Fibrillation In Cryptogenic Stroke Research Articles

Incidence of atrial fibrillation in cryptogenic stroke with patent foramen ovale closure: protocol for the prospective, observational PFO-AF study

IntroductionAfter closure of patent foramen ovale (PFO) due to stroke, atrial fibrillation (AF) occurs in up to one in five patients. However, data are sparse regarding the possible pre-existence of...

Assessment of left atrial appendage flow velocities to unmask atrial fibrillation in cryptogenic stroke

Abstract Funding Acknowledgements Type of funding sources: None. Background Hemostasis in the left atrial (LA) appendage (LAA) is a common cause of stroke, particularly in atrial fibrillation (AF). LAA flow have been determined to quantify LAA function. Objectives To investigate whether LAA peak flow velocities early after cryptogenic stroke have a predictive value for AF occurrence and to determine the determinants of impaired flow. Methods Consecutive cryptogenic stroke patients (139) were enrolled. LAA flow velocities during sinus rhythm were assessed early post-stroke with transesophageal echocardiography. All patients received rhythm monitoring using 7-day Holter and if negative, an implantable cardiac monitor. Results 47 Patients (34%) developed AF during a median follow-up of 554 days, median time to AF diagnosis was 93 days. Both, LAA filling (LAAfv) and emptying (LAAev) velocities were lower in stroke patients who developed AF (resp. 44.3±14.2 cm/s and 50.7±13.3 cm/s) compared with those who didn’t (resp. 59.8±14.0 cm/s and 76.8±17.3 cm/s). LAAev was the strongest predictor of AF with an AUC of 0.878 in ROC curve analysis and with optimal cut-off value of 55 cm/s. Age and mitral regurgitation were independent determinants of reduced LAAev. Conclusions Reduced LAA flow velocities can identify cryptogenic stroke patients at high risk of occult AF, and who may benefit from intensive rhythm monitoring or anticoagulation strategies.

Immediate implantable loop recorder implantation for detecting atrial fibrillation in cryptogenic stroke

IntroductionAtrial fibrillation (AF) is suspected as the main cause of stroke in the majority of patients presenting with cryptogenic stroke (CS). Implantable loop recorders (ILR's) are indicated for detecting AF in these patients.The short term (<1 month) and long-term AF detection rates in patients inserted with an ILR immediately after CS is reported. Secondly, we compare the safety of nurse led vs physician led ILR implantation in these patients. MethodsThis is a retrospective review of all patients who underwent inpatient ILR implantation (Medtronic Linq) between May 2020 and May 2022 at East Sussex Healthcare NHS trust. All patients were remotely monitored via the FOCUSONTM monitoring and triage service. ResultsA total of 186 subjects were included in the study and were followed up for a mean period of 363.0 +/− 222.6 days. The mean time between stroke and ILR was 7.0 +/− 5.5 days. The mean time between referral and ILR was 1.0 +/− 2.0 days. AF was detected in 25 (13.4%) patients. During the first 30 days of monitoring, AF was detected in 9 (4.8%) patients.The number of ILR implants performed by the specialist nurse was 107 (57.5%). There was no significant difference in the major complication rate (requiring device removal) between nurse and physician led implant (1 (0.95%) vs 0 (0%), p value = 0.389). ConclusionInpatient ILR for cryptogenic stroke is feasible. The rate of AF detection in the first month post CS is 4.8% however, more AF was detected up to one year post implant, suggesting rationale for proceeding directly to ILR implant in these patients before discharge to not delay treatment. A nurse led service is also viable with no significant difference in the major complication rate compared to physician led implants.

Non-conducted premature atrial complexes: A new independent predictor of atrial fibrillation in cryptogenic stroke

