|Year : 2021 | Volume
| Issue : 1 | Page : 5-9
Correlation of Global Longitudinal Strain with Functional Status of Patients with Left Ventricular Systolic Dysfunction
Lalit Mohan Rathi, Sanjeev Sanghvi, Rohit Mathur, Anil Baroopal
Department of Cardiology, Dr S N Medical College, Jodhpur, Rajasthan, India
|Date of Submission||03-Jul-2020|
|Date of Decision||26-Jul-2020|
|Date of Acceptance||17-Aug-2020|
|Date of Web Publication||04-Feb-2021|
Dr. Lalit Mohan Rathi
Department of Cardiology, Dr S N Medical College, Jodhpur, Rajasthan
Source of Support: None, Conflict of Interest: None
Background: Two-dimensional (2D) left ventricular ejection fraction (LVEF) is a well-known parameter to assess the functional status of the patients. Recently, global longitudinal strain (GLS) has emerged as a more sensitive tool for assessing left ventricular (LV) systolic function. We aimed to assess the superiority of GLS by 2D speckle-tracking echocardiography over 2D LVEF in patients with moderate-to-severe LV systolic dysfunction (LVSD) calculated using Simpson's biplane method of disks, in predicting the functional status of the patients. Materials and Methods: One hundred patients in age group 18–80 years with moderate-to-severe LVSD (2D LVEF <40%) were included. New York Heart Association class 4 patients and patients of rheumatic heart disease or valvular heart disease were excluded. 2D LVEF was calculated using Simpson's method. 2D GLS was assessed using automated function imaging technique. The Minnesota Living with Heart Failure Questionnaire (MLHFQ) was used to assess functional status of patients with moderate-to-severe LVSD. Results: Results showed that 2D GLS better correlated with functional status of the patients (P ≤ 0.0001) than 2D LVEF (P = 0.619). Patients who had better 2D GLS had better functional status according to MLHFQ. Conclusion: Correlation of functional status of patients with poor LVSD was superior with 2D GLS when compared to 2D LVEF. Since strain imaging is an inexpensive tool, it can be easily applied to assess functional status in large number of patients without adding any additional cost.
Keywords: Global longitudinal strain, left ventricular ejection fraction, speckle-tracking echocardiography
|How to cite this article:|
Rathi LM, Sanghvi S, Mathur R, Baroopal A. Correlation of Global Longitudinal Strain with Functional Status of Patients with Left Ventricular Systolic Dysfunction. J Indian Acad Echocardiogr Cardiovasc Imaging 2021;5:5-9
|How to cite this URL:|
Rathi LM, Sanghvi S, Mathur R, Baroopal A. Correlation of Global Longitudinal Strain with Functional Status of Patients with Left Ventricular Systolic Dysfunction. J Indian Acad Echocardiogr Cardiovasc Imaging [serial online] 2021 [cited 2021 Jul 23];5:5-9. Available from: https://www.jiaecho.org/text.asp?2021/5/1/5/308730
| Introduction|| |
Two-dimensional echocardiographic (2D echo) assessment of left ventricular ejection fraction (LVEF) is routinely used to guide patient management. It is also known to be an independent predictor of mortality. However, 2D LVEF by Simpson's biplane method is dependent on imaging plane and observer experience. It's accuracy varies with image quality. 2D LVEF has limitations of reproducibility and it is also not able to detect small changes in contractility.
The measurement of global longitudinal strain (GLS) using speckle-tracking echocardiography (STE) has emerged as a new modality for assessing left ventricular (LV) systolic function. The strengths of 2D GLS include better reproducibility and ability to detect minor changes in myocardial function. It is relatively operator independent. Studies have shown that 2D GLS can predict mortality more accurately than 2D LVEF.
Till date, superiority of 2D GLS over 2D LVEF has not been assessed to evaluate functional status of patients with moderate-to-severe left ventricular systolic dysfunction (LVSD).
