One-Year Outcomes of Emergency Department Patients With Atrial Fibrillation: A Prospective, Multicenter Registry in China
Angiology 1-8 ª The Author(s) 2014 Reprints and permission: sagepub.com/journalsPermissions.nav DOI: 10.1177/0003319714553936 ang.sagepub.com
Yan-Min Yang, MD, PhD1, Xing-Hui Shao, PhD1, Jun Zhu, MD, PhD1, Han Zhang, PhD1, Yao Liu, PhD1, Xin Gao, PhD1, Li-Tian Yu, MD, PhD1, Li-Sheng Liu, MD, PhD1, Li Zhao, MD2, Peng-Fei Yu, MD3, Hua Zhang, MD4, Qing He, MD5, and Xiao-Dan Gu, MD6
Abstract There is lack of data about patient characteristics, practice patterns, and long-term adverse outcomes in patients with atrial fibrillation (AF) attending emergency departments (EDs) in China. A total of 2016 patients from 20 representative EDs were included. During 1 year, all-cause mortality was 291 (14.6%) cases, stroke/noncentral nervous system systemic embolism rate was 159 (8.0%) cases, and major bleeding was 26 (1.3%) cases. Heart failure, the major cause of mortality, accounted for 43.0% of deaths. Of 375 (18.6%) patients who used warfarin at baseline, only 217 (57.9%) patients were still on anticoagulation therapy during 1-year follow-up. Compared with the patients who continued on warfarin, the mortality rate was higher in those who did not continue (15.9% vs 5.5%, P < .001). Patients seen in ED with AF appear to have a high incidence rate of long-term all-cause mortality and inadequate anticoagulation rate. Keywords atrial fibrillation, anticoagulation, long-time outcome, China
Introduction Atrial fibrillation (AF) is the most common cardiac arrhythmia, occurring in 1% to 2% of the general population.1 The incidence and prevalence of AF are increasing as a consequence of the aging population.2 The presence of AF independently increases the risk of mortality and morbidity, mainly due to its complication of stroke, congestive heart failure, and myocardial infarction.1,3 Survival may be associated with impaired quality of life and hospitalization, causing a high public health burden. The presence of AF confers a 5-fold increased risk of stroke; AF is responsible for 15% to 20% of all strokes. Furthermore, strokes due to AF are more severe than stroke occurring in patients without AF.4 Those patients who survive are more likely to have a recurrence than patients with other causes of stroke.5 For stroke prevention, trials have made it clear that vitamin K antagonists reduced stroke risk by 60%,6 and antiplatelet therapy was not effective. However, studies described the characteristic, management, and rates of adverse outcomes for patients with AF are largely gathered in the Western countries, and there is a scarcity of reliable information on the status of
AF in the Asian population.7,8 There are known ethnic difference between white population and nonwhite people, even after adjustment for comorbidities associated with AF. So, it is
1
Emergency and Intensive Care Center, Fuwai Hospital, Chinese Academy Of Medical Sciences and Peking Union Medical College, Beijing, China 2 Department of Emergency, Fu Xing Hospital, Capital Medical University, Beijing, China 3 Department of Cardiology, Pingdu People’s Hospital, Pingdu, Shandong, China 4 Department of Emergency, Qingdao Municipal Hospital, Qingdao, Shandong, China 5 Department of Emergency, West China Hospital, Sichuan University, Chengdu, Sichuan, China 6 Department of Emergency, Sixth People’s Hospital of Chengdu, Chengdu, Sichuan, China Corresponding Author: Jun Zhu, Emergency and Intensive Care Center, State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, No.167 Beilishilu, Beijing 100037, China. Email: [email protected]
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necessary to get a general idea about the current situation regarding AF in China. During the last decades, AF has become the most frequent arrhythmia seen in the emergency departments (EDs),9 and the prevalence will increase with the aging population.2,10,11 However, there is a lack of clarity about the optimal management of AF in EDs, and physician approaches appear to vary substantially. Underlying comorbidities, cause of AF, stability of the patients, and the medical conditions all impact on the appropriate treatment options. Furthermore, information about the characteristics and long-term outcomes of AF in EDs was limited. Therefore, studies on this point were needed to guide the treatment of AF in EDs. The purpose of our study is to evaluate the current conditions and treatment of AF in Chinese ED patients and to identify the adverse cardiac events during 1-year follow-up.
