Acta Neurol Scand 2015: 132: 125–131 DOI: 10.1111/ane.12366
© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd ACTA NEUROLOGICA SCANDINAVICA
Outcome of men and women after atrial fibrillation and stroke J€ onsson A-C, Ek J, Kremer C. Outcome of men and women after atrial fibrillation and stroke. Acta Neurol Scand 2015: 132: 125–131. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd. Objectives – Atrial fibrillation (AF) is a well-known risk factor for ischaemic stroke. The aim was to examine long-term outcome of men and women after stroke related to AF. Methods – Patients with AF and ischaemic stroke were followed up 1 year and 5 years after stroke. Level of dependence (Barthel Index), disability (modified Rankin Scale), risk factors, mortality and stroke prophylaxis before and after stroke were analysed. All parameters were compared between men and women. Results – From a cohort of 597 stroke patients during a one-year period, 155 patients (94 women/61 men) with stroke related to AF were included. Women were older than men at stroke onset and more men had a history of smoking and diabetes, but there was no difference in stroke severity. Only 111 patients had been diagnosed with AF before stroke. After 1 year 78 patients (45 women/33 men) and after 5 years 35 patients (21 women/14 men) were followed up. There was no difference in mortality after 5 years with 76% women and 73% men deceased. Half of both genders were independent 1 year after stroke, and after 5 years, approximately a third among women, but half of the men, were independent. Women were less frequently treated with warfarin before stroke (11% vs 28%), but warfarin and NOAC treatment had increased among both women and men at hospital discharge. Conclusions – There were no gender differences in long-term mortality after stroke related to AF. Men were significantly more often prescribed anticoagulants before stroke, a finding that indicates the need for further studies.
Introduction
Atrial fibrillation (AF) is the most common arrhythmia, affecting approximately 3% of the adult population in Sweden according to recent studies (1, 2). AF is more common among men than women, and the incidence of AF increases substantially after 65 years of age with its peak in the age range 80–89 years reaching a prevalence of 13.4% (1). AF is a well-known risk factor for stroke increasing the risk substantially compared to patients without AF (3, 4). The stroke risk for patients with AF is also related to other risk factors, and it has been found to be about 5% per year for patients age range 65–75 (5). Even though AF is more common among men in the general population, stroke related to AF is more common
A.-C. J€onsson1, J. Ek2, C. Kremer2 1 Department of Health Sciences, Lund University, Lund, Sweden; 2Department of Neurology, Sk ane University Hospital, Malm€o, Sweden
Key words: atrial fibrillation; gender; long term; men; mortality; outcome; stroke; women A.-C. J€onsson, Department of Health Sciences, Lund University, Box 157, 221 00 Lund, Sweden Tel.: +4646 2221976 Fax: +4646 2221808 e-mail: [email protected] Accepted for publication November 12, 2014
among women (6), and screening to detect AF is recommended in high risk groups (7). This higher risk for women is sustained even after adjustment for other risk factors, and female gender has therefore been identified as an independent risk factor for stroke among AF patients (8–10). Stroke related to AF has a higher short-term mortality compared to other aetiologies of ischaemic stroke (11), and AF appeared as a specific ischaemic stroke predictor of in-hospital mortality for women (12). However, studies of long-term outcome after stroke related to AF including differences between men and women are scarce. The aim of this study was therefore to study shortterm and long-term mortality, outcome, risk factors and secondary prevention after stroke related to AF among men and women. 125
J€ onsson et al. Methods
Characteristics at baseline
Sample
All 597 patients diagnosed with cerebral infarction or intracerebral haemorrhage at the Sk ane University Hospital, Malm€ o, Sweden, between 1 February 2008 and 31 January 2009 were registered and followed up 1 year after stroke (13). From the medical records, it was found that 183 (30.7%) of the 597 patients were diagnosed with atrial fibrillation (AF). Patients were considered to have AF if verified with electrocardiography (ECG) during the period of acute care at the hospital or if they were diagnosed with AF prior to or within 6 months after stroke. Only patients with AF as the most probable aetiology of stroke were included in the study. Patients with verified symptomatic carotid stenosis (n=4), intracerebral haemorrhage (n=14), other stroke etiology than AF (n=2), and patients with no signs of embolic infarction on computed tomography (CT) or magnetic resonance imaging (MRI), as well as patients with no symptoms related to the territory of infarction (n=8) were excluded. Thus, from the cohort of 183 patients with stroke and AF, 155 patients (26%) of the one-year cohort (n = 597) were included in this study. The sample flow in this study is further described in a flow chart (Fig. 1).
