[FG] Kühne MichaelHead of Research Unit Prof. Dr. med.Michael KühneOverviewMembersPublicationsProjects & CollaborationsProjects & Collaborations OverviewMembersPublicationsProjects & Collaborations Projects & Collaborations 4 foundShow per page10 10 20 50 Brain lesions and cognitive function in patients with versus without atrial fibrillation Research Project | 3 Project MembersRecent evidence suggests an increased risk of cognitive impairment and dementia in patients with atrial fibrillation (AF). Findings from the ongoing Swiss-AF cohort study in 2'415 patients showed that patients with AF have a high burden of cerebral infarcts and other vascular brain lesions on systematic brain magnetic resonance imaging (MRI) scanning. These lesions are associated with a significant loss in neurocognitive function, in their range comparable to one decade of age. Moreover, the vast majority (80%) of the detected brain lesions including infarcts were clinically silent, and they had a similar impact on cognitive performance as clinically overt stroke. However, cardiovascular comorbidities promoting the development of AF are very common in this well characterized AF population. Hence, the possibly causal role of AF cannot be evaluated since control patients in sinus rhythm with comparable comorbidities are lacking.Aim: The aim of the present study is to explore the causal role of AF in the development of brain lesions and cognitive deficits, independent of confounding cardiovascular risk factors and comorbidities. To this end, we plan to initiate a control group of patients in sinus rhythm (Swiss-AF Control study), who can be followed and compared to AF patients included in the Swiss-AF Cohort using the existing Swiss-AF network and infrastructure. Methodology: We will include patients aged =65 years in documented sinus rhythm and without a history of AF. The yearly study visits will take place at one of the 14 study centres already running the Swiss-AF Cohort Study. Detailed clinical history, resting electrocardiogram, vital parameters, extensive cognitive assessment, brain MRI screening and blood sampling will be performed at baseline and after 2 years comparable to the protocol of the Swiss-AF Cohort study. Potential Significance: Given the rising prevalence AF and vascular dementia studies assessing the potential relationship between those two growing epidemics are urgently needed. The comparison of control patients in sinus rhythm to the Swiss-AF cohort patients will enable us to explore potential causal interrelationships of AF with structural brain lesions and cognitive dysfunction. In addition, identifying mechanisms and new predictors of cognitive decline induced by AF will help to develop new prevention and treatment strategies. Thus, the proposed study has the potential to deliver important aspects for the planning of targeted interventional studies. Helping to better understanding the relationships between AF and dementia will have a high impact at the patient level and will also contribute to improve current issues of socioeconomics and public health. Mechanisms of cognitive decline in patients with atrial fibrillation: the Swiss AF-Brain Study Research Project | 3 Project MembersBACKGROUND: Atrial fibrillation (AF) is the most common cardiac arrhythmia, and a major cause of heart failure and stroke. Evidence has emerged that the risk of cognitive impairment and dementia is increased in patients with AF, even in the absence of stroke. Our current understanding of the mechanisms underlying cognitive decline in AF is limited. AIMS AND METHODS: The main research aims of this proposal are first, to discover mechanisms for cognitive decline in patients with AF. Second, we aim to develop risk models helping to identify those patients at greatest risk for cognitive decline. The present proposal is a Large Nested Study embedded in the Swiss Atrial Fibrillation Cohort (Swiss-AF, 33CS30_177520), which provides an ideal and unique framework to achieve our research aims. In Swiss-AF, we have recruited 2415 patients with AF and without dementia at baseline at 14 study sites in Switzerland and investigated them with brain magnetic resonance imaging (MRI) and blood sampling at baseline, as well as annual neurocognitive testing for a median follow-up duration of 3 years. In the present project, we aim to perform neurocognitive testing to assess cognitive decline in 900 patients 7 years after inclusion in the Swiss-AF Cohort. 