Methods The Chinese AF registry was a multicenter, prospective, observational study, in which 20 representative EDs from different areas participated. We enrolled patients who presented to an ED with AF or atrial flutter from November 2008 to October 2011, either as the primary or as the secondary diagnosis. The study was approved by the ethics committees of each institution, and all the patients enrolled in the registry gave their written consent for study participation. Eligible patients included identification of patients using electronic hospital databases recording ED diagnoses, review of electrocardiograms and telemetry recordings from the ED, and direct screening by ED staff and research personnel. Centers were encouraged to enroll patients as rapidly as possible, in order to minimize additional selection bias. Baseline data were collected from review of the participants’ ED, hospital records, and direct interview with patients and their treating physicians. Researchers from each site use a common case report form, which captures patient demographics, arrival time, information regarding AF, history, medication and interventions for AF, and outcome from the ED visit. Clinic follow-up for cardiac adverse events, outcome of AF and medications, and further visits to hospital was performed at 1 year after presentation to the study via telephone calls, and additional information needed was obtained by contacting the patient’s physicians. For blood pressure and heart rate, initial data at registration were documented. Definitions of the AF clinical types were consistent with the 2006 American College of Cardiology/ American Heart Association/European Society of Cardiology guidelines: paroxysmal AF refers to those AF episodes that terminate spontaneously and last 7 days, persistent AF refers to AF episodes that do not terminate spontaneously but do convert with either electrical or pharmacological cardioversion, and permanent AF refers to those AF episodes that do not terminate either spontaneously or with electrical or chemical cardioversion, or cardioversion has not been attempted. We combined persistent AF and permanent AF as sustained AF. Body mass index was calculated as weight in kg divided by the square of height in m. The CHADS2 (C, Congestive heart
failure; H, Hypertension; A, Age; D, Diabetes mellitus; S, previous Stroke or transient ischemic attack) is a validated score system for stroke risk estimation and is based on a scoring system in which 2 points are assigned for a prior stroke/transient ischemic attack, 1 point each for congestive heart failure, hypertension, age 75, and diabetes mellitus. For patients receiving oral anticoagulation, results of 3 recent international normalized ratio (INR) were obtained from the medical records. The main study outcomes included cause-specific mortality, stroke, noncentral nervous system (CNS) systemic embolism, and any major bleeds. Cause of death was obtained from the medical records or physician’s notes. Primary stroke outcome included all strokes, ischemic and hemorrhagic, that were associated with focal neurological symptoms lasting more than 24 hours. NonCNS systemic embolism was defined as the occurrence of myocardial infarction, pulmonary embolism, or peripheral embolism. Major bleeding was defined as fatal bleeding, and/or symptomatic bleeding in a critical area or organ, such as intracranial, intraspinal, intraocular, retroperitoneal, intra-articular or pericardial, or intramuscular with compartment syndrome, and/or bleeding causing a fall in hemoglobin level of 20 g/L (1.24 mmol/L), or leading to transfusion of 2 units of whole blood or red cells. Major adverse cardiac events included all-cause mortality, stroke, non-CNS systemic embolism, and major bleeding. The combined readmission rate included repeat visit to hospital for AF/flutter complications, repeat visit to hospital for heart failure, and repeat visit to hospital for myocardial infarction. We defined patients taking anticoagulation medicine on both enrollment and follow-up period as patients who remained on anticoagulation therapy, so did those with continued antiplatelet therapy. Data were collected through searching medical records and patient interview from each centers, and case report forms were sent to Fuwai hospital by fax. Using a validation plan, integrated in the data entry software, data were checked for missing or contradictory entries and values out of the normal range. Additional edit checks were performed by the staff in Fuwai hospital.
Statistics Basic characteristics were expressed as percentage. The comparison of discrete variables was done via the chi-square test. Continuous variables were presented as a mean with standard deviation and analyzed by t test. The relationship between subgroups and major adverse events were characterized using the odds ratio (OR) and corresponding 95% confidence interval (CI) from a multivariable logistic analysis. The data were analyzed with SPSS 17.0, and a P < .05 was considered significant (2-tailed test).
