Shinshu Med J, 67⑶：197～204, 2019

Ankle-Brachial Index as a Prognostic Indicator in Patientswith Atrial Fibrillation-A Subanalysis of the IMPACT-ABI Study
Yasutaka Oguchi1）2）＊, Tatsuya Saigusa1）, Soichiro Ebisawa1）
Ayako Okada1）, Hirohiko Motoki1） and Koichiro Kuwahara1）
1） Department of Cardiovascular Medicine, Shinshu University School of Medicine
2） Department of Cardiovascular Medicine, Aizawa Hospital

Background : The CHADS2 score is a well-established predictor for outcomes in patients with atrial fibrillation(AF). The ankle-brachial index (ABI) is a known tool for diagnosing peripheral artery disease and a predictor
for cardiovascular diseases ; however, it is unclear whether it can predict cardiovascular death, myocardial in­
farction [MI], and stroke (major adverse cardiovascular event (MACE)) in patients with AF. The aim of thisstudy was to investigate whether ABI could predict the prognosis in AF patients.
Methods : We measured ABI in 3131 consecutive patients who visited our cardiovascular center from 2005 to
2015, of which 401 had AF, and they were enrolled in this study. Three patients were excluded because their
ABI was inadequate or higher than 1.5. The mean age was 68.0±11.3 years old, and mean observation period
was 4.6±2.7 years. We examined the relationship between ABI and MACE.
Results : Of 398 patients, 52 (13.1 ％) had MACE. Patients with ABI ＜0.92 had an increased incidence of MACE
over those with ABI＞0.92 (17 of 66 vs. 35 of 332, HR 2.2, 95 ％ CI 1.3 to 3.6, p＝0.0056). Patients with CHADS2
score＞2 had a statistically insignificant increase in MACE over those with CHADS2＜1 (HR 1.6, 95 ％ CI 0.92 to
2.73, p＝0.12). Further, a CHA2DS2-VASc score＞2 showed a significant difference from that＜1 (HR 3.0, 95 ％ CI
1.2 to 7.4, p＝0.0079).
Conclusions : The ABI could predict the prognosis of patients with AF comparable to the CHADS2 or CHA2DS2VASc scores. Shinshu Med J 67 : 197―204, 2019
(Received for publication December 10, 2018 ; accepted in revised form February 12, 2019)
Key words : ABI, AF, CHADS2 score, CHA2DS2-VASc score
Abbreviations : ABI, ankle brachial index ; MACE, major adverse cardiovascular event ; BMI, body mass index ;CAD, coronary artery disease ; CHF, congestive heart failure ; HT, hypertension ; DM, diabetes mellitus ; SAS,
sleep apnea syndrome ; AF, atrial fibrillation ; MI, myocardial infarction ; ACE-I, angiotensin-converting enzyme
inhibitor ; ARB, angiotensin receptor blocker ; CCB, calcium channel blocker ; Hb, hemoglobin ; Cr, creatinine ;eGFR, estimated glomerular filtration rate ; T-Cho, total cholesterol ; HDL-Cho, high-density lipoprotein choles­
terol ; LDL-Cho, low-density lipoprotein cholesterol ; HbA1c, hemoglobin A1c ; CRP, C-reactive protein ;BNP, B-type-natriuretic peptide ; LVDd, left ventricular end diastolic diameter ; LVDs, left ventricular end sys­
tolic diameter ; LVEF, left ventricular ejection fraction ; LADs, left atrial diameter of systole ; LV, left ventricu­
lar ; NYHA, New York Heart Association ; RA, right atrial

Ⅰ＊

Corresponding author : Yasutaka Oguchi
Department of Cardiovascular Medicine,
Shinshu University School of Medicine,
3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan
E-mail : litatolad@yahoo.co.jp

No. 3, 2019

Introduction

The CHADS2 (congestive heart failure, hyperten­
sion, age ≥ 75 years, diabetes, stroke [doubled]) scoreand CHA2DS2-VASc (congestive heart failure, hy­
pertension, age ≥ 75 years [doubled], diabetes, stroke
197

Oguchi・Saigusa・Ebisawa et al.

