Thực trạng sử dụng thuốc chống huyết khối trong dự phòng đột quỵ trên người bệnh rung nhĩ

‘REAL-LIFE’ USE OF ANTITHROMBOTICS IN
ATRIAL FIBRILLATION PATIENTS FOR
STROKE PREVENTION AT CHO RAY HOSPITAL

NGUYEN THE QUYEN
Prof. NGUYEN VAN TRI


BACKGROUND

Good efficacy of Vitamin K Antagonist (VKA):
• Nonvavular AF: reduce stroke risk over 2.5 times 1

• Valvular AF: embolic events decrease 4 – 15 times 2

However, previous studies of using VKA remains low in Vietnam:
• Nonvavular AF: 7 – 13% use 3

• Valvular AF: 34% 4

This study will re-evaluate the situation.
1.
2.
3.
4.

Camm AJ, et al. Eur Heart J. 2010;31:2369-429.
Bonow RO, et al. J Am Coll Cardiol. 2008;52:e1-142.
Pham Chi Linh, Nguyen Van Si. HCMC University of Medical and Pharmacy. 2011.
Le Hoai Nam. Y Hoc Tp.Ho Chi Minh. 2014;18:209-14.

ESC 2012
ACC 2014

Optional

A score ≥ 3 is considered “high bleeding risk”
ESC recommends “caution” using OACs


STUDY OBJECTIVES

1.

Identify the using rate of antithrombotics in nonvalvular AF patients based on
the stroke risk stratification CHA2DS2-VASc.

2.

Identify the using rate of antithrombotics in nonvalvular AF patients based on
the bleeding risk stratification HAS-BLED.

3.

Identify the using rate of VKA in valvular AF patients based on the bleeding risk
stratification HAS-BLED.


STUDY METHODS
1. Study design

Prospective, cross-sectional study

2. Study population
All patients who were diagnosed AF during admission into Cho Ray hospital
from October 2013 to May 2014

3. Sample size
We use the proportion formular:
𝑍1−𝛼/2
n = p(1 − p)
d
•

2

Nonvalvular AF group:
p = 0,8 based on Pham Chi Linh study → n = 246 (N in our study = 258)

•

Valvular AF group:

p = 0,915 based on our pilot study from October 2013 to November 2013 →
n = 120 (N in our study= 132)


STUDY PROCESS


RESULTS

PATIENT CHARACTERISTIC

Population

Nonvalvular AF

Valvular AF

258

132

69,8 ± 15,9

54,5 ± 14,1

SAMPLE SIZE
Age
Male

132

(51,2)

41

(31,1)

Female

126

(48,8)

91

(68,9)

Heart failure(%)

86

(33,3)

63

(47,7)

History of stroke/TIA (%)

51

(19,8)

33

(25,0)

Diabetes (%)

46

(17,8)

3

(2,3)

History of major bleeding (%)

14

(5,4)

8

(6,1)

158
17

(61,2)

5

(3,8)

Sex catergory (%)

Hypertension (%)

BP ≥ 140/90mmHg
SBP > 160mmHg

History of myocardial infarction (%)

39

(10,8)
(15,1)


Objective 1

Identify the using rate of antithrombotics in nonvalvular AF
patients based on the stroke risk stratification CHA2DS2-VASc.


Stroke risk stratification CHA2DS2-VASc
in nonvalvular AF patients
% nonvalvular AF patients

n = 258

25

20.9

22.1

20

15

13.6

12.8

12
10

8.5
6.2

5

3.1
0.8

0
0

1

2

3

4

5

6

7

CHA2DS2-VASc score

STUDY

CHA2DS2-VASc = 0

CHA2DS2-VASc ≥ 2

GARFIELD

2,9%

84,4%

J-RHYTHM

6,6%

77,9%

Ours

6,2%

81,8%

8


The use of antithrombotics based on CHA2DS2-VASc score
in nonvalvular AF patients
% nonvalvular AF patients

n = 258

100%

14

90%
80%

43.7

70%

41.9

25
50

45.5

24.1

63.6
50

No antithrombotic
Antiplatelet
VKA

14.3

30%

20%

9.1

38.6
9.7

12.5

40%

29.6

57.1

60%

50%

18.2

48.4

43.8

46.3

47.4

36.4

28.6

10%

50
27.3

25

6

7

0%
0

1

2

3

4

5

8

CHA2DS2-VASc score

% patients with
CHA2DS2-VASc =
0 use OAC

% patients with
CHA2DS2-VASc ≥
2 use OAC

EORP-AF
Pilot

56,4%

78,0%

J-RHYTHM

71,1%

89,2%

Ours

43,8%

42,5%

STUDY

n = 211 (Nonvalvular AF patients with CHA2DS2-VASc ≥ 2)

VKA

22.7%
42.5%

Antiplatelet
No antithrombotic

34.8%


The univariate relationship between CHA2DS2-VASc and
antithrombotic use in nonvalvular AF patients

Reference value

Compared value

Use VKA

OR

95% CI

p

1,48

0,78 – 2,82

0,234

3,35

1,44 – 7,82

0,005

CHA2DS2-VASc < 2 CHA2DS2-VASc ≥ 2

Use Antiplatelet

Not follow the current guideline

Objective 2

Identify the using rate of antithrombotics in nonvalvular AF
patients based on the bleeding risk stratification HAS-BLED.