Results Baseline Characteristics A total of 2016 patients (1104 women) were enrolled. Baseline characteristics of the study population are summarized in
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Table 1. Atrial fibrillation was the primary reason for the ED visit in 40.9% of patients and 80.9% of patients had a previous diagnosis of AF. Hypertension was the most prevalent comorbidity (55.5%), followed by coronary artery disease (41.8%). The rates of permanent, persistent, and paroxysmal AF were 47%, 22.3%, and 30.7%, respectively. Among them, 375 (18.6%) patients were prescribed warfarin and 1281 (63.5%) had received antiplatelet therapy. The proportion of antithrombotic therapy by CHADS2 score is shown in Figure 1. After the ED visit, 47.8% of patients were discharged home, 52.0% were admitted to hospital, and 0.2% died during the ED visit.
One-Year Follow-Up We had 1-year follow-up data available for 98.8% of the baseline population. During 1-year follow-up, the incidence of major adverse events and readmission rate are as shown in Table 2. The incidence rates of all-cause mortality and stroke/non-CNS systemic embolism were 14.6% and 8.0%, respectively. The causes of death are shown in Figure 2. Heart failure was the major cause of mortality, which accounted for 43.0% of deaths. Other reasons included infection, stroke, sudden death, and so on. The readmission rate for AF complication, heart failure, and myocardial infarction was 20.5%, 16.6%, and 1.1%, respectively. The difference rate of all-cause mortality and stroke/nonCNS systemic embolism in subgroups is summarized in Tables 3 and 4. In those where AF was a primary diagnosis or patients with paroxysmal AF had a lower mortality rate (all P < .01) compared with those diagnosed with AF as its secondary diagnosis or with sustained AF. Patients who remained on antithrombotic therapy (defined as using warfarin or antiplatelet drugs at baseline and follow-up period) were associated with a better outcome (all P < .001). History of heart failure was a risk factor for death (OR: 1.718, 95% CI 1.227-2.406, P ¼ .002). But it was a protective factor for the occurrence of stroke (OR: 0.584, 95% CI 0.370-0.923, P ¼ .021). In addition, there was no difference in the incidence rates between patients with valvular heart disease and without. Figure 3 showed the incidence rates of all-cause mortality and stroke/non-CNS systemic embolism by CHASD2 score.
Treatment The percentage of patients who received cardioversion in ED electrical, spontaneous, and chemical was 0.3%, 5.7%, and 18.1%, respectively. The most frequently used chemical drug for cardioversion was amiodarone (69.3%), followed by propafenone (23%). During 1-year follow-up, patients receiving cardioversion, AF ablation, and AV node ablation were 56 (2.9%) cases, 36 (1.8%) cases, and 23 (1.2%) cases, respectively. Four persons had received pacemaker or implantable cardioverter defibrillator. Among 375 patients who were prescribed warfarin on admission, 217 (59.5%) remained on it, 114 (31.4%) had taken aspirin instead, and the others had stopped the anticoagulation therapy during the 1-year follow-up. Among the patients who were prescribed antiplatelet medicine on
