Luan an tom tat (eng) nghiên cứu hiệu quả liều nạp clopidogrel 600mg trên độ ngưng tập tiểu cầu và kết quả can thiệp động mạch vành qua da trong cấp cứu nhồi máu cơ tim cấp có ST chênh lên

MINISTRY OF EDUCATION
MINISTRY OF NATIONAL
AND TRAINING
DEFENSE
108 INSTITUTE OF CLINICAL MEDICAL AND
PHARMACEUTICAL SCIENCES
--------------------------------------------------------

BUI THI MIEN

STUDY EFFICACY OF 600MG LOADING DOSE OF
CLOPIDOGREL ON PLATELET AGGREGATION AND
OUTCOMES OF PERCUTANEOUS CORONARY
INTERVENTION IN ST SEGMENT ELEVATION
MYOCARDIAL INFARCTION
Major: Anesthesia Resuscitation
Code: 62.72.01.22

SUMMARY OF DOCTOR OF MEDICINE DISSERTATION

HANOI - 2018


The work was completed at:
108 INSTITUTE OF CLINICAL MEDICAL AND
PHARMACEUTICAL SCIENCES

Science facilitators:
1. Prof. Dr. Nguyen Quang Tuan
2. Assoc. Prof. Dr. Be Hong Thu

Reviewers:
1.
2.
3.

The dissertation will be protected at the Thesis Review Board at 108
Institute of Clinical Medical and Pharmaceutical Sciences
Time....

The dissertation can be found at:
1. National Library of Vietnam
2. Library of 108 Institute
Pharmaceutical Sciences

of

Clinical

Medical

and


1

BACKGROUND
Several studies have evaluated the efficacy of 300mg loading
dose of clopidogrel before percutaneous coronary intervention or
through fibrinolytics. When comparing normal dose of clopidogrel
(300 mg) with doubled dose of clopidogrel (600 mg), many studies

show that 600mg loading dose of clopidogrel works faster, and
inhibits ST aggregation more strongly and improves effectiveness of
clinically percutaneous coronary intervention. In order to reduce
waiting time, the 600 mg loading dose of clopidogrel inhibits TC
faster and more strongly. Within 2 hours after administration of
600mg loading dose of clopidogrel, the TC is almost completely
inhibited, which reduces the risk of thrombotic occlusion stenting
and side effects similarly to the 300mg loading dose of clopidogrel.
To evaluate the efficacy of 600mg loading dose of clopidogrel before
percutaneous coronary intervention in patients with ST segment
elevation myocardial perfusion, the study on efficacy of 600mg
loading dose of clopidogrel on platelet aggregation and outcomes of
percutaneous coronary intervention in ST segment elevation
myocardial infarction" was carried out for two purposes:
1.

Compare the efficacy of 600mg and 300mg loading

doses of clopidogrel on platelet aggregation in ST segment
elevation myocardial infarction patients with percutaneous
coronary intervention.
2.

Evaluate the efficacy of percutaneous coronary

intervention using 600mg loading dose of clopidogrel
clinically, subclinically and some undesirable effects.


2

CHAPTER 1
OVERVIEW

1.1.
ACUTE
ST
SEGMENT
MYOCARDIAL INFARCTION

ELEVATION

1.1.1. Diagnosis of ST segment elevation myocardial infarction
Table 1.1. Standards for diagnosis of myocardial infarction
Determination of increased cardiac markers (troponin is the most
commonly used) with at least one value higher than the 99th
percentile of the upper limit, with at least one of the following
criteria:
Symptoms of myocardial ischaemia.
Significant fluctuations of new ST-T or new possibility of
occurrence or completely new left bundle branch block.
Occurrence of Q wave on ECG.
The most recent imaging proof of alive cardiac muscles or new
occurrence of dyskinesia.
Determination of coronary thrombosis through angiography or
autopsy.
1.1.2. Treatment of ST segment elevation myocardial infarction
1.1.5.1. General initial treatment
Patients should be lying motionlessly on beds. If patients are
over anxious, tranquilizers should be given. Oxygen therapy is

indicated with SaO2 <90% or PaO2 <90% . Nitroglycerin is
sublingual, can be repeated every 5 minutes. Then vein catheter is set
up. Fast-absorbing aspirins should be given orally or through vein
catheter with a starting dose of 300 mg. Then treatment is continued
with 75-325 mg / day. 300mg or 600mg loading doses of clopidogrel
or 60mg prasugrel dose or 90mg ticagrelor dose is administrated
twice per day. Anticoagulant: heparin is injected into veins with dose


