Cardiol Res

Cardiology Research, ISSN 1923-2829 print, 1923-2837 online, Open Access

Article copyright, the authors; Journal compilation copyright, Cardiol Res and Elmer Press Inc

Journal website https://cr.elmerpub.com

Original Article

Volume 17, Number 1, February 2026, pages 32-42

Left Atrial Deformation Parameters After Myocardial Infarction With Low Triiodothyronine Syndrome and Their Prognostic Value

Figure 1. The study design. STEMI: ST-segment elevation myocardial infarction; 2D echo-STE: 2D echocardiography, speckle-tracking echocardiography; MI: myocardial infarction; HF: heart failure; LVEF: left ventricular ejection fraction; AF: atrial fibrillation; 2D: two-dimensional.

Figure 2. ROC curves for left atrium (LA) conduit phase strain rate and LA global longitudinal strain (GLS) predicting heart failure (a). LA volume index, LA volume, left ventricular end systolic volume (LVESV) (b), and LA reservoir strain (c) predicting all-cause death. AUC: area under the curve; CI: confidence interval; ROC: receiver operating characteristic.

**Table 1.** Clinical Characteristics of the Study Population
Characteristics	Low T3 group (fT3 < 3.2 pmol/L)	Control group (fT3 ≥ 3.2 pmol/L)	P value
^aValues are presented as mean ± standard deviation. BMI: body mass index; CRP: C-reactive protein; fT3: free triiodothyronine; fT4: free thyroxine; TSH: thyroid-stimulating hormone.
Male, n (%)	29 (65.9)	84 (87.5)	0.75
Female, n (%)	15 (34.1)	12 (12.5)
Age (years)	62.7 ± 9.9	56.3 ± 12.3	0.008
History of hypertension, n (%)	21 (61.8)	58 (60.4)	0.87
Hyperlipidemia, n (%)	21 (61.8)	36 (37.5)	0.014
BMI (kg/m²)	27.9 ± 5.5	27.9 ± 4.8	0.96
Troponin I (µg/mL)	41.1 ± 58.2	53.3 ± 84.4	0.46
High sensitivity CRP (mg/L)	23.4 ± 6.9^a	18.8 ± 3.7^a	0.03
fT3 (pmol/L)	3.12 ± 0.2	4.05 ± 0.1	0.029
fT4 (pmol/L)	13.75 ± 2.3	14.7 ± 2.8	0.47
TSH (mU/L), median (Q1; Q3)	1.86 (0.82; 3.48)	1.67 (1.23; 8.78)	0.51

Table 1. Clinical Characteristics of the Study Population

Characteristics

Low T3 group (fT3 < 3.2 pmol/L)

Control group (fT3 ≥ 3.2 pmol/L)

P value

^aValues are presented as mean ± standard deviation. BMI: body mass index; CRP: C-reactive protein; fT3: free triiodothyronine; fT4: free thyroxine; TSH: thyroid-stimulating hormone.

Male, n (%)

29 (65.9)

84 (87.5)

0.75

Female, n (%)

15 (34.1)

12 (12.5)

Age (years)

62.7 ± 9.9

56.3 ± 12.3

0.008

History of hypertension, n (%)

21 (61.8)

58 (60.4)

0.87

Hyperlipidemia, n (%)

21 (61.8)

36 (37.5)

0.014

BMI (kg/m²)

27.9 ± 5.5

27.9 ± 4.8

0.96

Troponin I (µg/mL)

41.1 ± 58.2

53.3 ± 84.4

0.46

High sensitivity CRP (mg/L)

23.4 ± 6.9^a

18.8 ± 3.7^a

0.03

fT3 (pmol/L)

3.12 ± 0.2

4.05 ± 0.1

0.029

fT4 (pmol/L)

13.75 ± 2.3

14.7 ± 2.8

0.47

TSH (mU/L), median (Q1; Q3)

1.86 (0.82; 3.48)