IntroductionAtrial fibrillation (AF) is the main cardiac cause of stroke, but it frequently remains undetected. In patients with cryptogenic stroke an Holter electrocardiogram (ECG) monitoring for AF is recommended. ObjectiveTo evaluate the prognostic role of Non-Conducted Premature Atrial Complexes (ncPACs) recorded on Holter ECG. MethodsWe prospectively enrolled consecutive patients admitted to the Stroke Unit of our hospital with a diagnosis of cryptogenic stroke between December 2018 and January 2020; all patients underwent 24-h Holter ECG monitoring during hospitalization. Two follow-up visits were scheduled, including a 24-h Holter ECG at 3 and 6 months to detect AF. ResultsAmong 112 patients, 58% were male with an average age of 72.2 ± 12.2 years. At follow-up, AF was diagnosed in 21.4% of the population. The baseline 24-h Holter ECG burden of ncPACs and Premature Atrial Complexes (PACs) was higher in patients with AF detected on follow-up (13.5 vs 2, p = 0.001; 221.5 vs 52; p = 0.01). ROC analysis showed that ncPACs had the best diagnostic accuracy in predicting AF (AUC:0.80; 95% CI 0.68–0.92). Cut-off value of ≥7 for ncPACs burden showed the highest accuracy with sensitivity of 62.5% and specificity 97.7% to predict AF onset at follow-up. Moreover, at multivariate Cox-proportional hazard analysis ncPACs burden ≥7 was a powerful independent predictor of AF onset (HR 12.4; 95% CI 4.8–32.8; p < 0.0001). ConclusionsNcPACs burden ≥7 represents a new predictor of AF that could guide the screening of this arrhythmia in cryptogenic stroke patients.

The Potential and Limitations of Mobile Health and Insertable Cardiac Monitors in the Detection of Atrial Fibrillation in Cryptogenic Stroke Patients: Preliminary Results From the REMOTE Trial.

AimThis paper presents the preliminary results from the ongoing REMOTE trial. It aims to explore the opportunities and hurdles of using insertable cardiac monitors (ICMs) and photoplethysmography-based mobile health (PPG-based mHealth) using a smartphone or smartwatch to detect atrial fibrillation (AF) in cryptogenic stroke and transient ischemic attack (TIA) patients.Methods and ResultsCryptogenic stroke or TIA patients (n = 39) received an ICM to search for AF and were asked to use a blinded PPG-based mHealth application for 6 months simultaneously. They were randomized to smartphone or smartwatch monitoring. In total, 68,748 1-min recordings were performed using PPG-based mHealth. The number of mHealth recordings decreased significantly over time in both smartphone and smartwatch groups (p < 0.001 and p = 0.002, respectively). Insufficient signal quality was more frequently observed in smartwatch (43.3%) compared to smartphone recordings (17.8%, p < 0.001). However, when looking at the labeling of the mHealth recordings on a patient level, there was no significant difference in signal quality between both groups. Moreover, the use of a smartwatch resulted in significantly more 12-h periods (91.4%) that were clinically useful compared to smartphone users (84.8%) as they had at least one recording of sufficient signal quality. Simultaneously, continuous data was collected from the ICMs, resulting in approximately 6,660,000 min of data (i.e., almost a 100-fold increase compared to mHealth). The ICM algorithm detected AF and other cardiac arrhythmias in 10 and 19 patients, respectively. However, these were only confirmed after adjudication by the remote monitoring team in 1 (10%) and 5 (26.3%) patients, respectively. The confirmed AF was also detected by PPG-based mHealth.ConclusionBased on the preliminary observations, our paper illustrates the potential as well as the limitations of PPG-based mHealth and ICMs to detect AF in cryptogenic stroke and TIA patients in four elements: (i) mHealth was able to detect AF in a patient in which AF was confirmed on the ICM; (ii) Even state-of-the-art ICMs yielded many false-positive AF registrations; (iii) Both mHealth and ICM still require physician revision; and (iv) Blinding of the mHealth results impairs compliance and motivation.

Abstract TP219: ACE2L: A Novel Scoring Tool With High Sensitivity And Specificity In Predicting Atrial Fibrillation In Cryptogenic Stroke

