Transthoracic echocardiography to rule out paroxysmal atrial fibrillation as a cause of stroke or transient ischemic attack

Low blood flow velocity in the left atrial appendage in sinus rhythm as a predictor of atrial fibrillation: results of a prospective cohort study with 3 years of follow-up

BACKGROUND

Atrial fibrillation (AF) is a common cause of cardioembolic stroke and can lead to severe and recurrent cerebrovascular events. Thus, identifying patients suffering from cardioembolic events caused by undetected AF is crucial. Previously, we found an association between increasing stroke severity and a decreasing left atrial appendage (LAA) blood flow velocity below 60 cm/s.

METHODS

This was a prospective single-center cohort study including hospitalized patients who underwent a transesophageal echocardiography (TEE) in sinus rhythm. The participants were divided into two groups (≥ 60 cm/s;<60 cm/s) based on their maximum LAA blood flow velocity. The results of the cardiovascular risk assessment and 24- to 72-hour ECG Holter were recorded. Follow-up appointments were scheduled at 3, 6, 12, 24 and 36 months. The primary endpoint was new-onset AF. The statistics included a Cox-proportional-hazard-model and a binary logistic regression. Numerical data or categorical data were analyzed with the Mann-Whitney U test or chi-square test.

RESULTS

A total of 166 patients were recruited. The median LAA blood flow velocity was 64 cm/s. New-onset AF was diagnosed in 22.9% of the patients. An LAA blood flow velocity ≤ 60 cm/s was associated with a threefold increased risk of new-onset AF (35.8% vs. 11.5%; HR3.56; CI95%1.70-7.46; p < 0.001), independently according to a multivariate analysis (p = 0.035). Furthermore, a decreasing LAA blood flow velocity was associated with an increased risk of new-onset AF (OR1.043; CI95%1.021-1.069; p < 0.001).

CONCLUSION

A low LAA blood flow velocity (≤ 60 cm/s) in sinus rhythm is prospectively associated with an increased risk of new-onset AF. Additional simple LAA-TEE examinations could help to identify patients who benefit from more accurate cardiac rhythm monitoring.

Swiss Stroke Society position paper on atrial fibrillation monitoring and management after ischaemic stroke: a shift from understanding the index stroke to preventing the next one

This position paper on the detection of atrial fibrillation after ischaemic stroke is a statement of the "Heart and Brain" committee of the Swiss Stroke Society. This position paper summarises present knowledge on the detection of atrial fibrillation after ischaemic stroke or transient ischaemic attack. An interdisciplinary standard for monitoring on the stroke unit and after discharge is proposed respecting recent developments and Swiss particularities. The main evolution in the field is that the role of atrial fibrillation screening after stroke or transient ischaemic attack has shifted from understanding the index stroke to preventing the next stroke; it therefore should also be performed in patients with certain other stroke aetiologies, e.g. symptomatic carotid artery stenosis. The duration of atrial fibrillation monitoring should be based on an individualised risk assessment incorporating clinical characteristics as well as cardiac and laboratory biomarkers. Given the paucity of randomised controlled data on this topic, this position paper intends to give practical advice to healthcare professionals involved in stroke care in Switzerland based on a consensus between experts in the field.

Non-invasive prediction of atrial cardiomyopathy characterized by multipolar high-density contact mapping

INTRODUCTION

Atrial cardiomyopathy (AC) establishes links between atrial fibrillation (AF), left atrial (LA) mechanical dysfunction, structural remodeling, and thromboembolic events. Early diagnosis of AC may impact AF treatment and stroke risk prevention. Modern endocardial contact-mapping provides high-resolution electro-anatomical (EA) maps of the LA, thus allowing to display the myocardial substrate based on impaired signal amplitude and to characterize AC. Correlation of invasively assessed AC using a novel, multipolar mapping catheter (OCTARAY™, Biosense Webster, limited market release) and LA echocardiographic parameters could form the basis for a set of echo parameters for non-invasive prediction of AC.

METHODS

We retrospectively identified 50 adult patients who underwent primary pulmonary vein isolation (PVI) for paroxysmal or persistent AF between 08/22 and 05/23 fulfilling the selection criteria: (i) EA mapping with a novel multipolar mapping catheter (Octaray®); (ii) acquisition of voltage maps in sinus rhythm (SR) with ≥ 5000 points/map; and (iii) transthoracic echocardiography acquired in SR ≤ 48 h before PVI. Exclusion criterion was previous LA ablation. We generated EA maps with two sets of upper voltage thresholds (0.2-0.5 mV and 0.2-1.0 mV) and assessed total LA low voltage area (LVA). As LVA thresholds for the classification of AC are not yet established, an unsupervised machine learning cluster analysis was performed using a Gaussian mixture model (GMM), and two groups of patients with mild and severe AC were identified. Based on these two groups, we selected echo parameters for further analysis by applying the Boruta algorithm. The predictive capacity of the selected parameters was evaluated using a support vector machine.

RESULTS

The mean age of the studied sample (n = 50) was 63 ± 11 years, 62% were men, 64% showed persistent AF, median CHA2DS2-VASc score was 2 (quartiles 1, 3), and NT-proBNP was 190 (71, 391) pg/ml. A median of 5771 (5217, 6988) points/map were acquired. GMM yielded clusters of mild AC (n = 28) and severe AC (n = 22). Median LVA was 0.6 cm2 (< 0.5 mV) resp. 4.1 cm2 (< 1.0 mV) in group mild AC and 6.9 cm2 (< 0.5 mV) resp. 27.2 cm2 (< 1.0 mV) in group severe AC. Several echocardiographic parameters differed between the groups of mild and severe AC: dynamic LA parameters (end diastolic LA reservoir strain: 24.5% (22, 29) vs 15% (12, 19), p < 0.001; LA reservoir strain at atrial contraction: 22% (19, 25) vs 15% (11, 18), p < 0.001, end diastolic LA contraction strain: 13% (8, 15) vs 7.5% (3, 13), p < 0.01) as well as LA end-systolic volume index to a´ ratio (LAVI/a': 297 (231,365) vs 510 (326,781), p < 0.01). Consistent distribution of NT-proBNP (mild AC: 125 (48,189) pg/ml, severe AC: 408 (254,557) pg/ml, p < 0.0001) and CHA2DS2-VASc score (mild AC: 1 (1-2), severe AC: 3 (3-4), p < 0.0001) served as proof of concept. Applying the selected echocardiographic parameters, the machine learning algorithm correctly identified both subgroups with a mean AUC of 0.9 (95% CI 0.83-0.99). At 12 months, AF recurrence rate was 10.7% in mild AC and 40.9% in severe AC (p < 0.05).

CONCLUSION

Among patients qualifying for PVI, machine learning analysis of high-resolution LA maps allowed to identify subgroups with mild and severe AC avoiding the use of arbitrary LVA thresholds. The subgroups were predicted non-invasively with good accuracy using a machine learning approach that incorporated a set of echocardiographic markers. This data could advance the clinical triage of patients with AF.

Left Atrial Function and Incident Heart Failure in Older Adults

BACKGROUND

Heart failure (HF) prevalence is increasing, especially among older adults. Left atrial (LA) dysfunction is often associated with HF, but it is unclear whether it may contribute to its development. We investigated whether measures of LA function can predict the development of HF in older adults without a history of cardiovascular events.

METHODS AND RESULTS

Seven hundred ninety-five participants from a triethnic (white, Black, Hispanic) community-based cohort of adults age ≥55 without a history of cardiovascular events underwent standard, three-dimensional, and speckle-tracking echocardiography. Left atrial volumes, LA strain, LA stiffness, and LA coupling index (LACI) were measured. Longitudinal follow-up was conducted, and new-onset HF was ascertained through standardized interviews, in-person visits, and active hospital surveillance of admission and discharge ICD-9 codes. Risk analysis with a cause-specific hazards regression model was used to assess the association of LA variables with incident HF, adjusting for other HF risk factors. The mean age was 70.9 ± 9.2 years (297 men, 498 women). During a mean follow-up of 11.4 years, new-onset HF occurred in 345 participants (43.4%). All measures of LA morphology and function were associated with incident HF (all P < .05). In multivariable analysis, LA stiffness and LACI (adjusted hazard ratio = 2.06; 95% CI, 1.08-3.94; adjusted hazard ratio = 1.25; 95% CI, 1.09-1.43, respectively) remained associated with incident HF. After further adjustment for left ventricular global longitudinal strain, only LACI remained associated with incident HF (adjusted hazard ratio = 1.22; 95% CI, 1.05-1.42).

CONCLUSIONS

Left atrial coupling index is a stronger independent predictor for incident HF in older adults than LA volumes and strain and may improve HF risk stratification.