[doubled], vascular disease, sex category [if female,

Medical Information Network Clinical Trials Registry

counted]) score are well-established predictors of(UMIN-CTR), as accepted by the International Com­1）

stroke in patients with atrial fibrillation (AF) . More­mittee of Medical Journal Editors (UMIN-ID ;over, they are known to be predictors of adverse car­

000020276). Of the initial 3,131 patients, 2730 werediovascular events2）-4）. On the other hand, the ankle-

excluded because of the presence of sinus rhythm

brachial index (ABI) is known as a tool for detecting

on admission, 2 subjects owing to ABI＞1.5, and 1

peripheral artery disease (PAD) with high speci­

with inadequate ABI data. Thus, we evaluated 398

ficity (low ABI (ABI ≤ 0.9), a strong predictor of fu­

patients who presented with atrial fibrillation on

5）-7）, and as aadmission. We divided the study cohort into 2 groups

predictor for cardiovascular diseases and all-cause

based on the ABI : a low ABI group (ABI＜0.92, n＝ture cardiovascular events and mortality
8）9）. However, the influence of the ABI in66), and high ABI group (ABI ≥ 0.92, n＝332). We also

predicting the disease outcome of AF patients has

analyzed the relation between ABI and prognosis

mortality

not been well researched. We think that ABI meas­(Fig. 1) and analyzed between CHADS2/CHA2DS2-

urement in AF patients has two clinical meanings.

VASc score and prognosis. The mean observation

First, we wanted to evaluate their prognosis using

period was 4.6±2.7 years.

only ABI, which is simple and non-invasive. Also, no

ＢDefinitions

other study has clarified this hitherto. The aim of the

Body mass index (BMI) was calculated as weightstudy was to investigate whether the ABI could predict(kg) divided by height squared (m2). Smoking habit

the prognosis in AF patients.

was defined as previous/current smoking status, asⅡＡ

Methods

Study design and patient population

obtained by an interview. Coronary artery disease
was defined as a history of angina and/or previous
MI. Hypertension was defined as systolic blood pres­This study was a sub-analysis of the impressive

sure ≥ 140 mmHg, diastolic blood pressure ≤ 90 mmHg,

predictive value of ABI for clinical long-term out­or the current use of anti-hypertensive agents. Dysli­

come in patients with cardiovascular disease exam­

pidemia was defined as serum total cholesterol levels

ined by the ABI (IMPACT-ABI) study. The IMPACT-≥ 220 mg/dL, low-density lipoprotein cholesterol levels

ABI study was a retrospective, single-center, obser-­≥ 140 mg/dL, high-density lipoprotein cholesterol

vational study. We retrospectively identified 4619

levels ≤ 40 mg/dL, triglyceride levels ≥ 150 mg/dL, orconsecutive patients admitted to Shinshu University

the use of lipid lowering agents. Diabetes mellitus

for any cardiovascular disease between January(DM) was defined as fasting blood glucose levels ≥2005 and December 2012. All patients had their ABI

126 mg/dL, casual plasma glucose levels ≥ 200 mg/

measured upon admission. Of 4619 patients, 1488

dL, HbA1c ≥ 6.5 ％, or the use of insulin or oral hypo­were excluded because of missing data on ABI, andglycemic agents. Stroke was defined as ischemic

the remaining 3131 patients were enrolled for our

stroke that persisted for ≥ 24 hours or evidence ofstudy. We obtained the clinical, demographic, andinfarction on magnetic resonance imaging in accor­

laboratory data from the electronic medical records.

dance with the statement from the American HeartThe follow-up data were collected from the medical

Association/American Stroke Association10）. Previous

records or by contacting the patients. This study

heart failure was defined as a prior diagnosis of

was performed in accordance with the Declaration

heart failure according to the Framingham criteria11）

of Helsinki and was approved by the ethics committee

or current treatment for heart failure. Sleep apneaof Shinshu University School of Medicine. As thissyndrome was defined as apnea hypopnea index

study was performed retrospectively without written(AHI)≧15 with or without symptoms12）. The echo­

informed consent, the data were analyzed anonymously.

cardiographic parameters included the left ventricu­

This study was registered with the University Hospitallar end diastolic diameter (LVDd), left ventricular

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Ankle-brachial index for AF patients

Hospitalization for cardiovascular disease, n = 3131
Exclusion criteria, n = 2733
1. Inadequate ABI data, n = 1
2. ABI > 1.5, n = 2
3. Sinus rhythm on admission, n = 2730