4 carotid stenosis 14 ICH 2 other etiology 8 not verified by CT or MRI
28 excluded
123 first-ever stroke 32 recurrent stroke
77 deceased
78 followed up 1 year after stroke 41 deceased 2 declined
35 followed up 5 years after stroke
Figure 1. Flow chart.
126
Follow-up one year after stroke
In the previous study of the one-year stroke population (n = 597), 391 survivors had been followed up one year after stroke (13). Data from the database collected 1 year after stroke were used to analyse the status of the patients with stroke and AF 1 year after stroke. Follow-up five years after stroke
Baseline 183 patients with stroke and AF
155 with stroke and AF included
Baseline characteristics and risk factors for stroke were retrospectively obtained from medical records and from the previous follow-up 1 year after stroke (13). Stroke severity was assessed with the National Institutes of Health Stroke Scale (NIHSS) scoring 0–42. Minor stroke was defined as NIHSS score ≤7, a moderate stroke as score 8–15 and a major stroke as ≥16 (14). Hypertension was defined as a blood pressure >139/89 mmHg with or without antihypertensive treatment (15). Level of dependence was assessed with the Barthel Index (BI) (16) and level of disability with the modified Rankin Scale (mRS) (17). BI score (range 0–100) was divided into three groups with a score 95–100 indicating independence, 60–90 minor dependence and 0–55 major dependence (18). The mRS (range 0–5) was divided into two groups; 0–2 (no symptoms, no significant or slight disability) and 3–5 (moderate, moderately severe or severe disability).
In this study, a follow-up was performed 5 years after stroke regarding dependence (BI), disability (mRS), blood pressure, smoking and stroke prophylactic treatment. The importance of hypertension and smoking in stroke prevention has been emphasized in the European Stroke Strategies (19). The same factors from the one-year followup are included in this study, except stroke prophylactic treatment, which was not registered at the one-year follow-up. The patients were followed up at the outpatient clinic, in the patient’s own home or in a nursing home with assistance from nurses. Mortality
Mortality in the acute stroke unit care, and at follow-up one and five years after stroke was analysed. For this analysis, only patients with a first-ever stroke were included. Date of death for those who were deceased was obtained from the Swedish population register or medical records.
Outcome of men and women with AF and stroke Statistical analysis
All continuous variables are presented as mean (SD) and were compared using the t-test. Categorical variables were examined by the Pearson’s chi-square test or the Fisher’s exact test. Survival after stroke was estimated using the Kaplan–Meier method and a comparison was made using the log-rank test. A P-value ≤0.05 was considered to be significant. All characteristics and assessments in the study were compared between men and women. Data were analysed using IBM SPSS Statistics version 21 (IBM Corp., Armonk, New York, USA).
Among the 155 patients, 111 individuals (65 [59%] women and 46 [41%] men) were diagnosed with AF or had an AF verified by ECG before stroke. Men were significantly more often prescribed warfarin, (28% vs 11%, P < 0.05). No stroke prophylactic medication was prescribed before stroke for 14 women (22%) and 12 men (26%) with no significant difference between men and women. However at discharge from the hospital, more patients had been diagnosed with AF (n = 113) and 16 women (26%) vs 17 men (33%) had been prescribed Warfarin or NOAC with no significant gender difference (Table 2). Follow-up one year after stroke
Ethical considerations
The study of the total population of 597 registered patients was approved by the Regional Ethical Review Board, Lund University, Registration No. 520/2007 (13). Results
Among the 155 patients eligible for analysis in the study (94 [61%] women and 61 [39%] men), 123 were diagnosed with a first-ever cerebral infarction (CI), that is 32 patients had a recurrent stroke. Women were on average 5 years older than men at baseline (84.8 8.1 vs 79.5 8.7 years, P < 0.001). Men were more often diagnosed with diabetes (31% vs 15%, P < 0.05) and more often had a history of smoking (54% vs 13% previous smokers, P < 0.01). Regarding stroke severity, hypertension and previous stroke, no differences between men and women were found (Table 1). Table 1 Baseline characteristics of 155 patients with atrial fibrillation and stroke
Characteristics* All patients Age, mean (SD), years Range Hypertension Diabetes Smoking Current smoker Previous smoker Stroke severity, NIHSS Minor stroke ≤7 Moderate stroke 8–15 Major stroke ≥16 Recurrent stroke
Women N (%)
Men N (%)
94 (61) 84.8 (8.1) 54.7–98.5 61 (65) 14 (15)
61 (39) 79.5 (8.7) 50.3–96.1 37 (61) 19 (31)
10 (12) 11 (13)
5 (8) 33 (54)
© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd ACTA NEUROLOGICA SCANDINAVICA