Left atrial volumetric/mechanical coupling index and atrial fibrillation in the embolic stroke of undetermined source

INTRODUCTION

Nowadays, no clear predictors of atrial fibrillation in patients with embolic stroke of undetermined source (ESUS) are known. Some echocardiographic parameters have been proposed as potential predictors of atrial fibrillation in patients with ESUS. The ratio between left atrial volume and tissue Doppler (TDI) a' provides the left atrial volumetric/mechanical coupling index (LACI) and represents a feasible surrogate for left atrial function, and might be useful to identify atrial fibrillation in this subset of patients.

METHODS AND RESULTS

All consecutive patients having undergone an implantable loop recorder (ILR) for ESUS between 2017 and 2022 were retrospectively enrolled. All patients were followed through remote monitoring and telephone visit for a minimum follow-up of 6 months.A total number of 129 patients (mean age: 72.2 ± 8.8 years; 55% of men) were analyzed. Patients developing atrial fibrillation presented higher baseline LACI (5.53 ± 2.52 vs. 3.25 ± 1.19, P < 0.001). The multivariate analysis showed that LACI was independently and significantly associated with atrial fibrillation (hazard ratio = 1.21, 95% confidence interval 1.09-1.32, P < 0.01). The best cut-off value of LACI was found to be 4.24.

DISCUSSION

Our data confirm that LACI is independently associated with atrial fibrillation in patients with ILR following ESUS, accounting for clinical or echocardiographic factors.

Reprint of: Scientific statement from the French neurovascular and cardiac societies for improved detection of atrial fibrillation after ischaemic stroke and transient ischaemic attack

Atrial fibrillation (AF) is the primary cause of ischaemic stroke and transient ischaemic attack (TIA). AF is associated with a high risk of recurrence, which can be reduced using optimal prevention strategies, mainly anticoagulant therapy. The availability of effective prophylaxis justifies the need for a significant, coordinated and thorough transdisciplinary effort to screen for AF associated with stroke. A recent French national survey, initiated and supported by the Société française neurovasculaire (SFNV) and the Société française de cardiologie (SFC), revealed many shortcomings, such as the absence or inadequacy of telemetry equipment in more than half of stroke units, insufficient and highly variable access to monitoring tools, delays in performing screening tests, heterogeneous access to advanced or connected ambulatory monitoring techniques, and a lack of dedicated human resources. The present scientific document has been prepared on the initiative of the SFNV and the SFC with the aim of helping to address the current shortcomings and gaps, to promote efficient and cost-effective AF detection, and to improve and, where possible, homogenize the quality of practice in AF screening among stroke units and outpatient post-stroke care networks. The working group, composed of cardiologists and vascular neurologists who are experts in the field and are nominated by their peers, reviewed the literature to propose statements, which were discussed in successive cycles, and maintained, either by consensus or by vote, as appropriate. The text was then submitted to the SFNV and SFC board members for review. This scientific statement document argues for the widespread development of patient pathways to enable the most efficient AF screening after stroke. This assessment should be carried out by a multidisciplinary team, including expert cardiologists and vascular neurologists.

Current and Clinically Relevant Echocardiographic Parameters to Analyze Left Atrial Function

The evaluation of the left atrial (LA) size using the LA volume index (LAVI) is clinically relevant due to its prognostic significance in various conditions. Nonetheless, adding a LA function assessment to the LAVI provides further clinical and prognostic information in different cardiovascular (CV) diseases. The assessment of LA function by echocardiography primarily includes volumetric measurements (LA ejection fraction [LAEF]), tissue Doppler imaging (TDI) (mitral annular late diastolic velocity [a']), and speckle-tracking methods, such as LA longitudinal reservoir strain (LA strain). This review analyzes and discusses the current medical evidence and potential clinical usefulness of these different methods to analyze LA function.

Scientific statement from the French neurovascular and cardiac societies for improved detection of atrial fibrillation after ischaemic stroke and transient ischaemic attack

Atrial fibrillation (AF) is the primary cause of ischaemic stroke and transient ischaemic attack (TIA). AF is associated with a high risk of recurrence, which can be reduced using optimal prevention strategies, mainly anticoagulant therapy. The availability of effective prophylaxis justifies the need for a significant, coordinated and thorough transdisciplinary effort to screen for AF associated with stroke. A recent French national survey, initiated and supported by the Société française neurovasculaire (SFNV) and the Société française de cardiologie (SFC), revealed many shortcomings, such as the absence or inadequacy of telemetry equipment in more than half of stroke units, insufficient and highly variable access to monitoring tools, delays in performing screening tests, heterogeneous access to advanced or connected ambulatory monitoring techniques, and a lack of dedicated human resources. The present scientific document has been prepared on the initiative of the SFNV and the SFC with the aim of helping to address the current shortcomings and gaps, to promote efficient and cost-effective AF detection, and to improve and, where possible, homogenize the quality of practice in AF screening among stroke units and outpatient post-stroke care networks. The working group, composed of cardiologists and vascular neurologists who are experts in the field and are nominated by their peers, reviewed the literature to propose statements, which were discussed in successive cycles, and maintained, either by consensus or by vote, as appropriate. The text was then submitted to the SFNV and SFC board members for review. This scientific statement document argues for the widespread development of patient pathways to enable the most efficient AF screening after stroke. This assessment should be carried out by a multidisciplinary team, including expert cardiologists and vascular neurologists.

Deep learning evaluation of echocardiograms to identify occult atrial fibrillation

Atrial fibrillation (AF) often escapes detection, given its frequent paroxysmal and asymptomatic presentation. Deep learning of transthoracic echocardiograms (TTEs), which have structural information, could help identify occult AF. We created a two-stage deep learning algorithm using a video-based convolutional neural network model that (1) distinguished whether TTEs were in sinus rhythm or AF and then (2) predicted which of the TTEs in sinus rhythm were in patients who had experienced AF within 90 days. Our model, trained on 111,319 TTE videos, distinguished TTEs in AF from those in sinus rhythm with high accuracy in a held-out test cohort (AUC 0.96 (0.95-0.96), AUPRC 0.91 (0.90-0.92)). Among TTEs in sinus rhythm, the model predicted the presence of concurrent paroxysmal AF (AUC 0.74 (0.71-0.77), AUPRC 0.19 (0.16-0.23)). Model discrimination remained similar in an external cohort of 10,203 TTEs (AUC of 0.69 (0.67-0.70), AUPRC 0.34 (0.31-0.36)). Performance held across patients who were women (AUC 0.76 (0.72-0.81)), older than 65 years (0.73 (0.69-0.76)), or had a CHA2DS2VASc ≥2 (0.73 (0.79-0.77)). The model performed better than using clinical risk factors (AUC 0.64 (0.62-0.67)), TTE measurements (0.64 (0.62-0.67)), left atrial size (0.63 (0.62-0.64)), or CHA2DS2VASc (0.61 (0.60-0.62)). An ensemble model in a cohort subset combining the TTE model with an electrocardiogram (ECGs) deep learning model performed better than using the ECG model alone (AUC 0.81 vs. 0.79, p = 0.01). Deep learning using TTEs can predict patients with active or occult AF and could be used for opportunistic AF screening that could lead to earlier treatment.

Echocardiographic parameters indicating left atrial reverse remodeling after catheter ablation for atrial fibrillation

Background

The echocardiographic parameters total atrial conduction time (PA-TDI duration), left atrial (LA) volume index (LAVI), and LA strain reflect adverse atrial remodeling and predict atrial fibrillation (AF).

Objectives

The aim of this study was to investigate echocardiographic parameters indicating reverse LA remodeling and potential associations with AF recurrence after pulmonary vein isolation (PVI).

Methods

This prospective observational study consecutively enrolled patients scheduled for PVI for symptomatic AF. Electrocardiogram (ECG) test and transthoracic echocardiography were performed the day before and after PVI and again 3 months later. AF recurrence was determined by Holter ECG at 3 months, and telephone follow-up at 12 months, after PVI. The parameters of LA remodeling [PA-TDI, LAVI, and LA strain analysis: reservoir strain (LASr), conduit strain (LAScd), contraction strain (LASct)] were determined by transthoracic echocardiography.

Results

A total of 48 patients were included in the study (mean age: 61.4 ± 12.2 years). PA-TDI significantly decreased the day after PVI compared with the baseline (septal PA-TDI 103 ± 13 vs. 82 ± 14.9 ms, p ≤ 0.001; lateral PA-TDI 122.4 ± 14.8 vs. 106.9 ± 14.4 ms, p ≤ 0.001) and at the 3-month follow-up (septal PA-TDI: 77.8 ± 14.5, p ≤ 0.001; lateral PA-TDI 105.2 ± 16.1, p ≤ 0.001). LAVI showed a significant reduction at the 3-month follow-up compared with the baseline (47.7 ± 14.4 vs. 40.5 ± 9.7, p < 0.05). LASr, LAScd, and LASct did not change after PVI compared with the baseline. AF recurred in 10 patients after PVI (21%). Septal PA-TDI, septal a', and LAVI/a' determined the day after PVI were associated with AF recurrence.