Table 1. Baseline Characteristics of the 2016 Patients With AF.a Characteristic Age, years BMI, kg/m2 Systolic blood pressure, mm Hg Diastolic blood pressure, mm Hg Heart rate, beats/min Mean CHADS2 scoreb Female gender, n (%) Primary AF diagnosis, n (%) Type of AF Paroxysmal AF, n (%) Persistent AF, n (%) Permanent AF, n (%) Cardiac complications Myocardial infarction, n (%) Coronary artery disease, n (%) Heart failure, n (%) Rheumatic heart disease, n (%) Permanent pacemaker, n (%) Hypertension, n (%) LVH, n (%) Left ventricular systolic dysfunction, n (%) Pericarditis, n (%) Valvular heart disease, n (%) Other risk factors Sleep apnea, n (%) Tobacco, n (%) Dementia or cognitive defects, n (%) COPD, n (%) Diabetes mellitus, n (%) Hyperthyroidism, n (%) Stroke or TIA, n (%) Major bleeding, n (%) CHADS2 scorea, n (%) 0 1 2 3 4 5 6 Medication ACE inhibitor b-blocker CCB Diuretics Digoxin Lipid-lowering medication
Patients (n ¼ 2016) 68.5 (13.3) 23.5 (3.6) 131.9 (23.3) 79.9 (14.7) 101.7 (29.4) 1.8 (1.4) 1104 (54.8) 825 (40.9) 618 (30.7) 452 (22.4) 945 (46.9) 148 (7.3) 843 (41.8) 753 (37.4) 318 (15.8) 64 (3.2) 1118 (55.5) 329 (16.3) 385 (19.1) 8 (0.4) 336 (16.7) 70 (3.5) 433 (21.5) 44 (2.2) 236 (11.7) 312 (15.5) 66 (3.3) 379 (18.8) 48 (2.5) 340 (16.9) 650 (32.3) 462 (22.9) 303 (15.0) 169 (8.4) 76 (3.8) 14 (0.7) 533 (26.5) 1015 (50.4) 573 (28.4) 857 (42.5) 718 (35.6) 528 (26.2)
Abbreviations: BMI, body mass index; TIA, transient ischemic attack; AF, atrial fibrillation; LVH, left ventricular hypertrophy; COPD, chronic obstructive pulmonary disease; ACE, inhibitor, angiotensin converting enzyme inhibitors; CCB, calcium channel blocker; SD, standard deviation. a Data are expressed as number (%) or mean (SD). b A risk stratification scheme for AF. A score of 0 to 6 is derived based on the following factors: congestive heart failure (1 point); hypertension (1 point); age > 75 years (1 point); diabetes mellitus (1 point), and previous stroke or TIA (2 point).
admission, 74% remained on it. For 1024 patients with a CHADS2 2, the anticoagulation rate was 15% at enrollment. Of them, 55.2% remained on warfarin during 1-year follow-up.
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Figure 1. A, Antithrombotic therapy at baseline. B, Antithrombotic therapy per CHADS2 risk score. CHADS2 indicates C, congestive heart failure (1 point); H, hypertension (1 point); A, age (age > 75 years, 1 point); D, diabetes mellitus (1 point); S, previous stroke or transient ischemic attack (2 point). Table 2. Major Adverse Events and Readmission Rate During 1-Year Follow-Up.a Events The MACE All-cause mortality Stroke Non-CNS systemic embolism Major bleeding Readmission rate For AF or flutter complication For heart failure For myocardial infarction
Number (%) 436 291 148 15 26 618 402
(21.9) (14.6) (7.4) (0.8) (1.3) (31.6) (20.5)
Continued Warfarin 25 11 12 1 7 63 42
(12.8%)b (5.6%)b (6.1%) (0.5%) (3.6%)b (32.1%) (21.4%)
325 (16.6) 30 (15.3%) 22 (1.1) 1 (0.5%)
Continued Aspirin 179 (19.7%)b 118 (13.0%)b 66 (7.3%) 3 (0.3%) 4 (0.4%)b 309 (34.3%) 198 (21.8%) 169 (18.8%) 15 (1.7%)
Abbreviations: MACE, major adverse cardiac events; AF, atrial fibrillation; CNS, central nervous system. a n ¼ 1992. b P < .05.
We also investigated why the patients with stroke risk (CHADS2 1) did not take anticoagulation therapy; 665 of them answered this question. Patient preference (38.9%) was the most common reason, followed by a difficulty INR testing (18.5%) and not been indicated (16.4%). Prior bleeding
Figure 2. Cause of death during 1-year follow-up (n ¼ 291).
complications and perceived increased risk of bleeding complication were the reasons in 10.1% and 6.2%, respectively.