Enrolled in this study, n = 398
Divided into two groups, based on ABI

Low ABI group (< 0.92)
N = 66

High ABI group (≥ 0.92)
N = 332

Fig. 1 Study design
Study flow diagram illustrating the inclusion process and exclusion criteria. Patientswere stratified into two groups based on their ankle-brachial index (ABI) values.

end systolic diameter (LVDs), and left ventricularsimultaneously. The ABI was obtained as a ratio ofejection fraction (LVEF), as estimated using thethe systolic blood pressure measured in the lower

Teichholz method. The estimated glomerular filtra­

extremity divided by the higher of the two systoliction rate (eGFR) was calculuated using the Japanese

blood pressures measured in the upper extremities.

equation to estimate kidney function as follows :The lower of the two results was used as the patient2－1.094eGFR (ml/min/1.73 m )＝194×serum creatinine

ABI for all analyses.

×age－0.287 for male patients, and the same formulaＤ

Endpoint

13）

multiplied by 0.739 for female patients . The all-

The primary endpoint of this study was the compos­

cause death was defined as any death recorded

ite of major adverse cardiovascular events (MACE),

during the follow-up period. Cardiovascular death

including cardiovascular death, myocardial infarction,

was defined as death resulting from acute myocardialand stroke. The secondary endpoint was all-cause

infarction (MI), significant cardiac arrhythmia,

death and cardiovascular death.

congestive heart failure (HF), stroke, or other cardio­

Ｅ

14）

Statistical analysis

vascular causes . MI was defined as a 2-fold rise in

Statistical analyses were performed using JMP

serum troponin I or creatine kinase-MB isoenzyme

13.0 (SAS Institute, Cary, NC, USA). Continuous

to at least twice the upper normal limits with acutevariables were summarized as mean±standard de­onset of prolonged typical ischemic chest pain, ST-

viation if normally distributed and as median andsegment elevation of at least 1 mm in 2 contiguousinterquartile range if not normally distributed. Nor­

electrocardiogram leads, or ST-segment depression

mal data distribution was assessed using the Shap­14）

of at least 0.5 mm in 2 contiguous leads .

iro-Wilk test. Categorical variables were reported as

Ｃnumbers and percentages and were compared using

ABI measurements
The ABI was determined with the patient at rest

the Chi-square test and the Mann-Whitney U testin the supine position for at least 10 minutes using

for continuous variables. Kaplan-Meier plots were

the form pulse wave velocity (PWV)/ABI (Omron

calculated from baseline to the time of occurrence ofColin, Tokyo, Japan), which is an automated oscillo­

cardiac event and were compared using the log-

metric device with four cuffs that can measure therank test. Adjusted odd ratios (OR) and 95 ％ confi­

blood pressure in both upper and lower extremities

dence interval (CI) for high ABI were obtained by

No. 3, 2019199

Oguchi・Saigusa・Ebisawa et al.

multiple logistic regression analysis. Univariate Cox

tensin converting enzyme inhibitors (ACEIs), and/or

proportional hazard analyses were performed to iden­

angiotensin receptor blockers (ARBs), and amiodarone

tify the independent predictors of MACE. The optimal

showed no difference ; however, the use of calcium

Receiver-Operating-Characteristic (ROC) curve cutoff

channel blockers was significantly higher in patientsvalue for prediction of MACE was considered as thewith low ABI.

value maximizing sensitivity plus specificity. The

Ｂ

Outcomes

proportional hazards assumption was verified withDuring the follow-up period (mean 4.6 years), alog (time) vs. log [-log (survival)] plots. The variables

total of 52 cases (13.1 ％) of MACE were recorded, in­that exhibited a P-value of＜0.05 in the univariate

cluding 37 of cardiovascular death, 4 of MI, and 11 ofanalysis were included in the multivariate model. The

stroke. Between the two groups, the low ABI groupmagnitude of the relationship between the variables

exhibited significantly higher values of MACE, withand MACE was expressed as the hazard ratio (HR)significant differences in MI ; however, no significant

and 95 ％ CI. P-values of＜ 0.05 were considereddifferences in cardiovascular death and stroke were

statistically significant.

observed.