Conclusion

Changes in echocardiographic parameters of LA remodeling and function indicate that functional electromechanical recovery preceded morphological reverse remodeling of the left atrium after PVI. Furthermore, these changes in echocardiographic parameters indicating LA reverse remodeling after PVI may identify patients at high risk of AF recurrence.

Echocardiographic Measures of Left Atrial Structure and Function and the Association with Atrial Fibrillation following Acute Coronary Syndrome

INTRODUCTION

Acute coronary syndrome (ACS) is associated with an increased risk of developing atrial fibrillation (AF). This arrhythmia is associated with adverse outcomes, making it important to identify high-risk patients. The aim was to evaluate the prognostic value of measures of left atrial (LA) structure and function in AF prediction following ACS.

METHODS

Three hundred and eighty-one patients who had a percutaneous coronary intervention for ACS were included in the study. Our endpoint was new-onset AF.

RESULTS

With a median follow-up time of 5.4 [3.9-6.8] years, 56 patients (14.7%) developed AF. Patients developing AF had significantly (p ≤ 0.05) increased maximal and minimal LA volumes (LAVmax and LAVmin, respectively). LAVmax and LAVmin remained significantly increased in AF patients when indexing to either body surface area (LAVmax/BSA and LAVmin/BSA, respectively), left ventricle length in end diastole (LAVmax/LVLd and LAVmin/LVLd, respectively), or late mitral annular diastolic velocity (LAVmax/a' and LAVmin/a', respectively), while LA expansion index (LAEi), LA emptying fraction (LAEF), and peak LA longitudinal strain (PALS) were decreased. In univariable Cox regressions, all LA measures were found to be predictors of AF. After multivariable adjustment for clinical and echocardiographic parameters, all measures reflecting atrial function (LAVmin, LAVmin/BSA, LAVmin/LVLd, LAVmin/a', LAVmax/a', LAEF, LAEi, and PALS) (p ≤ 0.05) but no structural measures (LAVmax, LAVmax/BSA, and LAVmax/LVLd) remained significant independent predictors of AF.

CONCLUSION

Echocardiographic measures of LA function are independent predictors of AF following ACS. Evaluation of LA function might improve the prognostic workup, aid in risk stratification for AF, and improve selection for further examinations.

A correlation of the ratio of left atrial volume to left ventricular ejection fraction in predicting atrial fibrillation in ischemic stroke

Background/Aim: The enlargement of left atrial volume index (LAVI) in diastolic dysfunction (DD) may predispose one to atrial fibrillation (AF) and is an important etiological reason for ischemic stroke (IS). The ratio of LAVI increase to left ventricular ejection fraction (LVEF) is a new parameter, and this work investigates the correlation between DD parameters, LAVI, LAVI/LVEF ratio, and AF in patients with sinus rhythm presenting with IS. Methods: Here, 108 consecutive individuals who were diagnosed with IS were included in the case-control study. The patients were divided into two groups: Those with AF events on rhythm Holters (AF group, n=57) and those without (control group, n=51). LAVI was calculated from the apical four- and two-chamber views before the mitral valve was opened. LVEF was calculated by Simpson's method. Results: The mean age of the AF group was 73.9 (6.3) years, and the control group was 72.1 (3.9) years. Hypertension, diabetes mellitus, glucose, HbA1c, CHA₂DS₂-VASc score, and previous stroke were higher in the AF group (P<0.05). LAVI (35.7 [25.3-38.2] vs 29.6 [27.7-30.9], P<0.001), the LAVI/LVEF ratio (0.7 [0.63-0.77] vs 0.5 [0.50-0.54], P<0.001), and the E/é ratio (14.6 [13.9-15.0] vs 10.7 [9.0-11.8], P<0.001) were higher in patients with AF. Multivariable analyses showed that LAVI (OR:7.985, 95%CI [2.586-4.767], P<0.001) and the LAVI/LVEF ratio (OR:0.010, 95% CI [0.000-0.007], P=0.015) were potential independent risk factors for AF events. A positive correlation was found between the CHA₂DS₂-VASc score and LAVI (P=0.032, r=0.407) and LAVI/LVEF ratio (P=0.041, r=0.253). Conclusion: We concluded that the increase in LAVI and LAVI/LVEF ratio increases the risk of IS by increasing the tendency to AF. These parameters are useful in predicting IS.

Circulating fibroblast activation protein α is reduced in acute ischemic stroke

Background

Fibroblast activation protein α (FAP), a membrane glycoprotein with dipeptidyl-peptidase and collagenase properties, is expressed in atherosclerotic plaques and remodeling of the extracellular matrix based on fibrosis. Fibrosis is a main contributor of atrial cardiomyopathies. In acute MI, circulating FAP is associated with outcome. Here, we investigated the correlation of circulating FAP to echocardiographic parameters of atrial remodeling and neurological impairment in acute ischemic stroke.

Methods

Circulating FAP plasma concentrations were determined by ELISA in 47 patients with acute stroke and 22 control patients without stroke. Echocardiography was performed in all participants. Laboratory analysis, National Institutes of Health Stroke Scale (NIHSS) scoring and prolonged Holter-ECG-monitoring were performed in all stroke patients.

Results

Patients with acute stroke had lower circulating FAP concentrations than the control cohort (92 ± 24 vs. 106 ± 22 ng/mL, P < 0.001). There was no difference between the circulating FAP concentration comparing stroke due to atrial fibrillation, embolic stroke of undetermined source (ESUS) or atherosclerotic origin. Septal atrial conduction time (sPA-TDI) and left atrial (LA) volume index to tissue Doppler velocity (LAVI/a') representing echocardiographic parameters of LA remodeling did not correlate with FAP concentrations (sPA-TDI: r = 0.123, p = 0.31; LAVI/a': r = 0.183, p = 0.132). Stroke severity as assessed by NIHSS inversely correlated with circulating FAP (r = -0.318, p = 0.04). FAP concentration had a fair accuracy for identifying stroke in the receiver operating characteristic (ROC) analysis (AUC = 0.710, 95% CI: 0.577-0.843). A FAP concentration of 101 ng/mL discriminated between presence and absence of stroke with a sensitivity of 72% and a specificity of 77%. Lower circulating FAP concentration was associated with cardio-cerebro-vascular events within 12 months after admission.

Conclusions

Our study is the first to associate FAP with echocardiographic parameters of LA-remodeling and function. FAP did not correlate with sPA-TDI and LAVI/a'. However, FAP was associated with stroke, neurological impairment, and cardio-cerebral events within 12 months. Therefore, FAP might enable individualized risk stratification in ischemic stroke.

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.

Echocardiographic Parameters to Predict Atrial Fibrillation in Clinical Routine-The EAHsy-AF Risk Score

Background

Echocardiographic parameters representing impaired left atrial (LA) function and remodeling are of high value to predict atrial fibrillation (AF). This study aimed to develop a prediction model for AF easily to apply in clinical routine containing echocardiographic parameters associated with LA remodeling and-function.

Methods and Results

This monocentric, semi-blinded, controlled analysis included 235 patients to derive a prediction model. This prediction model was tested in a validation cohort encompassing 290 cardiovascular inpatients. The derivation and validation cohort included 54 (23%) and 66 (23%) patients with AF, respectively. Transthoracic echocardiography, comprising parameters indicating left atrial remodeling [septal/lateral total atrial conduction time (s/l PA-TDI)] and left atrial volume indexed to a' (LAVI/a') was performed in each patient. Based on multivariable regressions analysis, four variables were enclosed into the EAHsy (Echocardiography, Age, Hypertension)-AF risk score for AF prediction: Hypertension, Age, LAVI/a' and septal PA-TDI. In the validation cohort discrimination was strong (C-statistic 0.987, 95%CI 0.974-0.991) with an adequately performed calibration. The EAHsy-AF risk score was associated with a more precise prediction of AF in comparison to commonly used AF-scores (CHADS₂-, ATLAS-, ARIC-, CHARGE-AF score).

Conclusion

The EAHsy-AF-Score containing age, hypertension and echocardiographic parameters of atrial dysfunction and remodeling precisely predicts the incidence of AF in a general population of patients with cardiovascular disease. The EAHsy-AF risk score may enable more selective rhythm monitoring in specific patients at high risk for AF.

Long-Term Follow-up of Enhanced Holter-Electrocardiography Monitoring in Acute Ischemic Stroke

Background and Purpose

Prolonged electrocardiography (ECG)-monitoring in stroke patients improves the detection of paroxysmal atrial fibrillation (pAF). However, most randomized studies only had short follow-up. We aimed to provide 3-year follow-up data for AF detection and stroke recurrence risk.

Methods

We randomized 402 patients aged ≥60 years with acute ischemic strokes without AF to either enhanced and prolonged monitoring (EPM; 3×10-day Holter-ECG-monitoring) or standard-of-care (≥24 hours ECG-monitoring). The endpoint of the current analysis was AF within 36 months analyzed by intention to treat. Long-term follow-up was performed for 36 months.

