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.

Safety of Anticoagulation in Patients Treated With Urgent Reperfusion for Ischemic Stroke Related to Atrial Fibrillation.

BACKGROUND AND PURPOSE: The optimal timing for starting oral anticoagulant after an ischemic stroke related to atrial fibrillation remains a challenge, mainly in patients treated with systemic thrombolysis or mechanical thrombectomy. We aimed at assessing the incidence of early recurrence and major bleeding in patients with acute ischemic stroke and atrial fibrillation treated with thrombolytic therapy and/or thrombectomy, who then received oral anticoagulants for secondary prevention. METHODS: We combined the dataset of the RAF and the RAF-NOACs (Early Recurrence and Major Bleeding in Patients With Acute Ischemic Stroke and Atrial Fibrillation Treated With Non-Vitamin K Oral Anticoagulants) studies, which were prospective observational studies carried out from January 2012 to March 2014 and April 2014 to June 2016, respectively. We included consecutive patients with acute ischemic stroke and atrial fibrillation treated with either vitamin K antagonists or nonvitamin K oral anticoagulants. Primary outcome was the composite of stroke, transient ischemic attack, symptomatic systemic embolism, symptomatic cerebral bleeding, and major extracerebral bleeding within 90 days from the inclusion. Treated-patients were propensity matched to untreated-patients in a 1:1 ratio after stratification by baseline clinical features. RESULTS: A total of 2159 patients were included, 564 (26%) patients received acute reperfusion therapies. After the index event, 505 (90%) patients treated with acute reperfusion therapies and 1287 of 1595 (81%) patients untreated started oral anticoagulation. Timing of starting oral anticoagulant was similar in reperfusion-treated and untreated patients (median 7.5 versus 7.0 days, respectively). At 90 days, the primary study outcome occurred in 37 (7%) patients treated with reperfusion and in 146 (9%) untreated patients (odds ratio, 0.74 [95% CI, 0.50-1.07]). After propensity score matching, risk of primary outcome was comparable between the 2 groups (odds ratio, 1.06 [95% CI, 0.53-2.02]). CONCLUSIONS: Acute reperfusion treatment did not influence the risk of early recurrence and major bleeding in patients with atrial fibrillation-related acute ischemic stroke, who started on oral anticoagulant.

Timing of initiation of oral anticoagulants in patients with acute ischemic stroke and atrial fibrillation comparing posterior and anterior circulation strokes.

INTRODUCTION: The aim of this study in patients with acute posterior ischaemic stroke (PS) and atrial fibrillation (AF) was to evaluate (1) the risks of recurrent ischaemic event and severe bleeding and (2) these risks in relation with oral anticoagulant therapy (OAT) and its timing. MATERIALS AND METHODS: Patients with PS were prospectively included; the outcome events of these patients were compared with those of patients with anterior stroke (AS) which were taken from previous registries. The primary outcome was the composite of stroke recurrence, transient ischaemic attack, symptomatic systemic embolism, symptomatic cerebral bleeding and major extracranial bleeding occurring within 90 days from acute stroke. RESULTS: A total of 2470 patients were available for the analysis: 473 (19.1%) with PS and 1997 (80.9%) with AS. Over 90 days, 213 (8.6%) primary outcome events were recorded: 175 (8.7%) in patients with AS and 38 (8.0%) in those with PS. In patients who initiated OAT within 2 days, the primary outcome occurred in 5 out of 95 patients (5.3%) with PS compared to 21 out of 373 patients (4.3%) with AS (OR 1.07; 95% CI 0.39-2.94). In patients who initiated OAT between days 3 and 7, the primary outcome occurred in 3 out of 103 patients (2.9%) with PS compared to 26 out of 490 patients (5.3%) with AS (OR 0.54; 95% CI 0.16-1.80). DISCUSSION: our findings suggest that, when deciding the time to initiate oral anticoagulation, the location of stroke, either anterior or posterior, does not predict the risk of outcome events. CONCLUSIONS: Patients with PS or AS and AF appear to have similar risks of ischaemic or haemorrhagic events at 90 days with no difference concerning the timing of initiation of OAT.

Potential Utility of Neurosonology in Paroxysmal Atrial Fibrillation Detection in Patients with Cryptogenic Stroke.