3

of 65-70 IU/kg body weight, then 15-18 IU/kg body weight/hour is
maintained. Sympathetic beta blockers: reduce mortality rate and
necrosis myocardial infarction. ACE inhibitors: may be given within
the first 24 hours if blood pressure is not low and there are no other
contraindications.
1.1.5.2. Reperfusion
The most important goal in treating acute myocardial
infarction is re-perfusion (re-circulating clotting) as soon as possible.
First phase coronary intervention is the immediate intervention
applied upon admission without using defibrinogenating agents.
1.2. CLOPIDOGREL
1.2.1. Mechanism of clopidogrel actions
Clopidogrel inhibits non-recovery TC selection through ADP,
mediated by the P2Y12 receptor located on the TC surface.
1.2.2. Absorption and distribution
Cmax of 3 mg/L appears 1 hour after repeated dosing.
1.2.3. Metabolism and excretion
The half-life excretion of carboxylic acid metabolites is 7 to 8
hours after single dose administration. 50% is excreted in urine and

about 46% is excreted in faeces.
1.2.4. Usage
The drug is taken orally, can be taken at the same time with
meals or not.
1.2.5. Undesired effects of clopidogrel
Blood clots, bleeding, gastrointestinal disorders, skin and
subcutaneous tissue disorders.


4

CHAPTER 2
RESEARCH SUBJECTS AND METHODOLOGY
2.1. SUBJECTS OF THE RESEARCH
Including patients diagnosed with acute ST-segment elevation
myocardial infarction with percutaenous coronary intervention at
Vietnam National Heart Institute from December 2011 and January
2014.
2.1.1. Criteria for selecting patients
All patients aged ≥ 18 hospitalized at Vietnam National Heart
Institute from December 2011 and January 2014 who were
diagnosed with acute ST-segment elevation myocardial infarction.
1. Diagnosis of acute ST-segment elevation myocardial infarction
was based on the criteria of the European Society of Clinical
Oncology (ESC 2012), American College of Cardiology (ACC
2013).
2. Patients were indicated with first phase percutaenous coronary
intervention as recommended by the Vietnam National Heart
Association [8].
3. Patients agreed to participate in the study.

2.1.2. Exclusion criteria
Previously

administrated

with

thrombolytic

agents,

anticoagulants, platelet aggregation inhibitors, anti-inflammatory
agents; taking oral anticoagulants for 10 days; contraindications to
use of anti- platelet aggregation agents.
2.2. RESEARCH METHODOLOGY
2.2.1. Research design
Prospective study, vertically follow-up, with comparisons.


5

2.2.2. Sample size and sampling method
2.2.2.1. Sample size
The formula for calculating sample size for comparative
studies was used
𝑛=

(𝑧𝛼/2 √2𝑝(1 − 𝑝) + 𝑧𝛽 √𝑝1 (1 − 𝑝1 ) + 𝑝2 (1 − 𝑝2 ))

2

2

2.2.2.2. Sampling method
After randomization, patients were divided into groups until
the end of the study. Obtained results: Group I: 46 patients received
600mg loading dose of clopidogrel; Group II: 50 patients received
300mg loading dose of clopidogrel.
2.2.3. Research facilities
2.2.3.1. Blood test
Biochemical tests of blood parameters, general analysis of
peripheral blood cells, measurement of platelet aggregation, basic
coagulation were carried out according to standards of departments
in Bach Mai Hospital .
2.2.3.2. Electrocardiogram
Patients

were

appointed

with

electrocardiogram

upon

admission and 1 hour after percutaneous coronary intervention.
2.2.3.3. Echocardiography
Echocardiography was performed at the Echocardiography

Department, Vietnam National Heart Institute, Bach Mai Hospital.
2.2.3.4. Coronary capture and intervention
Cardiovascular intervention unit, Vietnam National Heart
Institute, Bach Mai Hospital.