Introduction/Background: Stroke is a leading cause of serious, long-term disability and death worldwide. Atrial fibrillation (AF) is the most common form of sustained cardiac arrhythmia, and is associated with a high risk of ischemic stroke and thromboembolism. Many cryptogenic strokes may be due to underlying, undetected paroxysmal AF. We performed a retrospective evaluation of patients with a history of ischemic stroke who were subsequently diagnosed with AF in order to develop a novel risk score calculator to help guide management in patients with cryptogenic stroke. Methods: We evaluated patients with a history of ischemic stroke both with and without a subsequent diagnosis of AF. Patients with a pre-existing diagnosis of AF were excluded. 1 point was assigned for each of the following: (1) age &gt; 60; (2) cortical ischemic stroke; (3) embolic appearance on imaging; (4) p-wave terminal force &gt; 5000 μVms; (5) increased left atrial volume index; (6) lack of extracranial large vessel occlusion (LVO). Patients with ipsilateral extracranial LVO and patients with LVO &gt; 70% were excluded. Results: A total of 74 patients with a diagnosis of ischemic stroke were evaluated. Of these, 41 patients had a subsequent diagnosis of AF, and 33 patients did not. A score of 4 or higher correlated with a sensitivity of 86.8% (95% CI: 72.7%, 94.2%), specificity of 100% (95% CI 89.8%, 100%), PPV 100% (95% CI 89.6%, 100%), NPV 87.2% (95% CI 73.3%, 94.4%), negative likelihood ratio 0.13 (95% CI 5.8%, 29.8%), and accuracy 93.1% (95% CI 84.8%, 897%). Conclusions: The novel ACE2L scoring tool demonstrated high sensitivity and specificity in predicting atrial fibrillation in patients with ischemic stroke. This scoring tool utilizes factors readily accessible in the evaluation of acute stroke and is a simple tool that may be used to help guide further management. Future, prospective studies are needed to further validate this scoring tool.

Abstract 12656: Atrial Speckle Tracking Echocardiography for Detecting Atrial Fibrillation in Cryptogenic Stroke: A Meta-Analysis

Introduction: Cryptogenic stroke (CS) accounts for approximately twenty-five percent of ischemic stroke cases with atrial fibrillation (AF) accounting for thirty percent of CS cases. We aimed to investigate the utility of atrial speckle tracking (STE) in identifying patients at high risk of AF after CS and potentially guiding patients who will benefit from long term rhythm monitoring devices. Methods: Cochrane Library, MEDLINE, and EMBASE were searched for relevant studies. We included studies that examined patients with new CS without a history of AF, and further examined LA strain parameters (peak and/or reservoir strain). Continuous data were pooled as a mean difference (MD) comparing patients who developed AF versus(vs) no AF. We used inverse variance method with Paule-Mandel estimator for tau2 and Hartung-Knapp adjustment, for random effect analysis. Hazard ratios were pooled using a similar statistical method. I2 was used to assess heterogeneity. Results: Eleven observational studies met our criteria, and included 2834 patients with new CS. Of those, 377 patients developed AF on follow up and 2457 patients did not develop AF. The AF group vs no AF had significantly reduced LA reservoir strain (LARS) [MD: -8.95; 95% CI: -11.33, -6.57) I2= 85%, p&lt;0.001] at presentation. Further, a higher LARS was associated with a significantly lower incidence of AF after CS[HR: 0.93; 95%CI:0.89, 0.97)I2=0%]. Conclusion: Atrial reservoir strain is significantly lower in patients who developed AF after CS and a lower value is predictive of AF. More studies are needed to validate this data.

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

ObjetiveCryptogenic 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. MethodsSixty-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. ResultsAF 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). ConclusionThis 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

A comprehensive model to estimate underlying atrial fibrillation in cryptogenic stroke: the decrypting score