500 of these patients will additionally undergo follow-up brain MRI and blood sampling at 7 years. MRI includes assessment of vascular brain lesions, global and regional brain volume loss between baseline and 7 years, as well as advanced quantitative imaging: arterial spin labelling (ASL) to detect alterations of regional and global brain perfusion; resting-state functional MRI to reveal the impact of brain network function; magnetization prepared 2 rapid acquisition gradient echoes mapping (MP2RAGE) to quantify T1 relaxation times as a marker for micro-structural brain tissue integrity; and quantitative susceptibility mapping (QSM) to sensitively detect haemorrhages as well as quantify regional and global occult iron deposition as a marker of neurodegeneration. We will measure neurofilament light-chain (NfL) as a neuronal injury marker, as well as other brain pathology markers including glial fibrillary acidic protein (GFAP), and S100 protein (S100b) in the baseline and 7-year blood samples. In addition we will perform Mendelian randomisation studies using available genotyped data to identify risk factors causally related to cognitive decline. The risk model for cognitive decline will be constructed with the clinical, neuroimaging, and biomarker data at baseline of all 900 patients with AF followed-up at 7 years. SIGNIFICANCE: Mechanistic insights into cognitive decline in AF may help identify patients at risk and lead to the discovery of potential targets for prevention. Health Consequences of the Burden of Atrial Fibrillation - The Swiss-AF-Burden study Research Project | 1 Project MembersAtrial fibrillation (AF) is the most common arrhythmia in clinical practice, affecting approximately 1-3% of the general population in Switzerland. Despite the available evidence on the association of AF with stroke and systemic embolism, the underlying mechanisms of thrombogenesis with regard to rhythm and/or other factors are largely unknown. If the presence of AF per se is the main reason for thrombus formation, more AF episodes should result in more strokes. There is at least some evidence that non-paroxysmal AF is associated with a higher risk of stroke. However, the temporal relationship of AF episodes with the occurrence of strokes has been questioned. Therefore, the significance of AF burden, defined as the percentage of time in AF and its changes over time are currently largely unknown.Aims: The aim of this study is to increase our knowledge on the association between AF burden and its health consequences, mainly stroke/systemic embolism and cognitive dysfunction. Methodology: Patients from the SNSF funded Swiss-AF cohort study with paroxysmal and persistent AF will be asked to participate in the study. Based on 1) an enrollment rate of 40% of all Swiss-AF patients with paroxysmal and persistent AF (according to a pilot study), and 2) the participation of the top enrolling centers, it is expected to enroll 460 patients. All patients will get a 7-day Holter electrocardiogram (ECG), in order to assess the AF burden. The 7-day Holter ECG will be repeated after one year. A subsample of 100 patients will additionally get an implantable loop recorder to monitor their cardiac rhythm continuously over two years. Measurement of AF burden will be performed using an automated AF episode detection algorithm and manual validation. In addition to the cardiac monitoring, these patients will get a cardiac magnetic resonance imaging to assess cardiac structure and function at baseline. All other characteristics (clinical information, blood samples, brain MRI) and follow-up information are available within the Swiss-AF cohort. Potential Significance: This multicenter interdisciplinary project will provide novel and unique insights on the association of directly measured AF burden and its consequences. Whereas the infrastructure cohort grant Swiss-AF covers important variables including validated outcome events and an established biobank in a large number of AF patients, the association of AF with stroke and other brain lesions is currently limited by the fact that AF burden is not quantified and that information on cardiac function is not assessed systematically in our patient population. The added information of measuring AF burden and obtaining structural cardiac information in an AF patient population where brain MRIs are available, will provide further evidence towards a better understanding of the correlation between AF and stroke. Swiss Atrial Fibrillation Cohort Study Research Project | 7 Project MembersAtrial fibrillation (AF) is the most common cardiac arrhythmia in the general population. Due to the demographic change with increasing life expectancy, the incidence of AF is expected to further increase in the near future. Patients suffering from AF have an increased risk of serious complications, including stroke and heart failure. Recent studies found that patients with AF have an increased risk of cognitive decline and dementia over time. However, the magnitude of the problem, associated risk factors and underlying mechanisms remain unclear. Specific aims:1.To assess cognitive functions in patients with AF in the long-term2.To correlate structural brain damage and their short-term changes with long-term cognitive decline3.To quantify health care cost among patients with AF in SwitzerlandStatus of study: Enrollment of 2415 AF patients was completed in August 2017. Follow-up investigations are ongoing. Procedures: Study questionnaires, clinical examinations, blood samples (incl. genetics) for bio-banking, advanced 12-lead ECG, bMRI, cognitive assessments, disability, quality of life, and financial costs. Follow-up: Yearly clinical follow-up, covariate update, 12-lead ECG, cognitive assessments, and outcome evaluations. bMRI and blood sampling will be repeated after 2 years in all patients.Main clinical outcome measures: Death, stroke, systemic embolism, hospitalization for heart failure, myocardial infarction, any unplanned hospitalization, major bleeding and clinically relevant non-major bleedingPreliminary results: Overall, 2415 patients were enrolled in Swiss-AF. The mean age (± standard deviation) of the population was 73 ± 8.5 years; 27.1% were female. 