Results

Two hundred and seventy-four patients (80%) participated in the extended follow-up (median duration of follow-up was 36 months [interquartile range, 12 to 36]). During the first 6 months, more AF was documented in the EPM arm compared to the control arm (13.5% vs. 5.1%; 95% confidence interval, 2.9% to 14.4%; P=0.004). During months 6 to 36, AF was less detected in the EPM intervention arm than in the control arm (2.0% vs. 7.3%; 95% confidence interval, 0.7% to 9.9%; P=0.028). Overall, the detection rate of AF within 36 months was numerically higher within the EPM group (15.0% vs. 11.1%, P=0.30). Numerically less patients in the EPM arm had recurrent ischemic strokes (5.5% vs. 9.1%, P=0.18), transient ischemic attacks (3.0% vs. 4.5%, P=0.44) or died (4.5% vs. 6.6%, P=0.37).

Conclusions

Enhanced and prolonged ECG monitoring increased AF detection during the first six months, but there was significantly more clinical AF during months 6 to 36 observed in the usual-care arm. This suggests that EPM leads to an earlier detection of clinically relevant AF.

The significance of the morphology-voltage-P-wave duration (MVP) ECG score for prediction of in-hospital and long-term atrial fibrillation in ischemic stroke

BACKGROUND

Atrial fibrillation (AF) is the most common preventable cause of stroke. Diagnosis of new AF is frequent after acute ischemic stroke (AIS). We aimed to evaluate the predictive value of the recently developed morphology-voltage-P-wave duration (MVP) ECG risk score for in-hospital and long-term AF diagnosis following AIS.

MATERIAL AND METHODS

In this observational investigation, we evaluated the ability of the MVP ECG risk score to predict AF in 266 consecutive patients with AIS. The study population was divided into three groups according to their calculated MVP ECG risk score on admission electrocardiography. The groups were compared in terms of their predictive value for in-hospital and long-term AF diagnosis.

RESULTS

After adjustment for confounding baseline variables, MVP ECG risk score 5-6 group had 13.2 times higher rates of in-hospital AF compared to MVP ECG risk score 0-2 group, which was used as the reference group. For long-term follow-up, MVP ECG risk score 5-6 group had 5.2 times higher rates of long-term AF compared to MVP ECG risk score 0-2 group. A ROC analysis showed that the optimal cut-off value of the MVP ECG risk score to predict in-hospital AF was 4 with 78% sensitivity and 76% specificity (AUC: 0.80; 95% CI: 0.64-0.96; p < 0.001), the optimal cut-off value of the MVP ECG risk score to predict long-term AF was 3 with 85% sensitivity and 59% specificity (AUC: 0.81; 95% CI: 0.76-0.86; p < 0.001).

CONCLUSION

The MVP ECG risk score, which can be easily calculated from a surface ECG, can be used to guide who needs stricter monitoring for the diagnosis of long-term AF in patients with AIS.

Echocardiographic predictors of cardioembolic stroke due to underlying atrial fibrillation: Reliable left atrial remodeling signs in acute stroke

INTRODUCTION

Atrial remodeling due to high-burden atrial fibrillation (AF) is associated with cardioembolic stroke (CES). As not all CESs is caused by AF, we analyzed the diagnostic values of each echocardiographic parameter to distinguish likely AF-related CES in acute stroke patients while in non-AF rhythm.

METHODS

The data of consecutive patients with acute ischemic stroke in sinus rhythm between 2012 and 2015 were obtained. The echocardiographic parameters of patients with CES due to underlying AF (n = 61) and control patients (n = 319) with either large artery atherosclerosis or small-vessel occlusion were compared using receiver operating characteristic curves and logistic regression analyses. Each parameter was reassessed in acute stroke patients through a validation study using the same database with different periods of generalization.

RESULTS

CES patients with underlying AF showed a significantly larger left atrial volume index (LAVi), higher mitral inflow E wave (E), and lower A wave (A) than the controls. The area under the curve (AUC) (95% confidence interval) for diagnosing CES due to underlying AF was significantly higher for LAVi/A than for LAVi (0.785 versus 0.696, P < 0.01). Among patients aged >60 years, the E/A ratio had the highest AUC (0.857) of the parameters. The cut-off values were ≥ 0.70 (sensitivity, 55.7%; specificity, 90.9%) and ≥ 0.82 (sensitivity, 71.4%; specificity, 84.1%) for LAVi/A and the E/A ratio, respectively, in patients >60 years. The cut-off values of all parameters showed similar trends in a validation study.

CONCLUSION

LAVi/A is a useful indicator for distinguishing CES patients with underlying AF regardless of age, and the E/A ratio is reliable among patients aged >60 years in evaluation during acute stroke admission.

Left Atrial Volumetric/Mechanical Coupling Index: A Novel Predictor of Outcome in Heart Failure With Reduced Ejection Fraction

BACKGROUND

Left atrial assessment is complex, particularly in heart failure with reduced ejection fraction due to interactions with functional mitral regurgitation (FMR). Pilot data suggest that left atrial volumetric/mechanical coupling index (LACI) may be useful, but large outcome data are lacking.

METHODS

We enrolled a comprehensively characterized cohort of patients in sinus rhythm with heart failure with reduced ejection fraction diagnosis at Mayo Clinic from 2007 to 2011. Routinely measured left atrial volume index and tissue-doppler-imaging a' allowed LACI calculation as (left atrial volume index)/(tissue-doppler-imaging a'). Survival was the outcome measured.

RESULTS

The cohort's 4196 patients (69 [58-77] years, ejection fraction 40 [31-45]%) had mild FMR in 1505 and moderate-severe FMR in 1068. LACI was overall 5.06 (3.50-8.10) and increased with each FMR grade (3.86 [2.94-5.29] without FMR, 5.38 [3.80-8.02] with mild, 5.45 [1.49-8.07] with moderate/severe FMR; P<0.0001). At diagnosis, higher LACI was independently determined by more severe FMR and by higher left ventricular mass index, lower ejection fraction, higher E/e', and lower glomerular filtration rate (all P<0.0001). During follow-up 1588 (38%) patients died. In spline modeling, excess mortality appeared around LACI=6 and steeply increased thereafter (5-year survival 72±1% with LACI<6 and 49±2% with LACI ≥6, P<0.0001). Multivariable comprehensive adjustment showed LACI strong association with excess mortality (adjusted hazard ratio, 1.41 [1.23-1.61], P<0.0001 for LACI ≥6). Independent link to mortality persistent across FMR grades (adjusted hazard ratio, 1.45 [1.13-1.86], P=0.004 without FMR, 1.42 [1.16-1.77], P=0.0008 with mild FMR, and 1.38 [1.01-1.66], P=0.04 with moderate/severe FMR) without interaction (P=0.3). LACI independent impact on outcome was incremental to that of left atrial volume index, tissue-doppler-imaging a', or any other characteristic including the Meta-Analysis Global Group in Chronic-score (least significant P=0.02).

CONCLUSIONS

In this large cohort, left atrial volumetric/mechanical coupling measured by LACI in routine practice integrates the influence of several morphological/hemodynamic determinants but displays progressive deterioration with increasing FMR severity in heart failure with reduced ejection fraction. About outcome, higher LACI is strongly, independently, and incrementally associated with excess mortality, irrespective of FMR grade and in all subsets. Hence, LACI is a novel and critical measure in heart failure with reduced ejection fraction, quantifiable in routine practice, which should be integrated in prognostication and decision-making.

Implantable Cardiac Monitoring in the Secondary Prevention of Cryptogenic Stroke

OBJECTIVE

In this study, we sought to evaluate the impact of implantable cardiac monitoring (ICM) in the prevention of stroke recurrence after a cryptogenic ischemic stroke or transient ischemic attack (TIA).

METHODS

We evaluated consecutive patients with cryptogenic ischemic stroke or TIA admitted in a comprehensive stroke center during an 8-year period. We compared the baseline characteristics and outcomes between patients receiving conventional cardiac monitoring with repeated 24-hour Holter-monitoring during the first 5 years in the outpatient setting and those receiving continuous cardiac monitoring with ICM during the last 3 years. Associations on the outcomes of interest were further assessed in multivariable regression models adjusting for potential confounders.

RESULTS

We identified a total of 373 patients receiving conventional cardiac monitoring and 123 patients receiving ICM. Paroxysmal atrial fibrillation (PAF) detection was higher in the ICM cohort compared to the conventional cardiac monitoring cohort (21.1% vs 7.5%, p < 0.001). ICM was independently associated with an increased likelihood of PAF detection during follow-up (hazard ratio [HR] = 1.94, 95% confidence interval [CI] = 1.16-3.24) in multivariable analyses. Patients receiving ICM were also found to have significantly higher rates of anticoagulation initiation (18.7% vs 6.4%, p < 0.001) and lower risk of stroke recurrence (4.1% vs 11.8%, p = 0.013). ICM was independently associated with a lower risk of stroke recurrence during follow-up (HR = 0.32, 95% CI = 0.11-0.90) in multivariable analyses.

