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MINISTRY OF EDUCATION AND TRAINING

MINISTRY OF DEFENCE

108 INSTITUTE OF CLINICAL MEDICAL AND PHARMACEUTICAL SCIENCES

PHAM DANG HAI

RESEARCH ON THE CHANGES AND PREDICTIVE
VALUE OF LEFT VENTRICULAR LONGITUDINAL STRAIN
BY SPECKLE TRACKING ECHOCARDIOGRAPHY IN
SEPTIC SHOCK PATIENTS

Speciality: Anesthesiology and critical care
Code: 62720122

ABSTRACT OF MEDICAL PHD THESIS

Hà Nội – Năm 2019


THE THESIS WAS DONE IN: 108 INSTITUTE OF CLINICAL
MEDICAL AND PHARMACEUTICAL SCIENCES

Supervisor:
1. Ass. Prof. PhD. Le Thi Viet Hoa
2. Ass. Prof. PhD. Phạm Nguyen Son

Reviewer:
1.
2.

3.

This thesis will be presented at Institute Council at: 108 Institute of
Clinical Medical and Pharmaceutical Sciences
Day

Month

Year

The thesis can be found at:
1. National Library of Vietnam
2. Library

of

108

Institute

Pharmaceutical Sciences

of

Clinical

Medical

and

THE PUBLISHED ARTICLES RELATED TO THIS STUDY
1. Pham Dang Hai, Do Van Quyen, Le Thi Viet Hoa, Pham Nguyen
Son (2019) “Left ventricular systolic function in septic shock by
speckle-tracking echocardiography”, Journal of 108 clinical medicine
and pharmacy, vol 1 (1), pp.34-38
2. Pham Dang Hai, Do Van Quyen, Le Thi Viet Hoa, Pham Nguyen
Son (2019) “Prognostic value of global longitudinal strain in patients
with septic shock” Journal of 108 clinical medicine and pharmacy, vol
(1), pp.46-50.


1

INTRODUCTON
1. The urgent and demand of the study

Septic shock is the major cause of hospitalization and also the
leading cause of death in ICU. Septic shock can lead to organs
dysfunction including cardiovascular system. Prevalence of cardiac
dysfunction in patients with septic shock is aproximately 60-70%. This
disorder aggravates the condidtion of disease and increases the mortality
rate. Echocardiography is nowadays one of the first line investigations in
patients with septic shock because of its accessibility and noninvasive
nature. In sepsis and septic shock, however, assessment of myocardial
function by conventional echocardiographic parameters such as left
ventricular ejection fraction (LVEF) is affected to a large degree by
ongoing changes in preload and afterload conditions.
Speckle tracking echocardiography (STE) is a novel technology
of echocardiography. Compared to LVEF, STE is affected to a much

lesser degree by changes in ventricular loading conditions, angle independent and reproducible. This method based on a semi-automated
algorithm that tracks the displacement of acoustic “speckles” in the
myocardium, the change in length of myocardial segments are measured.
Global longitudinal strain is a valuable index in assessing left ventricular
function, in the prognosis of cardiovascular events and mortality
prognosis. In worldwide, the application of STE in clinical practice is
being studied, especially in investigating cardiac function in patients with
septic shock. However, there have not been any studies about it in
Vietnam. Therefore, this is a novel and scientific issue and maybe benefits
to doctors in the management of septic shock.


2
2. The new conclusions of this study

- Speckle tracking echocardiography can detect significant left
ventricular impairment in patients with septic shock, which was not
otherwise detectable by conventional echocardiography.
- GLS is valuable in prognosis of severity in patients with septic shock
through correlation with severity score (APACHE II, SOFA, SAPS2),
biomarker (NT-proBNP, hs-Troponin T, Lactat) and number of organ
dysfuctions.
- GLS has predictive mortality value in septic shock patients.
3. The aims of this study

- To evaluate some characteristics of changes in left ventricular
longitudinal strain by Speckle tracking echocardiography in patients with
septic shock.
- To determine the association of global longitudinal strain with some
prognostic factors in patients with septic shock.

4. The structure of thesis
The thesis includes 119 pages, with introduction and aims of study 2
pages. Chapter one: overview 34 pages, chapter two: subject and method
25 pages; chapter three: results 24 pages; chapter four: discussion 27
pages, conclusion and recommendation 3 pages. There are 27 tables of
data, 15 charts, 9 pictures and figures. The reference section has 169
articles including 157 English and 12 Vietnamese articles. Two study–
related articles were published.