45% of the patients had paroxysmal AF, whereas 29% and 26% had persistent and permanent AF, respectively. A history of stroke, bleeding, heart failure and hypertension was present in 13%, 26%, 15% and 69%, respectively. Median (interquartile range) CHA2DS2-VASc score was 3 (2-5). Of 2173 patients (90%) with oral anticoagulation, 56.2% were on non-vitamin-K antagonist oral anticoagulants.Impact: By establishing a national, comprehensive and interdisciplinary AF network, this cohort study is highly responsive to the current SNSF call for longitudinal studies and has the unique potential to provide important novel insights on long-term disease progression and clinical outcomes in patients with AF. The main focus on cognitive functioning and neurological complications is of major public health importance. Several major unmet clinical needs that will provide clinicians with better tools to take care of this growing patient population will be addressed. The current project also has a great potential to identify novel treatment targets for several important and currently unresolved public health problems, including AF, cognitive dysfunction or stroke. Detailed cost assessments will help to define more efficient patient care that will lead to less disability and reduced costs for the society as a whole. 1 1 OverviewMembersPublicationsProjects & Collaborations
Projects & Collaborations 4 foundShow per page10 10 20 50 Brain lesions and cognitive function in patients with versus without atrial fibrillation Research Project | 3 Project MembersRecent evidence suggests an increased risk of cognitive impairment and dementia in patients with atrial fibrillation (AF). Findings from the ongoing Swiss-AF cohort study in 2'415 patients showed that patients with AF have a high burden of cerebral infarcts and other vascular brain lesions on systematic brain magnetic resonance imaging (MRI) scanning. These lesions are associated with a significant loss in neurocognitive function, in their range comparable to one decade of age. Moreover, the vast majority (80%) of the detected brain lesions including infarcts were clinically silent, and they had a similar impact on cognitive performance as clinically overt stroke. However, cardiovascular comorbidities promoting the development of AF are very common in this well characterized AF population. Hence, the possibly causal role of AF cannot be evaluated since control patients in sinus rhythm with comparable comorbidities are lacking.Aim: The aim of the present study is to explore the causal role of AF in the development of brain lesions and cognitive deficits, independent of confounding cardiovascular risk factors and comorbidities. To this end, we plan to initiate a control group of patients in sinus rhythm (Swiss-AF Control study), who can be followed and compared to AF patients included in the Swiss-AF Cohort using the existing Swiss-AF network and infrastructure. Methodology: We will include patients aged =65 years in documented sinus rhythm and without a history of AF. The yearly study visits will take place at one of the 14 study centres already running the Swiss-AF Cohort Study. Detailed clinical history, resting electrocardiogram, vital parameters, extensive cognitive assessment, brain MRI screening and blood sampling will be performed at baseline and after 2 years comparable to the protocol of the Swiss-AF Cohort study. Potential Significance: Given the rising prevalence AF and vascular dementia studies assessing the potential relationship between those two growing epidemics are urgently needed. The comparison of control patients in sinus rhythm to the Swiss-AF cohort patients will enable us to explore potential causal interrelationships of AF with structural brain lesions and cognitive dysfunction. In addition, identifying mechanisms and new predictors of cognitive decline induced by AF will help to develop new prevention and treatment strategies. Thus, the proposed study has the potential to deliver important aspects for the planning of targeted interventional studies. Helping to better understanding the relationships between AF and dementia will have a high impact at the patient level and will also contribute to improve current issues of socioeconomics and public health. Mechanisms of cognitive decline in patients with atrial fibrillation: the Swiss AF-Brain Study Research Project | 3 Project MembersBACKGROUND: Atrial fibrillation (AF) is the most common cardiac arrhythmia, and a major cause of heart failure and stroke. Evidence has emerged that the risk of cognitive impairment and