Cardiac Longitudinal Function: GLS vs. MAPSE

Over the history of echocardiography, there have been a multitude of research studies on the feasibility, reproducibility and the prognostic values of different echocardiographic parameters in different disease groups. Fifty years later, no single echocardiographic parameter is unique for assessment of the cardiac structure and function. Even the most widely used measurement for left ventricle ejection fraction (LVEF) has important limitations, including low sensitivity for incident heart failure (HF), specifically HF with preserved ejection fraction (HFpEF). With the advent of speckle tracking echocardiography (STE), early detection of cardiac dysfunction before signs or symptoms of HF develop (stage A or B HF) has become a target of many researchers in the last 15 years. Although, there has been some success, there is still a long way to go. In this blog, I want to discuss the differences, advantages and the limitations of mitral annular plane systolic excursion (MAPSE) vs. global longitudinal strain (GLS).

MAPSE measures LV longitudinal shortening and it has been around for over 50 years. Reduction in MAPSE was described as a marker of LV dysfunction (Figure 1). Nowadays, newer and more refined echocardiographic technologies, such as strain, are used more widely for assessment of LV function and deformation. STE imaging has been around for quite a while and we celebrated it’s first decade just 4 years ago, whereas the technique described in 2004 (Leitman M-JASE) and clinical applications appeared around 2005 (Notomi Y- JACC). Since then, the interest has risen dramatically and so far, we have around 6,000 publications on this topic. GLS is the most studied among strain parameters and its prognostic value has been demonstrated in several clinical scenarios.

Figure 1: GLS vs. MAPSE – Fawaz Alenezi -2019.

 

	MAPSE (cm)	GLS (%)
Technique	Real time or reconstructed M-mode Measure mitral annular displacement	Speckle tracking Measure myocardial deformation
Advantages	Less dependent on image quality and almost (> 95%) is feasible Good correlation with LVEF Simple and fast Excellent reproducibility High temporal resolution More standardized Better than LVEF in some cases Vendor independent Not gender or BSA dependent	Assess regional and global longitudinal/radial/circumferential function, rotation/torsion, and ventricular synchrony Less angle dependent Better than LVEF in some cases Good correlation with LVEF
Disadvantages	Unable to detect regional abnormalities Angle dependent Age dependent Pericardial effusion: The interpretation of MAPSE should be carefully applied in case of a mobile apex. RV dysfunction: In patients with paradox septal motion, septal MAPSE is not only reflecting LV function but rather RV abnormalities Mitral valve disease and ring calcification: Sometimes in patients with mitral valve disease, the mitral ring is extremely calcified. In these patients, the direct MAPSE measurement at the mitral ring is not possible and longitudinal functional assessment should be done slightly more above in the myocardium Septal MI: Another limitation of this parameter is that small localized abnormalities (i.e. small areas of fibrosis) cannot be detected as it is only possible to assess longitudinal function of the complete wall LVH: In patients with LVH due to HTN or AS will have different values	Vendor dependent Although, assessment of regional function is the main advantages of strain, but studies still showing a large variability and is not ready to clinical use Variable in region of interest definition Highly dependent on image quality Gender and BSA dependent Need experience and time consuming Pre and after load dependent Rhythm and rate dependent Frame rate dependent

Table 1: Advantages and limitations of GLS vs. MAPSE- Fawaz Alenezi – 2019

 

What is thought to be the main advantage of STE over MAPSE is the ability of global and regional function assessment. However, with regard to regional (segmental) function, I think this is more challenging and there is still progress to be made. The challenges exist because we have only one segment to work with and less data to average. Tracking quality becomes more important, regional artifacts matters more, definition of sample position more relevant, and more importantly, we cannot simply measure peak values anymore. For regional analysis, the strain curve shape (not peak values, because peak values can be the same) become critical. Regional strain measurements have much higher variability among vendors when compared with GLS. Recently, the HUNT study (Stoylen A et al. 2018 –Wiley echocardiography journal) showed that MAPSE and GLS measured both as MAPSEn (n= normalized for end diastolic length) and GLS have similar biological variability in adults without improvement by normalizing for length for both.

In summary, I think both GLS and MAPSE are measuring the same cardiac function. GLS is robust, reproducible and has been shown to add unique data that can guide diagnosis and management. However, it is vendor, image quality and hemodynamics dependent that need more standardization and experience. On the other hand, MAPSE is simple, easy, available in every echo machine and, more importantly, feasible even in a poor image quality. But it is not measuring the global function. Further studies are needed to standardize vendors, recognize specific strain patterns, determine if there is loading conditions difference and head-to-head comparison between both methods.