1.67 (1.23; 8.78)

0.51

**Table 2.** Two-Dimensional, Transvalvular, Tissue Doppler, and Left Atrial Myocardial Deformation Parameters in the Acute Period of Myocardial Infarction
Parameters	Mean values (95% CI)	P value
fT3: free triiodothyronine; T3: triiodothyronine; CI: confidence interval; LVEDD: left ventricular end-diastolic diameter; LVESD: left ventricular end-systolic diameter; LVEDV: left ventricular end-diastolic volume; LVESV: left ventricular end-systolic volume; LVEF: left ventricular ejection fraction; LA: left atrium; E/E’: ratio of early diastolic transmitral flow velocity and early diastolic mitral annular velocity; GLS: global longitudinal strain.
LVEDD (mm)	48.9 (46.9 ± 50.8)	48.8 (47.8 ± 49.7)	0.634
LVESD (mm)	39.9 (37.7 ± 42.2)	39.4 (38.5 ± 40.2)	0.549
LVEDV (mL)	101.2 (95.1 ± 107.2)	107.9 (104.9 ± 110.7)	0.040
LVESV (mL)	37.9 (34.0 ± 41.8)	43.3 (41.1 ± 45.6)	0.006
LVEF (%)	40.9 (39.2 ± 42.5)	42.0 (38.5 ± 45.6)	0.364
LA volume (mL)	39.3 (34.9 ± 43.7)	38.6 (36.6 ± 40.6)	0.987
LA volume index (mL/m²)	20.1 (17.7 ± 22.6)	19.2 (18.3 ± 20.1)	0.845
E/E’	8.6 (7.1 ± 10.1)	8.4 (7.8 ± 8.9)	0.648
LA reservoir strain (%)	23.1 (18.6 ± 27.7)	22.3 (19.9 ± 24.6)	0.434
LA GLS (%)	22.1 (15.8 ± 28.5)	21.7 (18.4 ± 24.9)	0.641
LA conduit phase strain rate (s⁻¹)	0.8 (0.6 ± 0.9)	0.94 (0.85 ± 1.0)	0.040
LA contractile phase strain rate(s⁻¹)	0.9 (0.6 ± 1.2)	1.05 (0.9 ± 1.2)	0.425

Table 2. Two-Dimensional, Transvalvular, Tissue Doppler, and Left Atrial Myocardial Deformation Parameters in the Acute Period of Myocardial Infarction

Parameters

Mean values (95% CI)

P value

Low T3 group (fT3 < 3.2 pmol/L), n = 44

Control group (fT3 ≥ 3.2 pmol/L), n = 96

fT3: free triiodothyronine; T3: triiodothyronine; CI: confidence interval; LVEDD: left ventricular end-diastolic diameter; LVESD: left ventricular end-systolic diameter; LVEDV: left ventricular end-diastolic volume; LVESV: left ventricular end-systolic volume; LVEF: left ventricular ejection fraction; LA: left atrium; E/E’: ratio of early diastolic transmitral flow velocity and early diastolic mitral annular velocity; GLS: global longitudinal strain.

LVEDD (mm)

48.9 (46.9 ± 50.8)

48.8 (47.8 ± 49.7)

0.634

LVESD (mm)

39.9 (37.7 ± 42.2)

39.4 (38.5 ± 40.2)

0.549

LVEDV (mL)

101.2 (95.1 ± 107.2)

107.9 (104.9 ± 110.7)

0.040

LVESV (mL)

37.9 (34.0 ± 41.8)

43.3 (41.1 ± 45.6)

0.006

LVEF (%)

40.9 (39.2 ± 42.5)

42.0 (38.5 ± 45.6)

0.364

LA volume (mL)

39.3 (34.9 ± 43.7)

38.6 (36.6 ± 40.6)

0.987

LA volume index (mL/m²)

20.1 (17.7 ± 22.6)

19.2 (18.3 ± 20.1)

