Prediction of underlying atrial fibrillation in patients with a cryptogenic stroke: results from the NOR-FIB Study.

BACKGROUND: Atrial fibrillation (AF) detection and treatment are key elements to reduce recurrence risk in cryptogenic stroke (CS) with underlying arrhythmia. The purpose of the present study was to assess the predictors of AF in CS and the utility of existing AF-predicting scores in The Nordic Atrial Fibrillation and Stroke (NOR-FIB) Study. METHOD: The NOR-FIB study was an international prospective observational multicenter study designed to detect and quantify AF in CS and cryptogenic transient ischaemic attack (TIA) patients monitored by the insertable cardiac monitor (ICM), and to identify AF-predicting biomarkers. The utility of the following AF-predicting scores was tested: AS5F, Brown ESUS-AF, CHA2DS2-VASc, CHASE-LESS, HATCH, HAVOC, STAF and SURF. RESULTS: In univariate analyses increasing age, hypertension, left ventricle hypertrophy, dyslipidaemia, antiarrhythmic drugs usage, valvular heart disease, and neuroimaging findings of stroke due to intracranial vessel occlusions and previous ischemic lesions were associated with a higher likelihood of detected AF. In multivariate analysis, age was the only independent predictor of AF. All the AF-predicting scores showed significantly higher score levels for AF than non-AF patients. The STAF and the SURF scores provided the highest sensitivity and negative predictive values, while the AS5F and SURF reached an area under the receiver operating curve (AUC) > 0.7. CONCLUSION: Clinical risk scores may guide a personalized evaluation approach in CS patients. Increasing awareness of the usage of available AF-predicting scores may optimize the arrhythmia detection pathway in stroke units.

Atrial fibrillation in cryptogenic stroke and TIA patients in The Nordic Atrial Fibrillation and Stroke (NOR-FIB) Study: Main results.

Introduction: Secondary stroke prevention depends on proper identification of the underlying etiology and initiation of optimal treatment after the index event. The aim of the NOR-FIB study was to detect and quantify underlying atrial fibrillation (AF) in patients with cryptogenic stroke (CS) or transient ischaemic attack (TIA) using insertable cardiac monitor (ICM), to optimise secondary prevention, and to test the feasibility of ICM usage for stroke physicians. Patients and methods: Prospective observational international multicenter real-life study of CS and TIA patients monitored for 12 months with ICM (Reveal LINQ) for AF detection. Results: ICM insertion was performed in 91.5% by stroke physicians, within median 9 days after index event. Paroxysmal AF was diagnosed in 74 out of 259 patients (28.6%), detected early after ICM insertion (mean 48 ± 52 days) in 86.5% of patients. AF patients were older (72.6 vs 62.2; p < 0.001), had higher pre-stroke CHA2DS2-VASc score (median 3 vs 2; p < 0.001) and admission NIHSS (median 2 vs 1; p = 0.001); and more often hypertension (p = 0.045) and dyslipidaemia (p = 0.005) than non-AF patients. The arrhythmia was recurrent in 91.9% and asymptomatic in 93.2%. At 12-month follow-up anticoagulants usage was 97.3%. Discussion and conclusions: ICM was an effective tool for diagnosing underlying AF, capturing AF in 29% of the CS and TIA patients. AF was asymptomatic in most cases and would mainly have gone undiagnosed without ICM. The insertion and use of ICM was feasible for stroke physicians in stroke units.

Underlying causes of cryptogenic stroke and TIA in the nordic atrial fibrillation and stroke (NOR-FIB) study - the importance of comprehensive clinical evaluation.