3

Chapter one
OVERVIEW
1.1. Septic shock.
1.1.1. Definition of septic shock.
In 2016, A task force with expertise of society of Critical Care
Medicine and the European Society of Intensive Care Medicine gave
new definition of sepsis and septic shock.
- Sepsis is defined as life-threatening organ dysfunction caused by a
dysregulated host response to infection.
- Septic shock is defined as a subset of sepsis in which underlying
circulatory and cellular metabolism abnormalities are profound enough
to substantially increase mortality. Patients with septic shock can be
clinically identified by a vasopressor requirement to maintain a mean
arterial pressure of 65 mmHg or greater and serum lactate level greater
than 2 mmol/L in the absence of hypovolemia.
1.1.2. Risk factors of sepsis and septic shock
Some risk factors of sepsis and septic shock include:
- Intensive care unit admission

- Advanced age (≥ 65 years)
- Immunosuppression
- Diabetes and cancer
- Previous hospitalization
1.1.3. Prognosis of sepsis and septic shock
Prognostic factors include clinical characteristics that impact the
severity of sepsis, the host's response to infection, the site and type of
infection, and the timing and type of antimicrobial therapy.
1.2. Cardiac dysfunction in septic shock


4

1.2.1. The clinical characteristics of sepsis induced myocardial
dysfunction
- Increased cardiac output and decreased systemic vascular resistence
- Patients who survived had a depressed left ventricular EF and acute
left ventricular dilatation. However, nonsurvivors of septic shock
maintained normal left ventricular EF and volume.
1.2.2. Pathogenesis of sepsis induced myocardial dysfunction
- Role of coronary blood flow.
- Myocardium-depressing factors
- Autonomic dysregulation
- Dysfunction of intracellular Ca2+ transporters in cardiomyocytes
- Energetic starvation of cardiomyocytes
- Mitochondrial dysfunction and oxidative-nitrosative stress
1.3. Image methods evaluating cardiac function in septic shock
- Transthoracic echocardiography
- Cardiac magnetic resonance imaging
- Myocardial perfusion imaging (MPI)

1.4. Speckle tracking echocardiography
1.4.1. Parameters of speckle tracking echocardiography
- Strain
- Strain rate
1.4.2. Clinical applications
- Detection of subclinical myocardial dysfunction
- Monitoring response to treatment
- Role in acute coronary event
- As a measure of myocardial ischemia and viability
- Role in cardiac resynchronization therapy
- Assessment of LV diastolic function


5

- Assessment of RV function
- LA function
1.4.3. Some studies regarding speckle tracking echocardiography
in septic shock.
The first study evaluating this in 2014 by Landesberg et al
demonstrate the association between diastolic strain measured by
longitudinal strain early diastolic filling wave and in-hospital mortality
(Wald test = 6.6; p =0.02). A subsequent study by Orde et al (2014) on
60 adult patients with severe sepsis or septic shock, 33% of patients had
left ventricle (LV) dysfunction based on ejection fraction compared to
69% assessed with STE.
Lui et al (2015), the non-survivors exhibited GLSs that were less
negative than those of the survivors (non-survivors vs. survivors: -11.8 ±
4.5% vs. -15.0±3.6%, p <0.001), which indicated worse LV systolic
function. The patients with GLS ≥-13% exhibited higher ICU and inhospital mortality rates (hazard ratio: 4.34, p <0.001 and hazard ratio:

4.21, p <0.001, respectively). Cox regression analyses revealed that
higher Acute Physiology and Chronic Health Evaluation (APACHE) II
scores and less negative GLS were independent predictors of ICU and inhospital mortalities.
In SPECKSS study (2016), Septic shock group had a greater degree
of myocardial dysfunction measured by global longitudinal strain (GLS)
than sepsis group (-14.5 % vs -18.3 %, p < 0.001), and the myocardial
strain differed upon diagnosis and recovery (-14.5 % vs -16.0 %, P =
0.010). Conventional echocardiographic measurements such as LVEF
(59 % in the study group vs 61 % in the control group, p = 0.169) did not
differ between the two groups.