INTERPRETATION

ICM appears to be independently associated with a higher likelihood of PAF detection and anticoagulation initiation after a cryptogenic ischemic stroke or TIA. ICM was also independently related to lower risk of stroke recurrence in our cryptogenic stroke / TIA cohort. ANN NEUROL 2020;88:946-955.

miR-21 and NT-proBNP Correlate with Echocardiographic Parameters of Atrial Dysfunction and Predict Atrial Fibrillation

This study aimed to investigate the association of circulating biomarkers with echocardiographic parameters of atrial remodelling and their potential for predicting atrial fibrillation (AF). In patients with and without AF (n = 21 and n = 60) the following serum biomarkers were determined: soluble ST2 (sST2), Galectin-3 (Gal-3), N-terminal pro-brain natriuretic peptide (NT-proBNP), microRNA (miR)-21, -29a, -133a, -146b and -328. Comprehensive transthoracic echocardiography was performed in all participants. Biomarkers were significantly altered in patients with AF. The echocardiographic parameter septal PA-TDI, indicating left atrial (LA) remodelling, correlated with concentrations of sST2 (r = 0.249, p = 0.048), miR-21 (r = -0.277, p = 0.012), miR-29a (r = -0.269, p = 0.015), miR-146b (r = -0.319, p = 0.004) and miR-328 (r = -0.296, p = 0.008). In particular, NT-proBNP showed a strong correlation with echocardiographic markers of LA remodelling and dysfunction (septal PA-TDI: r = 0.444, p < 0.001, LAVI/a': r = 0.457, p = 0.001, SRa: r = 0.581, p < 0.001). Multivariate Cox regressions analysis highlighted miR-21 and NT-proBNP as predictive markers for AF (miR-21: hazard ratio (HR) 0.16; 95% confidence interval (CI) 0.04-0.7, p = 0.009; NT-proBNP: HR 1.002 95%CI 1.001-1.004, p = 0.006). Combination of NT-proBNP and miR-21 had the best accuracy to discriminate patients with AF from those without AF (area under the curve (AUC)= 0.843). Our findings indicate that miR-21 and NT-proBNP correlate with echocardiographic parameters of atrial remodeling and predict AF, in particular if combined.

Usefulness of the ACTEL Score to Predict Atrial Fibrillation in Patients with Cryptogenic Stroke

INTRODUCTION

To assess the probability of undetected atrial fibrillation (AF) in patients with ischemic stroke, we previously compared patients who were first diagnosed with AF with patients with large or small artery disease and obtained the MrWALLETS 8-item scoring system. In the present study, we utilized cryptogenic strokes (CS) as the control group, as AF is normally sought among CS patients.

METHODS

We retrospectively examined 191 ischemic stroke patients (72.5 ± 12.6 years), 68 with first diagnosed AF and 123 with CS, who had undergone 2 brain CT scans, echocardiography, carotid/vertebral ultrasound, continuous electrocardiogram monitoring and anamnestic/laboratory search for cardiovascular risk factors.

RESULTS

In logistic regression, 5 variables were independently associated with AF, forming the "ACTEL" score: Age ≥75 years (OR 2.42, 95% CI 1.18-4.96, p = 0.02; +1 point); hyperCholesterolemia (OR 0.38, 95% CI 0.18-0.78, p = 0.009; -1 point); Tricuspid regurgitation ≥ mild-to-moderate (OR 4.99, 95% CI 1.63-15.27, p = 0.005; +1 point); left ventricular End-diastolic volume <65 mL (OR 7.43, 95% CI 2.44-22.6, p = 0.0004; +1 point); Left atrium ≥4 cm (OR 4.57, 95% CI 1.97-10.62, p = 0.0004; +1 point). The algebraic sum of these points may range from -1 to +4. For AF identification, the area under the receiver operating characteristic curve was 0.80 (95% CI 0.73-0.87). With a cutoff of ≥2, positive predictive value was 80.8%, specificity 92.7% and sensitivity 55.9%.

CONCLUSIONS

The ACTEL score, a simplified and improved version of the MrWALLETS score, allows the identification of patients with first diagnosed AF, in the context of CSs, with a high positive predictive value.

Searching for Atrial Fibrillation Poststroke: A White Paper of the AF-SCREEN International Collaboration

Cardiac thromboembolism attributed to atrial fibrillation (AF) is responsible for up to one-third of ischemic strokes. Stroke may be the first manifestation of previously undetected AF. Given the efficacy of oral anticoagulants in preventing AF-related ischemic strokes, strategies of searching for AF after a stroke using ECG monitoring followed by oral anticoagulation (OAC) treatment have been proposed to prevent recurrent cardioembolic strokes. This white paper by experts from the AF-SCREEN International Collaboration summarizes existing evidence and knowledge gaps on searching for AF after a stroke by using ECG monitoring. New AF can be detected by routine plus intensive ECG monitoring in approximately one-quarter of patients with ischemic stroke. It may be causal, a bystander, or neurogenically induced by the stroke. AF after a stroke is a risk factor for thromboembolism and a strong marker for atrial myopathy. After acute ischemic stroke, patients should undergo 72 hours of electrocardiographic monitoring to detect AF. The diagnosis requires an ECG of sufficient quality for confirmation by a health professional with ECG rhythm expertise. AF detection rate is a function of monitoring duration and quality of analysis, AF episode definition, interval from stroke to monitoring commencement, and patient characteristics including old age, certain ECG alterations, and stroke type. Markers of atrial myopathy (eg, imaging, atrial ectopy, natriuretic peptides) may increase AF yield from monitoring and could be used to guide patient selection for more intensive/prolonged poststroke ECG monitoring. Atrial myopathy without detected AF is not currently sufficient to initiate OAC. The concept of embolic stroke of unknown source is not proven to identify patients who have had a stroke benefitting from empiric OAC treatment. However, some embolic stroke of unknown source subgroups (eg, advanced age, atrial enlargement) might benefit more from non-vitamin K-dependent OAC therapy than aspirin. Fulfilling embolic stroke of unknown source criteria is an indication neither for empiric non-vitamin K-dependent OAC treatment nor for withholding prolonged ECG monitoring for AF. Clinically diagnosed AF after a stroke or a transient ischemic attack is associated with significantly increased risk of recurrent stroke or systemic embolism, in particular, with additional stroke risk factors, and requires OAC rather than antiplatelet therapy. The minimum subclinical AF duration required on ECG monitoring poststroke/transient ischemic attack to recommend OAC therapy is debated.

Septal total atrial conduction time for prediction of atrial fibrillation in embolic stroke of unknown source: a pilot study

BACKGROUND

Subclinical atrial fibrillation (AF) is the underlying cause in a relevant part of patients with embolic stroke of unknown source (ESUS). This pilot study aims to identify novel echocardiographic parameters predicting AF subsequently detected in patients originally hospitalized with ESUS.

METHODS AND RESULTS

Patients with acute ischemic stroke [baseline diagnosis of ESUS (n = 69), stroke of macro- or microvascular cause (n = 16/25), stroke caused by AF (n = 5)] and controls with paroxysmal AF without acute ischemic stroke (n = 22) as well as healthy controls of young and old age (n = 21/17) in sinus rhythm were included (overall n = 175). Echocardiography was performed in all participants. Prolonged Holter-ECG-monitoring was performed in all stroke patients. In the overall cohort, septal total atrial conduction time (sPA-TDI), left atrial (LA) volume index to tissue Doppler velocity (LAVI/a`) and second negative peak strain rate during LA contraction (SRa), representing echocardiographic parameters of LA remodelling and function, were statistically significant different in patients with and without AF and predictive for subclinical AF (multivariate regression analysis: sPA-TDI: HR 1.06 [1.04-1.08], p < 0.001; LAVI/a`: HR 0.85, [0.74-0.97], p = 0.02; SRa: HR 2.35 [0.9-5.5], p = 0.05). Multivariate Cox regression analysis revealed sPA-TDI as an independent predictor of AF in ESUS patients (sPA-TDI: HR 1.10 [1.04-1.17], p = 0.001). A sPA-TDI of 126 ms strictly discriminated between presence and absence of subclinical AF within 48 h after initiation of Holter-ECG-monitoring in ESUS patients.

CONCLUSIONS

sPA-TDI seems to be a strong independent predictor of subclinical AF in patients hospitalized for ESUS and might support risk-stratified clinical decision making in these patients. Septal Total Atrial Conduction Time (sPA-TDI) determined by echocardiography for prediction of Atrial Fibrillation in Embolic Stroke of Unknown Source (ESUS).

The cardiac diagnostic work-up in stroke patients-A subanalysis of the Find-AFRANDOMISED trial

Background

The cardiac diagnostic workup of stroke patients, especially the value of echocardiography and enhanced and prolonged Holter-ECG monitoring, is still a matter of debate. We aimed to analyse the impact of pathologies detected by echocardiography and ECG monitoring on therapeutic decisions and prognosis.