BACKGROUND: Occult paroxysmal atrial fibrillation (PAF) is a common and potential treatable cause of cryptogenic stroke (CS). We sought to prospectively identify independent predictors of atrial fibrillation (AF) detection in patients with CS and sinus rhythm on baseline electrocardiogram (ECG), without prior AF history. We had hypothesized that cardiac arrhythmia detection during neurosonology examinations (Carotid Duplex (CDU) and Transcranial Doppler (TCD)) may be associated with higher likelihood of AF detection. METHODS: Consecutive CS patients were prospectively evaluated over a six-year period. Demographics, clinical and imaging characteristics of cerebral ischemia were documented. The presence of arrhythmia during spectral waveform analysis of CDU/TCD was recorded. Left atrial enlargement was documented during echocardiography using standard definitions. The outcome event of interest included PAF detection on outpatient 24-h Holter ECG recordings. Statistical analyses were performed using univariate and multivariate logistic regression models. RESULTS: A total of 373 patients with CS were evaluated (mean age 60 ± 11 years, 67% men, median NIHSS-score 4 points). The rate of PAF detection of any duration on Holter ECG recordings was 11% (95% CI 8%-14%). The following three variables were independently associated with the likelihood of AF detection on 24-h Holter-ECG recordings in both multivariate analyses adjusting for potential confounders: age (OR per 10-year increase: 1.68; 95% CI: 1.19-2.37; p = 0.003), moderate or severe left atrial enlargement (OR: 4.81; 95% CI: 1.77-13.03; p = 0.002) and arrhythmia detection during neurosonology evaluations (OR: 3.09; 95% CI: 1.47-6.48; p = 0.003). CONCLUSION: Our findings underline the potential utility of neurosonology in improving the detection rate of PAF in patients with CS.

Hemorrhagic Transformation in Patients With Acute Ischemic Stroke and Atrial Fibrillation: Time to Initiation of Oral Anticoagulant Therapy and Outcomes.

Background In patients with acute ischemic stroke and atrial fibrillation, early anticoagulation prevents ischemic recurrence but with the risk of hemorrhagic transformation ( HT ). The aims of this study were to evaluate in consecutive patients with acute stroke and atrial fibrillation (1) the incidence of early HT, (2) the time to initiation of anticoagulation in patients with HT , (3) the association of HT with ischemic recurrences, and (4) the association of HT with clinical outcome at 90 days. Methods and Results HT was diagnosed by a second brain computed tomographic scan performed 24 to 72 hours after stroke onset. The incidence of ischemic recurrences as well as mortality or disability (modified Rankin Scale scores >2) were evaluated at 90 days. Ischemic recurrences were the composite of ischemic stroke, transient ischemic attack, or systemic embolism. Among the 2183 patients included in the study, 241 (11.0%) had HT . Patients with and without HT initiated anticoagulant therapy after a mean 23.3 and 11.6 days, respectively, from index stroke. At 90 days, 4.6% (95% confidence interval, 2.3-8.0) of the patients with HT had ischemic recurrences compared with 4.9% (95% confidence interval, 4.0-6.0) of those without HT ; 53.1% of patients with  HT were deceased or disabled compared with 35.8% of those without HT . On multivariable analysis, HT was associated with mortality or disability (odds ratio, 1.71; 95% confidence interval, 1.24-2.35). Conclusions In patients with HT , anticoagulation was initiated about 12 days later than patients without HT . This delay was not associated with increased detection of ischemic recurrence. HT was associated with increased mortality or disability.

Duration of paroxysmal atrial fibrillation in cryptogenic stroke is not associated with stroke severity and early outcomes.