6

2.2.4. Research steps
 Thorough clinical examination according to symptoms.
 Full range of routine laboratory tests: ECG, cardiac Doppler
ultrasonography, biochemical tests of blood, general analysis of
peripheral blood cells, primary blood clotting, platelet aggregation
measurements (platelet aggregation and peripheral blood cells were
carried out twice: upon admission without clopidogrel dose and 4
hours after clopidogrel administration). Patients were given
anticoagulants and anti-platelet aggregation agents when they were
diagnosed with acute ST-segment elevation myocardial infarction.
Medications include anticoagulants, oral aspirin 300mg and oral
clopidogrel 300mg or 600mg before the intervention. Conservative
treatment was combined according to standards in both groups, such
as beta blockers, angiotensin converting enzyme inhibitors, statins,
proton pump inhibitors, etc. Capture and intervention of coronary at
the Cardiovascular Intervention Unit, Vietnam National Heart
Institute, Bach Mai Hospital.
 After the intervention, the same medications were applied to
both groups until the end of the study.
 Major clinical events during hospitalization and during followup period were monitored.
2.3. DATA PROCESSING
Data were processed according to medical statistical method

7

2.4. RESEARCH DESIGN
96 patients diagnosed ST segment elevation myocardial
infarction patients with percutaneous coronary intervention

Clinical examination, sub clinical tests and
conservative treatment under regimen.
Radom distribution

Group 1: 46 patients using 600mg loading
dose of clopidogrel before coronary
intervention

Group 2: 50 patients using 300mg loading
dose of clopidogrel before coronary
intervention

Percutaneous coronary
intervention

-

Comparing efficacy of 600mg loading dose of clopidogrel and 300mg
loading dose of clopidogrel on platelet aggregation
Evaluating efficacy of coronary intervention between two groups of
using 600mg loading dose of clopidogrel and 300mg loading dose of
clopidogrel

Conclusion:
- Objective 1
- Objective 2


8

CHAPTER 3
RESEARCH FINDINGS
In the period from December 2011 to January 2014, a study on
96 patients with acute ST-segment elevation myocardial infarction
treated at the Vietnam National Heart Institute, Bach Mai Hospital
was conducted. Patients were divided into two groups: Group I:
600mg loading dose of clopidogrel. Group II: 300mg loading dose of
clopidogrel.
3.1. GENERAL CHARACTERISTICS OF STUDY GROUPS
The majority of patients in both groups were aged 50 and
older, 90/96 patients, accounting for 93.7%. The average age of
patients was 64.8 ± 10.5. Age distribution between the two groups
was not statistically significant with p> 0.05. Male patients were
more than female patients, 70/96 patients, accounting for 72.9%.
There was no gender difference between the two groups with p>
0.05.
3.2 COMPARING EFFICACY OF 600MG LOADING DOSE
OF CLOPIDOGREL AND 300MG LOADING DOSE OF
CLOPIDOGREL ON PLATELET AGGREGATION OF WITH
ACUTE

ST

SEGMENT

ELEVATION

MYOCARDIAL

INFARCTION TREATED BY PERCUTANEOUS CORONARY
INTERVENTION.
3.2.1. Platelet aggregation before and after clopidogrel loading
dose between two groups.