Ⅲ
Ａ

Results

Baseline characteristics

Ｃ

Predictors of MACE
The univariate Cox proportional hazards analysis

showed that low ABI as well as higher CHA2DS2-

Baseline characteristics are summarized in Table 1.

VASc score ( ≥ 2) were independent predictors ofThis study enrolled 398 patients, with a median age

MACE. Multivariate Cox proportional hazards analy­of 68.0±11.3 years ; the majority of patients were

sis shows that adjusted for low ABI (＜0.92), CHA2DS2-

male (76.9 ％). The causes of admission among partic­

VASc score ≥ 2, LVEF, diabetes mellitus, congestive

ipants included acute myocardial infarction (1.5 ％),heart failure, and prescription of ACEIs, low ABI in­

unstable angina pectoris (0.5 ％), stable angina pecto­

dependently predicted a poorer prognosis (OR, 2.21 ;ris (17.3 ％ ), other atherosclerotic diseases (14.1 ％ ),95 ％ CI, 1.03-4.66 ; P＝0.039). (Table 2). The Kaplan-arrythmia (38.2 ％), heart failure (8.8 ％), and others

Meier analysis showed that the cumulative event-(19.3 ％). On the basis of the ABI, all patients were

free survival rate of MACE was markedly lower in

divided into two groups : 66 patients (16.6 ％) had low

patients with a low ABI (Fig. 2).

ABI, 332 patients (83.4 ％) had high ABI. No signifi­
cant differences were found in BMI, coronary artery

Ⅳ

Discussion

disease, hypertension, dyslipidemia, stroke, and sleep

To the best of our knowledge, this is the first re­apnea syndrome between each group. However, lowport demonstrating the predictive power of low ABIABI values were significantly associated with higher

on the prognosis of patients with AF. The major

smoking status and higher CHADS2 and CHA2DS2-

finding of this study was that low ABI could predict

VASc scores. An increased number of patients ex­

cardiovascular events as well as a high ( ≥ 2) CHADS2

hibited diabetes mellitus and congestive heart failureor CHA2DS2-VASc score. In patients with AF, higher

in the low ABI group. In the echocardiographic find­

CHADS2 or CHA2DS2-VASc score ( ≥ 2) is known to beings, there were no significant differences in mediana predictor of stroke1）. On the other hand, the prog­

LVDd, LVDs, and LADs ; however, patients with highnosis of AF patients with heart failure is poor15）, andABI showed significantly higher LVEF than those

it is known that their risk for stroke, hospitalization

with low ABI. A lower ABI was significantly associ­for heart failure, and death is high16）-19）. In such pa­

ated with greater levels of creatinine and B-type

tients, higher CHADS2 or CHA2DS2-VASc score ( ≥ 2)

natriuretic peptide (BNP) and lower levels of hemo­

is also known to be a predictor of hospitalization for

globin, estimated GFR, and HDL-Cho. At discharge,

worsening of heart failure and mortality3）. Ostergren

the prescription rates of drugs such as statins, angio­

and Sleight20）. demonstrated that low ABI predicted

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Ankle-brachial index for AF patients
Table 1
Variables

Baseline Characteristics

Overall Population

ABI ≥ 0.92

ABI＜0.92(n＝398)(n＝332)(n＝66)

Mean age (years)
Male gender, n (％)
Smoking, n (％)
Body mass index (kg/m2)

68±11308 (77)
161 (38)67±11254 (77)
126 (38)72±11
54 (82)35 (53)

23±4

23±4

23±4

0.161

CHADS2 score

1.6±1.2

1.5±1.2

2.2±0.2＜0.00012.7±1.7

2.5±1.6

3.8±0.2＜0.0001229 (58)
98 (25)130 (33)
131 (33)
51 (13)82 (21)
12 (3)

184 (55)
70 (21)103 (31)114 (34)
41 (12)62 (19)10 (4)

45 (68)28 (42)27 (41)
17 (26)10 (15)20 (30)
2 (4)

0.058
0.0005
0.150
0.198
0.546
0.045
1.00

80 (20)143 (36)155 (39)116 (29)113 (28)
22 (6)

64 (20)117 (36)124 (38)
87 (27)91 (28)19 (6)

16 (24)26 (39)31 (47)29 (44)22 (33)
3 (5)