The current definition of paroxysmal atrial fibrillation (PAF) requires an arbitrary cut-off of >30s, but in clinical practice cryptogenic stroke (CS) patients with PAF duration of ≤30s are not usually excluded from anticoagulation therapy. We sought to evaluate the clinical relevance of short-duration (≤30s) PAF in CS. Consecutive CS patients with no prior AF history and sinus-rhythm on baseline electrocardiography (ECG) were prospectively evaluated over a three-year period. Baseline stroke severity was assessed by NIHSS-scores. All patients underwent 24-hour Holter-ECG during hospitalization. ECG recordings were analyzed by two blinded investigators using dedicated analysis software. Total time in AF was calculated as the sum of each individual AF episode for patients with multiple episodes during monitoring. Patients were dichotomized in two groups using PAF total duration (≤30s & >30s). Early recurrent stroke and favorable functional outcome (FFO, defined as mRS-grades of 0-1) were evaluated during a three-month follow-up period. A total of 184 patients (66% men, mean age 57±11years) with CS (median NIHSS-score 4, IQR: 2-7) were evaluated. PAF of any duration was detected in 23 individuals (13%; 95%CI: 8%-18%). Among these patients the prevalence of brief PAF was 57% (n=13). The two groups did not differ (p>0.2) in terms of demographics, vascular risk factors and NIHSS-scores. Early recurrent stroke and FFO rates were similar (p>0.4) in the two groups. Duration of PAF is not associated with baseline stroke severity and early outcomes in patients with CS and should not influence anticoagulation decision in these patients.

Intravenous thrombolysis for ischemic stroke in the golden hour: propensity-matched analysis from the SITS-EAST registry.

As there are scarce data regarding the outcomes of acute ischemic stroke (AIS) patients treated with intravenous thrombolysis (IVT) within 60 min from symptom onset ("golden hour"), we sought to compare outcomes between AIS patients treated within [GH(+)] and outside [GH(-)] the "golden hour" by analyzing propensity score matched data from the SITS-EAST registry. Clinical recovery (CR) at 2 and 24 h was defined as a reduction of ≥10 points on NIHSS-score or a total NIHSS-score of ≤3 at 2 and 24 h, respectively. A relative reduction in NIHSS-score of ≥40% at 2 h was considered predictive of complete recanalization (CREC). Symptomatic intracranial hemorrhage (sICH) was defined using SITS-MOST criteria. Favorable functional outcome (FFO) was defined as a mRS-score of 0-1 at 3 months. Out of 19,077 IVT-treated AIS patients, 71 GH(+) patients were matched to 6882 GH(-) patients, with no differences in baseline characteristics (p > 0.1). GH(+) had higher rates of CR at 2 (31.0 vs. 12.4%; p < 0.001) and 24 h (41 vs. 27%; p = 0.010), CREC at 2 h (39 vs. 21%; p < 0.001) and FFO (46.5 vs. 34.0%; p = 0.028) at 3 months. The rates of sICH and 3-month mortality did not differ (p > 0.2) between the two groups. GH(+) was associated with 2-h CR (OR: 5.34; 95% CI 2.53-11.03) and CREC (OR: 2.38; 95% CI 1.38-4.09), 24-h CR (OR: 1.88; 95% CI 1.08-3.26) and 3-month FFO (OR: 2.02; 95% CI 1.15-3.54) in multivariable logistic regression models adjusting for potential confounders. In conclusion, AIS treated with IVT within the GH seems to have substantially higher odds of early neurological recovery, CREC, 3-month FFO and functional improvement.

Prestroke CHA2DS2-VASc Score and Severity of Acute Stroke in Patients with Atrial Fibrillation: Findings from RAF Study.

BACKGROUND AND PURPOSE: The aim of this study was to investigate for a possible association between both prestroke CHA2DS2-VASc score and the severity of stroke at presentation, as well as disability and mortality at 90 days, in patients with acute stroke and atrial fibrillation (AF). METHODS: This prospective study enrolled consecutive patients with acute ischemic stroke, AF, and assessment of prestroke CHA2DS2-VASc score. Severity of stroke was assessed on admission using the National Institutes of Health Stroke Scale (NIHSS) score (severe stroke: NIHSS ≥10). Disability and mortality at 90 days were assessed by the modified Rankin Scale (mRS <3 or ≥3). Multiple logistic regression was used to correlate prestroke CHA2DS2-VASc and severity of stroke, as well as disability and mortality at 90 days. RESULTS: Of the 1020 patients included in the analysis, 606 patients had an admission NIHSS score lower and 414 patients higher than 10. At 90 days, 510 patients had mRS ≥3. A linear correlation was found between the prestroke CHA2DS2-VASc score and severity of stroke (P = .001). On multivariate analysis, CHA2DS2-VASc score correlated with severity of stroke (P = .041) and adverse functional outcome (mRS ≥3) (P = .001). A logistic regression with the receiver operating characteristic graph procedure (C-statistics) evidenced an area under the curve of .60 (P = .0001) for severe stroke. Furthermore, a correlation was found between prestroke CHA2DS2-VASc score and lesion size. CONCLUSIONS: In patients with AF, in addition to the risk of stroke, a high CHA2DS2-VASc score was independently associated with both stroke severity at onset and disability and mortality at 90 days.