9
70
60
50
40

Group 600 mg

30

Group 300 mg

20
10
0
Before

After

Diagram 3.2. Platelet aggregation before and after clopidogrel
loading dose between two groups.
Comment: Platelet aggregation level before clopidogrel loading
dose between the two groups is not statistically significant with p>
0.05. Platelet aggregation level after clopidogrel loading dose
between the two groups was statistically significant with p <0.05.
3.2.2. Response level of two groups
Table 3.15 Response level of two groups
Group
Response level
Non- response ( A <10%)
Average response ( A: 10% 30%)
Good response ( A>
30%)
Total
Average % of response

600mg

300mg

Patients

%

Patients

%

2

4.3

2

4.0

13

28,3

24

48,0

31

67,4

24

48,0

46
100
45,98 ± 22,69

50

100
34,95 ± 18,95


10

p

< 0,05

80

Percentage

67,4

Non response

60

Average response
48,0 48,0

Good response

40
28,3

Group of 600mg
20

4,0

4,3

0

Group 600mg

Group 300mg

Figure 3.3. Response level of two groups
Comments: The proportion of patients with good response to 600mg
loading dose of clopidogrel group was significantly higher than that
of the 300mg loading dose of clopidogrel group with p <0.05.
3.3.

EVALUATING

CORONARY

EFFICACY

INTERVENTION

OF
WHEN

PERCUTANEOUS
USING

600MG

LOADING DOSE OF CLOPIDOGREL CLINICALLY, SUB
CLINICALLY AND FOLLOW-UP.
3.3.1. Results of coronary intervention between the two groups
3.3.1.1. Electrocardiography fluctuations after coronary
intervention between the two groups


11

Table 3.19. Electrocardiographic fluctuations after coronary
intervention between the two groups
Time of doing
ECG
Group

600mg

300mg

Comments:

Before
intervention

After
intervention

p

before

Patient
s

%

Patient
s

%

Elevation

46

100

1

2,2

Partial
reduction

0

0

38

82,6

Back to
normal

0

0

7

15,2

Elevation

50

100

8

16,0

Partial
reduction

0

0

40

80,0

Back to
normal

0

0

2

4,0

p of 2 groups

p> 0.05

Electrocardiographic

and after

<0.05

<0.05

p <0.05

fluctuations

after

coronary

intervention in 600mg loading dose of clopidogrel group compared
to 300mg loading dose of clopidogrel was statistically significant
with p <0.05.
3.3.1.2. Changes in coronary artery flow (TIMI) after coronary
intervention between the two groups


12

Table 3.20. Changes in coronary artery flow (TIMI) after coronary
intervention between the two groups
Time of TIMI

Before
intervention

After
intervention

p
before

Group

Group of
600mg

Group of
300mg

General

Patient
s

%

Patients

%

TIMI 0

17

37,0

0

0

TIMI 1

29

63,0

0

0

TIMI 2

0

0

2

4,3

TIMI 3

0

0

44

95,7

TIMI 0

20

40,0

0

0

TIMI 1

30

60,0

0

0

TIMI 2

0

0

11

22,0

TIMI 3

0

0

39

78,0

TIMI 0

37

38,5

0

0

TIMI 1

59

61,5

0

0

TIMI 2

0

0

13

13,5

TIMI 3

0

0

83

86,5

p of 2 groups

> 0.05

and after

<0.0
5

<0.0
5

<0.0

5

<0.05

Comment: After the intervention, in the group of 600mg loading
dose of clopidogrel, 44 patients achieved TIMI 3 (95.7%) and 2
patients reached TIMI 2 (4.3%), in the group of 300mg loading dose
of clopidogrel, 39 patients reached TIMI 3 (78.0%) and 11 patients


13

reached TIMI 2 (22.0%), the difference was statistically significant
between the two groups with p <0.05.
3.3.1.3. Changes in myocardial perfusion level (TMP) after
coronary intervention between the two groups
Table 3.21. Changes in myocardial perfusion level (TMP) after
coronary intervention between the two groups
Number of
patients

Ratio (%)