Abstract Introduction Cryptogenic stroke (CS) represents up to 30% of ischemic strokes. Since atrial fibrillation (AF) can be detected in up to one-third of CS, there is a clinical need for estimating the probability of underlying AF in CS to guide the optimal secondary prevention strategy. Surrogate markers of left atrial dysfunction such as left atrial size, left atrial strain (LAS) and NTproBNP has been described as predictors of AF in patients with CS. However the evidence about AF markers in comprehensive and prospective studies in CS is still limited. Purpose The present study was designed to develop the first score to predict underlying AF in CS patients that includes markers of atrial dysfunction. To reach our aim we developed a comprehensive analysis including clinical, laboratory, electrocardiografic and advanced echocardiographic variables in patients with CS. Methods Sixty-three consecutive patients with ischemic stroke or transient ischemic attack with ABCD2 scale ≥4 of unknown etiology were prospectively recruited. Clinical, laboratory, electrocardiografic and echocardiographic variables were collected. All patients underwent 15 days wearable Holter monitoring. Main objective was the Decryptoring score creation to predict AF in CS. Score variables were initially selected by a univariate logistic regression and, thereafter, the score points were derived according to a multivariant analysis. Results AF was detected in 15 patients (24%). Patients in the AF group were older (81.4±6.9 vs 76.5±7.8 years; p=0.035. There was no difference in sex between groups. Regarding cardiovascular risk factors patients who developed AF had more often hypertension (87% vs 52%; p=0.018) without differences in diabetes, dyslipidemia and tobacco consumption. T troponin and NTproBNP were higher in the AF group (47±55.9 vs 16.8±12.4 ng/L; p=0.018 and 1379±1650 vs 317±496 ng/ml; p=0.001 respectively). There were no differences in ECG parameters such as p wave voltage, interatrial block, PR interval or QRS. LAS reservoir, LAS conduct and LAS contraction were lower in patients with AF (18.6±4.6 vs 32.1±10.9%; 8±4.3 vs 15.6±8%; 10.5±3.4 vs 16.6±7 respectively, all p&amp;lt;0.001). Age &amp;gt;75 (9 points), hypertension (1 point), Troponin T &amp;gt;40 ng/L (8.5 points), NTproBNP &amp;gt;200 pg/ml (0.5 points), LAS reservoir &amp;lt;25.3% (24.5 points) and LAS conduct &amp;lt;10.4% (0.5 points) were included in the score. The rate of AF detection was 0% among patients with a score of &amp;lt;10 and 80% among patients with a score &amp;gt;35. Conclusion The proposed score offers an accurate AF prediction in patients with CS providing a new clinical tool to orient the optimal treatment in these patients. Funding Acknowledgement Type of funding sources: Other. Main funding source(s): Spanish Society of Cardiology

Implantable loop recorder to detect atrial fibrillation in cryptogenic stroke: A real-world experience

Paroxysmal atrial fibrillation (AF) represents one of the main mechanisms underlying cryptogenic stroke (CS). Trials have shown that prolonged cardiac monitoring through Implantable Loop Recorders (ILR) allows higher AF detection frequency after CS compared with routine follow-up and 24 h Holter monitoring, reaching 30% rate at 3 years. We aimed at assessing whether these data are reproducible in clinical practice.

Cost-effectiveness of insertable cardiac monitors for diagnosis of atrial fibrillation in cryptogenic stroke in Australia.

IntroductionDetection of atrial fibrillation (AF) is required to initiate oral anticoagulation (OAC) after cryptogenic stroke (CS). However, paroxysmal AF can be difficult to diagnose with short term cardiac monitoring. Taking an Australian payer perspective, we evaluated whether long‐term continuous monitoring for 3 years with an insertable cardiac monitor (ICM) is cost‐effective for preventing recurrent stroke in patients with CS.MethodsA lifetime Markov model was developed to simulate the follow‐up of patients, comparing long‐term continuous monitoring with an ICM to monitoring by conventional care. We used a linked evidence approach to estimate the rates of recurrent stroke when AF detection leads to initiation of OAC, as detected using ICM during the lifetime of the device or as detected using usual care. All diagnostic and patient management costs were modeled. Other model inputs were determined by literature review. Probabilistic sensitivity analysis (PSA) was undertaken to explore the effect of parameter uncertainty according to CHADS2 score and OAC treatment effect.ResultsIn the base‐case analysis, the model predicted an incremental cost‐effectiveness ratio (ICER) of A$29 570 per quality‐adjusted life year (QALY). Among CHADS2 subgroups analyses, the ICER ranged from A$26 342/QALY (CHADS2 = 6) to A$42 967/QALY (CHADS2 = 2). PSA suggested that the probabilities of ICM strategy being cost‐effective were 53.4% and 78.7%, at thresholds of $30 000 (highly cost‐effective) and $50 000 per QALY (cost‐effective), respectively.ConclusionsLong‐term continuous monitoring with an ICM is a cost‐effective intervention to prevent recurrent stroke in patients following CS in the Australian context.