Discussion To the best of our knowledge, this is the first multicenter, observational study to report the characteristics and long-
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Table 3. Death Rate in Each Subgroup and Associations Between Factors and All-Cause Mortality in Patients With AF Presenting to EDs.a Univariable
Secondary AF diagnosis No Yes Heart failure No Yes Valvular heart disease No Yes Stick to warfarin No Yes Stick to antiplatelet therapy No Yes Type of AF Sustained AF Paroxysmal AF
Multivariable
Number (%)
OR (95% CI)
P Value
OR (95% CI)
P Value
65 (7.94) 226 (19.28)
2.771 (2.070-3.711)
Angiology 1-8 ª The Author(s) 2014 Reprints and permission: sagepub.com/journalsPermissions.nav DOI: 10.1177/0003319714553936 ang.sagepub.com
Yan-Min Yang, MD, PhD1, Xing-Hui Shao, PhD1, Jun Zhu, MD, PhD1, Han Zhang, PhD1, Yao Liu, PhD1, Xin Gao, PhD1, Li-Tian Yu, MD, PhD1, Li-Sheng Liu, MD, PhD1, Li Zhao, MD2, Peng-Fei Yu, MD3, Hua Zhang, MD4, Qing He, MD5, and Xiao-Dan Gu, MD6
Abstract There is lack of data about patient characteristics, practice patterns, and long-term adverse outcomes in patients with atrial fibrillation (AF) attending emergency departments (EDs) in China. A total of 2016 patients from 20 representative EDs were included. During 1 year, all-cause mortality was 291 (14.6%) cases, stroke/noncentral nervous system systemic embolism rate was 159 (8.0%) cases, and major bleeding was 26 (1.3%) cases. Heart failure, the major cause of mortality, accounted for 43.0% of deaths. Of 375 (18.6%) patients who used warfarin at baseline, only 217 (57.9%) patients were still on anticoagulation therapy during 1-year follow-up. Compared with the patients who continued on warfarin, the mortality rate was higher in those who did not continue (15.9% vs 5.5%, P < .001). Patients seen in ED with AF appear to have a high incidence rate of long-term all-cause mortality and inadequate anticoagulation rate. Keywords atrial fibrillation, anticoagulation, long-time outcome, China
Introduction Atrial fibrillation (AF) is the most common cardiac arrhythmia, occurring in 1% to 2% of the general population.1 The incidence and prevalence of AF are increasing as a consequence of the aging population.2 The presence of AF independently increases the risk of mortality and morbidity, mainly due to its complication of stroke, congestive heart failure, and myocardial infarction.1,3 Survival may be associated with impaired quality of life and hospitalization, causing a high public health burden. The presence of AF confers a 5-fold increased risk of stroke; AF is responsible for 15% to 20% of all strokes. Furthermore, strokes due to AF are more severe than stroke occurring in patients without AF.4 Those patients who survive are more likely to have a recurrence than patients with other causes of stroke.5 For stroke prevention, trials have made it clear that vitamin K antagonists reduced stroke risk by 60%,6 and antiplatelet therapy was not effective. However, studies described the characteristic, management, and rates of adverse outcomes for patients with AF are largely gathered in the Western countries, and there is a scarcity of reliable information on the status of
AF in the Asian population.7,8 There are known ethnic difference between white population and nonwhite people, even after adjustment for comorbidities associated with AF. So, it is
1
Emergency and Intensive Care Center, Fuwai Hospital, Chinese Academy Of Medical Sciences and Peking Union Medical College, Beijing, China 2 Department of Emergency, Fu Xing Hospital, Capital Medical University, Beijing, China 3 Department of Cardiology, Pingdu People’s Hospital, Pingdu, Shandong, China 4 Department of Emergency, Qingdao Municipal Hospital, Qingdao, Shandong, China 5 Department of Emergency, West China Hospital, Sichuan University, Chengdu, Sichuan, China 6 Department of Emergency, Sixth People’s Hospital of Chengdu, Chengdu, Sichuan, China Corresponding Author: Jun Zhu, Emergency and Intensive Care Center, State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, No.167 Beilishilu, Beijing 100037, China. Email: [email protected]
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necessary to get a general idea about the current situation regarding AF in China. During the last decades, AF has become the most frequent arrhythmia seen in the emergency departments (EDs),9 and the prevalence will increase with the aging population.2,10,11 However, there is a lack of clarity about the optimal management of AF in EDs, and physician approaches appear to vary substantially. Underlying comorbidities, cause of AF, stability of the patients, and the medical conditions all impact on the appropriate treatment options. Furthermore, information about the characteristics and long-term outcomes of AF in EDs was limited. Therefore, studies on this point were needed to guide the treatment of AF in EDs. The purpose of our study is to evaluate the current conditions and treatment of AF in Chinese ED patients and to identify the adverse cardiac events during 1-year follow-up.