0.845

E/E’

8.6 (7.1 ± 10.1)

8.4 (7.8 ± 8.9)

0.648

LA reservoir strain (%)

23.1 (18.6 ± 27.7)

22.3 (19.9 ± 24.6)

0.434

LA GLS (%)

22.1 (15.8 ± 28.5)

21.7 (18.4 ± 24.9)

0.641

LA conduit phase strain rate (s⁻¹)

0.8 (0.6 ± 0.9)

0.94 (0.85 ± 1.0)

0.040

LA contractile phase strain rate(s⁻¹)

0.9 (0.6 ± 1.2)

1.05 (0.9 ± 1.2)

0.425

**Table 3.** Left Ventricular and Atrial Parameters 6 Months After Myocardial Infarction
Parameters	Mean values (95% CI)	P value
fT3: free triiodothyronine; T3: triiodothyronine; CI: confidence interval; LVEDD: left ventricular end-diastolic diameter; LVESD: left ventricular end-systolic diameter; LVEDV: left ventricular end-diastolic volume; LVESV: left ventricular end-systolic volume; EF: ejection fraction; LA: left atrium; E/E’: ratio of early diastolic transmitral flow velocity and early diastolic mitral annular velocity.
LVEDD (mm)	51.0 (47.4 ± 54.6)	51.3 (50.1 ± 52.4)	0.588
LVESD (mm)	42.9 (39.4 ± 46.6)	42.3 (41.3 ± 43.4)	0.641
LVESV (mL)	43.6 (34.4 ± 52.7)	47.4 (44.6 ± 50.3)	0.312
LVEDV (mL)	107.3 (94.3 ± 120.3)	111.1 (107.4 ± 114.8)	0.443
EF (%)	40.4 (34.7 ± 46.1)	40.0 (38.2 ± 41.8)	0.451
LA volume (mL)	56.1 (40.9 ± 71.3)	50.9 (47.4 ± 54.5)	0.030
LA index volume (mL/m²)	28.5 (21.6 ± 35.3)	25.2 (23.6 ± 26.7)	0.040
E/E’	9.4 (6.9 ± 11.9)	8.6 (7.3 ± 9.9)	0.061

Table 3. Left Ventricular and Atrial Parameters 6 Months After Myocardial Infarction

Parameters

Mean values (95% CI)

P value

Low T3 group (fT3 < 3.2), n = 44

Control group (fT3 ≥ 3.2), n = 96

fT3: free triiodothyronine; T3: triiodothyronine; CI: confidence interval; LVEDD: left ventricular end-diastolic diameter; LVESD: left ventricular end-systolic diameter; LVEDV: left ventricular end-diastolic volume; LVESV: left ventricular end-systolic volume; EF: ejection fraction; LA: left atrium; E/E’: ratio of early diastolic transmitral flow velocity and early diastolic mitral annular velocity.

LVEDD (mm)

51.0 (47.4 ± 54.6)

51.3 (50.1 ± 52.4)

0.588

LVESD (mm)

42.9 (39.4 ± 46.6)

42.3 (41.3 ± 43.4)

0.641

LVESV (mL)

43.6 (34.4 ± 52.7)

47.4 (44.6 ± 50.3)

0.312

LVEDV (mL)

107.3 (94.3 ± 120.3)

111.1 (107.4 ± 114.8)

0.443

EF (%)

40.4 (34.7 ± 46.1)

40.0 (38.2 ± 41.8)

0.451

LA volume (mL)

56.1 (40.9 ± 71.3)

50.9 (47.4 ± 54.5)

0.030

LA index volume (mL/m²)

28.5 (21.6 ± 35.3)

25.2 (23.6 ± 26.7)

0.040

E/E’

9.4 (6.9 ± 11.9)

8.6 (7.3 ± 9.9)