Abstract 15866: The Utility of Extended Electrocardiographic Monitoring for Detecting Atrial Fibrillation in Cryptogenic Stroke in the African-american Population

Introduction: Cryptogenic stroke comprises about 25% of all ischemic strokes. Depending on modality and duration of ECG monitoring, subclinical atrial fibrillation (AF) is detectable in 2.7-30% of cryptogenic stroke patients. Hypothesis: Extended ECG monitoring has not been studied in the African American (AA) population. This retrospective study aims to study the incidence and risk factors of subclinical AF in African-Americans. Methods: We retrospectively reviewed 96 patients who received implantable loop recorders (ILR) for detecting subclinical atrial fibrillation after cryptogenic stroke. In the vast majority of patients, the ILR was implanted during the index hospitalization. Binary univariate and multivariate analyses were performed to determine predictors for AF detection. Results: AF was detected in 29% of patients (28/96) at 1000 days. All AF that was detected was exquisitely paroxysmal and ranged in duration between 0.05-103 minutes (mean 8.4 minutes with SD= 22.1 minutes). Baseline characteristics of patients are presented (Table 1A). Binary univariate analysis revealed the use of non-dihydropyridine calcium-channel blockers to be associated with decreased odds of AF detection. (Table 1B, C). Multivariate analysis found coronary artery disease diagnosis to be associated with increased odds of AF detection. Fifty-percent of the events in the AF group were detected within the first 36 days of loop recorder implantation (Fig 1). Conclusions: AF detection in our population occurs very early after index stroke and at significantly higher rates than reported in the CRYSTAL AF trial. Baseline characteristics have a poor predictive ability for the detection of AF. These findings emphasize the need for pre-discharge ILR implantation to improve AF detection in all patients with cryptogenic stroke.

Paroxysmal Atrial Fibrillation in Cryptogenic Stroke Patients With Major-Vessel Occlusion.

Background and Purpose: To determine whether acute major-vessel occlusion (MVO) predicts atrial fibrillation (AF) in cryptogenic stroke (CS) patients, we analyzed the association between acute MVO and AF detected by insertable cardiac monitoring (ICM).Methods: We conducted a retrospective, multicenter, observational study of patients with CS who underwent ICM implantation between October 2016 and March 2018. In this analysis, we included follow-up data until June 2018. We analyzed the association of MVO with AF detected by ICM.Results: We included 84 consecutive patients with CS who underwent ICM implantation. The proportion of patients with newly detected AF by ICM was higher in patients with MVO than in those without (41% [12/29] vs. 13% [7/55], p < 0.01) within 90 days of ICM implantation. The MVO was associated with AF after adjustment for each clinically relevant factor.Conclusions: MVO was independently associated with AF detection in patients with CS, which suggests that MVO may be a useful predictor of latent AF. It is therefore essential to actively assess latent AF in patients with CS presenting with MVO.

In-thrombus thrombin secretion: a new diagnostic marker of atrial fibrillation in cryptogenic stroke

BackgroundEndovascularly retrieved clots are a potential resource for diagnosing stroke etiology, which may influence secondary prevention treatment. In this study we measured thrombin activity eluted by serially washing clots.MethodsClots were...

Association between electrocardiographic and echocardiographic atrial abnormalities and prognosis in cryptogenic stroke

Background and PurposeThe role of atrial fibrillation in cryptogenic stroke (CS) is well known. However, the usefulness of left atrial (LA) electrical and morphological abnormalities to identify more disabling strokes in sinus rhythm patients is less studied. We evaluated the association between electrocardiographic P-wave abnormalities and echocardiographic LA measures with neurological disability in patients with cryptogenic stroke. MethodsIn a retrospective cohort, we included all consecutive hospitalized patients with cryptogenic stroke. Patients were classified according to modified Rankin scale at hospital discharge and at 3 months. LA abnormalities were identified by electrocardiographic (ECG) P-wave, axis and LA enlargement criteria, and by bidimensional echocardiograph through left atrial diameter and volume index. ResultsAmong the 143 patients with CS (63.4 ± 14.2 years, 53% women), 70 patients were classified as non-disabling stroke (Rankin score < 2) and 73 patients as disabling stroke (Rankin score ≥ 2) at hospital discharge. On echocardiogram, more patients with disabling stroke presented with enlarged LA volume index (48% vs. 25%; p = 0.01). This difference remained significant after adjustment for age, gender, CHA2DS2-VASc and NIHSS scores (p = 0.02) and even when the LA volume index was analyzed as a continuous variable (p = 0.055). Also, enlarged LA volume index was more prevalent (52% vs. 25%; p = 0.03) among those with disabling stroke at 3 months after hospital discharge. Among ECG criteria, only the LA enlargement assessed by downward deflection was more prevalent in disabling stroke. ConclusionOur study demonstrated an association between left atrial enlargement, assessed by downward deflection from ECG and volume index from echocardiogram, and more disabling cryptogenic strokes. This information could help to identify patients with poorer prognosis, or a subgroup where atrial cardiopathy may play a role in cardioembolic pathway.