Methods

Find-AF_RANDOMISED was a prospective multicenter study which randomised 398 acute ischemic stroke patients ≥ 60 years to enhanced and prolonged Holter-ECG monitoring or usual stroke unit care. This substudy compared therapeutic consequences of echocardiography and routine Holter-ECG or enhanced and prolonged Holter-ECG monitoring, respectively, and prognosis of patients with or without pathologic findings in echocardiography or Holter-ECG monitoring.

Results

50.3% received enhanced and prolonged Holter-ECG monitoring and 49.7% routine ECG monitoring. 82.9% underwent transthoracic echocardiography (TTE), 38.9% transesophageal echocardiography (TEE) and 25.6% both procedures. 14/89 TEE pathologies and 1/90 TTE pathology led to a change in therapy, resulting in a number needed to change decision (NNCD) of 12 and 330 (p < 0.001), respectively. In comparison, enhanced and prolonged Holter-ECG monitoring found atrial fibrillation (AF) in 27 of 200 patients, and routine ECG monitoring in twelve of 198 patients, leading to therapeutic changes in all patients (NNCD 8 and 17, respectively, p < 0.001).

Conclusions

Most changes in therapeutic decisions were triggered by enhanced and prolonged Holter-ECG monitoring, which should therefore play a more prominent role in future guidelines. Echocardiography identifies a patient group at high cardiovascular risk, but rarely result in therapeutic changes. Whether this patient group requires further cardiovascular workup remains unknown. This should be further investigated by interdisciplinary neurocardiologic teams and in appropriate future trials.

Trial registration

ClinicalTrials.gov NCT01855035

Development and validation of a score to detect paroxysmal atrial fibrillation after stroke

OBJECTIVE

Prolonged monitoring times (72 hours) are recommended to detect paroxysmal atrial fibrillation (pAF) after ischemic stroke but this is not yet clinical practice; therefore, an individual patient selection for prolonged ECG monitoring might increase the diagnostic yield of pAF in a resource-saving manner.

METHODS

We used individual patient data from 3 prospective studies (n_total = 1,556) performing prolonged Holter-ECG monitoring (at least 72 hours) and centralized data evaluation after TIA or stroke in patients with sinus rhythm. Based on the TRIPOD (Transparent Reporting of a Multivariable Prediction Model for Individual Prognosis or Diagnosis) guideline, a clinical score was developed on one cohort, internally validated by bootstrapping, and externally validated on 2 other studies.

RESULTS

pAF was detected in 77 of 1,556 patients (4.9%) during 72 hours of Holter monitoring. After logistic regression analysis with variable selection, age and the qualifying stroke event (categorized as stroke severity with NIH Stroke Scale [NIHSS] score ≤5 [odds ratio 2.4 vs TIA; 95% confidence interval 0.8-6.9, p = 0.112] or stroke with NIHSS score >5 [odds ratio 7.2 vs TIA; 95% confidence interval 2.4-21.8, p < 0.001]) were found to be predictive for the detection of pAF within 72 hours of Holter monitoring and included in the final score (Age: 0.76 points/year, Stroke Severity NIHSS ≤5 = 9 points, NIHSS >5 = 21 points; to Find AF [AS5F]). The high-risk group defined by AS5F is characterized by a predicted risk between 5.2% and 40.8% for detection of pAF with a number needed to screen of 3 for the highest observed AS5F points within the study population. Regarding the low number of outcomes before generalization of AS5F, the results need replication.

CONCLUSION

The AS5F score can select patients for prolonged ECG monitoring after ischemic stroke to detect pAF.

CLASSIFICATION OF EVIDENCE

This study provides Class I evidence that the AS5F score accurately identifies patients with ischemic stroke at a higher risk of pAF.

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.

Relevance of supraventricular runs detected after cerebral ischemia

OBJECTIVE

Prolonged ECG monitoring after stroke frequently reveals short paroxysmal atrial fibrillation (pAF) and supraventricular (SV) runs. The minimal duration of atrial fibrillation (AF) required to induce cardioembolism, the relevance of SV runs, and whether short pAF results from cerebral damage itself are currently being debated. We aimed to study the relevance of SV runs and short pAF detected by prolonged Holter ECG after cerebral ischemia during long-term follow-up.

METHODS

Analysis is from the prospective Find-AF trial (ISRCTN46104198). We included patients with acute cerebral ischemia. Those without AF on admission received 7-day Holter ECG monitoring. We differentiated patients with AF on admission (AF-adm), with pAF (>30 seconds), with SV runs (>5 beats but <30 seconds in a 24-hour ECG interval), and without SV runs (controls). During follow-up, those with baseline pAF received another 7-day Holter ECG to examine AF persistence.

RESULTS

A total of 254 of 281 initially included patients were analyzed (mean age 70.0 years, 45.3% female). Forty-three (16.9%) had AF-adm. A total of 211 received 7-day Holter ECG monitoring: 27 (12.8%) had pAF, 67 (31.8%) had SV runs, and 117 (55.5%) were controls. During a mean 3.7 years of follow-up, the SV runs group had more recurrent strokes (p = 0.04) and showed numerically more novel AF (12% vs 5%, p = 0.09) than the controls. Seventy-five percent of the patients with manifest pAF detected after cerebral ischemia still had AF during follow-up (50% paroxysmal, 50% persisting/permanent).

CONCLUSIONS

Patients with cerebral ischemia and SV runs had more recurrent strokes and numerically more novel AF during follow-up and could benefit from further prolonged ECG monitoring. pAF detected after stroke is not a temporal phenomenon.

A score for paroxysmal atrial fibrillation in acute ischemic stroke

Aim Many patients with ischemic stroke have paroxysmal atrial fibrillation that may be difficult to detect. We sought to identify markers of paroxysmal atrial fibrillation and construct a score that may help the clinician to select patients for anticoagulation even if investigations do not disclose atrial fibrillation. Methods A group of patients with acute ischemic stroke and TIA and documented paroxysmal atrial fibrillation was compared to a group of patients with ischemic stroke and TIA and no known paroxysmal atrial fibrillation and sinus rhythm on Holter monitoring. Clinical features, blood tests, ECG, and MRI findings were compared. Sensitivity and specificity of significant markers for paroxysmal atrial fibrillation were calculated. A simple score based on independent markers for paroxysmal atrial fibrillation was constructed. Results Out of 3480 patients with TIA or ischemic stroke, 237 (19%) had paroxysmal atrial fibrillation and 1002 (81%) had sinus rhythm. On univariate analyses, significant markers for paroxysmal atrial fibrillation included increasing age, females, prior ischemic stroke, myocardial infarction, other heart diseases, pathologic troponin, embolic stroke and stroke in different arterial territories (all P < .01). A score including age dichotomized at 75 years, cardiac disease and troponin was constructed. Conclusion We identified many markers for paroxysmal atrial fibrillation and constructed a score that may help the clinician to select patients for anticoagulation even if investigations do not disclose paroxysmal atrial fibrillation.

Atrial Fibrillation Predictors on Mobile Cardiac Telemetry in Cryptogenic Ischemic Stroke

Background and Purpose

The objective of our study was to evaluate magnetic resonance imaging (MRI) and echocardiographic characteristics that would identify patients with cryptogenic ischemic stroke (IS) and transient ischemic attack (TIA) who subsequently developed paroxysmal atrial fibrillation (PAF) on mobile cardiac outpatient telemetry (MCOT).

Methods

All patients with cryptogenic IS or TIA seen at the Emory University Hospital and Emory University Hospital Midtown from January 1, 2009, to June 30, 2013, who underwent MCOT were included in this analysis. Location (cortical, high subcortical, or neither) of current and prior strokes on MRI and left atrial (LA) functional and anatomical echocardiographic parameters were evaluated to determine their association with subsequent detection of PAF.

Results

Of 132 patients, 17 (13%) had evidence of newly diagnosed PAF on MCOT (mean duration of monitoring = 25 days). The presence (vs absence) of ≥1 cortical infarct on baseline MRI was a significant predictor of identifying PAF (odds ratio: 5.2, 95% confidence interval: 1.3-19; P = .01). On baseline echocardiography, patients who had PAF (vs non-PAF) had significantly higher mean LA diameters (4.2 vs 3.7 cm, P = .03) and lower tissue Doppler velocity (a'; 5.5 vs 13.5 cm/s, P = .03). In receiver operating characteristic analysis, the ratio of LA volume index to the septal Doppler velocity (LAVI/a') of >4.6 was associated with a higher likelihood of PAF. Combining MRI with echocardiographic variables did not improve the predictive ability beyond echocardiography alone.

Conclusion

Although the presence of cortical-based infarcts on MRI in patients with cryptogenic IS or TIA increases the likelihood of detecting PAF on MCOT, LA functional and anatomic parameters alone best predicted which patients subsequently had PAF.