dementia is increased in patients with AF, even in the absence of stroke. Our current understanding of the mechanisms underlying cognitive decline in AF is limited. AIMS AND METHODS: The main research aims of this proposal are first, to discover mechanisms for cognitive decline in patients with AF. Second, we aim to develop risk models helping to identify those patients at greatest risk for cognitive decline. The present proposal is a Large Nested Study embedded in the Swiss Atrial Fibrillation Cohort (Swiss-AF, 33CS30_177520), which provides an ideal and unique framework to achieve our research aims. In Swiss-AF, we have recruited 2415 patients with AF and without dementia at baseline at 14 study sites in Switzerland and investigated them with brain magnetic resonance imaging (MRI) and blood sampling at baseline, as well as annual neurocognitive testing for a median follow-up duration of 3 years. In the present project, we aim to perform neurocognitive testing to assess cognitive decline in 900 patients 7 years after inclusion in the Swiss-AF Cohort. 500 of these patients will additionally undergo follow-up brain MRI and blood sampling at 7 years. MRI includes assessment of vascular brain lesions, global and regional brain volume loss between baseline and 7 years, as well as advanced quantitative imaging: arterial spin labelling (ASL) to detect alterations of regional and global brain perfusion; resting-state functional MRI to reveal the impact of brain network function; magnetization prepared 2 rapid acquisition gradient echoes mapping (MP2RAGE) to quantify T1 relaxation times as a marker for micro-structural brain tissue integrity; and quantitative susceptibility mapping (QSM) to sensitively detect haemorrhages as well as quantify regional and global occult iron deposition as a marker of neurodegeneration. We will measure neurofilament light-chain (NfL) as a neuronal injury marker, as well as other brain pathology markers including glial fibrillary acidic protein (GFAP), and S100 protein (S100b) in the baseline and 7-year blood samples. In addition we will perform Mendelian randomisation studies using available genotyped data to identify risk factors causally related to cognitive decline. The risk model for cognitive decline will be constructed with the clinical, neuroimaging, and biomarker data at baseline of all 900 patients with AF followed-up at 7 years. SIGNIFICANCE: Mechanistic insights into cognitive decline in AF may help identify patients at risk and lead to the discovery of potential targets for prevention. Health Consequences of the Burden of Atrial Fibrillation - The Swiss-AF-Burden study Research Project | 1 Project MembersAtrial fibrillation (AF) is the most common arrhythmia in clinical practice, affecting approximately 1-3% of the general population in Switzerland. Despite the available evidence on the association of AF with stroke and systemic embolism, the underlying mechanisms of thrombogenesis with regard to rhythm and/or other factors are largely unknown. If the presence of AF per se is the main reason for thrombus formation, more AF episodes should result in more strokes. There is at least some evidence that non-paroxysmal AF is associated with a higher risk of stroke. However, the temporal relationship of AF episodes with the occurrence of strokes has been questioned. Therefore, the significance of AF burden, defined as the percentage of time in AF and its changes over time are currently largely unknown.Aims: The aim of this study is to increase our knowledge on the association between AF burden and its health consequences, mainly stroke/systemic embolism and cognitive dysfunction. Methodology: Patients from the SNSF funded Swiss-AF cohort study with paroxysmal and persistent AF will be asked to participate in the study. Based on 1) an enrollment rate of 40% of all Swiss-AF patients with paroxysmal and persistent AF (according to a pilot study), and 2) the participation of the top enrolling centers, it is expected to enroll 460 patients. All patients will get a 7-day Holter electrocardiogram (ECG), in order to assess the AF burden. The 7-day Holter ECG will be repeated after one year. A subsample of 100 patients will additionally get an implantable loop recorder to monitor their cardiac rhythm continuously over two years. Measurement of AF burden will be performed using an automated AF episode detection algorithm and manual validation. In addition to the cardiac monitoring, these patients will get a cardiac magnetic resonance imaging to assess cardiac structure and function at baseline. All other characteristics (clinical information, blood samples, brain MRI) and follow-up information are available within the Swiss-AF cohort. Potential Significance: This multicenter interdisciplinary project will provide novel and unique insights on the association of directly measured AF burden and its consequences. Whereas the infrastructure cohort grant Swiss-AF covers important variables including validated outcome events and an established biobank in a large number of AF patients, the association of AF with