Methods The Chinese AF registry was a multicenter, prospective, observational study, in which 20 representative EDs from different areas participated. We enrolled patients who presented to an ED with AF or atrial flutter from November 2008 to October 2011, either as the primary or as the secondary diagnosis. The study was approved by the ethics committees of each institution, and all the patients enrolled in the registry gave their written consent for study participation. Eligible patients included identification of patients using electronic hospital databases recording ED diagnoses, review of electrocardiograms and telemetry recordings from the ED, and direct screening by ED staff and research personnel. Centers were encouraged to enroll patients as rapidly as possible, in order to minimize additional selection bias. Baseline data were collected from review of the participants’ ED, hospital records, and direct interview with patients and their treating physicians. Researchers from each site use a common case report form, which captures patient demographics, arrival time, information regarding AF, history, medication and interventions for AF, and outcome from the ED visit. Clinic follow-up for cardiac adverse events, outcome of AF and medications, and further visits to hospital was performed at 1 year after presentation to the study via telephone calls, and additional information needed was obtained by contacting the patient’s physicians. For blood pressure and heart rate, initial data at registration were documented. Definitions of the AF clinical types were consistent with the 2006 American College of Cardiology/ American Heart Association/European Society of Cardiology guidelines: paroxysmal AF refers to those AF episodes that terminate spontaneously and last 7 days, persistent AF refers to AF episodes that do not terminate spontaneously but do convert with either electrical or pharmacological cardioversion, and permanent AF refers to those AF episodes that do not terminate either spontaneously or with electrical or chemical cardioversion, or cardioversion has not been attempted. We combined persistent AF and permanent AF as sustained AF. Body mass index was calculated as weight in kg divided by the square of height in m. The CHADS2 (C, Congestive heart
failure; H, Hypertension; A, Age; D, Diabetes mellitus; S, previous Stroke or transient ischemic attack) is a validated score system for stroke risk estimation and is based on a scoring system in which 2 points are assigned for a prior stroke/transient ischemic attack, 1 point each for congestive heart failure, hypertension, age 75, and diabetes mellitus. For patients receiving oral anticoagulation, results of 3 recent international normalized ratio (INR) were obtained from the medical records. The main study outcomes included cause-specific mortality, stroke, noncentral nervous system (CNS) systemic embolism, and any major bleeds. Cause of death was obtained from the medical records or physician’s notes. Primary stroke outcome included all strokes, ischemic and hemorrhagic, that were associated with focal neurological symptoms lasting more than 24 hours. NonCNS systemic embolism was defined as the occurrence of myocardial infarction, pulmonary embolism, or peripheral embolism. Major bleeding was defined as fatal bleeding, and/or symptomatic bleeding in a critical area or organ, such as intracranial, intraspinal, intraocular, retroperitoneal, intra-articular or pericardial, or intramuscular with compartment syndrome, and/or bleeding causing a fall in hemoglobin level of 20 g/L (1.24 mmol/L), or leading to transfusion of 2 units of whole blood or red cells. Major adverse cardiac events included all-cause mortality, stroke, non-CNS systemic embolism, and major bleeding. The combined readmission rate included repeat visit to hospital for AF/flutter complications, repeat visit to hospital for heart failure, and repeat visit to hospital for myocardial infarction. We defined patients taking anticoagulation medicine on both enrollment and follow-up period as patients who remained on anticoagulation therapy, so did those with continued antiplatelet therapy. Data were collected through searching medical records and patient interview from each centers, and case report forms were sent to Fuwai hospital by fax. Using a validation plan, integrated in the data entry software, data were checked for missing or contradictory entries and values out of the normal range. Additional edit checks were performed by the staff in Fuwai hospital.
Statistics Basic characteristics were expressed as percentage. The comparison of discrete variables was done via the chi-square test. Continuous variables were presented as a mean with standard deviation and analyzed by t test. The relationship between subgroups and major adverse events were characterized using the odds ratio (OR) and corresponding 95% confidence interval (CI) from a multivariable logistic analysis. The data were analyzed with SPSS 17.0, and a P < .05 was considered significant (2-tailed test).