6

Innocenti et al (2018), Analyses through ROC curves focusing on
day-7 mortality show that less negative GLS (AUC 0.73, p = 0.001). In

multivariate analyses, mortality by day-7 follow-up is more likely per
higher GLS (i.e., indicative of worst systolic dysfunction, HR 1.22/%,
p = 0.005) and the same analysis by 28-day follow-up, LV GLS is an
independent prognostic value ((RR 1,14; KTC 95%: 1,03–1,26, p =
0,009).
Some issues need further research
- To determine the prognostic value of the severity through the
correlation between GLS with scores such as SOFA, APACHE II and
SAPS 2 as well as biomarkers (hs-Troponin T, NT-proBNP, Lactat).
- To determine cut- off value of GLS in predictor of mortality.
Chapter two
SUBJECTS AND METHOD
2.1. Subjects

From May 2017 to December 2018, we prospectively studied
127 patients admitted to the ICU of 108 Military Central Hospital,
divided 2 groups: 90 patients with septic shock and 37 patients with
sepsis.
2.1.1. Study group
Include criteria.
- Age 18 years or older,
- Diagnosis of septic shock according to SCCM/ESICM (2016)
Exclude criteria.
Patients were excluded if they met one of the following criteria:
- Active diagnoses directly relating to myocardial dysfunction, such as
acute myocardial infarction, myocarditis and post-cardiopulmonary
resuscitation status;


7

- Significant underlying cardiac conditions, such as congenital heart
disease, valvular heart disease, and cardiomyopathy.
2.1.2. Control group
Inclusion criteria.
- Age 18 years or older,
- Diagnosis of sepsis according to SCCM/ESICM (2016)
Exclusion criteria.
Patients were excluded if they met one of the following criteria:
- Active diagnoses directly relating to myocardial dysfunction, such as
acute myocardial infarction, myocarditis and post-cardiopulmonary
resuscitation status;
- Significant underlying cardiac conditions, such as congenital heart
disease, valvular heart disease, and cardiomyopathy.

2.1.3. Withdrawal criteria in study
- Patients who are eligible for study but the patient's family demands
to stop the management.
- Poor quality echocardiography images do not qualify for analysis.
2.2. Methods
2.2.1. Study design
Prospective study, cross-sectional description and comparison
with the control group.
2.2.2. Sample size
Convenience sampling
2.2.3. Research facilities
- Hemodynamic and respiratory monitoring devices
- Machines for continuous renal replacement therapy
- Hematological and biochemical tests are performed on multiparameter testing machines at 108 Military Central Hospital.


8

- Vivid S5 Cardiovascular Ultrasound Machine.
2.2.4. Research contents and evaluation criteria
2.2.4.1. Some general characteristics in patients with septic shock
- Clinical and subclinical characteristics in patients with septic shock
+ Determining characteristics of age, gender, number of organ
dysfunction, score of severity.
+ Describe some biochemical test results.
- Identify several mortality-related clinical and subclinical factors in
patients with septic shock.
- Results (the mean length of stay in the ICU, percentage of mechanical
ventilation, length of stay on mechanical ventilation, percentage of
CRRT and mortality).

2.2.4.2. Some characteristics of changes in left ventricular
longitudinal strain by speckle tracking echocardiography in patients
with septic shock.
Content 1: left ventricular longitudinal strain by speckle tracking
echocardiography in evaluating left ventricular systolic function versus
left ventricular ejection fraction by conventional echocardiography
° Evaluation criteria:
- Left ventricular ejection fraction by conventional echocardiography in
septic shock group compared with sepsis group.
-

Left

ventricular

longitudinal

strain

by

speckle

tracking

echocardiography in septic shock group compared with sepsis group
- The prevalence of left ventricular systolic dysfunction by speckle
tracking echocardiography versus by conventional echocardiography.
- The prevalence of left ventricular systolic dysfunction by speckle
tracking echocardiography in the group of septic shock with preserved

left ventricular ejection fraction.