stroke and other brain lesions is currently limited by the fact that AF burden is not quantified and that information on cardiac function is not assessed systematically in our patient population. The added information of measuring AF burden and obtaining structural cardiac information in an AF patient population where brain MRIs are available, will provide further evidence towards a better understanding of the correlation between AF and stroke. Swiss Atrial Fibrillation Cohort Study Research Project | 7 Project MembersAtrial fibrillation (AF) is the most common cardiac arrhythmia in the general population. Due to the demographic change with increasing life expectancy, the incidence of AF is expected to further increase in the near future. Patients suffering from AF have an increased risk of serious complications, including stroke and heart failure. Recent studies found that patients with AF have an increased risk of cognitive decline and dementia over time. However, the magnitude of the problem, associated risk factors and underlying mechanisms remain unclear. Specific aims:1.To assess cognitive functions in patients with AF in the long-term2.To correlate structural brain damage and their short-term changes with long-term cognitive decline3.To quantify health care cost among patients with AF in SwitzerlandStatus of study: Enrollment of 2415 AF patients was completed in August 2017. Follow-up investigations are ongoing. Procedures: Study questionnaires, clinical examinations, blood samples (incl. genetics) for bio-banking, advanced 12-lead ECG, bMRI, cognitive assessments, disability, quality of life, and financial costs. Follow-up: Yearly clinical follow-up, covariate update, 12-lead ECG, cognitive assessments, and outcome evaluations. bMRI and blood sampling will be repeated after 2 years in all patients.Main clinical outcome measures: Death, stroke, systemic embolism, hospitalization for heart failure, myocardial infarction, any unplanned hospitalization, major bleeding and clinically relevant non-major bleedingPreliminary results: Overall, 2415 patients were enrolled in Swiss-AF. The mean age (± standard deviation) of the population was 73 ± 8.5 years; 27.1% were female. 45% of the patients had paroxysmal AF, whereas 29% and 26% had persistent and permanent AF, respectively. A history of stroke, bleeding, heart failure and hypertension was present in 13%, 26%, 15% and 69%, respectively. Median (interquartile range) CHA2DS2-VASc score was 3 (2-5). Of 2173 patients (90%) with oral anticoagulation, 56.2% were on non-vitamin-K antagonist oral anticoagulants.Impact: By establishing a national, comprehensive and interdisciplinary AF network, this cohort study is highly responsive to the current SNSF call for longitudinal studies and has the unique potential to provide important novel insights on long-term disease progression and clinical outcomes in patients with AF. The main focus on cognitive functioning and neurological complications is of major public health importance. Several major unmet clinical needs that will provide clinicians with better tools to take care of this growing patient population will be addressed. The current project also has a great potential to identify novel treatment targets for several important and currently unresolved public health problems, including AF, cognitive dysfunction or stroke. Detailed cost assessments will help to define more efficient patient care that will lead to less disability and reduced costs for the society as a whole. 1 1
Brain lesions and cognitive function in patients with versus without atrial fibrillation Research Project | 3 Project MembersRecent evidence suggests an increased risk of cognitive impairment and dementia in patients with atrial fibrillation (AF). Findings from the ongoing Swiss-AF cohort study in 2'415 patients showed that patients with AF have a high burden of cerebral infarcts and other vascular brain lesions on systematic brain magnetic resonance imaging (MRI) scanning. These lesions are associated with a significant loss in neurocognitive function, in their range comparable to one decade of age. Moreover, the vast majority (80%) of the detected brain lesions including infarcts were clinically silent, and they had a similar impact on cognitive performance as clinically overt stroke. However, cardiovascular comorbidities promoting the development of AF are very common in this well characterized AF population. Hence, the possibly causal role of AF cannot be evaluated since control patients in sinus rhythm with comparable comorbidities are lacking.Aim: The aim of the present study is to explore the causal role of AF in the development of brain lesions and cognitive deficits, independent of confounding cardiovascular risk factors and comorbidities. To this end, we plan to initiate a control group of patients in sinus rhythm (Swiss-AF Control study), who can be followed and compared to AF patients included in the Swiss-AF Cohort using the existing Swiss-AF network and infrastructure. Methodology: We will include patients aged =65 years in documented sinus