TMP 0

0

0

TMP 1

0

0

TMP 2

2

4,3

TMP 3

44

95,7

TMP 0

0

0

TMP 1

0

0

TMP 2

14

28,0

TMP 3

36

72,0

Group

Group of 600mg

Group of 300mg

p of 2 groups

<0.05

Comments: The number of patients with TMP 3 perfusion was
higher in the 600mg loading dose of clopidogrel group than those in
the 300mg loading dose of clopidogrel group, which was statistically
significant with p <0.05.
3.3.2. Results in early clinical treatment and follow-up


14

3.3.2.1. Comparing chest pain symptoms in both groups before and
after coronary intervention
Table 3.24. Compare chest pain symptoms in both groups before and
Group

Chest
pain

600mg
300mg

Yes
No
Yes
No

p 2 groups

after coronary intervention
Before
After
intervention
intervention
Patients
%
Patients
%
40
87,0
10

21,7
6
13,0
36
78,3
47
94,0
22
44,0
3
6,0
28
56,0
> 0.05
<0.05

p before
and after

<0.01
<0.01

Comment: Greatly reduced chest pain symptoms in the 600mg
loading dose of clopidogrel group was more significantly significant
than those in the 300mg loading dose of clopidogrel group with p
<0.05 .
3.3.2.2. Comparing NYHA between the two groups after coronary
intervention
Table 3.25. Compare NYHA between the two groups after coronary
intervention

Group
NYHA
Grade I
Grade II
Total
p

Group of 600mg

Group of 300mg

Patients

%

Patients

%

44
2
46

95,7
4,3
100

41
9
50

82,0
18,0
100

<0.05


15

Comment: The difference in NYHA between the two groups after
the intervention was statistically significant with p <0.05.
3.3.2.3. Comparing Killip between the two groups after coronary
intervention
Table 3.26. Compare Killip between the two groups after coronary
intervention
Group
Killip
Grade I
Grade II
Total
p

Group of 600mg

Group of 300mg

Patients

%

Patients

%

45
1
46

97,8
2,2
100

43
7
50

86,0
14,0
100

<0.05

Comment: The difference in Killip between the two groups after the
intervention was statistically significant with p <0.05.
3.3.2.4. Survival rate from vertical follow-up between the two 600
mg and 300 mg loading doses of clopidogrel


16

Figure 3.11. Survival rate from vertical follow-up between the two
groups
Comments: Survival rate from vertical follow-up between the two
600 mg and 300 mg loading doses of clopidogrel was not statistically
significant with p> 0.05.
3.3.2.5. Cardiovascular events during follow-up between the two
groups
Table 3.29. Cardiovascular events during follow-up between the two
groups
Cardiovascular
events
Fatality
Stroke
Recurrent
myocardium
Recurrent occluded
stent
No events
Total

Group of 600mg
Patients
%
1
2,2
0
0

Group of 300mg

p
Patients
%
> 0.05
2
4,0
0
0

0

0

0

0

0

0

0

0

45
46

97,8
100

48
50

96,0
100

> 0.05

Comments: The group of 600mg loading dose of clopidogrel
reported 1 case of fatality, the group of 300mg loading dose of
clopidogrel reported 2 cases of fatality during follow-up, this
difference was not statistically significant with p> 0,05. There were
no cases of cerebrovascular accident, recurrent MI, recurrent
occluded stent during follow-up in both groups.
3.3.3. Complications and undesired effects


17

There were no cases of complications from intervention
between the two groups. Both groups in our study did not report any
adverse effects after the use of 300mg loading dose of clopidogrel
and 600 mg loading dose of clopidogrel.


18

CHAPTER 4
DISCUSSIONS

4.1.