9

Content 2: Some characteristics of changes in left ventricular
longitudinal strain by speckle tracking echocardiography in patients with
septic shock.
° Evaluation criteria:
- Left ventricular longitudinal strain at the study times: Timing of septic
shock onset (T0) and timing of septic shock recovery (T1).
- Left ventricular longitudinal strain at the time of T0 by age group
- Left ventricular longitudinal strain at time of T0 by gender
- Left ventricular longitudinal strain at time of T0 according to the
number of organs dysfunction.
- Left ventricular longitudinal strain at time T0 according to
microbiological causes (gram negative bacteria, gram-positive bacteria
and fungi).
- Left ventricular longitudinal strain at the time of T0 in the survivor and
nonsurvivor group at the hospital.
2.2.4.3. The association of global longitudinal strain with some
prognostic factors in patients with septic shock.
Content 1: The association of GLS with some prognostic factors in
patients with septic shock.
° Evaluation criteria:
- Assessement of correlation between GLS and the severity score
(APACHE II, SOFA, SAPS2) in patients with septic shock.
- Determination of correlation between GLS and some biomarkers in
severity prognosis in patients with septic shock (NT-proBNP, CK-MB,
hs-Troponin T, lactate).

- Determination of correlation between GLS and the number of organs
dysfunction.


10

Content 2: the value of left ventricular global longitudinal strain in the
prognosis of mortality in patients with septic shock.
° Evaluation criteria:
- Analyzing the ROC curve in the mortality prognosis of GLS compared
to APACHE II score, SOFA score and SAPS 2 score.
- Analyzing the ROC curve in the mortality prognosis of GLS
compared to serum NT-proBNP, hs-troponin T and lactat.
- Analysis of ROC curve of GLS in mortality prognosis when combined
with APACHE II, SOFA and SAPS2 score compared to GLS alone.
- Analysis of ROC curve of GLS in mortality prognosis when combined
with NT-proBNP, hs-Troponin T and Lactat compared with GLS alone.
- Univariate and multivariate regression analysis of GLS and other
parameters to predict the mortality.
2.2.5. Conducting research and data collection
2.2.5.1. Time to conduct research
- T0: Timing of septic shock onset
- T1: Timing of septic shock recovery
2.2.5.2. Enrollment of patients
2.2.5.3. Collection of the initial parameters
2.2.5.4. Management of the septic shock patients according SCC 2016
2.2.5.5. The main techniques protocol. in the study
(1). Two-dimensional transthoracic echocardiography: measure the
left ventricular ejection fraction (Simpson)
(2). Two-dimensional speckle tracking echocardiography

- Collect images from the apical four-chamber, apical two-chamber and
three-chamber views, takes each image with 3 consecutive cardiac
cycles. Then copy these images to the CD.


11

- Image analysis using EchoPAC software (version 112, GE - USA)
following the steps below:
+ Select images in each recorded apical four-chamber, two-chamber and
three-chamber views.
+ Choose 3 points (two points on either side of the valve, 1 point at the
heart's apex)
+ The software will automatically trace along the border of the left
ventricular endothelium according to each views to be analyzed. If the
automated frame selection seems inaccurate, the same can be adjusted
manually.Then the software will automatically analyze to find the strain
of each view and global longitudinal strain.
- Left ventricular systolic function parameters:
+ Apical four-chamber longitudinal strain
+ Apical three-chamber longitudinal strain
+ Apical two-chamber longitudinal strain
2.2.6. Criteria using in the study
- Sepsis and septic shock according to SCCM/ESICM (2016)
- Organ dysfunction according to Knaus (1989)
- Left ventricular systolic dysfunction by conventional
echocardiography according to ESC (2016)
- Left ventricular systolic dysfunction by STE according to Dalla (2012)
2.2.7. Statistics and data analysis
All data were assessed by SPSS Software, version 20.0 and Medcalc

14.8.1.0


12

Chapter 3
RESULTS
3.1. Some general characteristics of the research group
3.1.1. Clinical and subclinical characteristics in the research group
- The average age is 68.8 ± 15.1 years, men (74.4%).
- Site of infection from the respiratory and digestive tract accounts for the
majority (47.8% and 38.9%).
- Serum lactate and procalcitonin level at the timing of septic shock onset
was significantly higher than the timing of septic shock recovery and
sepsis group.
3.1.2. Several mortality-related clinical and subclinical factors in
patients with septic shock.
- The average APACHE II, SOFA, SAPS 2 scores and the number of
dysfunctional organs in non-survivor group was significantly higher
than in the survivor group. Serum NT-proBNP in non-survivor group
was higher than in survivor group (p <0.05).
3.1.3. Results of treatment in the research group
In septic shock group, percentage of mechanical ventilation (88.9%),
percentage of CRRT (57.3%) and in-hospital mortality rate (43.3%).
3.2. Some characteristics of changes in left ventricular longitudinal
strain in patients with septic shock.
3.2.1. Left ventricular longitudinal strain in evaluating left
ventricular systolic function versus left ventricular ejection fraction