Bleeding risk stratification HAS-BLED
in nonvalvular AF patients
% nonvalvular AF patients

n = 258

45

38.8

40

33.3

35
30
25
20

18.6

15
10

7
2.3

5
0
0

1

2

3

4

HAS-BLED score

STUDY

HAS-BLED = 0

HAS-BLED = 1 - 2

HAS-BLED ≥ 3

AMADEUS

7,8%

68,1%

24,1%

J-RHYTHM

14,3%

70,0%%

15,7%

Ours

18,6%

72,1%

9,3%


The
use of
antithrombotics
based
on HAS-BLED
score
2.1.2. tình
hình
sử
dụng thuốc

chống
huyết khối
in nonvalvular AF patients
% nonvalvular AF patients with
CHA2DS2-VASc ≥ 2

n = 211

100%
90%
80%

37.5

16.7

17.8

26.9

20

70%
60%

37.8

30.8

12.5

No antithrombotic

50

Antiplatelet

60

50%

VKA

40%
30%
20%

50

44.4

42.3

33.3
20

10%
0%
0

1

2

3

4

HAS-BLED score

STUDY

% patients with HASBLED = 0 use OAC

% patients with HASBLED = 1 – 2 use OAC

% patients with HASBLED ≥ 3 use OAC

J-RHYTHM

86,8%

89,7%

86,3%

EORP-AF Pilot

78,9%

78,5% - 84,5%

66,7% - 71,1%

Ours

50,0%

43,5%

30,4%


The univariate relationship between HAS-BLED and
antithrombotic use in nonvalvular AF patients

Reference value

Compared value

Use VKA

HAS-BLED ≤ 2
Use Antiplatelet

Not follow the current guideline

OR

95% CI

p

0,57

0,23 – 1,43

0,232

2,49

1,07 – 5,83

0,035

HAS-BLED > 2


The multivariate relationship between CHA2DS2-VASc, HAS-BLED and
antithrombotic use in nonvalvular AF patients

Our study

Reference value

Compared value

Use OAC

CHA2DS2-VASc < 2

CHA2DS2-VASc ≥ 2

42,5%

HAS-BLED ≤ 2

HAS-BLED > 2

CHA2DS2-VASc < 2

CHA2DS2-VASc ≥ 2

HAS-BLED ≤ 2

HAS-BLED > 2

OR

95% CI

p

1,56 0,82 – 2,99

0,178

0,53

0,21 – 1,34

0,178

3,12 1,33 – 7,32

0,009

2,15

0,081

Use Antiplatelet

Not follow the current guideline

0,91 – 5,06


Objective 3

Identify the using rate of VKA in valvular AF patients based on
the bleeding risk stratification HAS-BLED.


Bleeding risk stratification HAS-BLED
in valvular AF patients

% valvular AF patients

n = 132

50

43.9

45
40

35

30.3
30
25

20.5
20
15
10

4.5

5

0
0

1

HAS-BLED score

2

3


2.2.2.

The use of VKA based on HAS-BLED score
tình hình sử
dụng AF
thuốc
chống huyết
in valvular
patients
n = 132

% valvular AF
patients

n = 132

khối

100%
90%

6.1%

100
93.2

88.9

80%

VKA

70%

No VKA

60%

85.7

50%

93.9%

40%
30%
20%
10%

STUDY

% patients use VKA

RELY – China

42%

Le Hoai Nam

34%

Ours

94%

Each point of
HAS-BLED score rises

0%
0

1

2

3

HAS-BLED score
VKA

Reference value Compared value
VKA

No VKA

No VKA

OR

95% CI

p

2,32

1,03 – 5,24

0,042


CONCLUSION
In nonvalvular AF population, many patients need
to prevent stroke (81,8% CHA2DS2-VASc ≥ 2)
And most of them have little bleeding risk (90,7%
HAS-BLED ≤ 2), however the using rate of VKA
remains low (42,5%).
In valvular AF population, the using rate of VKA
really achieves actual success (94%).