Outcome of men and women after atrial fibrillation and stroke J€ onsson A-C, Ek J, Kremer C. Outcome of men and women after atrial fibrillation and stroke. Acta Neurol Scand 2015: 132: 125–131. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd. Objectives – Atrial fibrillation (AF) is a well-known risk factor for ischaemic stroke. The aim was to examine long-term outcome of men and women after stroke related to AF. Methods – Patients with AF and ischaemic stroke were followed up 1 year and 5 years after stroke. Level of dependence (Barthel Index), disability (modified Rankin Scale), risk factors, mortality and stroke prophylaxis before and after stroke were analysed. All parameters were compared between men and women. Results – From a cohort of 597 stroke patients during a one-year period, 155 patients (94 women/61 men) with stroke related to AF were included. Women were older than men at stroke onset and more men had a history of smoking and diabetes, but there was no difference in stroke severity. Only 111 patients had been diagnosed with AF before stroke. After 1 year 78 patients (45 women/33 men) and after 5 years 35 patients (21 women/14 men) were followed up. There was no difference in mortality after 5 years with 76% women and 73% men deceased. Half of both genders were independent 1 year after stroke, and after 5 years, approximately a third among women, but half of the men, were independent. Women were less frequently treated with warfarin before stroke (11% vs 28%), but warfarin and NOAC treatment had increased among both women and men at hospital discharge. Conclusions – There were no gender differences in long-term mortality after stroke related to AF. Men were significantly more often prescribed anticoagulants before stroke, a finding that indicates the need for further studies.
Introduction
Atrial fibrillation (AF) is the most common arrhythmia, affecting approximately 3% of the adult population in Sweden according to recent studies (1, 2). AF is more common among men than women, and the incidence of AF increases substantially after 65 years of age with its peak in the age range 80–89 years reaching a prevalence of 13.4% (1). AF is a well-known risk factor for stroke increasing the risk substantially compared to patients without AF (3, 4). The stroke risk for patients with AF is also related to other risk factors, and it has been found to be about 5% per year for patients age range 65–75 (5). Even though AF is more common among men in the general population, stroke related to AF is more common
A.-C. J€onsson1, J. Ek2, C. Kremer2 1 Department of Health Sciences, Lund University, Lund, Sweden; 2Department of Neurology, Sk ane University Hospital, Malm€o, Sweden
Key words: atrial fibrillation; gender; long term; men; mortality; outcome; stroke; women A.-C. J€onsson, Department of Health Sciences, Lund University, Box 157, 221 00 Lund, Sweden Tel.: +4646 2221976 Fax: +4646 2221808 e-mail: [email protected] Accepted for publication November 12, 2014
among women (6), and screening to detect AF is recommended in high risk groups (7). This higher risk for women is sustained even after adjustment for other risk factors, and female gender has therefore been identified as an independent risk factor for stroke among AF patients (8–10). Stroke related to AF has a higher short-term mortality compared to other aetiologies of ischaemic stroke (11), and AF appeared as a specific ischaemic stroke predictor of in-hospital mortality for women (12). However, studies of long-term outcome after stroke related to AF including differences between men and women are scarce. The aim of this study was therefore to study shortterm and long-term mortality, outcome, risk factors and secondary prevention after stroke related to AF among men and women. 125
J€ onsson et al. Methods
Characteristics at baseline
Sample
All 597 patients diagnosed with cerebral infarction or intracerebral haemorrhage at the Sk ane University Hospital, Malm€ o, Sweden, between 1 February 2008 and 31 January 2009 were registered and followed up 1 year after stroke (13). From the medical records, it was found that 183 (30.7%) of the 597 patients were diagnosed with atrial fibrillation (AF). Patients were considered to have AF if verified with electrocardiography (ECG) during the period of acute care at the hospital or if they were diagnosed with AF prior to or within 6 months after stroke. Only patients with AF as the most probable aetiology of stroke were included in the study. Patients with verified symptomatic carotid stenosis (n=4), intracerebral haemorrhage (n=14), other stroke etiology than AF (n=2), and patients with no signs of embolic infarction on computed tomography (CT) or magnetic resonance imaging (MRI), as well as patients with no symptoms related to the territory of infarction (n=8) were excluded. Thus, from the cohort of 183 patients with stroke and AF, 155 patients (26%) of the one-year cohort (n = 597) were included in this study. The sample flow in this study is further described in a flow chart (Fig. 1).