Prognostic value of trans-thoracic echocardiography in patients with acute stroke and atrial fibrillation: findings from the RAF study.

Anticoagulant therapy is recommended for the secondary prevention of stroke in patients with atrial fibrillation (AF). T he identification of patients at high risk for early recurrence, which are potential candidates to prompt anticoagulation, is crucial to justify the risk of bleeding associated with early anticoagulant treatment. The aim of this study was to evaluate in patients with acute ischemic stroke and AF the association between findings at trans-thoracic echocardiography (TTE) and 90 days recurrence. In consecutive patients with acute ischemic stroke and AF, TTE was performed within 7 days from hospital admission. Study outcomes were recurrent ischemic cerebrovascular events (stroke or TIA) and systemic embolism. 854 patients (mean age 76.3 ± 9.5 years) underwent a TTE evaluation; 63 patients (7.4%) had at least a study outcome event. Left atrial thrombosis was present in 11 patients (1.3%) among whom 1 had recurrent ischemic event. Left atrial enlargement was present in 548 patients (64.2%) among whom 51 (9.3%) had recurrent ischemic events. The recurrence rate in the 197 patients with severe left atrial enlargement was 11.7%. On multivariate analysis, the presence of atrial enlargement (OR 2.13; 95% CI 1.06-4.29, p = 0.033) and CHA2DS2-VASc score (OR 1.22; 95% CI 1.04-1.45, p = 0.018, for each point increase) were correlated with ischemic recurrences. In patients with AF-associated acute stroke, left atrial enlargement is an independent marker of recurrent stroke and systemic embolism. The risk of recurrence is accounted for by severe atrial enlargement. TTE-detected left atrial thrombosis is relatively uncommon.

Early Recurrence and Cerebral Bleeding in Patients With Acute Ischemic Stroke and Atrial Fibrillation: Effect of Anticoagulation and Its Timing: The RAF Study.

BACKGROUND AND PURPOSE: The best time for administering anticoagulation therapy in acute cardioembolic stroke remains unclear. This prospective cohort study of patients with acute stroke and atrial fibrillation, evaluated (1) the risk of recurrent ischemic event and severe bleeding; (2) the risk factors for recurrence and bleeding; and (3) the risks of recurrence and bleeding associated with anticoagulant therapy and its starting time after the acute stroke. METHODS: The primary outcome of this multicenter study was the composite of stroke, transient ischemic attack, symptomatic systemic embolism, symptomatic cerebral bleeding and major extracranial bleeding within 90 days from acute stroke. RESULTS: Of the 1029 patients enrolled, 123 had 128 events (12.6%): 77 (7.6%) ischemic stroke or transient ischemic attack or systemic embolism, 37 (3.6%) symptomatic cerebral bleeding, and 14 (1.4%) major extracranial bleeding. At 90 days, 50% of the patients were either deceased or disabled (modified Rankin score ≥3), and 10.9% were deceased. High CHA2DS2-VASc score, high National Institutes of Health Stroke Scale, large ischemic lesion and type of anticoagulant were predictive factors for primary study outcome. At adjusted Cox regression analysis, initiating anticoagulants 4 to 14 days from stroke onset was associated with a significant reduction in primary study outcome, compared with initiating treatment before 4 or after 14 days: hazard ratio 0.53 (95% confidence interval 0.30-0.93). About 7% of the patients treated with oral anticoagulants alone had an outcome event compared with 16.8% and 12.3% of the patients treated with low molecular weight heparins alone or followed by oral anticoagulants, respectively (P=0.003). CONCLUSIONS: Acute stroke in atrial fibrillation patients is associated with high rates of ischemic recurrence and major bleeding at 90 days. This study has observed that high CHA2DS2-VASc score, high National Institutes of Health Stroke Scale, large ischemic lesions, and type of anticoagulant administered each independently led to a greater risk of recurrence and bleedings. Also, data showed that the best time for initiating anticoagulation treatment for secondary stroke prevention is 4 to 14 days from stroke onset. Moreover, patients treated with oral anticoagulants alone had better outcomes compared with patients treated with low molecular weight heparins alone or before oral anticoagulants.