Holter-electrocardiogram-monitoring in patients with acute ischaemic stroke (Find-AFRANDOMISED): an open-label randomised controlled trial

BACKGROUND

Atrial fibrillation is a major risk factor for recurrent ischaemic stroke, but often remains undiagnosed in patients who have had an acute ischaemic stroke. Enhanced and prolonged Holter-electrocardiogram-monitoring might increase detection of atrial fibrillation. We therefore investigated whether enhanced and prolonged rhythm monitoring was better for detection of atrial fibrillation than standard care procedures in patients with acute ischaemic stroke.

METHODS

Find-AF_randomised is an open-label randomised study done at four centres in Germany. We recruited patients with acute ischaemic stroke (symptoms for 7 days or less) aged 60 years or older presenting with sinus rhythm and without history of atrial fibrillation. Patients were included irrespective of the suspected cause of stroke, unless they had a severe ipsilateral carotid or intracranial artery stenosis, which were the exclusion criteria. We used a computer-generated allocation sequence to randomly assign patients in a 1:1 ratio with permuted block sizes of 2, 4, 6, and 8, stratified by centre, to enhanced and prolonged monitoring (ie, 10-day Holter-electrocardiogram [ECG]-monitoring at baseline, and at 3 months and 6 months of follow-up) or standard care procedures (ie, at least 24 h of rhythm monitoring). Participants and study physicians were not masked to group assignment, but the expert committees that adjudicated endpoints were. The primary endpoint was the occurrence of atrial fibrillation or atrial flutter (30 sec or longer) within 6 months after randomisation and before stroke recurrence. Because Holter ECG is a widely used procedure and not known to harm patients, we chose not to assess safety in detail. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT01855035.

FINDINGS

Between May 8, 2013, and Aug 31, 2014, we recruited 398 patients. 200 patients were randomly assigned to the enhanced and prolonged monitoring group and 198 to the standard care group. After 6 months, we detected atrial fibrillation in 14% of 200 patients in the enhanced and prolonged monitoring group (27 patients) versus 5% in the control group (nine of 198 patients, absolute difference 9·0%; 95% CI 3·4-14·5, p=0·002; number needed to screen 11).

INTERPRETATION

Enhanced and prolonged monitoring initiated early in patients with acute ischaemic stroke aged 60 years or older was better than standard care for the detection of atrial fibrillation. These findings support the consideration of all patients aged 60 years or older with stroke for prolonged monitoring if the detection of atrial fibrillation would result in a change in medical management (eg, initiation of anticoagulation).

FUNDING

Boehringer Ingelheim.

Long-term Arrhythmia Monitoring in Cryptogenic Stroke: Who, How, and for How Long?

Cryptogenic stroke and transient ischemic attack (TIA) account for approximately one-third of stroke patients [1]. Paroxys-mal atrial fibrillation (PAF) has been suggested as a major etiology of these cryptogenic strokes [2, 3]. PAF can be difficult to diagnose because it is intermittent, often brief, and asymptomatic. PAF might be more prevalent than persistent atrial fibrillation in stroke and TIA patients, especially in younger populations [4, 5]. In patients with atrial fibrillation, anticoagulation provides significant risk reduction [6]. A new generation of oral anticoagulants has been approved for non-valvular atrial fibrillation, providing a variety of therapeutic options for patients with atrial fibrillation and risk of stroke [7]. Prior practice included an admission electrocardiogram (ECG) and continuous telemetry monitoring while in hospital [8]. However, this approach can lead to under-detection of brief asymptomatic events, which can occur at variable intervals, often outside of the hospital setting. Technological advancements have led to devices that can monitor cardiac rhythms outside of the hospital for longer durations resulting in higher yield of detection of atrial fibrillation events. Moreover, recent studies show that the normal monitoring time for arrhythmias may be shorter than ideal in order to detect atrial fibrillation, and increasing this interval could significantly improve detection of atrial fibrillation in these patients [9, 10]. The aim of this study is to review the literature in order to define what subgroup of patients, with what methodologies, and for how long monitoring for atrial fibrillation should occur in patients presenting with cryptogenic stroke.

Echocardiographic measures of atrial function may predict atrial fibrillation in stroke patients

OBJECTIVE

In patients with a prior stroke or transient ischemic attack (TIA) and atrial fibrillation anticoagulant treatment is indicated. This study's purpose was to investigate if echocardiography can predict unknown AF in patients after stroke.

DESIGN

Prospectively, 174 stroke/TIA patients without diagnosed AF underwent echocardiographic evaluation including tissue Doppler imaging (TDI) focusing on functional parameters of the left atrium and left ventricular diastolic function. AF screening was performed during 30 d.

RESULTS

Fifteen patients (8.6%) were diagnosed with AF. Echocardiography in the AF group compared to those without AF, showed larger left atrial volume index (LAVI), (37.2 ± 6.7 vs. 31.6 ± 8.6 ml/m(2), p = 0.018), lower A' velocities in ventricular (5.9 ± 2.2 vs. 7.2 ± 1.6, p = 0.010) and atrial (4.8 ± 1.4 vs. 5.9 ± 1.4, p = 0.013) septa, higher LAVI/A' in ventricular septum (6.7 (5.0-8.7) vs. 4.2 (3.2-5.5), p = 0.001) and atrial septum (8.5 (5.9-11.0) vs. 5.1 (4.1-6.8), p = 0.003). Receiver operating characteristic analyses to detect AF was performed, area under the curve for LAVI was 0.71 (0.61-0.83), p = 0.008, and for LAVI/A' in ventricular septum 0.76 (0.59-0.93), p = 0.006 and atrial septum 0.78 (0.63-0.93), p = 0.002, respectively.

CONCLUSIONS

LAVI and measures of atrial contraction as measured by TDI predict unknown AF in patients after an stroke/TIA and may be used to detect silent AF.

An update on insertable cardiac monitors: examining the latest clinical evidence and technology for arrhythmia management

Continuous cardiac rhythm monitoring has undergone compelling progress over the past decades. Cardiac monitoring has emerged from 12-lead electrocardiograms being performed at the discretion of the treating physician to in-hospital telemetry, Holter monitoring, prolonged external event monitoring and most recently toward insertable device monitoring for several years. Significant advantages and disadvantages pertaining to these monitoring options will be addressed in this review. Insertable cardiac monitors have several advantages over external monitoring techniques and may signify a clinical turning point in the field of arrhythmia management. However, their role in the detection of paroxysmal atrial fibrillation after cryptogenic strokes has yet to evolve. This will be the main focus of this review. Issues surrounding patient selection, clinical relevance and determination of cost-effectiveness for prolonged cardiac monitoring require further studies. Furthermore, insertable cardiac monitoring has not only the potential to augment diagnostic capabilities but also to improve the management of paroxysmal atrial fibrillation.

Diagnosing Paroxysmal Atrial Fibrillation in Patients With Ischemic Strokes and Transient Ischemic Attacks Using Echocardiographic Measurements of Left Atrium Function

Twenty-five to 35 percentage of stroke cases are cryptogenic, and it has been demonstrated that paroxysmal atrial fibrillation (AF) is the causal agent in up to 25% of these incidents. The purpose of this study was to investigate if left atrial (LA) parameters have value for diagnosing paroxysmal AF in patients with ischemic stroke (IS) and transient ischemic attack (TIA). We retrospectively analyzed 219 patients who after acute IS or TIA underwent a transthoracic echocardiographic examination. Patients were designated as patients with paroxysmal AF if they had one or more reported incidents of AF before or after their echocardiographic examination. Patients in the paroxysmal AF group were significantly older and had higher CHA2DS2-VASc score than patients without paroxysmal AF (p <0.05 for both). None of the conventional echocardiographic parameters were significantly associated with paroxysmal AF. However, the atrial measurements evaluating LA function (min LA volume and LA emptying fraction) were significantly different (LA emptying fraction: 45% ± 10% vs 50% ± 10%, p = 0.004; minimal LA volume: 30.2 ml ± 17.3 ml vs 24 ml ± 10 ml, p = 0.035 in patients with paroxysmal AF, even after adjustment for age, gender, CHA2DS2-VASc score, and stroke severity [p <0.05 for both]). By combining the cut-off values of age, LA emptying fraction, and minimal LA volume the diagnostic accuracy of paroxysmal AF was improved, resulting in a sensitivity of 95% and negative predictive value of 97%. In conclusion, in patients with IS and TIA, LA function measurements (minimal LA volume and LA emptying fraction) are independently associated with paroxysmal AF and may improve risk stratification for paroxysmal AF presence after IS or TIA.

Predicting Paroxysmal Atrial Fibrillation in Cerebrovascular Ischemia Using Tissue Doppler Imaging and Speckle Tracking Echocardiography

BACKGROUND

Often the underlying cause of cerebral ischemia (CI) cannot be found during a routine diagnostic investigation, but paroxysmal atrial fibrillation (PAF) could be the culprit.

AIM

The objective of the study is to investigate whether advanced echocardiography improves the diagnostic approach for PAF in CI.