rhythm and without a history of AF. The yearly study visits will take place at one of the 14 study centres already running the Swiss-AF Cohort Study. Detailed clinical history, resting electrocardiogram, vital parameters, extensive cognitive assessment, brain MRI screening and blood sampling will be performed at baseline and after 2 years comparable to the protocol of the Swiss-AF Cohort study. Potential Significance: Given the rising prevalence AF and vascular dementia studies assessing the potential relationship between those two growing epidemics are urgently needed. The comparison of control patients in sinus rhythm to the Swiss-AF cohort patients will enable us to explore potential causal interrelationships of AF with structural brain lesions and cognitive dysfunction. In addition, identifying mechanisms and new predictors of cognitive decline induced by AF will help to develop new prevention and treatment strategies. Thus, the proposed study has the potential to deliver important aspects for the planning of targeted interventional studies. Helping to better understanding the relationships between AF and dementia will have a high impact at the patient level and will also contribute to improve current issues of socioeconomics and public health.
Mechanisms of cognitive decline in patients with atrial fibrillation: the Swiss AF-Brain Study Research Project | 3 Project MembersBACKGROUND: Atrial fibrillation (AF) is the most common cardiac arrhythmia, and a major cause of heart failure and stroke. Evidence has emerged that the risk of cognitive impairment and dementia is increased in patients with AF, even in the absence of stroke. Our current understanding of the mechanisms underlying cognitive decline in AF is limited. AIMS AND METHODS: The main research aims of this proposal are first, to discover mechanisms for cognitive decline in patients with AF. Second, we aim to develop risk models helping to identify those patients at greatest risk for cognitive decline. The present proposal is a Large Nested Study embedded in the Swiss Atrial Fibrillation Cohort (Swiss-AF, 33CS30_177520), which provides an ideal and unique framework to achieve our research aims. In Swiss-AF, we have recruited 2415 patients with AF and without dementia at baseline at 14 study sites in Switzerland and investigated them with brain magnetic resonance imaging (MRI) and blood sampling at baseline, as well as annual neurocognitive testing for a median follow-up duration of 3 years. In the present project, we aim to perform neurocognitive testing to assess cognitive decline in 900 patients 7 years after inclusion in the Swiss-AF Cohort. 500 of these patients will additionally undergo follow-up brain MRI and blood sampling at 7 years. MRI includes assessment of vascular brain lesions, global and regional brain volume loss between baseline and 7 years, as well as advanced quantitative imaging: arterial spin labelling (ASL) to detect alterations of regional and global brain perfusion; resting-state functional MRI to reveal the impact of brain network function; magnetization prepared 2 rapid acquisition gradient echoes mapping (MP2RAGE) to quantify T1 relaxation times as a marker for micro-structural brain tissue integrity; and quantitative susceptibility mapping (QSM) to sensitively detect haemorrhages as well as quantify regional and global occult iron deposition as a marker of neurodegeneration. We will measure neurofilament light-chain (NfL) as a neuronal injury marker, as well as other brain pathology markers including glial fibrillary acidic protein (GFAP), and S100 protein (S100b) in the baseline and 7-year blood samples. In addition we will perform Mendelian randomisation studies using available genotyped data to identify risk factors causally related to cognitive decline. The risk model for cognitive decline will be constructed with the clinical, neuroimaging, and biomarker data at baseline of all 900 patients with AF followed-up at 7 years. SIGNIFICANCE: Mechanistic insights into cognitive decline in AF may help identify patients at risk and lead to the discovery of potential targets for prevention.
Health Consequences of the Burden of Atrial Fibrillation - The Swiss-AF-Burden study Research Project | 1 Project MembersAtrial fibrillation (AF) is the most common arrhythmia in clinical practice, affecting approximately 1-3% of the general population in Switzerland. Despite the available evidence on the association of AF with stroke and systemic embolism, the underlying mechanisms of thrombogenesis with regard to rhythm and/or other factors are largely unknown. If the presence of AF per se is the main reason for thrombus formation, more AF episodes should result in more strokes. There is at least some evidence that non-paroxysmal AF is associated with a higher risk of stroke. However, the temporal relationship of AF episodes with the occurrence of strokes has been questioned. Therefore, the significance of AF burden, defined as the percentage of time in AF and its changes over time are currently largely unknown.Aims: The aim of this study is to