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Seasonality, incidence and prognosis in atrial fibrillation and stroke in Denmark and New Zealand

OBJECTIVES: There are relatively few large studies of seasonal variation in the occurrence of stroke in patients with atrial fibrillation (AF). We investigated the seasonal variation in incidence rates of hospitalisation with stroke in patients from Denmark and New Zealand. DESIGN: Cohort study. SET...

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Autores principales: Christensen, Anette Luther, Rasmussen, Lars Hvilsted, Baker, Michael G, Lip, Gregory Y H, Dethlefsen, Claus, Larsen, Torben Bjerregaard
Formato: Online Artículo Texto
Lenguaje:English
Publicado: BMJ Group 2012
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3432837/
https://www.ncbi.nlm.nih.gov/pubmed/22923628
http://dx.doi.org/10.1136/bmjopen-2012-001210
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author Christensen, Anette Luther
Rasmussen, Lars Hvilsted
Baker, Michael G
Lip, Gregory Y H
Dethlefsen, Claus
Larsen, Torben Bjerregaard
author_facet Christensen, Anette Luther
Rasmussen, Lars Hvilsted
Baker, Michael G
Lip, Gregory Y H
Dethlefsen, Claus
Larsen, Torben Bjerregaard
author_sort Christensen, Anette Luther
collection PubMed
description OBJECTIVES: There are relatively few large studies of seasonal variation in the occurrence of stroke in patients with atrial fibrillation (AF). We investigated the seasonal variation in incidence rates of hospitalisation with stroke in patients from Denmark and New Zealand. DESIGN: Cohort study. SETTING: Nationwide hospital discharge data from Denmark and New Zealand. PARTICIPANTS: 243 381 (median age 75) subjects having a first-time hospitalisation with AF in Denmark and 51 480 (median age 76) subjects in New Zealand constituted the study population. Subjects with previous hospitalisation with stroke were excluded. PRIMARY AND SECONDARY EFFECT MEASURES: Peak-to-trough ratio of the seasonal variation in incidence rates of stroke in AF patients adjusted for an overall trend was primary effect measure and was assessed using a log-linear Poisson regression model. Secondary effect measures were incidence rate ratios of AF and 30-day case fatality for stroke patients. RESULTS: Incidence rates of AF per 1000 person-years in Denmark increased by 5.4% (95% CI 5.3% to 5.7%) for patients aged <65 and 5% (95% CI 4.9% to 5.1%) for patients aged ≥65, whereas the increase was 0.2% (95% CI −0.2% to 0.6%) for patients aged <65 and 2.6% (95% CI 2.4% to 2.8%) for patients aged ≥65 in New Zealand. In Denmark 36 088 subjects were hospitalised with stroke, and 7518 subjects in New Zealand, both showing peaks during winter with peak-to-trough ratios of 1.22 and 1.27, respectively and a decreasing trend. The 30-day case fatality risk for stroke patients having AF is now (2000–2008) about 20% in both countries. CONCLUSIONS: Although incidence rates of hospitalisation with stroke in patients with AF have decreased in recent years, stroke remains a common AF complication with a high case fatality risk. The marked winter peak in incidence rates of hospitalisation with stroke in AF patients suggests that there are opportunities to reduce this complication. Further studies are necessary to identify how to optimise treatment of AF and prevention of stroke.
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spelling pubmed-34328372012-09-11 Seasonality, incidence and prognosis in atrial fibrillation and stroke in Denmark and New Zealand Christensen, Anette Luther Rasmussen, Lars Hvilsted Baker, Michael G Lip, Gregory Y H Dethlefsen, Claus Larsen, Torben Bjerregaard BMJ Open Cardiovascular Medicine OBJECTIVES: There are relatively few large studies of seasonal variation in the occurrence of stroke in patients with atrial fibrillation (AF). We investigated the seasonal variation in incidence rates of hospitalisation with stroke in patients from Denmark and New Zealand. DESIGN: Cohort study. SETTING: Nationwide hospital discharge data from Denmark and New Zealand. PARTICIPANTS: 243 381 (median age 75) subjects having a first-time hospitalisation with AF in Denmark and 51 480 (median age 76) subjects in New Zealand constituted the study population. Subjects with previous hospitalisation with stroke were excluded. PRIMARY AND SECONDARY EFFECT MEASURES: Peak-to-trough ratio of the seasonal variation in incidence rates of stroke in AF patients adjusted for an overall trend was primary effect measure and was assessed using a log-linear Poisson regression model. Secondary effect measures were incidence rate ratios of AF and 30-day case fatality for stroke patients. RESULTS: Incidence rates of AF per 1000 person-years in Denmark increased by 5.4% (95% CI 5.3% to 5.7%) for patients aged <65 and 5% (95% CI 4.9% to 5.1%) for patients aged ≥65, whereas the increase was 0.2% (95% CI −0.2% to 0.6%) for patients aged <65 and 2.6% (95% CI 2.4% to 2.8%) for patients aged ≥65 in New Zealand. In Denmark 36 088 subjects were hospitalised with stroke, and 7518 subjects in New Zealand, both showing peaks during winter with peak-to-trough ratios of 1.22 and 1.27, respectively and a decreasing trend. The 30-day case fatality risk for stroke patients having AF is now (2000–2008) about 20% in both countries. CONCLUSIONS: Although incidence rates of hospitalisation with stroke in patients with AF have decreased in recent years, stroke remains a common AF complication with a high case fatality risk. The marked winter peak in incidence rates of hospitalisation with stroke in AF patients suggests that there are opportunities to reduce this complication. Further studies are necessary to identify how to optimise treatment of AF and prevention of stroke. BMJ Group 2012 2012-08-24 /pmc/articles/PMC3432837/ /pubmed/22923628 http://dx.doi.org/10.1136/bmjopen-2012-001210 Text en © 2012, Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions. This is an open-access article distributed under the terms of the Creative Commons Attribution Non-commercial License, which permits use, distribution, and reproduction in any medium, provided the original work is properly cited, the use is non commercial and is otherwise in compliance with the license. See: http://creativecommons.org/licenses/by-nc/3.0/ and http://creativecommons.org/licenses/by-nc/3.0/legalcode.
spellingShingle Cardiovascular Medicine
Christensen, Anette Luther
Rasmussen, Lars Hvilsted
Baker, Michael G
Lip, Gregory Y H
Dethlefsen, Claus
Larsen, Torben Bjerregaard
Seasonality, incidence and prognosis in atrial fibrillation and stroke in Denmark and New Zealand
title Seasonality, incidence and prognosis in atrial fibrillation and stroke in Denmark and New Zealand
title_full Seasonality, incidence and prognosis in atrial fibrillation and stroke in Denmark and New Zealand
title_fullStr Seasonality, incidence and prognosis in atrial fibrillation and stroke in Denmark and New Zealand
title_full_unstemmed Seasonality, incidence and prognosis in atrial fibrillation and stroke in Denmark and New Zealand
title_short Seasonality, incidence and prognosis in atrial fibrillation and stroke in Denmark and New Zealand
title_sort seasonality, incidence and prognosis in atrial fibrillation and stroke in denmark and new zealand
topic Cardiovascular Medicine
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3432837/
https://www.ncbi.nlm.nih.gov/pubmed/22923628
http://dx.doi.org/10.1136/bmjopen-2012-001210
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