13

Table 3.11: Conventional echocardiographic characteristics at T0
in the study group
Group

Sepsis

Septic shock

(n = 37)

(n = 90)

p

Dd (mm)

49,6 ± 5,1

45,7 ± 7,0

p > 0,05

Ds (mm)

33,4 ± 5,5

29,8 ± 5,4

p > 0,05

Vd (ml)

117,9 ± 28,8

99,2 ± 34,8

p > 0,05

Vs (ml)

47,4 ± 21,4

36,6 ± 16,5

p > 0,05

LVOT (mm)

20,56 ± 1,25

20,05 ± 1,73

p > 0,05

VTI (cm)

19,26 ± 3,95

19,05 ± 4,02

p > 0,05

FS (%)

32,8 ± 5,8

34,7 ± 5,9

p > 0,05

LVEF (%)

60,5 ± 8,5

63,5 ± 8,2

p > 0,05

Parameters

(Simpson)
There were no significant differences in left ventricular ejection fraction
in two groups.
Table 3.12. Left ventricular longitudinal strain at timing of T0 in
the study group
Group

Sepsis

Septic shock

(n = 37)

(n = 90)

p

LS-4C (%)

-17,0 ± 2,7

-14,5± 3,3

p < 0,01

LS-2C (%)

-16,9 ± 2,8

-14,3± 3,9

p < 0,01

LS-3C (%)

-17,1 ± 2,6

-15,1± 3,7

p < 0,01

GLS (%)

-17,1 ± 3,3

-14,6 ± 3,3

p < 0,01

Parameters

Left ventricular systolic function via left ventricular longitudinal strain
in septic shock group was lower than that in sepsis group.


14

12.2%
87.8%

Left ventricular systolic dysfunction
Non-Left ventricular systolic dysfunction
Chart 3.1. Percentage of left ventricular systolic dysfunction by
conventional echocardiography in septic shock patients
Percentage of left ventricular systolic dysfunction in septic
shockpatients by conventional echocardiograpy (12.2%)

echocardiography (12.2%)

44.4% 55.6%

Left ventricular systolic dysfunction
Non-Left ventricular systolic dysfunction
Chart 3.2. Percentage of left ventricular systolic dysfunction by
speckle tracing echocardiography in septic shock patients
Percentage of left ventricular systolic dysfunction in septic
shock patients by speckle trcking echocardiograpy (55.6%)


15

Table 3.15. The relationship between left ventricular longitudinal
strain and left ventricular ejection fraction at the timing of T0 in
septic shock group.
< 50%

≥ 50%

(n = 11)

(n = 79)

p

LS-4C (%)

-11,9 ± 3,8

-14,6 ± 3,2

p < 0,01

LS-2C (%)

-10,4 ± 4,1

-14,6 ± 3,7

p < 0,01

LS-3C (%)

-9,6 ± 3,6

-15,5 ± 3,4

p < 0,01

GLS (%)

-10,6 ± 3,7

-14,9 ± 3,1

p < 0,01

LVEF
Parameters

Left ventricular systolic function via left ventricular
longitudinal strain in LVEF < 50% was lower than that in LVEF ≥ 50%.

49.4% 50.6%

Left ventricular systolic dysfunction

Non-Left ventricular systolic dysfunction
Chart 3.2. Percentage of left ventricular systolic dysfunction by
speckle tracking echocardiography in septic shock patients with
preserved left ventricular ejection fraction
Percentage of left ventricular systolic dysfunction by speckle tracing
echocardiography in septic shock patients with preserved left
ventricular ejection fraction (50.6%)


16

3.2.2. Changes in left ventricular longitudinal strain by speckle
tracking echocardiography in patients with septic shock.
Table 3.14. Left ventricular longitudinal strain at times in septic
shock
Times
T0
T1
Parameters
(n = 90)
(n = 57 )
p
LS-4C (%)