BACKGROUND: Cryptogenic stroke is a heterogeneous condition, with a wide spectrum of possible underlying causes for which the optimal secondary prevention may differ substantially. Attempting a correct etiological diagnosis to reduce the stroke recurrence should be the fundamental goal of modern stroke management. METHODS: Prospective observational international multicenter study of cryptogenic stroke and cryptogenic transient ischemic attack (TIA) patients clinically monitored for 12 months to assign the underlying etiology. For atrial fibrillation (AF) detection continuous cardiac rhythm monitoring with insertable cardiac monitor (Reveal LINQ, Medtronic) was performed. The 12-month follow-up data for 250 of 259 initially included NOR-FIB patients were available for analysis. RESULTS: After 12 months follow-up probable stroke causes were revealed in 43% patients, while 57% still remained cryptogenic. AF and atrial flutter was most prevalent (29%). In 14% patients other possible causes were revealed (small vessel disease, large-artery atherosclerosis, hypercoagulable states, other cardioembolism). Patients remaining cryptogenic were younger (p < 0.001), had lower CHA2DS2-VASc score (p < 0.001) on admission, and lower NIHSS score (p = 0.031) and mRS (p = 0.016) at discharge. Smoking was more prevalent in patients that were still cryptogenic (p = 0.014), while dyslipidaemia was less prevalent (p = 0.044). Stroke recurrence rate was higher in the cryptogenic group compared to the group where the etiology was revealed, 7.7% vs. 2.8%, (p = 0.091). CONCLUSION: Cryptogenic stroke often indicates the inability to identify the cause in the acute phase and should be considered as a working diagnosis until efforts of diagnostic work up succeed in identifying a specific underlying etiology. Timeframe of 6-12-month follow-up may be considered as optimal. TRIAL REGISTRATION: ClinicalTrials.gov Identifier NCT02937077, EudraCT 2018-002298-23.

Vascular risk factor control and adherence to secondary preventive medication after ischaemic stroke.

BACKGROUND: Studies regarding adequacy of secondary stroke prevention are limited. We report medication adherence, risk factor control and factors influencing vascular risk profile following ischaemic stroke. METHODS: A total of 664 home-dwelling participants in the Norwegian Cognitive Impairment After Stroke study, a multicenter observational study, were evaluated 3 and 18 months poststroke. We assessed medication adherence by self-reporting (4-item Morisky Medication Adherence Scale) and medication persistence (defined as continuation of medication(s) prescribed at discharge), achievement of guideline-defined targets of blood pressure (BP) (<140/90 mmHg), low-density lipoprotein cholesterol (LDL-C) (<2.0 mmol L-1 ) and haemoglobin A1c (HbA1c) (≤53 mmol mol-1 ) and determinants of risk factor control. RESULTS: At discharge, 97% were prescribed antithrombotics, 88% lipid-lowering drugs, 68% antihypertensives and 12% antidiabetic drugs. Persistence of users declined to 99%, 88%, 93% and 95%, respectively, at 18 months. After 3 and 18 months, 80% and 73% reported high adherence. After 3 and 18 months, 40.7% and 47.0% gained BP control, 48.4% and 44.6% achieved LDL-C control, and 69.2% and 69.5% of diabetic patients achieved HbA1c control. Advanced age was associated with increased LDL-C control (OR 1.03, 95% CI 1.01 to 1.06) and reduced BP control (OR 0.98, 0.96 to 0.99). Women had poorer LDL-C control (OR 0.60, 0.37 to 0.98). Polypharmacy was associated with increased LDL-C control (OR 1.29, 1.18 to 1.41) and reduced HbA1c control (OR 0.76, 0.60 to 0.98). CONCLUSION: Risk factor control is suboptimal despite high medication persistence and adherence. Improved understanding of this complex clinical setting is needed for optimization of secondary preventive strategies.

Multidomain intervention for the prevention of cognitive decline after stroke - a pooled patient-level data analysis.

BACKGROUND AND PURPOSE: The aim of this pooled patient-level data analysis was to test if multidomain interventions, addressing several modifiable vascular risk factors simultaneously, are more effective than usual post-stroke care for the prevention of cognitive decline after stroke. METHODS: This pooled patient-level data analysis included two randomized controlled trials using a multidomain approach to target vascular risk factors in stroke patients and cognition as primary outcome. Changes from baseline to 12 months in the trail making test (TMT)-A, TMT-B and 10-words test were analysed using stepwise backward linear mixed models with study as random factor. Two analyses were based on the intention-to-treat (ITT) principle using different imputation approaches and one was based on complete cases. RESULTS: Data from 322 patients (157 assigned to multidomain intervention and 165 to standard care) were analysed. Differences between randomization groups for TMT-A scores were found in one ITT model (P = 0.014) and approached significance in the second ITT model (P = 0.087) and for complete cases (P = 0.091). No significant intervention effects were found for any of the other cognitive variables. CONCLUSION: We found indications that multidomain interventions compared with standard care can improve the scores in TMT-A at 1 year after stroke but not those for TMT-B or the 10-words test. These results have to be interpreted with caution due to the small number of patients.