0.061

**Table 4.** Two-Dimensional, Transvalvular and Tissue Doppler Parameters Between Group 1 and Group 2 in the Acute Period of Myocardial Infarction and After 6 Months of Myocardial Infarction
Parameters		Mean values (95% CI)	P value
CI: confidence interval; EF: ejection fraction; LVEDD: left ventricular end-diastolic diameter; LVESD: left ventricular end-systolic diameter; LVEDV: left ventricular end-diastolic volume; LVESV: left ventricular end-systolic volume; LVEF: left ventricular ejection fraction; LA: left atrium; E/E’: ratio of early diastolic transmitral flow velocity and early diastolic mitral annular velocity.
LVEDD (mm)	At baseline	45.7 (44.0 ± 46.5)	50.4 (49.3 ± 51.1)	< 0.0001
	After 6 months	47.7 (46.0 ± 49.5)	52.8 (48.4 ± 53.6)	< 0.0001
LVESD (mm)	At baseline	36.6 (35.1 ± 37.3)	40.7 (39.6 ± 41.3)	< 0.0001
	After 6 months	39.6 (37.7 ± 41.9)	44.3 (43.8 ± 45.2)	0.0003
LVEDV (mL)	At baseline	107.1 (100.5 ± 113.8)	107.4 (104.1 ± 110.8)	0.94
	After 6 months	108.4 (101.2 ± 115.9)	111.6 (106.3 ± 116.9)	0.512
LVESV (mL)	At baseline	33.0 (29.5 ± 34.5)	46.8 (43.9 ± 48.1)	< 0.0001
	After 6 months	37.3 (34.1 ± 40.0)	51.5 (48.8 ± 53.2)	< 0.0001
LVEF (%)	At baseline	54.3 (52.3 ± 55.3)	33.8 (32.7 ± 34.1)	< 0.0001
	After 6 months	51.5 (48.9 ± 54.1)	35.1 (33.9 ± 37.1)	< 0.0001
LA volume (mL)	At baseline	34.3 (30.4 ± 38.2)	40.2 (37.9 ± 42.1)	0.008
	After 6 months	45.1 (37.7 ± 48.3)	53.1 (48.8 ± 57.1)	0.034
LA volume index (mL/m²)	At baseline	17.6 (15.9 ± 19.3)	19.8 (18.7 ± 20.9)	0.034
	After 6 months	20.9 (18.6 ± 23.3)	27.0 (24.1 ± 28.8)	0.014
E/E’	At baseline	8.0 (6.7 ± 9.4)	8.5 (7.8 ± 9.3)	0.486
	After 6 months	8.2 (6.2 ± 9.8)	9.3 (7.1 ± 11.5)	0.521

Table 4. Two-Dimensional, Transvalvular and Tissue Doppler Parameters Between Group 1 and Group 2 in the Acute Period of Myocardial Infarction and After 6 Months of Myocardial Infarction

Parameters

Mean values (95% CI)

P value

Group 1(EF ≥ 50%), n = 26

Group 2 (EF ≤ 40%), n = 68

CI: confidence interval; EF: ejection fraction; LVEDD: left ventricular end-diastolic diameter; LVESD: left ventricular end-systolic diameter; LVEDV: left ventricular end-diastolic volume; LVESV: left ventricular end-systolic volume; LVEF: left ventricular ejection fraction; LA: left atrium; E/E’: ratio of early diastolic transmitral flow velocity and early diastolic mitral annular velocity.

