markers and stroke mechanism was evaluated using logistic regression analyses.

RESULTS

159 patients (25.1% of total study population) had a cardiac mechanism. On multivariate analysis, admission initial stroke severity (OR 1.04, 95 CI% 1.004-1.07, p < 0.05) history of heart failure (OR 3.03, 95% CI 1.19-7.73, p < 0.05), ECG abnormalities and high BNP value (OR 4.34, 95% CI 2.59-7.29, p < 0.05) were associated with pure cardiac stroke mechanism.

CONCLUSION

High BNP value measured within 48 h after stroke admission is an independent predictor of cardiac stroke mechanism. Its measurement might be used to improve the selection of patients for whom further cardiologic investigations such as continuous long term ECG monitoring would be the most useful. BNP should be added to the standard admission-work-up for stroke patients.

Expert opinion paper on atrial fibrillation detection after ischemic stroke

This expert opinion paper on atrial fibrillation detection after ischemic stroke includes a statement of the "Heart and Brain" consortium of the German Cardiac Society and the German Stroke Society. This paper was endorsed by the Stroke Unit-Commission of the German Stroke Society and the German Atrial Fibrillation NETwork. In patients with ischemic stroke, detection of atrial fibrillation should usually lead to a change in secondary stroke prevention, since oral anticoagulation is superior to antiplatelet drugs. The detection of previously undiagnosed atrial fibrillation can be improved in patients with ischemic stroke to optimize stroke prevention. This paper summarizes the present knowledge on atrial fibrillation detection after ischemic stroke. We propose an interdisciplinary standard for a "structured analysis of ECG monitoring" on the stroke unit as well as a staged diagnostic scheme for the detection of atrial fibrillation. Since the optimal duration and mode of ECG monitoring has not yet been finally established, this paper is intended to give advice to physicians who are involved in stroke care. In line with the nature of an expert opinion paper, labeling of classes of recommendations is not provided, since many statements are based on the expert opinion, reported case series and clinical experience. Therefore, this paper is not intended as a guideline.

Autonomic Nervous System and Stress to Predict Secondary Ischemic Events after Transient Ischemic Attack or Minor Stroke: Possible Implications of Heart Rate Variability

Transient ischemic attack (TIA) and minor stroke have high risks of recurrence and deterioration into severe ischemic strokes. Risk stratification of TIA and minor stroke is essential for early effective treatment. Traditional tools have only moderate predictive value, likely due to their inclusion of the limited number of stroke risk factors. Our review follows Hans Selye’s fundamental work on stress theory and the progressive shift of the autonomic nervous system (ANS) from adaptation to disease when stress becomes chronic. We will first show that traditional risk factors and acute triggers of ischemic stroke are chronic and acute stress factors or “stressors,” respectively. Our first review shows solid evidence of the relationship between chronic stress and stroke occurrence. The stress response is tightly regulated by the ANS whose function can be assessed with heart rate variability (HRV). Our second review demonstrates that stress-related risk factors of ischemic stroke are correlated with ANS dysfunction and impaired HRV. Our conclusions support the idea that HRV parameters may represent the combined effects of all body stressors that are risk factors for ischemic stroke and, thus, may be of important predictive value for the risk of subsequent ischemic events after TIA or minor stroke.

Atrial fibrillation detected after stroke is related to a low risk of ischemic stroke recurrence

Objective

To compare the risk of 1-year ischemic stroke recurrence between atrial fibrillation (AF) diagnosed after stroke (AFDAS) and sinus rhythm (SR) and investigate whether underlying heart disease is as frequent in AFDAS as it is in AF known before stroke (KAF).

Methods

In this retrospective cohort study, we included all ischemic stroke patients admitted to institutions participating in the Ontario Stroke Registry from July 1, 2003, to March 31, 2013. Based on heart rhythm assessed during admission, we classified patients as AFDAS, KAF, or SR. We modeled the relationship between heart rhythm groups and 1-year ischemic stroke recurrence by using Cox regression adjusted for multiple covariates (e.g., oral anticoagulants). We compared the prevalence of coronary artery disease, myocardial infarction, and heart failure among the 3 groups.