0.408
0.679
0.215
0.0079
0.457
1.00

61±16
5.0±0.8
3.4±1.4
4.7±1.062±16
5.0±0.8
3.3±1.5
4.7±1.1

58±16
5.1±1.0
3.4±1.1
4.7±1.0

0.044
0.110
0.549
0.704

14.1±2.0

14.2±2.3

13.5±2.3

0.012956±23187±4151±15
107±3058±22
187±4052±14106±3045±24
186±4445±15
112±340.00160.963
0.00070.185

6.27±0.9253±3526.2±1.0232±3176.3±0.8357±479

0.317
0.0088CHA2DS2-VASc score

Comorbidities
Hypertension, n (％)
Diabetes mellitus, n (％)
Coronary artery disease, n (％)
Dyslipidemia, n (％)
Stroke, n (％)
Congestive heart failure, n (％)
Sleep apnea syndrome, n (％)
Medications
ACEIs, n (％)
ARBs, n (％)β-blockers, n (％)
CCB, n (％)
Statin, n (％)
Amiodarone, n (％)
Echocardiographic data
LVEF (％)
LV end-diastolic dimension (cm)
LV end-systolic dimension (cm)LA end-systolic dimension (cm)Laboratory data
Hemoglobin (g/dL)
eGFR (mL/min/1.73 m2)
Total cholesterol (mg/dL)
HDL-cholesterol (mg/dL)
LDL-cholesterol (mg/dL)
Hemoglobin A1c (％)

BNP (pg/mL)

P-value0.00310.420
0.0283CHADS2, congestive heart failure/hypertension/age ≥ 75 years old/diabetes/stroke [doubled] ; CHA2DS2-VASc,
congestive heart failure/hypertension/age ≥75 years old [doubled]/diabetes/stroke [doubled]/vascular disease/sex
category [if female, counted] ; ACE-I, angiotensin-converting enzyme inhibitor ; ARB, angiotensin receptor blocker ;CCB, calcium channel blocker ; LVEF, left ventricular ejection fraction ; eGFR, estimated glomerular filtration rate ;HDL, high-density lipoprotein ; LDL, low-density lipoprotein ; BNP, B-type-natriuretic peptide ; LA, left atrial.

cardiovascular mortality and development of future

flammation is a triggering factor of atherosclerotic

heart failure.

plaque rupture. AF is also associated with the in­

We showed that low ABI was associated with in­

flammatory state such as obesity, diabetes mellitus,

creased incidence of MACE and all-cause mortality

hypertension, heart failure, metabolic syndrome andas well as higher CHADS2 or CHA2DS2-VASc scoresedentary lifestyle21）. In this regard, ABI serves as a

( ≥ 2) in patients with AF. AF and atherosclerosis aremeasure of atherosclerosis, and thus, lower ABI canknown to be a chronic inflammatory disease and in­indicate vascular abnormalities causing adverse car­No. 3, 2019

201

Oguchi・Saigusa・Ebisawa et al.
Table 2
VariablesMale
Age (years)
BMI (kg/m2)
Smoking
ABI＜0.92
CHADS2 ≥ 2

CHA2DS2-VASc ≥ 2

Coronary artery disease
Hypertension
Dyslipidemia
Diabetes mellitus
StrokeCongestive heart failure
Echocardiographic data
LVEF (％)
LVDd (cm)
LVDs (cm)Medication
Statin
ACEIs
ARBs
Beta-blockers
CCB
Amiodarone
Laboratory data
Hemoglobin (g/dL)
eGFR (mL/min/1.73 m2)
Total cholesterol (mg/dL)
LDL-cholesterol (mg/dL)
Hemoglobin A1c (％)

BNP (pg/mL)

Cox Regression Analysis for MACE

Unadjusted HR (95 ％ CI)

P0.58 (0.30-1.15)
1.03 (1.00-1.07)

0.117
0.026

1.00 (0.93-1.08)
1.05 (0.63-1.73)
2.76 (1.37-5.38)

0.999
0.858
0.0054

1.69 (0.92-3.16)

0.094

3.35 (1.41-9.90)
0.62 (0.34-1.08)
0.98 (0.59-1.63)
0.61 (0.34-1.06)
1.76 (1.02-3.01)
1.34 (0.64-2.62)
1.89 (1.06-3.30)