4 carotid stenosis 14 ICH 2 other etiology 8 not verified by CT or MRI
28 excluded
123 first-ever stroke 32 recurrent stroke
77 deceased
78 followed up 1 year after stroke 41 deceased 2 declined
35 followed up 5 years after stroke
Figure 1. Flow chart.
126
Follow-up one year after stroke
In the previous study of the one-year stroke population (n = 597), 391 survivors had been followed up one year after stroke (13). Data from the database collected 1 year after stroke were used to analyse the status of the patients with stroke and AF 1 year after stroke. Follow-up five years after stroke
Baseline 183 patients with stroke and AF
155 with stroke and AF included
Baseline characteristics and risk factors for stroke were retrospectively obtained from medical records and from the previous follow-up 1 year after stroke (13). Stroke severity was assessed with the National Institutes of Health Stroke Scale (NIHSS) scoring 0–42. Minor stroke was defined as NIHSS score ≤7, a moderate stroke as score 8–15 and a major stroke as ≥16 (14). Hypertension was defined as a blood pressure >139/89 mmHg with or without antihypertensive treatment (15). Level of dependence was assessed with the Barthel Index (BI) (16) and level of disability with the modified Rankin Scale (mRS) (17). BI score (range 0–100) was divided into three groups with a score 95–100 indicating independence, 60–90 minor dependence and 0–55 major dependence (18). The mRS (range 0–5) was divided into two groups; 0–2 (no symptoms, no significant or slight disability) and 3–5 (moderate, moderately severe or severe disability).
In this study, a follow-up was performed 5 years after stroke regarding dependence (BI), disability (mRS), blood pressure, smoking and stroke prophylactic treatment. The importance of hypertension and smoking in stroke prevention has been emphasized in the European Stroke Strategies (19). The same factors from the one-year followup are included in this study, except stroke prophylactic treatment, which was not registered at the one-year follow-up. The patients were followed up at the outpatient clinic, in the patient’s own home or in a nursing home with assistance from nurses. Mortality
Mortality in the acute stroke unit care, and at follow-up one and five years after stroke was analysed. For this analysis, only patients with a first-ever stroke were included. Date of death for those who were deceased was obtained from the Swedish population register or medical records.
Outcome of men and women with AF and stroke Statistical analysis
All continuous variables are presented as mean (SD) and were compared using the t-test. Categorical variables were examined by the Pearson’s chi-square test or the Fisher’s exact test. Survival after stroke was estimated using the Kaplan–Meier method and a comparison was made using the log-rank test. A P-value ≤0.05 was considered to be significant. All characteristics and assessments in the study were compared between men and women. Data were analysed using IBM SPSS Statistics version 21 (IBM Corp., Armonk, New York, USA).
Among the 155 patients, 111 individuals (65 [59%] women and 46 [41%] men) were diagnosed with AF or had an AF verified by ECG before stroke. Men were significantly more often prescribed warfarin, (28% vs 11%, P < 0.05). No stroke prophylactic medication was prescribed before stroke for 14 women (22%) and 12 men (26%) with no significant difference between men and women. However at discharge from the hospital, more patients had been diagnosed with AF (n = 113) and 16 women (26%) vs 17 men (33%) had been prescribed Warfarin or NOAC with no significant gender difference (Table 2). Follow-up one year after stroke
Ethical considerations
The study of the total population of 597 registered patients was approved by the Regional Ethical Review Board, Lund University, Registration No. 520/2007 (13). Results
Among the 155 patients eligible for analysis in the study (94 [61%] women and 61 [39%] men), 123 were diagnosed with a first-ever cerebral infarction (CI), that is 32 patients had a recurrent stroke. Women were on average 5 years older than men at baseline (84.8 8.1 vs 79.5 8.7 years, P < 0.001). Men were more often diagnosed with diabetes (31% vs 15%, P < 0.05) and more often had a history of smoking (54% vs 13% previous smokers, P < 0.01). Regarding stroke severity, hypertension and previous stroke, no differences between men and women were found (Table 1). Table 1 Baseline characteristics of 155 patients with atrial fibrillation and stroke
Characteristics* All patients Age, mean (SD), years Range Hypertension Diabetes Smoking Current smoker Previous smoker Stroke severity, NIHSS Minor stroke ≤7 Moderate stroke 8–15 Major stroke ≥16 Recurrent stroke
Women N (%)
Men N (%)
94 (61) 84.8 (8.1) 54.7–98.5 61 (65) 14 (15)
61 (39) 79.5 (8.7) 50.3–96.1 37 (61) 19 (31)
10 (12) 11 (13)
5 (8) 33 (54)