Results

Among 23,376 ischemic stroke patients, 15,885 had SR, 587 AFDAS, and 6,904 KAF. At 1 year, 39 (6.6%) patients with AFDAS, 661 (9.6%) with KAF, and 1,269 (8.0%) with SR had recurrent ischemic strokes (p = 0.0001). AFDAS-related ischemic stroke recurrence adjusted risk was not different from that of SR (hazard ratio 0.90 [95% confidence interval 0.63, 1.30]; p = 0.57). Prevalence of coronary artery disease (18.2% vs 34.7%; p < 0.0001), myocardial infarction (11.6% vs 20.5%; p < 0.0001), and heart failure (5.5% vs 16.8%; p < 0.0001) were lower in AFDAS relative to KAF.

Conclusions

The lack of difference in 1-year ischemic stroke recurrence between AFDAS and SR and the lower prevalence of heart disease in AFDAS compared to KAF suggest that the underlying pathophysiology of AFDAS may differ from that of KAF.

The complexity of atrial fibrillation newly diagnosed after ischemic stroke and transient ischemic attack: advances and uncertainties

Purpose of review

Atrial fibrillation is being increasingly diagnosed after ischemic stroke and transient ischemic attack (TIA). Patient characteristics, frequency and duration of paroxysms, and the risk of recurrent ischemic stroke associated with atrial fibrillation detected after stroke and TIA (AFDAS) may differ from atrial fibrillation already known before stroke occurrence. We aim to summarize major recent advances in the field, in the context of prior evidence, and to identify areas of uncertainty to be addressed in future research.

Recent findings

Half of all atrial fibrillations in ischemic stroke and TIA patients are AFDAS, and most of them are asymptomatic. Over 50% of AFDAS paroxysms last less than 30 s. The rapid initiation of cardiac monitoring and its duration are crucial for its timely and effective detection. AFDAS comprises a heterogeneous mix of atrial fibrillation, possibly including cardiogenic and neurogenic types, and a mix of both. Over 25 single markers and at least 10 scores have been proposed as predictors of AFDAS. However, there are considerable inconsistencies across studies. The role of AFDAS burden and its associated risk of stroke recurrence have not yet been investigated.

Summary

AFDAS may differ from atrial fibrillation known before stroke in several clinical dimensions, which are important for optimal patient care strategies. Many questions remain unanswered. Neurogenic and cardiogenic AFDAS need to be characterized, as it may be possible to avoid some neurogenic cases by initiating timely preventive treatments. AFDAS burden may differ in ischemic stroke and TIA patients, with distinctive diagnostic and treatment implications. The prognosis of AFDAS and its risk of recurrent stroke are still unknown; therefore, it is uncertain whether AFDAS patients should be treated with oral anticoagulants.

Early Elevated Troponin Levels After Ischemic Stroke Suggests a Cardioembolic Source

Background and Purpose—

Elevated cardiac troponin is a marker of cardiac disease and has been recently shown to be associated with embolic stroke risk. We hypothesize that early elevated troponin levels in the acute stroke setting are more prevalent in patients with embolic stroke subtypes (cardioembolic and embolic stroke of unknown source) as opposed to noncardioembolic subtypes (large-vessel disease, small-vessel disease, and other).

Methods—

We abstracted data from our prospective ischemic stroke database and included all patients with ischemic stroke during an 18-month period. Per our laboratory, we defined positive troponin as ≥0.1 ng/mL and intermediate as ≥0.06 ng/mL and <0.1 ng/mL. Unadjusted and adjusted regression models were built to determine the association between stroke subtype (embolic stroke of unknown source and cardioembolic subtypes) and positive and intermediate troponin levels, adjusting for key confounders, including demographics (age and sex), clinical characteristics (hypertension, hyperlipidemia, diabetes mellitus, renal function, coronary heart disease, congestive heart failure, current smoking, and National Institutes of Health Stroke Scale score), cardiac variables (left atrial diameter, wall-motion abnormalities, ejection fraction, and PR interval on ECG), and insular involvement of infarct.