-14,5± 3,3
-17,2 ± 3,1
p < 0,01
LS-2C (%)
-14,3± 3,9
-17,2 ± 2,4
p < 0,01
LS-3C (%)
-15,1± 3,7
-18,5 ± 4,3
p < 0,01
GLS (%)
-14,6 ± 3,3
-17,8 ± 2,4
p < 0,01
Left ventricular systolic function via left ventricular longitudinal strain
at the timing of septic shock recovery improved compared to at the
timing of septic shock onset
Table 3.20. Left ventricular longitudinal strain at timing of T0
between nonsurvivor and survivor group in septic shock patients
Outcome Nonsurvivor
Survivor
Parameters
(n = 39)
(n = 51)
p
LS-4C (%)
-12,8 ± 3,1
-15,7 ± 2,9
p < 0,01

LS-2C (%)
-12,7 ± 3,9
-15,5 ± 3,4
p < 0,01
LS-3C (%)
-13,6 ± 3,7
-16,3 ± 3,3
p < 0,01
GLS (%)
-13,1 ± 3,2
-15,8 ± 2,9
p < 0,01
Left ventricular systolic function via left ventricular longitudinal strain
in survivor group was significantly better than nonsurvivor group.
3.3. The association of global longitudinal strain with some
prognostic factors in patients with septic shock.
3.3.1. The association of GLS with some prognostic factors at
timing of T0 in patients with septic shock.
- GLS has a positive correlation, the moderate level with the SOFA
score (r = 0.3; p < 0.01), the APACHE II score (r = 0.48; p <0.01),


17

SAPS 2 score (r = 0.31; p < 0.01) and was strongly correlated with the
number of organs dysfunction (r = 0.6, p < 0.01).
- GLS has a positive, moderate correlation with serum NT-proBNP (r =
0.39; p <0.05), hs-Troponin T (r = 0.35; p < 0.01), lactate (r = 0.3; p
<0.05) and weak correlation with CK-MB (r = 0.28; p < 0.01).
3.3.2. The value of left ventricular global longitudinal strain in the

prognosis of mortality in patients with septic shock.
Table 3.21. Compare the value of GLS with APACHE II, SOFA
and SAPS 2 score at timing of T0 in predicting of mortality.
Parameters

Cut-off

sensitivity

Specificity

AUC

CI 95%

p

GLS (%)

-14.2

66.7%

84.3%

0.76

0.66 – 0.85

p < 0.01

APACHE II

19

79.5%

72.5%

0.78

0.63 – 0.91

p < 0.01

SOFA

9

82.1%

52.9%

0.73

0.62– 0.81

p < 0.01

SAPS 2

47

69.2%

74.5%

0.72

0.61– 0.81

p < 0.01

GLS has a very fair prognostic mortality value with AUC 0.76 (p < 0.001),
at cut-off value -14.2%, sensitivity 66.7% and specificity 84.3%.
APACHE II, SOFA and SAPS 2 score has a very fair prognostic mortality
value in septic shock patients.
Table 3.22. Compare the value of GLS with serum NT-proBNP, hsTroponin T and Lactat at timing of T0 in predicting of mortality.
Parameters

Cut-off

sensitivity

Specificity

AUC

CI 95%

p

GLS (%)

-14.2

66.7%

84.3%

0.76

0.66 – 0.85

< 0.01

NT-proBNP
(pg/ml)
hs-Troponin
(pg/ml)
Lactat
(mmol/l)

14037

35.1%

89.1%

0.58

0.47 – 0.68

> 0.05

0.033

91.7%

25%

0.52

0.40– 0.62

> 0.05

5

48.7%

72.5%

0.57

0.46– 0.68

> 0.05

The serum NT-proBNP, hs-Troponin T and Lactat level at T0 had not

predictive mortality value in patients with septic shock.


18

Table 3.25. Compare the predictive mortality value of GLS with
other parameters in septic shock patients
Parameters
GLS (AUC = 0.77)
APACHE II (AUC = 0.78)
p > 0.05
SOFA (AUC = 0.73)
p > 0.05
SAPS 2 (AUC = 0.72)
p > 0.05
NT-proBNP (AUC = 0.58)
p < 0.05
hs-Troponin T (AUC = .,52)
p < 0.05
Lactat (AUC = 0.57)
p < 0.05
GLS + APACHE II (AUC = 0.8)
p > 0.05
GLS + SOFA (AUC = 0.79)
p > 0.05
GLS + SAPS 2 (AUC = 0.79)
p > 0.05
GLS + NT-proBNP (AUC = 0.77)
p > 0.05
GLS + hs-Troponin T (AUC = 0.79)