GENERAL

CHARACTERISTICS

OF

RESEARCH

GROUPS
Of 96 patients in the study, the group of 600mg loading dose
of clopidogrel showed an average age of 62.7 ± 9.8 (42-79), the
group of 300mg loading dose of clopidogrel was 66.8 ± 10, 8 (39 89), this difference was not statistically significant with p> 0.05.
Those results are similar to many published studies at home and
abroad. The mean age in the study is 64.8 ± 10.5 years. The majority
of patients in the study were aged 50 or older (90/96 patients
accounting for 93.7%) .
The percentage of males suffering from MI was higher than
that of females in both groups (70 male patients, accounting for
72.9% and 26 female patients, accounting for 27.1%). The difference
of sex ratio between the two groups was not statistically significant
with p> 0.05.
4.2. EFFICACY OF 600MG AND 300MG LOADING DOSES
OF CLOPIDOGREL ON PLATELET AGGREGATION OF
ACUTE ST SEGMENT ELEVATION MYOCARDIAL
INFARCTION TREATED BY PERCUTANEOUS CORONARY
INTERVENTION.
4.2.1. Discussing platelet counts, platelet aggregation prior to and
after treatment of each group and between the two groups

Diagram 3.2 reveals that after using 600mg loading dose of
clopidogrel, platelet aggregation of patients were decreased
significantly compared to those of 300mg loading dose of
clopidogrel. This difference was statistically significant with p <0.05.


19

4.2.2. Discussing response level of the two groups
The results in Table 3.15 and Diagram 3.3 show that the
proportion of patients responding to 600mg loading dose of
clopidogrel was better than that of the 300mg loading dose of
clopidogrel, which is statistically significant with p <0.05. The
ARMYDA-2 study concludes that use of 600mg loading dose of
clopidogrel 6 to 8 hours before coronary intervention is safe and
reduces the incidence of myocardial infarction around the procedure
compared to the usual loading dose of clopidogrel 300mg.
4.3. EVALUATING EFFICACY OF PERCUTANEOUS
CORONARY INTERVENTION OF USING 600MG LOADING
DOSE
OF
CLOPIDOGREL
CLINICALLY,
SUB
CLINICALLY AND SOME ADVERSE EFFECTS
4.3.1. Discussing the results of coronary intervention
4.3.1.1. Electrocardiogram fluctuations before and after coronary
intervention
Before the intervention, the difference in ECG between the
two groups was not statistically significant with p> 0.05. After

intervention, the group of 600mg loading dose of clopidogrel
reported 1 patient with no change in electrocardiogram, 38 patients
with partly reduced elevation and 7 patients with ECG back to
normal status. The group of 300mg loading dose of clopidogrel
reported 8 patients without fluctuations in electrocardiogram, 40
patients with partly reduced elevation and 2 patients with ECG back
to normal status. ECG fluctuations in the 600mg loading dose of
clopidogrel group versus the 300mg loading dose of clopidogrel
group were statistically significant with p <0.05 (Table 3.19).
Nguyen Quang Tuan reported that the ST segment with only


20

reduction of its elevation to <70% before the treatment showed
mortality rate of 4.5 times higher than that of the ST segment with ≥
70% or greater decrease in its elevation.
4.3.1.2 Coronary artery flow (TIMI) after interventions between the
two groups
After intervention, most patients improved the TIMI flow
rate that causes MI. The results in Table 3.20 shows that after the
intervention, the group of 600 mg loading dose of clopidogrel
reported 44 patients reaching TIMI 3 and 2 patients reaching TIMI 2,
the group of 300mg loading dose of clopidogrel reported 39 patients
reaching TIMI 3 and 11 patients reaching TIMI 2, the difference was
statistically significant between the two groups with p <0.05. The
proportion of patients reaching TIMI 2 in our study was 13.5% that
is equivalent to that of Nguyen Quang Tuan.
4.3.1.3 Cardiac perfusion rate (TMP) after intervention between
the two groups

In our study, after the intervention, the group of 600mg
loading dose of clopidogrel reported 44 patients reaching TMP 3 and
2 patients reaching TMP 2, the group of 300mg loading dose of
clopidogrel reported 43 patients reaching TMP 3 and 7 patients
reaching TMP 2. The difference in TMP between the two groups was
statistically significant with p <0.05 (Table 3.21). According to
Nguyen Quang Tuan, patients with unimproved cardiac perfusion
after intervention (TMP 0-1) reported a higher mortality risk in the
first 30 days, within one year and during follow-up period than
patients with partial improvement (TMP 2) or patients with normal
perfusion (TMP 3) of 30.5 times; 5.7 times and 7 times, respectively.