Results—

We identified 1234 patients, of whom 1129 had admission troponin levels available; 10.0% (113/1129) of these had a positive troponin. In fully adjusted models, there was an association between troponin positivity and embolic stroke of unknown source subtype (adjusted odds ratio, 4.46; 95% confidence interval, 1.03–7.97; P =0.003) and cardioembolic stroke subtype (odds ratio, 5.00; 95% confidence interval, 1.83–13.63; P =0.002).

Conclusions—

We found that early positive troponin after ischemic stroke may be independently associated with a cardiac embolic source. Future studies are needed to confirm our findings using high-sensitivity troponin assays and to test optimal secondary prevention strategies in patients with embolic stroke of unknown source and positive troponin.

Prevalence and Risk Factors for Paroxysmal Atrial Fibrillation and Flutter Detection after Cryptogenic Ischemic Stroke

INTRODUCTION

Long-term cardiac monitoring with implantable loop recorders (ILRs) has revealed occult paroxysmal atrial fibrillation and flutter (PAF) in a substantial minority of cryptogenic ischemic stroke (CIS) patients. Herein, we aim to define the prevalence, clinical relevance, and risk factors for PAF detection following early poststroke ILR implantation.

MATERIALS AND METHODS

A retrospective study of CIS patients (n = 100, mean age 65.8 years; 52.5% female) who underwent ILR insertion during, or soon after, index stroke admission. Patients were prospectively followed by the study cardiac electrophysiologist who confirmed the PAF diagnosis. Univariate and multivariate analyses compared clinical, laboratory, cardiac, and imaging variables between PAF patients and non-PAF patients.

RESULTS

PAF was detected in 31 of 100 (31%) CIS patients, and anticoagulation was initiated in almost all (30 of 31, 96.8%). Factors associated with PAF detection include older age (mean [year] 72.9 versus 62.9; P = .003), white race (odds ratio [OR], 4.5; confidence interval [CI], 1.8-10.8; P = .001), prolonged PR interval (PR > 175 ms; OR, 3.3; CI, 1.2-9.4; P = .022), larger left atrial (LA) diameter (mean [cm] 3.7 versus 3.5; P = .044) and LA volume index (mean [cc/m²]; 30.6 versus 24.2; P = .014), and lower hemoglobin (Hb)A1c (mean [%] 6.0 versus 6.4; P = .036). Controlling for age, obesity (body mass index > 30 kg/m²; OR, 1.2; CI, 1.1-1.4; P = .033) was independently associated with PAF detection.

DISCUSSION

PAF was detected with high prevalence following early postcryptogenic stroke ILR implantation and resulted in significant management changes. Older age, increased PR interval, LA enlargement, and lower HbA1c are significantly associated with PAF detection. Controlling for age, obesity is an independent risk factor. A larger prospective study is warranted to confirm these findings.

Atrial cardiopathy: a mechanism of cryptogenic stroke

INTRODUCTION

Cryptogenic stroke accounts for approximately 30% of all ischemic strokes. Recently, atrial cardiopathy diagnosed by the presence of one of its serum, imaging, or electrocardiogram biomarkers has been shown to be associated with ischemic stroke, particularly of embolic subtypes. Areas covered: This paper aims to summarize data on occult atrial fibrillation and stroke, provide an overview on mechanisms, such as inflammation and fibrosis, of stroke in atrial cardiopathy, critically review data on biomarkers of atrial cardiopathy and their association with stroke, and suggest therapeutic implications, including directions for future research. Expert commentary: Atrial cardiopathy may constitute one of the mechanisms in cryptogenic stroke, and patients with evidence of atrial cardiopathy constitute a group of patients in whom clinical trials are warranted to test anticoagulation versus antiplatelet therapy to reduce stroke recurrence risk. In addition, more studies are needed to determine the degree of overlap between these atrial cardiopathy biomarkers and which one is more useful in predicting the risk of stroke and response to anticoagulation therapy.