LVEDD (mm)

At baseline

45.7 (44.0 ± 46.5)

50.4 (49.3 ± 51.1)

< 0.0001

After 6 months

47.7 (46.0 ± 49.5)

52.8 (48.4 ± 53.6)

< 0.0001

LVESD (mm)

At baseline

36.6 (35.1 ± 37.3)

40.7 (39.6 ± 41.3)

< 0.0001

After 6 months

39.6 (37.7 ± 41.9)

44.3 (43.8 ± 45.2)

0.0003

LVEDV (mL)

At baseline

107.1 (100.5 ± 113.8)

107.4 (104.1 ± 110.8)

0.94

After 6 months

108.4 (101.2 ± 115.9)

111.6 (106.3 ± 116.9)

0.512

LVESV (mL)

At baseline

33.0 (29.5 ± 34.5)

46.8 (43.9 ± 48.1)

< 0.0001

After 6 months

37.3 (34.1 ± 40.0)

51.5 (48.8 ± 53.2)

< 0.0001

LVEF (%)

At baseline

54.3 (52.3 ± 55.3)

33.8 (32.7 ± 34.1)

< 0.0001

After 6 months

51.5 (48.9 ± 54.1)

35.1 (33.9 ± 37.1)

< 0.0001

LA volume (mL)

At baseline

34.3 (30.4 ± 38.2)

40.2 (37.9 ± 42.1)

0.008

After 6 months

45.1 (37.7 ± 48.3)

53.1 (48.8 ± 57.1)

0.034

LA volume index (mL/m²)

At baseline

17.6 (15.9 ± 19.3)

19.8 (18.7 ± 20.9)

0.034

After 6 months

20.9 (18.6 ± 23.3)

27.0 (24.1 ± 28.8)

0.014

E/E’

At baseline

8.0 (6.7 ± 9.4)

8.5 (7.8 ± 9.3)

0.486

After 6 months

8.2 (6.2 ± 9.8)

9.3 (7.1 ± 11.5)

0.521

**Table 5.** Left Atrial Myocardial Deformation Parameters Between Group 1 and Group 2 in the Acute Period of Myocardial Infarction and After 6 Months of Myocardial Infarction
Parameters		Mean values (95% CI)	P value
CI: confidence interval; EF: ejection fraction; LA: left atrial; GLS: global longitudinal strain.
LA reservoir strain (%)	At baseline	30.7 (22.1 ± 39.3)	21.6 (19.8 ± 23.1)	0.019
	After 6 months	28.1 (19.3 ± 36.9)	23.4 (19.7 ± 27.1)	0.234
LA GLS (%)	At baseline	26.9 (19.4 ± 34.5)	21.1 (17.4 ± 24.8)	0.116
	After 6 months	25.05 (14.5 ± 35.5)	14.35 (9.3 ± 19.3)	0.048
LA conduit phase strain rate (s⁻¹)	At baseline	0.8 (0.6 ± 1.0)	0.92 (0.8 ± 1.1)	0.275
	After 6 months	1.14 (0.8 ± 1.4)	0.79 (0.7 ± 0.9)	0.018
LA contractile phase strain rate (s⁻¹)	At baseline	1.2 (0.9 ± 1.5)	0.98 (0.8 ± 1.2)	0.104
	After 6 months	1.39 (0.9 ± 1.8)	0.92 (0.7 ± 1.1)	0.036

Table 5. Left Atrial Myocardial Deformation Parameters Between Group 1 and Group 2 in the Acute Period of Myocardial Infarction and After 6 Months of Myocardial Infarction

Parameters

Mean values (95% CI)

P value

Group 1 (EF ≥ 50%), n = 26

Group 2 (EF ≤ 40%), n = 68

CI: confidence interval; EF: ejection fraction; LA: left atrial; GLS: global longitudinal strain.

LA reservoir strain (%)

At baseline

30.7 (22.1 ± 39.3)

21.6 (19.8 ± 23.1)

0.019

After 6 months

28.1 (19.3 ± 36.9)

23.4 (19.7 ± 27.1)

0.234

LA GLS (%)

At baseline

26.9 (19.4 ± 34.5)

21.1 (17.4 ± 24.8)

0.116

After 6 months

25.05 (14.5 ± 35.5)

14.35 (9.3 ± 19.3)

0.048

LA conduit phase strain rate (s⁻¹)

At baseline

0.8 (0.6 ± 1.0)

0.92 (0.8 ± 1.1)