The aim of this study was to assess whether 2D GLS is better correlated with functional status of the patients when compared to 2D LVEF in those aged 18–80 years with moderate-to-severe LVSD.
| Materials and Methods|| |
The study was conducted at the Department of Cardiology, MDM Hospital attached to Dr. S. N. Medical College, Jodhpur. It was a hospital based observational study. A total of 100 patients between the age of 18 and 80 years of either gender presenting with moderate-to-severe LVSD (2D LVEF <40%) were included. Out of these 100 patients, 79 patients had ischemic cardiomyopathy and 21 had dilated cardiomyopathy. A detailed clinical history was obtained, and examination of all these patients was performed. Basic routine blood tests were done for all participants. Informed consent for participation in this study was obtained.
- Patients in New York Heart Association functional class 4
- Patients of rheumatic heart disease or valvular heart disease
- Poor echo window
- Critically ill patient.
Echocardiographic study was done with GE Healthcare, Vivid Ultrasound E9 echocardiography machine according to the American Society of Echocardiography guidelines. Data acquisition was performed using 3.5 MHz transducer. 2D LVEF was assessed by Simpson's biplane method of disks. 2D GLS was calculated by using automated function imaging technique using an apical 3-chamber view, apical 4-chamber view, and apical 2-chamber view. During analysis, the endocardial border was manually traced at an end-systolic frame and then software automatically tracked these markers. A mean global strain value for the entire LV was automatically displayed on the bulls-eye map of LV strain [Figure 1]. All echocardiograms were performed by two operators in a blinded manner and interobserver and intraobserver variability for GLS was 2.2% ± 1.8% and 1.2% ± 1%, respectively.
|Figure 1: Global longitudinal strain bulls-eye map of a patient of ischemic cardiomyopathy|
Click here to view
The Minnesota Living with Heart Failure Questionnaire (MLHFQ) was used to assess functional status of the patients with moderate-to-severe LVSD. Permission for using this questionnaire was taken from University of Minnesota. The copy of full license agreement and format of questionnaire is attached [Supplementary Material, Annexure 1] [Additional file 1]. Collected data was analyzed with appropriate statistical tests. For uniformity reasons, categorical variables were presented as frequencies and percentages and were compared using Chi-square test. Correlation coefficient (r) was used to calculate association between GLS and functional status.
| Results|| |
A total of 100 patients were included during the study period from March 2019 to January 2020. [Table 1] presents baseline characteristics of the patients. The study population consisted of 87 (87%) males and 13 (13%) females; the mean age of participants was 64.59 ± 5.29 years. Among the traditional risk factors, 53% were hypertensive, 35% were diabetic and 30% were tobacco chewer. Most patients were treated with aspirin (70%), b-blockers (79%), angiotensin-converting enzyme inhibitors or angiotensin receptor blockers (62%), and diuretics (82%). Rational for not using angiotensin receptor neprilysin inhibitors (ARNI) was affordability, as majority of our patients were taking medicines from hospital supply and it does not have ARNI in the list. The mean 2D LVEF was 22.47 ± 7.51. The mean 2D GLS was − 9.99 ± 1.82. The mean score of MLHFQ was 23.86 ± 7.24 [Table 2]. It was observed that GLS is better correlated with functional status of the patients (P < 0.0001) than 2D LVEF (P = 0.619) [Table 3]. There was a linear relationship between functional status and 2D GLS [Figure 2] but there was no such relationship between functional status and 2D LVEF [Figure 3]. Results were statistically significant in all age group of patients specially in males [Table 4] and [Table 5]. Patients who had better GLS had better score according to the MLHFQ.
|Table 2: Mean of 2D LVEF, 2D GLS and MLHFQ score according to age and sex|
Click here to view
|Table 3: Correlation between functional status of the patients according to MLHFQ score and 2DLVEF and 2DGLS|
Click here to view
|Figure 2: Relationship between functional status of the patients and two-dimensional global longitudinal strain (2D GLS)|
Click here to view
|Figure 3: Relationship between functional status of the patients and two-dimensional left ventricular ejection fraction (2D LVEF)|
Click here to view
|Table 4: Correlation between functional status of the patients and 2DLVEF and 2DGLS according to age|
Click here to view
|Table 5: Correlation between functional status of the patients and 2DLVEF and 2DGLS according to sex|
Click here to view
| Discussion|| |
The findings of the present study showed that 2D GLS significantly better correlated with functional status of the patients than 2D LVEF. Although 2D LVEF is the most established parameter to assess LV function but in the past decade GLS has emerged as a more sensitive and reproducible parameter for LV function assessment. At present, STE is used as a novel technique to allow the assessment of 2D GLS and till now there was no study which correlated functional status of the patients with 2D GLS, so we compared both parameters (2D LVEF and 2D GLS) with the functional status and the results showed that 2D GLS had a better correlation.
