International Journal of Neuroscience, 2014; Early Online: 1–5 Copyright © 2014 Informa Healthcare USA, Inc. ISSN: 0020-7454 print / 1543-5245 online DOI: 10.3109/00207454.2014.986266
ORIGINAL ARTICLE
Hospital mortality from atrial fibrillation associated with ischemic stroke: a national data report Kannikar Kongbunkiat,1,3 Narongrit Kasemsap,1,3 Suporn Travanichakul,1,3 Kaewjai Thepsuthammarat,2 Somsak Tiamkao,1,3 and Kittisak Sawanyawisuth1,4
Int J Neurosci Downloaded from informahealthcare.com by Nyu Medical Center on 05/02/15 For personal use only.
1
Department of Medicine, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand; 2 Clinical Epidemiology Unit, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand; 3 North-eastern Stroke Research Group, Khon Kaen University; 4 Research Center in Back, Neck, Other Joint Pain and Human Performance (BNOJPH), Khon Kaen University, Khon Kaen, Thailand Purpose: To study factors associated with poor outcomes in acute ischemic stroke patients with atrial fibrillation (AF) by using a national database. Materials and Methods: This study was a retrospective analytical study by retrieving data from the Thailand national database system for universal coverage (UC) health insurance system. All adult patients aged over 18 years who were admitted with acute ischemic stroke during the fiscal years 2004–2012 by the appropriate ICD codes were searched. Eligible patients with AF were categorized as alive or dead during hospital stay. The mortality rate and factors associated with in-hospital mortality were studied. Results: There were 522,699 patients diagnosed as acute stroke; 277,291 patients (53.1%) had acute ischemic stroke. Of those with ischemic stroke, 25,319 patients (9.1%) had AF. The mortality rates of acute ischemic stroke with AF were 14.1% and without AF were 6.2%, (p < 0.001). Significant factors associated with mortality in acute stroke patients with AF by multivariate logistic regression were female gender (adjusted odds ratio; AOR 1.28), co-morbid diseases such as diabetes (AOR 1.28), hypertension (AOR 1.26), rt-PA treatment (AOR 0.55), and stroke complications, such as pneumonia (AOR 2.60), septicemia (AOR 6.50), or gastrointestinal bleeding (AOR 2.16). Conclusions: At the national level, AF caused a higher mortality rate in acute ischemic stroke than in non-AF patients. Gender, co-morbid diseases, rt-PA treatment, and stroke complications were associated with mortality in acute ischemic stroke with AF. KEYWORDS: stroke, atrial fibrillation, mortality, hospital, national data
Introduction Stroke is the leading neurological disease and causes neurological sequels. Stroke patients with atrial fibrillation (AF) have a 2 times higher risk for death compared with those who did not have AF [1]. Generally, risk for acute ischemic stroke is increased by age and 3.5% each one year of age after 75 years old [2]. This risk will dramatically increase to 4–5 times if AF is existed [1]. The prevalence rate of AF is 0.36% in populations of an age over 30 years [3]. Previous studies showed that AF is a poor prognostic factor in ischemic stroke for disabilities or deaths [4–9].
Having AF in acute ischemic stroke increased the risk of death within 30 days twice as compared with those who have sinus rhythm. In addition, hemorrhagic transformation after recombinant tissue-type plasminogen activator (rt-PA) treatment occurred 1.71 times more in AF patients than patients without AF [10] particularly in Asian populations [11,12]. AF was found to be a good prognostic factor in stroke treatment if the baseline National Institutes of Health Stroke Scale (NIHSS) was higher than 10 and patients received rt-PA treatment [13]. Most recent studies indicated that AF is a poor prognostic factor in stroke. Here, we studied factors associated with poor outcomes in acute ischemic stroke patients with AF by using the Thai national database.
Received 9 September 2014; revised 5 November 2014; accepted 6 November 2014.
Methods
Correspondence: Kittisak Sawanyawisuth, MD, PhD, Department of Medicine, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand. Tel.: 66-43363664. Fax: 66-43348399. E-mail: [email protected]
This study was a retrospective analytical study by retrieving data from the Thailand national database 1
Int J Neurosci Downloaded from informahealthcare.com by Nyu Medical Center on 05/02/15 For personal use only.
2
K. Kongbunkiat et al.
system for the universal coverage health insurance system (UC). The UC system is a basic health insurance for Thai people and covers 75.2% of the total population [6]. All patients who were diagnosed as having acute ischemic stroke (ICD-10: I63.0-I63.9, and I65.0-I65.9, I66.0-I66.9, G45), and AF/atrial flutter (ICD-10 code: I48.0-I48.9) were studied. The stroke diagnosis is based on computed tomography of the brain. We excluded hemorrhagic stroke including intracerebral hemorrhage and subarachnoid hemorrhage. All patients with an age over 18 years old and admitted all over Thailand during the fiscal years 2004–2012 (26th December 2003 till 29th January 2013) were selected. Treatment outcomes of acute ischemic stroke were studied including mortality, length of hospital stay, hospital costs, and complications such as ventilator use (ICD9-cm: 96.04, 96.70-96.72), cerebral edema or brain herniation and those who required craniotomy/craniectomy (ICD9-cm 01.24,01.25), received tracheostomy (ICD-9 cm: 31.1, 31.2) suggesting a dependent status or modified Rankin scale > 5), decubitus ulcer (ICD-10: L89), pneumonia (ICD-10: J13/J69), urinary tract infection (ICD-10: N30/N39), deep vein thrombosis (ICD-10: I80), pulmonary embolism (ICD-10: I26), status epilepticus (ICD-10: G41), septicemia (ICD-10: A40/A41), and gastrointestinal bleeding (ICD-10: K92.0-K92.2). Hospital costs were calculated as adjusted RW (1 unit of adjusted RW equals 9600 Baht or USD 320 [1USD equals 30
Baht]; an average value for primary, secondary, and tertiary care hospitals).