0.275

After 6 months

1.14 (0.8 ± 1.4)

0.79 (0.7 ± 0.9)

0.018

LA contractile phase strain rate (s⁻¹)

At baseline

1.2 (0.9 ± 1.5)

0.98 (0.8 ± 1.2)

0.104

After 6 months

1.39 (0.9 ± 1.8)

0.92 (0.7 ± 1.1)

0.036

**Table 6.** Two-Dimensional and Left Atrial Myocardial Deformation Parameters Between Group 1 and Group 3 in the Acute Period and After 6 Months of Myocardial Infarction
Parameters	Mean values (95% CI)	P value
CI: confidence interval; EF: ejection fraction; LA: left atrial; LVESV: left ventricular end-systolic volume; LVEF: left ventricular ejection fraction.
LA reservoir strain (%) in the acute period	30.7 (22.1 ± 39.3)	22.2 (17.8 ± 26.6)	0.045
LVESV (mL) after 6 months	37.3 (34.1 ± 40.0)	42.9 (39.8 ± 45.9)	0.039
LVEF (%) after 6 months	51.5 (48.9 ± 54.1)	42.9 (40.5 ± 45.1)	< 0.0001
LA volume index (mL/m²) after 6 months	20.9 (18.6 ± 23.3)	25.8 (22.9 ± 28.6)	0.037
LA conduit phase strain rate (s⁻¹) after 6 months	1.14 (0.8 ± 1.4)	0.82 (0.7 ± 0.9)	0.018
LA contractile phase strain rate (s⁻¹) after 6 months	1.39 (0.9 ± 1.8)	0.86 (0.6 ± 1.1)	0.022

Table 6. Two-Dimensional and Left Atrial Myocardial Deformation Parameters Between Group 1 and Group 3 in the Acute Period and After 6 Months of Myocardial Infarction

Parameters

Mean values (95% CI)

P value

Group 1 (EF ≥ 50%), n = 26

Group 3 (EF 41–49%), n = 46

CI: confidence interval; EF: ejection fraction; LA: left atrial; LVESV: left ventricular end-systolic volume; LVEF: left ventricular ejection fraction.

LA reservoir strain (%) in the acute period

30.7 (22.1 ± 39.3)

22.2 (17.8 ± 26.6)

0.045

LVESV (mL) after 6 months

37.3 (34.1 ± 40.0)

42.9 (39.8 ± 45.9)

0.039

LVEF (%) after 6 months

51.5 (48.9 ± 54.1)

42.9 (40.5 ± 45.1)

< 0.0001

LA volume index (mL/m²) after 6 months

20.9 (18.6 ± 23.3)

25.8 (22.9 ± 28.6)

0.037

LA conduit phase strain rate (s⁻¹) after 6 months

1.14 (0.8 ± 1.4)

0.82 (0.7 ± 0.9)

0.018

LA contractile phase strain rate (s⁻¹) after 6 months

1.39 (0.9 ± 1.8)

0.86 (0.6 ± 1.1)

0.022

**Table 7.** Multivariate Logistic Regression Analysis Data for Predicting MACEs
Parameters	Exp(B)	95% CI	P
CI: confidence interval; LA: left atrial; LVEF: left ventricular ejection fraction.
LA conduit phase strain rate	9.971	8.72–11.34	0.008
LA volume index	1.186	0.84–1.26	0.004
LA reservoir strain	0.958	0.72–1.27	0.042
LVEF	0.944	0.81–1.32	0.021

Table 7. Multivariate Logistic Regression Analysis Data for Predicting MACEs

Parameters

Exp(B)

95% CI

CI: confidence interval; LA: left atrial; LVEF: left ventricular ejection fraction.

LA conduit phase strain rate

9.971

8.72–11.34

0.008

LA volume index

1.186

0.84–1.26

0.004

LA reservoir strain

0.958

0.72–1.27

0.042

LVEF

0.944

0.81–1.32

0.021