Results Baseline Characteristics A total of 2016 patients (1104 women) were enrolled. Baseline characteristics of the study population are summarized in
Downloaded from ang.sagepub.com at Selcuk Universitesi on January 14, 2015
Yang et al
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Table 1. Atrial fibrillation was the primary reason for the ED visit in 40.9% of patients and 80.9% of patients had a previous diagnosis of AF. Hypertension was the most prevalent comorbidity (55.5%), followed by coronary artery disease (41.8%). The rates of permanent, persistent, and paroxysmal AF were 47%, 22.3%, and 30.7%, respectively. Among them, 375 (18.6%) patients were prescribed warfarin and 1281 (63.5%) had received antiplatelet therapy. The proportion of antithrombotic therapy by CHADS2 score is shown in Figure 1. After the ED visit, 47.8% of patients were discharged home, 52.0% were admitted to hospital, and 0.2% died during the ED visit.
One-Year Follow-Up We had 1-year follow-up data available for 98.8% of the baseline population. During 1-year follow-up, the incidence of major adverse events and readmission rate are as shown in Table 2. The incidence rates of all-cause mortality and stroke/non-CNS systemic embolism were 14.6% and 8.0%, respectively. The causes of death are shown in Figure 2. Heart failure was the major cause of mortality, which accounted for 43.0% of deaths. Other reasons included infection, stroke, sudden death, and so on. The readmission rate for AF complication, heart failure, and myocardial infarction was 20.5%, 16.6%, and 1.1%, respectively. The difference rate of all-cause mortality and stroke/nonCNS systemic embolism in subgroups is summarized in Tables 3 and 4. In those where AF was a primary diagnosis or patients with paroxysmal AF had a lower mortality rate (all P < .01) compared with those diagnosed with AF as its secondary diagnosis or with sustained AF. Patients who remained on antithrombotic therapy (defined as using warfarin or antiplatelet drugs at baseline and follow-up period) were associated with a better outcome (all P < .001). History of heart failure was a risk factor for death (OR: 1.718, 95% CI 1.227-2.406, P ¼ .002). But it was a protective factor for the occurrence of stroke (OR: 0.584, 95% CI 0.370-0.923, P ¼ .021). In addition, there was no difference in the incidence rates between patients with valvular heart disease and without. Figure 3 showed the incidence rates of all-cause mortality and stroke/non-CNS systemic embolism by CHASD2 score.
Treatment The percentage of patients who received cardioversion in ED electrical, spontaneous, and chemical was 0.3%, 5.7%, and 18.1%, respectively. The most frequently used chemical drug for cardioversion was amiodarone (69.3%), followed by propafenone (23%). During 1-year follow-up, patients receiving cardioversion, AF ablation, and AV node ablation were 56 (2.9%) cases, 36 (1.8%) cases, and 23 (1.2%) cases, respectively. Four persons had received pacemaker or implantable cardioverter defibrillator. Among 375 patients who were prescribed warfarin on admission, 217 (59.5%) remained on it, 114 (31.4%) had taken aspirin instead, and the others had stopped the anticoagulation therapy during the 1-year follow-up. Among the patients who were prescribed antiplatelet medicine on
Table 1. Baseline Characteristics of the 2016 Patients With AF.a Characteristic Age, years BMI, kg/m2 Systolic blood pressure, mm Hg Diastolic blood pressure, mm Hg Heart rate, beats/min Mean CHADS2 scoreb Female gender, n (%) Primary AF diagnosis, n (%) Type of AF Paroxysmal AF, n (%) Persistent AF, n (%) Permanent AF, n (%) Cardiac complications Myocardial infarction, n (%) Coronary artery disease, n (%) Heart failure, n (%) Rheumatic heart disease, n (%) Permanent pacemaker, n (%) Hypertension, n (%) LVH, n (%) Left ventricular systolic dysfunction, n (%) Pericarditis, n (%) Valvular heart disease, n (%) Other risk factors Sleep apnea, n (%) Tobacco, n (%) Dementia or cognitive defects, n (%) COPD, n (%) Diabetes mellitus, n (%) Hyperthyroidism, n (%) Stroke or TIA, n (%) Major bleeding, n (%) CHADS2 scorea, n (%) 0 1 2 3 4 5 6 Medication ACE inhibitor b-blocker CCB Diuretics Digoxin Lipid-lowering medication