Cost-Effectiveness of Extended Electrocardiogram Monitoring for Atrial Fibrillation After Stroke: A Systematic Review.

Management of cryptogenic stroke involves the identification of modifiable risk factors, such as atrial fibrillation (AF). Extended rhythm monitoring increases AF detection rates but at an increased device cost compared with conventional Holter monitoring. The objective of the study was to identify and synthesize the existing literature on the cost-effectiveness of prolonged rhythm monitoring devices for AF detection in cryptogenic stroke. We conducted a systematic review of available economic evaluations of prolonged ECG monitoring for AF detection following cryptogenic stroke compared with standard care. Of the 530 unique citations, 8 studies assessed the cost-utility of prolonged ECG monitoring compared with standard care following cryptogenic stroke. The prolonged ECG monitoring strategies included 7-day ambulatory monitoring, 30-day external loop recorders or intermittent ECG monitoring, and implantable loop recorders. The majority of cost-utility analyses reported incremental cost-effectiveness ratios below $50 000 per QALY gained; and two studies reported a cost-savings. There is limited economic literature on the cost-effectiveness of extended ECG monitoring devices for detection of atrial fibrillation in cryptogenic stroke. In patients with cryptogenic stroke, extended ECG monitoring for AF detection may be economically attractive when traditional willingness-to-pay thresholds are adopted. However, there was substantial variation in the reported ICERs. The direct comparison of cost-effectiveness across technologies is limited by heterogeneity in modeling assumptions.

Abstract WMP109: Implementation of a Clinical Score for Predicting Atrial Fibrillation in Cryptogenic Stroke

Background: The HAVOC score was developed to predict the risk of atrial fibrillation (AF) in patients with embolic events of undetermined origin. The purpose of this study was to evaluate the utility of the HAVOC score to predict AF in patients with cryptogenic stroke, included in a secondary prevention program (PROTEGE-ACV). Methods: patients with cryptogenic stroke were included. HAVOC score (one point each for peripheral vascular disease and obesity with body mass index &gt;30, two points each for hypertension, age &gt; 75, valvular heart disease, and coronary artery disease, 4 points for congestive heart failure) was calculated for all patients. AF was tracked by serial cardiac holter during the first 3 years of follow-up. Results: from December 2006 to December 2018, 836 patients with cryptogenic stroke were included. Mean age was 75 ± 13 years and 54% were women. The AF was detected in 14% of patients in the first year, 30% in the second year and 35% in the third year. When patients without AF (n: 544) and patients with AF (N: 292) were compared, a higher prevalence of women (59% vs. 50%, P0.01) and heart failure (37% vs. 20%, P0.001) were observed in patients with AF. The HAVOC score was significantly higher among patients with AF [median 4 with interquartile range (IQR) 2-5] than those without AF [median 2.0 (IQR 0-3)], p = 0.01. In the follow-up, all patients with a baseline HAVOC score greater than 4 developed AF. Conclusions: The HAVOC score is a simple tool based on clinical data, that can be useful for determining a high-risk AF population among patients with cryptogenic stroke.

Abstract 22: Incidence Rate of Atrial Fibrillation in Cryptogenic Stroke: Results From the Reveal LINQ Real-World Registry

Objectives: To determine the incidence rate of AF in real-world patients with prior cryptogenic stroke (CS) or transient ischemic attack (TIA) and to assess the impact of using an insertable cardiac monitor (ICM) on treatments. Methods: The Reveal LINQ registry is an ongoing, observational, multi-center study evaluating the role of the ICM in the patient care pathway. Patients with prior CS or TIA were included. Patients without device data or without any contact after ICM insertion, with a history of AF, prior known atrial ablation, or hemorrhagic stroke were excluded. Device data were adjudicated by at least 2 independent reviewers. Patients were considered to have AF if they had a ≥2 min episode, and to not have AF if no AF was found after 1 year of monitoring. Patients without AF and without 1 year of follow-up were excluded from the general analysis due to limited follow-up time but were included in the AF incidence rates calculation for completeness. Results: In total, 192 patients (61±14 years, 61% male, mean CHA2DS2-VASc score 3.8±1.4) from 29 centers in 8 countries were included. Reasons for monitoring were CS (96%) and TIA (4%). During an average follow-up of 19±6 months, AF was detected in 36 (19%) patients and the incidence of first episode of AF ≥2 min, ≥1 h, ≥6 h, and ≥24 h was 16.7%, 7.9%, 3.7% and 1.7% at 24 months, respectively (figure). Patients with AF were older (68±14 years vs. 60±14, p&lt;0.001). Anticoagulant treatment was initiated in 29 (15%) patients during follow-up , while 14 of 45 initially on anticoagulants discontinued the treatment (13 were free of AF after 1-year follow-up and 1 had a single episode). Other AF-related clinical actions included ablations in 5 patients (2.6%), 1 electrical cardioversion (0.5%) and 3 IPG implants (1.6%). Conclusion: ICM monitoring in cryptogenic stroke/TIA patients is currently being used by clinicians for treatment decisions, but the impact on clinical events and quality of life requires ongoing investigation.