0.0047
0.090
0.938
0.081
0.043
0.428
0.031

0.97 (0.96-0.99)
1.00 (0.99-1.01)
1.01 (0.99-1.03)

0.00480.889
0.292

1.12 (0.56-2.15)
2.41 (1.22-4.66)
0.94 (0.48-1.78)
1.01 (0.53-1.89)
1.50 (0.77-2.83)
1.22 (0.28-3.78)

0.747
0.0126
0.858
0.982
0.228
0.760

0.89 (0.77-1.03)

0.124

0.99 (0.97-1.01)
1.00 (0.99-1.01)
1.00 (0.98-1.02)

0.397
0.630
0.512

1.05 (0.75-1.43)
1.00 (0.99-1.00)

0.771
0.098

Adjusted HR (95 ％ CI)P2.21 (1.03-4.66)

0.039

1.91 (0.78-5.41)

0.184

0.94 (0.43-1.98)

0.883

1.04 (0.46-2.23)

0.923

0.97 (0.95-1.00)

0.015

1.76 (0.81-3.70)

0.140

BMI, body mass index ; CHADS2, congestive heart failure/hypertension/age ≥ 75 years old/diabetes/stroke [doubled] ;CHA2DS2-VASc, congestive heart failure/hypertension/age ≥ 75 years old [doubled]/diabetes/stroke [doubled]/vasculardisease/sex category [if female, counted] ; ACEIs, angiotensin-converting enzyme inhibitor ; ARBs, angiotensin
receptor blocker ; CCB, calcium channel blocker ; LVEF, left ventricular ejection fraction ; LVDd, left ventricular end
diastolic diameter ; LVDs, left ventricular end systolic diameter ; LA, left atrial ; eGFR, estimated glomerular filtration
rate ; HDL, high-density lipoprotein ; LDL, low-density lipoprotein ; BNP, B-type-natriuretic peptide.

diovascular events and heart failure in the future.

to detect a sufficient number of cardiovascular events,

Thus, we should be cautious in AF patients withthis study has several potential limitations. First, it

low ABI, because this patient population is more

was a single center, retrospective analysis and in­likely to experience cardiovascular events in the future

volved patients who were hospitalized for cardiovas­

than those with higher ABI. There is a possibility

cular disease. Thus, our study population may notthat early intervention in AF patients with low ABI

be representative of the general population. Second,

can help in preventing the progression of the cardio­

the patients who were enrolled in this registry had

vascular disease.

heterogeneous baseline cardiovascular diseases, soＡsample bias might have affected the results of theLimitations
While our study included data from a large sample
202

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Ankle-brachial index for AF patients

Fig. 2 Kaplan-Meier plot
Kaplan-Meier plot for cardiovascular death, myocardial infarction [MI], and stroke (MACE).
Two groups of patients were included in the analysis. The patients were assigned to a groupaccording to their ankle-brachial index (ABI) value.

time of hospitalization, so the data might not be

mission can predict the prognosis of patients withright in patients with AF. Reports suggest that theAF, similar to the CHADS2 or CHA2DS2-VASc scores

accuracy of ABI in patients with atrial fibrillationand can be useful to predict cardiovascular events

decreases ; however, other reports suggest that atrial

and prevent progression of cardiovascular diseases.

22）

fibrillation does not affect ABI data . Finally, weⅥhave no data regarding changes of medication or
habits that could affect the prognosis during the ob­servation period.

Acknowledgement

The authors acknowledge the secretarial and tech­nical assistance of Minako Aono

Ｖ Conclusion
We found that ABI measured at the time of ad­References
1） Chao TF, Liu CJ : Should Atrial Fibrillation Patients With 1 Additional Risk Factor of the CHA2DS2-VASc Score(Beyond Sex) Receive Oral Anticoagulation ? Am J Coll Cardiol 65 : 635-642, 2015
2） Chao TF, Lin YJ : CHADS (2) and CHA (2)-VASc score in the prediction of clinical outcomes in patients with atrial
fibrillation after catheter ablation. Am J Cardiol 58 : 2380-2385, 2011
3） Nakagawa K, Hirai T : Chronic kidney disease and CHADS (2) score independently predict cardiovascular eventsand mortality in patients with nonvalvular atrial fibrillation. Am J Cardiol 107 : 912-916, 2011
4） Larsen TB, Lip GY : Added predictive ability of the CHA2DS2VASc risk score for stroke and death in patients with
No. 3, 2019

