Relation between left atrial strain and exercise tolerance in patients with mild mitral stenosis: An insight from 2D speckle-tracking echocardiography

Left atrial myopathy in rheumatic mitral stenosis; three-dimensional and speckle tracking echocardiography study

BACKGROUND

In developing countries, rheumatic mitral valve stenosis (MS) is still a problem and its progression leads to left atrial (LA) damage. Due to the complexity of the LA geometry, currently used techniques like antero-posterior dimension (LAD) and 2D echo derived LA volume (LAV) have several limitations that are corrected by 3D derived LA volumes in addition to functional evaluation.

PURPOSE

To assess the LA functions using 2D speckle tracking echocardiography and 3D transthoracic echocardiography in patients with clinically significant MS in comparison to normal healthy subjects.

RESULTS

Fifty patients and 50 healthy controls were studied. Patients' mean age was 40.2 ± 8.8 years, the majority were female 45(81.8%). 3D indexed LA maximum (LAVmaxI) and minimum (LAVminI) volumes were significantly higher in MS than in the control group, whereas 3D LA EF was significantly lower in MS than in the control group (p 0.001). LA strain reservoir, conduit, and contraction parameters were significantly lower in the MS group than in the control group (p = 0.001). However, only 3D LAEF, 2D LASr, 2D LAScd, and 2D LASct showed a correlation with the mitral valve area with a p < 0.05, but 3D LAVmaxI and 3D LAVminI did not. Additionally, in the comparison of severe and very severe mitral stenosis subgroups, 3D LAVmaxI and 3D LAVminI did not show any statistically significant differences between the two groups, although 3D LAEF, 2D LASr, 2D LAScd, and 3D LASct showed significant difference between the two groups (p < 0.05).

CONCLUSIONS

Left atrial functional and structural remodelling has been highlighted in patients with significant rheumatic MS. However, left atrial functional assessment by 3D echocardiography and 2D speckle tracking echocardiography correlate better with mitral valve area than conventional LA size measurements. Whether the functional assessment of the LA has an additive predictive value with regards to patient outcome needs to be interrogated.

Left atrial strain as a surrogate parameter for successful percutaneous ballon mitral valvotomy?

BACKGROUND

Severe mitral stenosis (MS) leads to morphological and functional changes in the left atrium (LA) causing dysfunction. Relieving mitral obstruction improves the LA mechanics and structural remodelling. However, this is not taken as a measure of successful Ballon Mitral Valvotomy (BMV) in clinical practice.

METHODS

We studied the relationship between LA strain and severe MS and the short-term effect of BMV on LA mechanics in a prospective observational single-centre study.

RESULTS

Peak atrial longitudinal strain (PALS) was impaired in patients (n = 40) with severe MS and improved 24 h following BMV (11.93 ± 3.29% vs 14.96 ± 3.59%, p < 0.001). There was a significant decrease in transmitral gradient (12.0 ± 4 mmHg vs 3.2 ± 1.6 mmHg, p < 0.001) and systolic pulmonary artery pressure (sPAP) (42.0 ± 8 mmHg vs 40.0 ± 4.8 mmHg, p < 0.001) after the procedure. Mitral valve area (1.03 ± 0.27 cm2 vs 1.81 ± 0.31 cm2, p < 0.001) significantly increased after the procedure. Peak atrial longitudinal strain failed to predict the success of the procedure as (AUC: 0.53; 95% CI, 0.32-0.75, p = 0.791). A cut-off value of 11.42% demonstrated a sensitivity of 64.7% and specificity of 66.7%. (R = 0.33; 95% CI 0.09, 0.6, p = 0.038).

CONCLUSION

Peak atrial longitudinal strain shows a significant improvement following a successful BMV. This increase in values reflects an improvement in clinical status and function class in follow-up. While PALS offers promise, it has limitations. Therefore, it seems reasonable to consider PALS as a supportive indicator alongside established markers like MV area and pressure gradient for assessing procedural success.