increase our knowledge on the association between AF burden and its health consequences, mainly stroke/systemic embolism and cognitive dysfunction. Methodology: Patients from the SNSF funded Swiss-AF cohort study with paroxysmal and persistent AF will be asked to participate in the study. Based on 1) an enrollment rate of 40% of all Swiss-AF patients with paroxysmal and persistent AF (according to a pilot study), and 2) the participation of the top enrolling centers, it is expected to enroll 460 patients. All patients will get a 7-day Holter electrocardiogram (ECG), in order to assess the AF burden. The 7-day Holter ECG will be repeated after one year. A subsample of 100 patients will additionally get an implantable loop recorder to monitor their cardiac rhythm continuously over two years. Measurement of AF burden will be performed using an automated AF episode detection algorithm and manual validation. In addition to the cardiac monitoring, these patients will get a cardiac magnetic resonance imaging to assess cardiac structure and function at baseline. All other characteristics (clinical information, blood samples, brain MRI) and follow-up information are available within the Swiss-AF cohort. Potential Significance: This multicenter interdisciplinary project will provide novel and unique insights on the association of directly measured AF burden and its consequences. Whereas the infrastructure cohort grant Swiss-AF covers important variables including validated outcome events and an established biobank in a large number of AF patients, the association of AF with stroke and other brain lesions is currently limited by the fact that AF burden is not quantified and that information on cardiac function is not assessed systematically in our patient population. The added information of measuring AF burden and obtaining structural cardiac information in an AF patient population where brain MRIs are available, will provide further evidence towards a better understanding of the correlation between AF and stroke.
Swiss Atrial Fibrillation Cohort Study Research Project | 7 Project MembersAtrial fibrillation (AF) is the most common cardiac arrhythmia in the general population. Due to the demographic change with increasing life expectancy, the incidence of AF is expected to further increase in the near future. Patients suffering from AF have an increased risk of serious complications, including stroke and heart failure. Recent studies found that patients with AF have an increased risk of cognitive decline and dementia over time. However, the magnitude of the problem, associated risk factors and underlying mechanisms remain unclear. Specific aims:1.To assess cognitive functions in patients with AF in the long-term2.To correlate structural brain damage and their short-term changes with long-term cognitive decline3.To quantify health care cost among patients with AF in SwitzerlandStatus of study: Enrollment of 2415 AF patients was completed in August 2017. Follow-up investigations are ongoing. Procedures: Study questionnaires, clinical examinations, blood samples (incl. genetics) for bio-banking, advanced 12-lead ECG, bMRI, cognitive assessments, disability, quality of life, and financial costs. Follow-up: Yearly clinical follow-up, covariate update, 12-lead ECG, cognitive assessments, and outcome evaluations. bMRI and blood sampling will be repeated after 2 years in all patients.Main clinical outcome measures: Death, stroke, systemic embolism, hospitalization for heart failure, myocardial infarction, any unplanned hospitalization, major bleeding and clinically relevant non-major bleedingPreliminary results: Overall, 2415 patients were enrolled in Swiss-AF. The mean age (± standard deviation) of the population was 73 ± 8.5 years; 27.1% were female. 45% of the patients had paroxysmal AF, whereas 29% and 26% had persistent and permanent AF, respectively. A history of stroke, bleeding, heart failure and hypertension was present in 13%, 26%, 15% and 69%, respectively. Median (interquartile range) CHA2DS2-VASc score was 3 (2-5). Of 2173 patients (90%) with oral anticoagulation, 56.2% were on non-vitamin-K antagonist oral anticoagulants.Impact: By establishing a national, comprehensive and interdisciplinary AF network, this cohort study is highly responsive to the current SNSF call for longitudinal studies and has the unique potential to provide important novel insights on long-term disease progression and clinical outcomes in patients with AF. The main focus on cognitive functioning and neurological complications is of major public health importance. Several major unmet clinical needs that will provide clinicians with better tools to take care of this growing patient population will be addressed. The current project also has a great potential to identify novel treatment targets for several important and currently unresolved public health problems, including AF, cognitive dysfunction or stroke. Detailed cost assessments will help to define more efficient patient care that will lead to less disability and reduced costs for the society as a whole.