p > 0.05
GLS + Lactat (AUC = 0.77)
p > 0.05
The GLS has predictive mortality value similar to APACHE II, SOFA,
SAPS 2 score (p > 0.05) and better than serum NT-proBNP, hsTroponin T and Lactat at T0 (p < 0.05).
Bảng 3.27. Multiple logistic regression analysis of risk factors for
mortality in septic shock
Factors
OR
CI 95%
p
2.9
0.8 – 10.9
p > 0.05
Age (year)
1.8
0.5 – 6.3
p > 0.05
Lactate > 5 mmol/l
2.4
0.6 – 10.0
p > 0.05
Vasoactive-inotrope score > 22,5
4.4
1.3– 15.1
GLS > -14,2%
p < 0.05
6.1
1.5– 24.8
APACHE II > 19 points

p < 0.05
2.0
0.5 – 7.5
p > 0.05
NT-ProBNP > 14037 pg/ml
GLS > -14.2% and APACHE II > 19 points were independent
prognostic factors in predicting mortality in septic shock patients.


19

Chapter 4
DISCUSSION
4.1. Common characteristics of patients
4.1.1. Clinical and subclinical characteristics in the research group
- The average age in septic shock group was 68.8 ± 15.1 years; the lowest
age was 23 years old and the highest age was 98 years old. The average
age in the nonsurvivor group was 68.4 ± 17.4 (age) not different from the
survivor group 69.1 ± 13.1 (age). Men accounted for the majority, in the
group of septic shock was 74.4%, in the septic group was 89.2%. There
is no gender difference between the two groups. The results of our study
are similar to some authors such as Bui Thi Huong Giang (2015), Orde
et al (2014), Palmier (2015).
- Site of infection from respiratory and digestive tract accounted for
47.8% and 38.9%, respectively. Compared with other studies: Bui Thi
Huong Giang (2016), respiratory tract (37.2%), digestive tract (29.5%).
- The positive blood culture rate in the septic shock was 35.6%. Gram
negative bacteria accounted for 65.6% in which the highest percentage of
Escherichia Coli (43.7%). Compared with other studies: Pham Thi Ngoc
Thao (2013), positive blood culture rate (33.9%), gram negative bacteria

(83.8%) of which Acinetobacter was the most common cause (27%).
- Lactate and procalcitonin level at the timing of septic shock onset was
significantly higher than the time of septic shock recovery and sepsis
group. The NT-proBNP level in the nonsurvivor group was higher than
in the survivor group (p <0.05). The results are similar to Tran Thi Nhu
Thuy (2013), Varpula (2007), Zhao HY (2011) and De Geer (2015).
4.12. Results of treatment in the research group
- The percentage of patients with mechanical ventilation in the group of
septic shock was 88.9% significantly higher than that of septicemia was
62% (p < 0.001). In septic shock group, the average duration of


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mechanical ventilation was 6.1 days. The average duration of treatment
in intensive care units was 7.9 days and in-hospital mortality was 43.3%.
4.2. Some characteristics of changes in left ventricular longitudinal
strain by speckle tracking echocardiography in patients with septic
shock.
4.2.1. Left ventricular longitudinal strain in evaluating left
ventricular systolic function versus ejection fraction
- Global longitudinal strain in septic shock group was lower than that in
sepsis group (-14.6 ± 3.3% versus -17.1 ± 3.3%, p <0.01). Left ventricular
ejection fraction (LVEF) has no difference between the two groups. The
percentage of left ventricular systolic dysfunction in patients with septic
shock by conventional echocardiography was 12.2% and by speckle
tracking echocardiography was 55.6%. The percentage of left ventricular
systolic dysfunction in the septic shock group with preserved LVEF was
50.6%. Compared with other studies: Orde (2012), 33% of patients
with left ventricular systolic dysfunction by conventional

echocardiography compared with 69% of that by speckle tracking
echocardiography. Similar to Dalla and cs (2015), Shahul et al (2015),
Ng and cs (2016) and Yang (2017). Therefore, studies have shown that
STE can detect early left ventricular systolic dysfunction in septic shock
patients whose conventional echocardiography is not detectable.
4.2.2. Some characteristics of changes in left ventricular longitudinal
strain by STE in patients with septic shock.
- Left ventricular systolic function via left ventricular longitudinal strain
at the timing of septic shock recovery improved compared to at the timing
of septic shock onset. Similar to the study of Ng and cs (2016).
- GLS in men (-14.7 ± 3.5%) was not different from women (-14.5 ±
3.1%), (p> 0.05). Similar to the study of Yingchoncharoen (2013) and
Alcidi (2018).