The role of multi-modality imaging for the assessment of left atrium and left atrial appendage: a clinical consensus statement of the European Association of Cardiovascular Imaging (EACVI), European Heart Rhythm Association (EHRA) of the European Society of Cardiology (ESC)

Structural, architectural, contractile, or electrophysiological alterations may occur in the left atrium (LA). The concept of LA cardiopathy is supported by accumulating scientific evidence demonstrating that LA remodelling has become a cornerstone diagnostic and prognostic marker. The structure and the function of the LA and left atrial appendage (LAA), which is an integral part of the LA, are key elements for a better understanding of multiple clinical conditions, most notably atrial fibrillation, cardioembolism, heart failure, and mitral valve diseases. Rational use of various imaging modalities is key to obtain the relevant clinical information. Accordingly, this clinical consensus document from the European Association of Cardiovascular Imaging, in collaboration with the European Heart Rhythm Association, provides comprehensive, up-to-date, and evidence-based guidance to cardiologists and cardiac imagers for the best practice of imaging LA and LAA for the diagnosis, management, and prognostication of the patients.

Left atrial function in patients with rheumatic mitral stenosis: addressing prognostic insights beyond atrial fibrillation prediction

Aims

Rheumatic mitral stenosis (MS) frequently leads to impaired left atrial (LA) function because of pressure overload, highlighting the underlying atrial pathology. Two-dimensional speckle tracking echocardiography (2D-STE) offers early detection of LA dysfunction, potentially improving risk assessment in patients with MS. This study aims to evaluate the predictive value of LA function assessed by 2D-STE for clinical outcomes in patients with MS.

Methods and results

Between 2011 and 2021, patients with MS underwent LA function assessment using 2D-STE, with focus on the reservoir phase (LASr). Atrial fibrillation (AF) development constituted the primary outcome, with death or valve replacement as the secondary outcome. Conditional inference trees were employed for analysis, validated through sample splitting. The study included 493 patients with MS (mean valve area 1.1 ± 0.4 cm2, 84% female). At baseline, 166 patients (34%) had AF, with 62 patients (19%) developing AF during follow-up. LASr emerged as the primary predictor for new-onset AF, with a threshold of 17.9%. Over a mean 3.8-year follow-up, 125 patients (25%) underwent mitral valve replacement, and 32 patients (6.5%) died. A decision tree analysis identified key predictors such as age, LASr, severity of tricuspid regurgitation (TR), net atrioventricular compliance (C n), and early percutaneous mitral valvuloplasty, especially in patients aged ≤49 years, where LASr, with a threshold of 12.8%, significantly predicted adverse outcomes.

Conclusion

LASr emerged as a significant predictor of cardiovascular events in this MS cohort, validated through a decision tree analysis. Patients were stratified into low- or high-risk categories for adverse outcomes, taking into account LASr, age, TR severity, and C n.

Potential Diagnostic and Prognostic Values of Left Atrial Strain in Valvular Heart Disease

There has been increasing evidence supporting the importance of left atrial (LA) functional analysis and measurement in various physiologic and pathologic cardiovascular conditions due to its high diagnostic and prognostic values. Assessment of LA strain (LAS) has emerged as an early marker of subclinical LA dysfunction. Using speckle-tracking echocardiography, LAS can be measured in all phases of LA function (reservoir, conduit, and booster pump). In valvular heart disease (VHD), surgical and nonsurgical interventions should be performed before irreversible left ventricular (LV) and/or LA myocardial dysfunction. The current guidelines recommended using LV strain as a parameter for early detection and timely intervention. Currently, many published data have shown the diagnostic and prognostic values of LAS in VHD, which is encouraging to integrate LAS during echo assessment. In this review, we aim to collect the current data about the clinical utility of LAS changes in risk stratification, predicting outcome, and guiding the time of intervention in VHD. The review summarized these data according to the type of valve pathologies.