Statistical analyses Acute ischemic stroke patients with AF in the database were divided into two groups; alive or dead at discharge from the summary discharge sheet. Baseline and clinical characteristics of patients between groups were compared using descriptive statistics. Univariate logistic regression analyses were applied to calculate the crude odds ratios (OR) of individual variables for death at discharge. All clinically significant variables or a p-value less than 0.20 by univariate analyses were included in subsequent multivariate logistic regression analyses. Analytical results were presented as crude OR, adjusted OR, and 95% confidence intervals (CI). Data analyses were performed with STATA software (College station, Texas, USA).
Results There were 522,699 patients diagnosed as acute stroke; 32,929 patients (6.3%) had AF. Acute ischemic stroke accounted for 53.1% of all patients or 277, 291 patients; 25,319 patients (9.1%) had AF.The mortality rate of acute ischemic stroke with AF was 14.1% or 3577 patients (Flow chart 1). The national rate of rt-PA treatment was 0.82% for all acute ischemic strokes.
Acute stroke 522,699 paents
Atrial fibrillaon 32,929 paents (6.3%)
Acute ischemic stroke 277,291 paents (53.1%)
No atrial fibrillaon 251,972 paents (90.9%)
Atrial fibrillaon 25,319 paents (9.1%)
Survived at discharge 21,742 paents (85.9%)
Died at discharge 3,577 (14.1%)
Flow chart 1. Numbers of acute stroke patients in Thailand during the fiscal years 2004–2012 categorized by types and outcomes.
International Journal of Neuroscience
Hospital mortality from atrial fibrillation associated with ischemic stroke Table 1.
Univariate analysis of factors associated with hospital mortality of acute ischemic stroke (I63.x) with atrial fibrillation (I48.x).
Factors
Int J Neurosci Downloaded from informahealthcare.com by Nyu Medical Center on 05/02/15 For personal use only.
3
Male Female Age, years
ORIGINAL ARTICLE
Hospital mortality from atrial fibrillation associated with ischemic stroke: a national data report Kannikar Kongbunkiat,1,3 Narongrit Kasemsap,1,3 Suporn Travanichakul,1,3 Kaewjai Thepsuthammarat,2 Somsak Tiamkao,1,3 and Kittisak Sawanyawisuth1,4
Int J Neurosci Downloaded from informahealthcare.com by Nyu Medical Center on 05/02/15 For personal use only.
1
Department of Medicine, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand; 2 Clinical Epidemiology Unit, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand; 3 North-eastern Stroke Research Group, Khon Kaen University; 4 Research Center in Back, Neck, Other Joint Pain and Human Performance (BNOJPH), Khon Kaen University, Khon Kaen, Thailand Purpose: To study factors associated with poor outcomes in acute ischemic stroke patients with atrial fibrillation (AF) by using a national database. Materials and Methods: This study was a retrospective analytical study by retrieving data from the Thailand national database system for universal coverage (UC) health insurance system. All adult patients aged over 18 years who were admitted with acute ischemic stroke during the fiscal years 2004–2012 by the appropriate ICD codes were searched. Eligible patients with AF were categorized as alive or dead during hospital stay. The mortality rate and factors associated with in-hospital mortality were studied. Results: There were 522,699 patients diagnosed as acute stroke; 277,291 patients (53.1%) had acute ischemic stroke. Of those with ischemic stroke, 25,319 patients (9.1%) had AF. The mortality rates of acute ischemic stroke with AF were 14.1% and without AF were 6.2%, (p < 0.001). Significant factors associated with mortality in acute stroke patients with AF by multivariate logistic regression were female gender (adjusted odds ratio; AOR 1.28), co-morbid diseases such as diabetes (AOR 1.28), hypertension (AOR 1.26), rt-PA treatment (AOR 0.55), and stroke complications, such as pneumonia (AOR 2.60), septicemia (AOR 6.50), or gastrointestinal bleeding (AOR 2.16). Conclusions: At the national level, AF caused a higher mortality rate in acute ischemic stroke than in non-AF patients. Gender, co-morbid diseases, rt-PA treatment, and stroke complications were associated with mortality in acute ischemic stroke with AF. KEYWORDS: stroke, atrial fibrillation, mortality, hospital, national data
Introduction Stroke is the leading neurological disease and causes neurological sequels. Stroke patients with atrial fibrillation (AF) have a 2 times higher risk for death compared with those who did not have AF [1]. Generally, risk for acute ischemic stroke is increased by age and 3.5% each one year of age after 75 years old [2]. This risk will dramatically increase to 4–5 times if AF is existed [1]. The prevalence rate of AF is 0.36% in populations of an age over 30 years [3]. Previous studies showed that AF is a poor prognostic factor in ischemic stroke for disabilities or deaths [4–9].