Bertini et al. had taken 1060 patients of chronic ischemic cardiomyopathy and evaluated the prognostic value of GLS as a new index of LV systolic function to predict long-term outcome. During follow-up, compared with survivors, patients who died had greater impairment of LV GLS (P < 0.001). After dichotomizing the population on the basis of the median value of LV GLS (−11.5%), patients with a LV GLS <−11.5% had superior outcome compared with the patients with a LV GLS >-11.5% (P < 0.001 for both).
Stanton et al. analyzed 546 patients of coronary artery disease (CAD) and showed that 2D GLS assessed with 2D STE had incremental value over LVEF in prediction of outcome. The authors also showed that 2D GLS assessment was more reproducible as compared with 2D LVEF assessment.
Radwan et al. included 80 patients of stable angina and evaluated the diagnostic accuracy of LV GLS obtained by 2D STE in prediction of severity of CAD. Study showed that measurement of 2D GLS was sensitive and accurate tool in the prediction of severe CAD.
- The number of patients in the study was small
- Long-term follow-up was not done. To know the prognostic value of GLS, long-term follow-up is required
- Radial and circumferential strains were not explored. However, it is proved that longitudinal deformation is a more sensitive marker of cardiac function compared with radial or circumferential strain.
| Conclusion|| |
2D GLS with STE is significantly related to the functional status of the patients with moderate-to-severe LVSD. It showed better correlation with the functional status than the conventionally used 2DLVEF measured by Simpson's method. Hence, along with 2DLVEF, 2DGLS should also be measured in daily routine practice for better management of the patients.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Medvedofsky D, Maffessanti F, Weinert L, Tehrani DM, Narang A, Addetia K, et al
. 2D and 3D echocardiography – Derived indices of left ventricular function and shape: Relationship with mortality. JACC Cardiovasc Imaging 2018;11:1569-79.
King A, Thambyrajah J, Leng E, Stewart MJ. Global longitudinal strain: A useful everyday measurement? Echo Res Pract 2016;3:85-93.
Lang RM, Badano LP, Mor-Avi V, Afilalo J, Armstrong A, Ernande L, et al
. Recommendations for cardiac chamber quantification by echocardiography in adults: An update from the American Society of Echocardiography and the European Association of Cardiovascular Imaging. J Am Soc Echocardiogr 2015;28:1-39.e14.
Anwar AM. Global and segmental myocardial deformation by 2D speckle tracking compared to visual assessment. World J Cardiol 2012;4:341-6.
Chryssanthopoulos SN, Dritsas A, Cokkinos DV. Activity questionnaires: A useful tool in accessing heart failure patients. Int J Cardiol 2005;105:294-9.
Bertini M, Ng AC, Antoni ML, Nucifora G, Ewe SH, Auger D, et al
. Global longitudinal strain predicts long-term survival in patients with chronic ischemic cardiomyopathy. Circ Cardiovasc Imaging 2012;5:383-91.
Stanton T, Leano R, Marwick TH. Prediction of all-cause mortality from global longitudinal speckle strain: Comparison with ejection fraction and wall motion scoring. Circ Cardiovasc Imaging 2009;2:356-64.
Radwan H, Hussein E. Value of global longitudinal strain by two dimensional speckle tracking echocardiography in predicting coronary artery disease severity. Egypt Heart J 2017;69:95-101.
Chan J, Hanekom L, Wong C, Leano R, Cho GY, Marwick TH. Differentiation of subendocardial and transmural infarction using two-dimensional strain rate imaging to assess short-axis and long-axis myocardial function. J Am Coll Cardiol 2006;48:2026-33.
[Figure 1], [Figure 2], [Figure 3]
[Table 1], [Table 2], [Table 3], [Table 4], [Table 5]