METHODS

The study included 286 CI patients with an echocardiogram in sinus rhythm. Patients were divided by PAF occurrence (PAF: n = 86, non-PAF: n = 200). PAF was defined as 1 or more reported episodes of atrial fibrillation. Echocardiograms consisted of conventional measures, tissue Doppler imaging (TDI), and speckle tracking. TDI was performed to acquire myocardial peak velocities during systole/ventricular contraction (global s'), early diastole/ventricular filling (global e'), and late diastole/atrial contraction (global a'). Speckle tracking was performed for myocardial strain analysis, thereby retrieving global longitudinal strain and global strain rate (s, e, a) values.

RESULTS

Patients with PAF exhibited significantly impaired atrial contractile measures: global a' (-7.0 cm/second versus -5.7 cm/second, P < .001) and global strain rate a (.97 second(-1) versus .81 second(-1), P < .001). Both were univariable markers of PAF, and along with age remained the only independent significant determinants of PAF after multivariable logistic regression. Area under the curve (AUC) for age, global a', and global strain rate a significantly exceeded AUC for age alone (.79 versus .76, P = .032). Cutoff values with the highest sensitivity and specificity for these 3 parameters improved the diagnostic accuracy (sensitivity = 97%, specificity = 32%, negative predictive value = 95%, and positive predictive value = 38%).

CONCLUSIONS

Atrial contractile measures by advanced echocardiography are significant determinants of PAF in CI. However, there is no discriminatory power to make them clinically useful at the current moment.

Atrial Cardiopathy and Cryptogenic Stroke: A Cross-sectional Pilot Study

BACKGROUND

There is increasing evidence that left atrial dysfunction or cardiopathy is associated with ischemic stroke risk independently of atrial fibrillation. We aimed to determine the prevalence of atrial cardiopathy biomarkers in patients with cryptogenic stroke.

METHODS

We included consecutive patients with ischemic stroke enrolled in the New York Columbia Collaborative Specialized Program of Translational Research in Acute Stroke registry between December 1, 2008, and April 30, 2012. Medical records were reviewed and patients with a diagnosis of cryptogenic stroke were identified. Atrial cardiopathy was defined as at least one of the following: serum N-terminal probrain natriuretic peptide (NT-proBNP) level greater than 250 pg/mL, P-wave terminal force velocity in lead V1 (PTFV1) on electrocardiogram (ECG) greater than 5000 µV⋅ms, or severe left atrial enlargement (LAE) on echocardiogram. We compared clinical, echocardiographic, and radiological characteristics between patients with and without atrial cardiopathy.

RESULTS

Among 40 patients with cryptogenic stroke, 63% had at least one of the biomarkers of atrial cardiopathy; 49% had elevated NT-proBNP levels, 20% had evidence of increased PTFV1 on ECG, and 5% had severe LAE. Patients with atrial cardiopathy were more likely to be older (76 versus 62 years, P = .012); have hypertension (96% versus 33%, P < .001), hyperlipidemia (60% versus 27%, P = .05), or coronary heart disease (28% versus 0%, P = .033); and less likely to have a patent foramen ovale (4% versus 40%, P = .007).

CONCLUSION

There is a high prevalence of biomarkers indicative of atrial cardiopathy in patients with cryptogenic stroke. Clinical trials are needed to determine whether these patients may benefit from anticoagulation to prevent stroke.

Potential new uses of non-vitamin K antagonist oral anticoagulants to treat and prevent stroke

BACKGROUND

Non-vitamin K antagonist oral anticoagulant (NOAC) drugs are at least equivalent to warfarin for ischemic stroke prevention in patients with atrial fibrillation and have a lower risk of intracranial hemorrhage. The role of these agents in the prevention and treatment of other types of cerebrovascular disease remains unclear.

METHODS

We reviewed the literature (randomized trials, exploratory comparative studies, and case series) on the use of NOACs in patients with atrial fibrillation, venous thromboembolism, and cerebrovascular disease independent of atrial fibrillation.

RESULTS

The literature on the use of NOACs for treatment and prevention of cerebrovascular disease in patients without atrial fibrillation is sparse. The potential benefit of vitamin K antagonists over antiplatelet agents for primary and secondary prevention in certain subsets of patients with cerebrovascular disease is offset by the increased risk of major and intracranial hemorrhage. Given that NOACs are equivalent to vitamin K antagonists in preventing ischemic stroke and systemic embolism in patients with atrial fibrillation with less bleeding risk, clinical trials are needed to investigate the short- and long-term use of NOACs in populations of patients with other forms of cerebrovascular disease, including those with cryptogenic stroke with or without evidence of patent foramen ovale and low ejection fraction, cervical artery dissection, large artery atherosclerosis, venous thrombosis, and stuttering lacunar stroke.

CONCLUSION

There may be a role for NOACs in stroke prevention and treatment beyond atrial fibrillation. Randomized controlled trials are needed to compare NOACs to current stroke prevention and treatment strategies in certain subgroups of patients with cerebrovascular disease.

Diagnosing Paroxysmal Atrial Fibrillation: Are Biomarkers the Solution to This Elusive Arrhythmia?

Atrial fibrillation (AF) is the commonest sustained arrhythmia globally and results in significantly increased morbidity and mortality including a fivefold risk of stroke. Paroxysmal atrial fibrillation (PAF) constitutes approximately half of all AF cases and is thought to represent an early stage of the disease. This intermittent form of atrial arrhythmia can be a challenge to identify and as a result many affected individuals are not prescribed appropriate antithrombotic therapy and hence are at risk of stroke and thromboembolism. Despite these adverse outcomes there have been relatively few diagnostic advances in the field since the introduction of the Holter monitor in 1949. This review aims to establish the available evidence for electrophysiological, molecular, and morphological biomarkers to improve the detection of PAF with reference to the underlying mechanisms for the condition.

Left atrial enlargement and stroke recurrence: the Northern Manhattan Stroke Study

BACKGROUND AND PURPOSE

Although left atrial enlargement (LAE) increases incident stroke risk, the association with recurrent stroke is less clear. Our aim was to determine the association of LAE with recurrent stroke most likely related to embolism (cryptogenic and cardioembolic) and all ischemic stroke recurrences.

METHODS

We followed 655 first ischemic stroke patients in the Northern Manhattan Stroke Study for ≤5 years. LA size from 2D echocardiography was categorized as normal LAE (52.7%), mild LAE (31.6%), and moderate-severe LAE (15.7%). We used Cox proportional hazard models to calculate the hazard ratios and 95% confidence intervals for the association of LA size and LAE with recurrent cryptogenic/cardioembolic and total recurrent ischemic stroke.

RESULTS

LA size was available in 529 (81%) patients. Mean age at enrollment was 69±13 years; 45.8% were male, 54.0% Hispanic, and 18.5% had atrial fibrillation. Over a median of 4 years, there were 65 recurrent ischemic strokes (29 were cardioembolic or cryptogenic). In multivariable models adjusted for confounders, including atrial fibrillation and heart failure, moderate-severe LAE compared with normal LA size was associated with greater risk of recurrent cardioembolic/cryptogenic stroke (adjusted hazard ratio 2.83, 95% confidence interval 1.03-7.81), but not total ischemic stroke (adjusted hazard ratio 1.06, 95% confidence interval, 0.48-2.30). Mild LAE was not associated with recurrent stroke.

CONCLUSION

Moderate to severe LAE was an independent marker of recurrent cardioembolic or cryptogenic stroke in a multiethnic cohort of ischemic stroke patients. Further research is needed to determine whether anticoagulant use may reduce risk of recurrence in ischemic stroke patients with moderate to severe LAE.

Relation of left atrial dysfunction to ischemic stroke in patients with coronary heart disease (from the heart and soul study)

This study sought to determine whether left atrial (LA) dysfunction independently predicts ischemic stroke. Atrial fibrillation (AF) impairs LA function and is associated with ischemic stroke. However, ischemic stroke frequently occurs in patients without known AF. The direct relation between LA function and risk of ischemic stroke is unknown. We performed transthoracic echocardiography at rest in 983 subjects with stable coronary heart disease. To quantify LA dysfunction, we used the left atrial function index (LAFI), a validated formula incorporating LA volumes at end-atrial systole and diastole. Cox proportional hazards models were used to evaluate the association between LAFI and ischemic stroke or transient ischemic attack (TIA). Over a mean follow-up of 7.1 years, 58 study participants (5.9%) experienced an ischemic stroke or TIA. In patients without known baseline AF or warfarin therapy (n = 893), participants in the lowest quintile of LAFI had >3 times the risk of ischemic stroke or TIA (hazard ratio 3.3, 95% confidence interval 1.1 to 9.7, p = 0.03) compared with those in the highest quintile. For each standard deviation (18.8 U) decrease in LAFI, the hazard of ischemic stroke or TIA increased by 50% (hazard ratio 1.5, 95% confidence interval 1.0 to 2.1, p = 0.04). Among measured echocardiographic indexes of LA function, including LA volume, LAFI was the strongest predictor of ischemic stroke or TIA. In conclusion, LA dysfunction is an independent risk factor for stroke or TIA, even in patients without baseline AF.