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- GLS in the group of ≥ 60 years old (-14.8 ± 3.4%) was not significantly
different from the group of < 60 years old (-14.2 ± 3.3%). Results are
similar to Rachid Abou (2017) and different from Menting (2016).
- GLS in in-hospital nonsurvivor group (-13.1 ± 3.2%) was significantly
lower than survivor group (-15.8 ± 2.9%), (p < 0.01). The results are
similar to those of Chang et al (2015), Juan et al (2017), De Geer (2015)
and Yang et al (2017).
4.3. The association of global longitudinal strain with some
prognostic factors in patients with septic shock.
4.3.1. The association of GLS with some prognostic factors at timing
of T0 in patients with septic shock.
- GLS has a positive correlation, the moderate level with the SOFA score
(r = 0.3; p < 0.01), the APACHE II score (r = 0.48; p <0.01), SAPS 2

score (r = 0.31; p < 0.01) and was strongly correlated with the number of
organs dysfunction (r = 0.6, p < 0.01). Compared with other studies:
Hassanin (2018), GLS correlated with APACHE II (r = 0.88, p < 0.001).
- GLS has a positive correlation, moderate level with hs-Troponin T (r =
0.35; p < 0.01), lactate (r = 0.3; p <0.05) and weak correlation with CKMB (r = 0.28; p < 0.01). Compared with other studies: De Geer (2015),
GLS correlated with serum hs-Troponin T level (r = 0.35); Liu (2012).
- GLS has a positive moderate correlation with serum NT-proBNP (r =
0.39; p <0.05). Compared with other studies: Ersbøll M (2012), NTproBNP has a positive correlation with GLS (r = 0.62, p <0.0001); De
Vecchis (2015), correlation between log (NT-proBNP) and GLS (r = 0.8;
p <0.01)
- GLS has a positive, moderate correlation with serum lactate level (r =
0.3; p <0.05). Our result is similar to Lanspa (2015).
4.3.2. The value of left ventricular global longitudinal strain in the
prognosis of mortality in patients with septic shock.


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- GLS has a very fair prognostic value for septic shock with AUC 0.76 (p
< 0.001), at cut-off value -14.2%, sensitivity 66.7% and specificity 84.3%.
Our result is similar to Hassanin (2018), GLS on day 1 had a good
predictive mortality value with an area under the ROC curve (AUC 0.9),
cut-off value (-16.8%), sensitivity (100%), specificity (86%). GLS is an
independent factor in the prognosis of mortality in patients with severe
sepsis and septic shock.
- The study of Chang et al (2015), Cut-off value of GLS > -13% was
associated with mortality in patients with septic shock (HR 4.34, 95% CI:
2.1 to 8.9). Palmieri et al (2015), GLS is associated with mortality on the
28th day, less negative GLS (or closer to 0%) was the higher the mortality
rate (HR 1.16%; p = 0.05). Innocenti et al (2018), GLS had a prognostic

value of mortality within 7 days with an area under the ROC curve (AUC
0.75, p = 0.001). in multivariate analyses, mortality by day-7 follow-up
is more likely per higher GLS (i.e., indicative of worst systolic
dysfunction, HR 1.22/%, p = 0.005); mortality by day-28 follow-up is
more likely per higher GLS (RR 1.14; 95% CI: 1.03–1.26, p = 0.009).
The results show that GLS is a valuable factor of mortality prognosis in
patients with septic shock.
- The GLS in our study had predictive mortality value similar to the
APACHE II, SOFA, SAPS 2 score with the AUC of 0.78, 0.73 and 0.72,
respectively (p > 0.05). The predictive mortality value of GLS is higher
than with serum NT-proBNP, hs-Troponin T and Lactat (p < 0.05).
- GLS > -14.2% increased the risk of mortality by 10.7 times compared
to GLS group < -14.2%. In multivariate regression analysis with variables
including age, lactate level, NT-ProBNP, APACHE II score, Vasoactiveinotrope score, and GLS. Results showed that GLS > -14.2% and