203

Oguchi・Saigusa・Ebisawa et al.
atrial fibrillation : the prospective Danish Diet, Cancer, and Health cohort study. Circ Cardiovasc Qual Outcomes 5 :335-342, 2012
5） Dachun X, Jue L : Sensitivity and specificity of the ankle-brachial index to diagnose peripheral artery disease : astructured review. Vasc Med 15 : 361-369, 2010
6） Fowkes FG, Murray GD : Ankle brachial index combined with Framingham Risk Score to predict cardiovascular
events and mortality : a meta-analysis. Jama 300 : 197-208, 2008
7） Rooke TW, Hirsch AT : 2011 ACCF/AHA focused update of the guideline for the management of patients with
peripheral artery disease (updating the 2005 guideline). Vasc Med 16 : 452-476, 20118） Vanholder R, Massy Z : Chronic kidney disease as cause of cardiovascular morbidity and mortality. Nephrol Dial
Transplant 20 : 1048-1056, 2005
9） Go AS, Chetow GM : Chronic kidney disease and the risk of death, cardiovascular events, and hospitalization. N Engl
J Med 351 : 1296-1305, 2004
10） Sacco RL, Kasner SE : American Heart Association Stroke Council, Council on Cardiovascular Surgery andAnesthesia ; Council on Cardiovascular Radiology and Intervention ; Council on Cardiovascular and Stroke Nursing ;Council on Epidemiology and Prevention ; Council on Peripheral Vascular Disease ; Council on Nutrition, Physical
Activity and Metabolism. An updated definition of stroke for the 21st century : a statement for healthcare professionals
from the American Heart Association/American Stroke Association. Stroke 44 : 2064-2089, 201311） McKee PA, Castelli WP : The natural history of congestive heart failure : the Framingham study. N Engl J Med
285 : 1441-1446,1971
12） Westchester IL : American Academy of Sleep Medicine. The International Classification of Sleep Disorders :Diagnostic and Coding Manual. 2nd ed, American Academy of Sleep Medicine, 200513） Matsuo S, Imai E : Revised equations for estimated GFR from serum creatinine in Japan. Am J Kidney Dis 53 : 982992, 200914） Thygesen K, Alpert JS : Joint ESC/ACCF/AHA/WHF Task Force for the Redefinition of Myocardial Infarction.
Universal definition of myocardial infarction. Circulation 116 : 2634-2653, 200715） Nassir F. Marrouche : Catheter Ablation for Atrial Fibrillation with Heart Failure. N Engl J Med 378 : 417-427, 201816） Dries DL, Exner DV : Atrial fibrillation is associated with an increased risk for mortality and heart failure progression
in patients with asymptomatic and symptomatic left ventricular systolic dysfunction : a retrospective analysis of the
SOLVD trials : Studies of Left Ventricular Dysfunction. J Am Coll Cardiol 32 : 695-703,1998
17） Wang TJ, Larson MG : Temporal relations of atrial fibrillation and congestive heart failure and their joint influenceon mortality : the Framingham Heart Study. Circulation 107 : 2920-2925, 2003
18） Ponikowski P, Voors AA : 2016 ESC guidelines for the diagnosis and treatment of acute and chronic heart failure :the Task Force for the diagnosis and treatment of acute and chronic heart failure of the European Society ofCardiology (ESC) : developed with the special contribution of the Heart Failure Association (HFA) of the ESC. Eur J
Heart Fail 18 : 891-975,201619） Kirchhof P, Benussi S : 2016 ESC guidelines for the management of atrial fibrillation developed in collaboration with
EACTS. Europace 18 : 1609-1678, 201620） Ostergren J, Sleight P : Impact of ramipril in patients with evidence of clinical or subclinical peripheral arterial disease.
Eur Heart J 25 : 17-24, 2004
21） Silva RM : Influence of Inflammation and Atherosclerosis in Atrial Fibrillation. Curr Atheroscler Rep 19 : 2, 201722） Dabrowski M, Lewandowski J : Atrial fibrillation does not affect ankle-brachial index measured using the Doppler
method. Hypertens Res 41 : 60-65, 2018（2018. 12. 10 received；2019. 2. 12 accepted）

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