21

4.3.2. Discussing early clinical results and through follow-up
4.3.2.1. Change in chest pain symptoms between the two groups
before and after coronary intervention
The results in Table 3.24 show that the symptoms of chest
pain prior to intervention between the two groups were not
statistically significant with p >0.05. After the intervention, lower
chest pain symptoms in the group of 600mg loading dose of
clopidogrel were statistically significant compared to those in the
group of 300mg loading dose of clopidogrel with p <0.05. According
to Nguyen Quang Tuan, patients with a history of chest pain had a
higher risk of fatality than patients without a history of chest pain.
4.3.2.2. Fluctuations in NYHA and Killip levels before and after
coronary intervention
Results of Table 3.25 show that, after the intervention, the
group of 600mg loading dose of clopidogrel reported 2 patients with

NYHA level II; the group of 300mg loading dose of clopidogrel
reported 9 patients with NYHA level II. Differences in NYHA
between the two groups after the intervention were statistically
significant with p <0.05. Table 3.26 indicates that, after intervention,
in the group of 600mg loading dose of clopidogrel, lower number of
patients with Killip 2 was statistically significant compared to that in
the group of 300mg loading dose of clopidogrel. In Tran Tra Giang's
study, 85.1% of patients showed no signs of clinical cardiac failure,
10.6% of patients showed mild heart failure (Killip II), in which 2
patients reported cardiogenic shock (Killip IV) accounting for 4.3%.
4.3.2.3. Successful outcomes for patients
In the vertical follow-up phase as shown in Diagram 3.11 and
Table 3.29, the group of 600mg loading dose of clopidogrel reported


22

1 case of fatality and the group of 300mg loading dose of clopidogrel
reported 2 cases of fatality, but the mortality difference was not
statistically significant between the two groups with p> 0.05. The
fatality rate in our study (3.13%) was lower than that of Nguyen
Quang Tuan (18.1%).
4.3.3. Discussing cardiovascular complications, adverse events
during hospitalization and follow-up between the two groups
The success rate for patients in our study was very high at
100% in both groups, which is higher than that of study by Nguyen
Quang Tuan (91.6%). No patients reported complications during
hospitalization as well as follow-up period. This suggests that 600mg
loading dose of clopidogrel is comparably safe as of 300mg loading
dose of clopidogrel.

23

CONCLUSION
After studying 96 cases of acute ST segment elevation
myocardial infarction with percutaneous coronary intervention and
comparing 600mg loading dose of clopidogrel to 300mg loading
dose of clopidogrel, the following outcomes are presented:
1. Efficacy of 600mg clopidogrel dose versus 300mg clopidogrel
dose:
- Platelet aggregation in the 600mg loading dose of clopidogrel
group was significantly lower than that in the 300mg loading dose
of clopidogrel group with p <0.05 (33.0% ± 14.5% vs. 40.9%
14.1%).
- The 600mg loading dose of clopidogrel group showed better
response than 300mg loading dose of clopidogrel group with p
<0.05 (45.98% ± 22.69% versus 34.95% ± 18.95%).
- No adverse events occurred with the use of 600mg loading dose of
clopidogrel and 300mg loading dose of clopidogrel.
- The use of 600mg loading dose of clopidogrel was as safe as that of
300mg loading dose of clopidogrel.
2. Efficacy of percutaneous coronary intervention in acute ST
segment elevation myocardial infarction:

- Decreased chest pain symptoms were statistically significant in the
group of 600mg loading dose of clopidogrel compared to that in the
group of 300mg loading dose of clopidogrel with p <0.05.

- NYHA was improved in the group of 600mg loading dose of

clopidogrel than that in the group of 300mg loading dose of
clopidogrel; the difference was statistically significant with p
<0.05.