Patients (n ¼ 2016) 68.5 (13.3) 23.5 (3.6) 131.9 (23.3) 79.9 (14.7) 101.7 (29.4) 1.8 (1.4) 1104 (54.8) 825 (40.9) 618 (30.7) 452 (22.4) 945 (46.9) 148 (7.3) 843 (41.8) 753 (37.4) 318 (15.8) 64 (3.2) 1118 (55.5) 329 (16.3) 385 (19.1) 8 (0.4) 336 (16.7) 70 (3.5) 433 (21.5) 44 (2.2) 236 (11.7) 312 (15.5) 66 (3.3) 379 (18.8) 48 (2.5) 340 (16.9) 650 (32.3) 462 (22.9) 303 (15.0) 169 (8.4) 76 (3.8) 14 (0.7) 533 (26.5) 1015 (50.4) 573 (28.4) 857 (42.5) 718 (35.6) 528 (26.2)
Abbreviations: BMI, body mass index; TIA, transient ischemic attack; AF, atrial fibrillation; LVH, left ventricular hypertrophy; COPD, chronic obstructive pulmonary disease; ACE, inhibitor, angiotensin converting enzyme inhibitors; CCB, calcium channel blocker; SD, standard deviation. a Data are expressed as number (%) or mean (SD). b A risk stratification scheme for AF. A score of 0 to 6 is derived based on the following factors: congestive heart failure (1 point); hypertension (1 point); age > 75 years (1 point); diabetes mellitus (1 point), and previous stroke or TIA (2 point).
admission, 74% remained on it. For 1024 patients with a CHADS2 2, the anticoagulation rate was 15% at enrollment. Of them, 55.2% remained on warfarin during 1-year follow-up.
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Figure 1. A, Antithrombotic therapy at baseline. B, Antithrombotic therapy per CHADS2 risk score. CHADS2 indicates C, congestive heart failure (1 point); H, hypertension (1 point); A, age (age > 75 years, 1 point); D, diabetes mellitus (1 point); S, previous stroke or transient ischemic attack (2 point). Table 2. Major Adverse Events and Readmission Rate During 1-Year Follow-Up.a Events The MACE All-cause mortality Stroke Non-CNS systemic embolism Major bleeding Readmission rate For AF or flutter complication For heart failure For myocardial infarction
Number (%) 436 291 148 15 26 618 402
(21.9) (14.6) (7.4) (0.8) (1.3) (31.6) (20.5)
Continued Warfarin 25 11 12 1 7 63 42
(12.8%)b (5.6%)b (6.1%) (0.5%) (3.6%)b (32.1%) (21.4%)
325 (16.6) 30 (15.3%) 22 (1.1) 1 (0.5%)
Continued Aspirin 179 (19.7%)b 118 (13.0%)b 66 (7.3%) 3 (0.3%) 4 (0.4%)b 309 (34.3%) 198 (21.8%) 169 (18.8%) 15 (1.7%)
Abbreviations: MACE, major adverse cardiac events; AF, atrial fibrillation; CNS, central nervous system. a n ¼ 1992. b P < .05.
We also investigated why the patients with stroke risk (CHADS2 1) did not take anticoagulation therapy; 665 of them answered this question. Patient preference (38.9%) was the most common reason, followed by a difficulty INR testing (18.5%) and not been indicated (16.4%). Prior bleeding
Figure 2. Cause of death during 1-year follow-up (n ¼ 291).
complications and perceived increased risk of bleeding complication were the reasons in 10.1% and 6.2%, respectively.
Discussion To the best of our knowledge, this is the first multicenter, observational study to report the characteristics and long-
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Yang et al
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Table 3. Death Rate in Each Subgroup and Associations Between Factors and All-Cause Mortality in Patients With AF Presenting to EDs.a Univariable
Secondary AF diagnosis No Yes Heart failure No Yes Valvular heart disease No Yes Stick to warfarin No Yes Stick to antiplatelet therapy No Yes Type of AF Sustained AF Paroxysmal AF
Multivariable
Number (%)
OR (95% CI)
P Value
OR (95% CI)
P Value
65 (7.94) 226 (19.28)
2.771 (2.070-3.711)