Impact of dabigatran on platelet function and fibrinolysis.

BACKGROUND: We sought to evaluate the potential enhanced fibrinolytic and antiplatelet activity of dabigatran etexilate (DE) due to decreased thrombin levels in patients with stroke or transient ischemic attack and non-valvular atrial fibrillation (NVAF). METHODS: Consecutive patients with cerebrovascular diseases and NVAF that were treated with DE in a tertiary university hospital. Fibrinolysis and platelet function were assessed by thromboelastometry (ROTEM) and platelet function analyzer (PFA)-100, respectively, before and after treatment with DE. Conventional coagulation tests, endogenous thrombin potential (ETP) and hemoclot thrombin inhibitors (HTI), were also performed in order to detect any possible correlation between dabigatran plasma levels, its anticoagulant activity and the intensity of platelet dysfunction or fibrinolysis. RESULTS: A total of nineteen patients fulfilled our inclusion criteria (mean age 62.3±7.2years; 47% males; median CHADS2-score: 3; interquartile range: 2-4). DE treatment was associated with a significant reduction of the lysis index (LI60) at 60min (p=0.036), and prolongation of the PFA-100 CEPI closure time (p=0.024). After dabigatran treatment, abnormal PFA-100 results were obtained in two patients (11%, 95% CI: 2%-33%). DE levels (determined by HTI) were strongly inversely correlated (rho=-0.85; p<0.001) with the area under the curve (AUC) values in ETP assay. Νo association was found between HTI and PFA-100 CEPI CT (p=0.64), or LI60 measurements (p=0.60). CONCLUSIONS: Our findings indicate that DE might affect platelet function and fibrinolysis and highlight the potential role of ETP as an alternative option in DE monitoring. The intensity and clinical relevance of DE antiplatelet and fibrinolytic effects require further investigation.

Dabigatran etexilate for secondary stroke prevention: the first year experience from a multicenter short-term registry.

BACKGROUND: There are growing concerns for the side effects of dabigatran etexilate (dabigatran), including higher incidence of dyspepsia and gastrointestinal bleeding. We conducted a multicenter early implementation study to prospectively evaluate the safety, efficacy and adherence to dabigatran for secondary stroke prevention. METHODS: Consecutive atrial fibrillation (AF) patients with ischemic stroke (IS) or transient ischemic attack (TIA) received dabigatran for secondary stroke prevention during their hospital stay according to American Heart Association recommendations at five tertiary care stroke centers. The study population was prospectively followed and outcomes were documented. The primary and secondary safety outcomes were major hemorrhage and all other bleeding events respectively defined according to RE-LY trial methodology. RESULTS: A total of 78 AF patients (mean age 71 ± 9years; 54% men; 81% IS, 19% TIA; median CHADS2 (Congestive heart failure, Hypertension, diabetes mellitus, age >75 years, prior stroke or TIA); range 2-5) score 4 were treated with dabigatran [(110mg bid (74%); 150mg bid (26%)]. During a mean follow-up period of 7 ± 5 months (range 1-18) we documented no cases of IS, TIA, intracranial hemorrhage, systemic embolism or myocardial infarction in AF patients treated with dabigatran. There were two (2.6%) major bleeding events (lower gastrointestinal bleeding) and two (2.6%) minor bleedings [hematuria (n = 1) and rectal bleeding (n = 1)]. Dabigatran was discontinued in 26% of the study population with high cost being the most common reason for discontinuation (50%). DISCUSSION: Our pilot data indicate that dabigatran appears to be safe for secondary stroke prevention during the first year of implementation of this therapy. However, high cost may limit the long-term treatment of AF patients with dabigatran, leading to early discontinuation.