Having AF in acute ischemic stroke increased the risk of death within 30 days twice as compared with those who have sinus rhythm. In addition, hemorrhagic transformation after recombinant tissue-type plasminogen activator (rt-PA) treatment occurred 1.71 times more in AF patients than patients without AF [10] particularly in Asian populations [11,12]. AF was found to be a good prognostic factor in stroke treatment if the baseline National Institutes of Health Stroke Scale (NIHSS) was higher than 10 and patients received rt-PA treatment [13]. Most recent studies indicated that AF is a poor prognostic factor in stroke. Here, we studied factors associated with poor outcomes in acute ischemic stroke patients with AF by using the Thai national database.
Received 9 September 2014; revised 5 November 2014; accepted 6 November 2014.
Methods
Correspondence: Kittisak Sawanyawisuth, MD, PhD, Department of Medicine, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand. Tel.: 66-43363664. Fax: 66-43348399. E-mail: [email protected]
This study was a retrospective analytical study by retrieving data from the Thailand national database 1
Int J Neurosci Downloaded from informahealthcare.com by Nyu Medical Center on 05/02/15 For personal use only.
2
K. Kongbunkiat et al.
system for the universal coverage health insurance system (UC). The UC system is a basic health insurance for Thai people and covers 75.2% of the total population [6]. All patients who were diagnosed as having acute ischemic stroke (ICD-10: I63.0-I63.9, and I65.0-I65.9, I66.0-I66.9, G45), and AF/atrial flutter (ICD-10 code: I48.0-I48.9) were studied. The stroke diagnosis is based on computed tomography of the brain. We excluded hemorrhagic stroke including intracerebral hemorrhage and subarachnoid hemorrhage. All patients with an age over 18 years old and admitted all over Thailand during the fiscal years 2004–2012 (26th December 2003 till 29th January 2013) were selected. Treatment outcomes of acute ischemic stroke were studied including mortality, length of hospital stay, hospital costs, and complications such as ventilator use (ICD9-cm: 96.04, 96.70-96.72), cerebral edema or brain herniation and those who required craniotomy/craniectomy (ICD9-cm 01.24,01.25), received tracheostomy (ICD-9 cm: 31.1, 31.2) suggesting a dependent status or modified Rankin scale > 5), decubitus ulcer (ICD-10: L89), pneumonia (ICD-10: J13/J69), urinary tract infection (ICD-10: N30/N39), deep vein thrombosis (ICD-10: I80), pulmonary embolism (ICD-10: I26), status epilepticus (ICD-10: G41), septicemia (ICD-10: A40/A41), and gastrointestinal bleeding (ICD-10: K92.0-K92.2). Hospital costs were calculated as adjusted RW (1 unit of adjusted RW equals 9600 Baht or USD 320 [1USD equals 30
Baht]; an average value for primary, secondary, and tertiary care hospitals).
Statistical analyses Acute ischemic stroke patients with AF in the database were divided into two groups; alive or dead at discharge from the summary discharge sheet. Baseline and clinical characteristics of patients between groups were compared using descriptive statistics. Univariate logistic regression analyses were applied to calculate the crude odds ratios (OR) of individual variables for death at discharge. All clinically significant variables or a p-value less than 0.20 by univariate analyses were included in subsequent multivariate logistic regression analyses. Analytical results were presented as crude OR, adjusted OR, and 95% confidence intervals (CI). Data analyses were performed with STATA software (College station, Texas, USA).
Results There were 522,699 patients diagnosed as acute stroke; 32,929 patients (6.3%) had AF. Acute ischemic stroke accounted for 53.1% of all patients or 277, 291 patients; 25,319 patients (9.1%) had AF.The mortality rate of acute ischemic stroke with AF was 14.1% or 3577 patients (Flow chart 1). The national rate of rt-PA treatment was 0.82% for all acute ischemic strokes.
Acute stroke 522,699 paents
Atrial fibrillaon 32,929 paents (6.3%)
Acute ischemic stroke 277,291 paents (53.1%)
No atrial fibrillaon 251,972 paents (90.9%)
Atrial fibrillaon 25,319 paents (9.1%)
Survived at discharge 21,742 paents (85.9%)
Died at discharge 3,577 (14.1%)
Flow chart 1. Numbers of acute stroke patients in Thailand during the fiscal years 2004–2012 categorized by types and outcomes.
International Journal of Neuroscience
Hospital mortality from atrial fibrillation associated with ischemic stroke Table 1.
Univariate analysis of factors associated with hospital mortality of acute ischemic stroke (I63.x) with atrial fibrillation (I48.x).
Factors
Int J Neurosci Downloaded from informahealthcare.com by Nyu Medical Center on 05/02/15 For personal use only.
3
Male Female Age, years
