Uncovering underlying aetiologies in cryptogenic stroke: The Nordic Atrial Fibrillation and Stroke (NOR-FIB) Study
Abstract
The best treated stroke is the one we have prevented. To achieve this goal optimal secondary prevention must be tailored to the underlying cause. Knowing the aetiology makes it possible to treat patients following the evidence-based medicine principle and successfully prevent new ischaemia. The current knowledge suggests that atrial fibrillation could be suspected in a substantial proportion of cryptogenic stroke. Transient arrhythmia can however easily be missed under the short-term monitoring in the acute phase, exposing patient to an unnecessary risk of recurrent stroke. The aim of this thesis was to investigate the burden of atrial fibrillation and clinical predictors of the arrhythmia in cryptogenic stroke patients monitored with insertable cardiac monitor (ICM) for 12 months, as well as the spectrum of other probable or possible underlying stroke causes. The NOR-FIB study was an international, multicentre, prospective, observational trial conducted between January 2017 and September 2021 and finally included 259 patients. Systematic atrial fibrillation screening with ICM detected atrial fibrillation in almost one in three patients previously classified as cryptogenic. Overall, extended diagnostic work-up and reassessment of the initial findings performed within the first year after stroke and TIA resulted in revealing underlying cause in nearly one in two patients initially labelled as cryptogenic. Uncovering the specific aetiology led to improvement of patient’s secondary prevention lowering the risk of stroke recurrence. Our findings suggest that a thorough diagnostic evaluation is essential in determining pathogenesis of cryptogenic ischaemic events and securing optimal preventive treatment. Furthermore, the use of ICM was proven manageable for stroke physicians and seems feasible to be implemented in the arrhythmia detection pathway in stroke units.List of papers
Paper I: Ratajczak-Tretel B, Tancin Lambert A, Al-Ani R, Arntzen K, Bakkejord GK, Bekkeseth H, Bjerkeli V, Eldøen G, Gulsvik A, Halvorsen B, Høie GA, Ihle-Hansen H, Ihle-Hansen H, Ingebrigtsen S, Johansen H, Kremer C, Krogseth SB, Kruuse C, Kurz M, Nakstad I, Novotny V, Næss H, Qazi R, Rezaj MK, Rørholt DM, Steffensen LH, Sømark J, Tobro H, Truelsen TC, Wassvik L, Ægidius KL, Atar D, Aamodt AH. Atrial fibrillation in cryptogenic stroke and TIA patients in The Nordic Atrial Fibrillation and Stroke (NOR-FIB) Study: Main results. Eur Stroke J. 2023 Mar;8(1):148-156. doi: 10.1177/23969873221123122. The article is included in the thesis. Also available at: https://doi.org/10.1177/23969873221123122 |
Paper II: Ratajczak-Tretel B, Tancin Lambert A, Al-Ani R, Arntzen K, Bakkejord GK, Bekkeseth HMO, Bjerkeli V, Eldøen G, Gulsvik AK, Halvorsen B, Høie GA, Ihle-Hansen H, Ihle-Hansen H, Ingebrigtsen S, Kremer C, Krogseth SB, Kruuse C, Kurz M, Nakstad I, Novotny V, Naess H, Qazi R, Rezaj MK, Rørholt DM, Steffensen LH, Sømark J, Tobro H, Truelsen TC, Wassvik L, Ægidius KL, Atar D, Aamodt AH; NOR-FIB study Group. Underlying causes of cryptogenic stroke and TIA in The Nordic Atrial Fibrillation and Stroke (NOR-FIB) Study – the importance of comprehensive clinical evaluation. BMC Neurology 23, 115 (2023). doi:10.1186/s12883-023-03155-0. The article is included in the thesis. Also available at: https://doi.org/10.1186/s12883-023-03155-0 |
Paper III: Ratajczak-Tretel B, Tancin Lambert A, Al-Ani R, Arntzen K, Bakkejord GK, Bekkeseth HMO, Bjerkeli V, Eldøen G, Gulsvik AK, Halvorsen B, Høie GA, Ihle-Hansen H, Ihle-Hansen H, Ingebrigtsen S, Kremer C, Krogseth SB, Kruuse C, Kurz M, Nakstad I, Novotny V, Naess H, Qazi R, Rezaj MK, Rørholt DM, Steffensen LH, Sømark J, Tobro H, Truelsen TC, Wassvik L, Ægidius KL, Atar D, Aamodt AH; NOR-FIB study Group. Prediction of Underlying Atrial Fibrillation in Patients with a Cryptogenic Stroke: Results from the NOR-FIB study. J Neurol 270, 4049–4059 (2023). doi: 10.1007/s00415-023-11680-8. An accepted version in included in the thesis. The published version is available at: https://doi.org/10.1007/s00415-023-11680-8 |