P Wave Dispersion and Silent Atrial Fibrillation in Cryptogenic Stroke: The Pathogenic Role of Inflammation

Cryptogenic stroke (CS) represents 25% of ischemic strokes. Especially after CS, the detection of atrial fibrillation (AF) is important because it provides clues to the mechanism of stroke. However, the relationship between AF and stroke appears more complex than a simple cause-effect mechanism, suggesting that the association between AF and stroke may be due to other systemic and atrial factors including systemic inflammation that may lead to atrial remodeling and subsequent atrial cardiopathy. The aim of this study was to evaluate the relationship among different electrocardiographic parameters, inflammatory markers and in-hospital AF occurrence after acute CS. 222 patients with CS underwent 12-lead resting ECG at admission and 7-day in-hospital ECG monitoring. The following indices were evaluated: P-wave dispersion (PWD), P-wave index, P-wave axis, atrial size and high-sensitivity-C reactive protein (CRP). AF was detected in 44 patients. AF-group had significantly higher PWD, P-wave index, PR interval, CRP and greater frequency of abnormal P-wave axis in comparison with no-AF group. There was a significant correlation between CRP and PWD (r=0.28). By using the mediation analysis, performed according to the "bootstrapping" method, we found that PWD is a significant mediator variable of the relationship between CRP and AF occurrence, accounting for 40% of the association. In cryptogenic stroke, high PWD is partly due to systemic inflammation that increases AF risk possibly via atrial electric remodeling. These findings could also suggest inflammation as a possible therapeutic target in order to prevent atrial electrical alterations and finally AF occurrence in CS.

319 Appropriate Duration of Extended Cardiac Monitoring for Atrial Fibrillation in Cryptogenic Stroke

Abstract Background Strokes due to cardio embolism are generally more severe and prone to early and long term recurrence. All forms of anticoagulant therapy are associated with a two thirds risk reduction in acute ischaemic stroke associated with atrial fibrillation. Establishing a diagnosis of paroxysmal atrial fibrillation can be a challenging one. Our study will attempt to answer the question as to what duration of extended cardiac monitoring is required when screening for atrial fibrillation in cryptogenic stroke. Methods We examined the time of atrial fibrillation initial diagnosis in 50 patients with an original working diagnosis of cryptogenic stroke but later have atrial fibrillation confirmed on extended monitoring. All patients wore the external loop recorder from 1 day to 3 weeks’ duration. On return of the device, data from the external loop recorder was downloaded, and reviewed by a consultant cardiologist. The total duration of monitoring using the external loop recorder was recorded. The time to first episode of algorithm detected atrial fibrillation was recorded. Results The mean duration of extended cardiac monitoring using the external loop recorder was 120.1days By seven days, atrial fibrillation had been detected in 94% of patients. By 72 hours, atrial fibrillation had been detected in 78% of patients. The mean age of participants was 58.3 years. 54.4% were female. The mean time to detection of atrial fibrillation was 52.9 hours. The median time to detection of atrial fibrillation was 34.2 hours. Conclusion External loop recorders present an opportunity for detection of paroxysmal atrial fibrillation in high risk individuals. Our study shows the feasibility and accuracy of a screening duration of seven days in the high risk post ischaemic stroke population. A one week screening timeframe allows us to screen twice as many patients for paroxysmal atrial fibrillation. Successful screening for atrial fibrillation in this high risk group allows the commencement of acceptable and safe anticoagulant therapy.