Left atrium reservoir function is central in patients with rheumatic mitral stenosis

We investigated the relationship between Left Atrium strain reservoir function and symptoms and its impact on modulating Left Ventricular mechanics, diastolic filling, stroke volume, mean trans-mitral gradient and pulmonary pressure in mitral stenosis (MS) patients. We examined 195 full spectrum MS patients which were divided into two groups: Group 1 (n = 109) included patients with NYHA I & II functional class and group 2 (n = 86) included patients with NYHA III & IV functional class. LA strain reservoir function and classical echocardiographic parameters were calculated. LASr was significantly higher in group 1 versus group 2 in patients with MVA ≤ 1cm2 [8.8(6.0-12.6) vs 6.8(4.1-8.9), p = 0.03) and when 1cm2 < MVA ≤ 1.5 cm2 [10.0 (5.4-13.8) vs 6.7(4.5-9.0), p = 0.02). In patients with Pulmonary Hypertension, group 1 had significantly higher LASr than group 2 [11.1(6.6-14.8) vs 5.9(4.3-9.0), p = 0.002) By multivariate analysis, diabetes (OR = 4.11, 95%CI: 1.6-10.4), stroke (OR = 2.9, 95%CI: 1.1-7.9), LASr (OR = 0.9, 95%CI: 0.80-0.99) and LV ejection fraction (LVEF)(OR = 0.9, 95%CI: 0.91-0.99) were independently associated with NYHA functional class. LASr was significantly and positively correlated to MVA (r = 0.3, p < 10-3), stroke volume (r = 0.25, p = 10-3), mitral inflow (r = 0.4, p < 10-3) and LVEF(r = 0.14, p = 0.05). It was significantly and negatively correlated to left ventricular strain (r = -0.65, p < 10-3), LA indexed volume (r = -0.40, p < 10-3), maximum tricuspid regurgitation velocity (r = -0.25, p = 0.003), MTMG (r = -0.25, p = 10-3), and heart rate (r = -0.4, p < 10-3). We demonstrated a large range of interaction between LASr and mitral valve echocardiographic parameters. This may explain the reasons we identified LASr as an independent factor for MS functional tolerance.

Cardiac Imaging for the Assessment of Left Atrial Mechanics Across Heart Failure Stages

The left atrium (LA) is emerging as a key element in the pathophysiology of several cardiac diseases due to having an active role in contrasting heart failure (HF) progression. Its morphological and functional remodeling occurs progressively according to pressure or volume overload generated by the underlying disease, and its ability of adaptation contributes to avoid pulmonary circulation congestion and to postpone HF symptoms. Moreover, early signs of LA dysfunction can anticipate and predict the clinical course of HF diseases before the symptom onset which, particularly, also applies to patients with increased risk of HF with still normal cardiac structure (stage A HF). The study of LA mechanics (chamber morphology and function) is moving from a research interest to a clinical application thanks to a great clinical, prognostic, and pathophysiological significance. This process is promoted by the technological progress of cardiac imaging which increases the availability of easy-to-use tools for clinicians and HF specialists. Two-dimensional (2D) speckle tracking echocardiography and feature tracking cardiac magnetic resonance are becoming essential for daily practice. In this context, a deep understanding of LA mechanics, its prognostic significance, and the available approaches are essential to improve clinical practice. The present review will focus on LA mechanics, discussing atrial physiology and pathophysiology of main cardiac diseases across the HF stages with specific attention to the prognostic significance. Imaging techniques for LA mechanics assessment will be discussed with an overlook on the dynamic (under stress) evaluation of the chamber.

Left atrial function by two-dimensional speckle tracking echocardiography in patients with severe rheumatic mitral stenosis and pulmonary hypertension

We studied left atrial (LA) function in severe rheumatic mitral stenosis (MS) patients using two-dimensional speckle tracking echocardiography (STE). Eighty patients with isolated severe MS in sinus rhythm and 40 controls underwent comprehensive echocardiography including STE derived LA strain [reservoir strain (LASr), conduit strain (LAScd) and contractile strain (LASct)]. The mean MVA was 0.93 ± 0.21 cm2. The mean values of LASr (14.73 ± 8.59%), LAScd (-7.61 ± 4.47%) and LASct (-7.16 ± 5.15%) in patients were significantly lower (p < 0.001) vs. controls 44.11 ± 10.44%, -32.45 ± 7.63%, -11.85 ± 6.77% respectively and showed decreasing trend with increasing MS severity and higher NYHA class. In conclusion, LA dysfunction is prevalent in severe MS irrespective of NYHA functional class.