Global longitudinal strain in severe aortic stenosis

Left Ventricular Diastolic Dysfunction Predicts Global Longitudinal Strain Recovery after Surgical Aortic Valve Replacement

BACKGROUND AND OBJECTIVES

In patients with severe aortic stenosis (AS), left ventricular systolic dysfunction is one of the main predictors of adverse events after surgical aortic valve replacement (SAVR). However, more patients undergo surgery earlier, often with preserved systolic function. In these cases, global longitudinal strain (GLS) has been proposed as a marker of ventricular remodeling post-surgery. This study aims to evaluate GLS variation in patients undergoing SAVR and explore differences across the diastolic dysfunction classes.

METHODS

From June 2020 to March 2023, patients with AS and preserved ejection fraction (EF) requiring SAVR were enrolled. Echocardiographic evaluations were conducted preoperatively, seven days post-surgery, and twelve months after surgery. Patients were divided into two groups based on the severity of diastolic dysfunction: Group A (grade I) and Group B (grades II-III).

RESULTS

The final analysis included 108 patients (mean age 71.3 ± 7.2 years). Twenty-two patients (20.4%) also underwent coronary artery bypass grafting (CABG). The preoperative EF averaged 61.6 ± 6.03%, with no significant differences between groups. Preoperative GLS was 16 ± 4.3%, decreasing to 12.8 ± 3.4% postoperatively (p < 0.0001). GLS was comparable between the groups preoperatively (p = 0.185) and postoperatively (0.854). After twelve months, GLS improved in both groups (Group A: 17.7 ± 3.4%, Group B: 15.7 ± 3.2%, p < 0.0001), but only Group A showed significant improvement from preoperative values (p = 0.018). SAVR improved GLS regardless of CABG intervention.

CONCLUSIONS

SAVR in patients with preserved LVEF results in an early reduction in GLS, regardless of diastolic dysfunction. After twelve months, GLS improved significantly, with significant recovery only in patients with mild dysfunction.

Myocardial strain of the left ventricle by speckle tracking echocardiography: From physics to clinical practice

Speckle tracking echocardiography (STE) is a reliable imaging technique of recognized clinical value in several settings. This method uses the motion of ultrasound backscatter speckles within echocardiographic images to derive myocardial velocities and deformation parameters, providing crucial insights on several cardiac pathological and physiological processes. Its feasibility, reproducibility, and accuracy have been widely demonstrated, being myocardial strain of the various chambers inserted in diagnostic algorithms and guidelines for various pathologies. The most important parameters are Global longitudinal strain (GLS), Left atrium (LA) reservoir strain, and Global Work Index (GWI): based on large studies the average of the lower limit of normality are -16%, 23%, and 1442 mmHg%, respectively. For GWI, it should be pointed out that myocardial work relies primarily on non-invasive measurements of blood pressure and segmental strain, both of which exhibit high variability, and thus, this variability constitutes a significant limitation of this parameter. In this review, we describe the principal aspects of the theory behind the use of myocardial strain, from cardiac mechanics to image acquisition techniques, outlining its limitation, and its principal clinical applications: in particular, GLS have a role in determine subclinical myocardial dysfunction (in cardiomyopathies, cardiotoxicity, target organ damage in ambulatory patients with arterial hypertension) and LA strain in determine the risk of AF, specifically in ambulatory patients with arterial hypertension.

Artificial Intelligence Enabled Fully Automated CMR Function Quantification for Optimized Risk Stratification in Patients Undergoing Transcatheter Aortic Valve Replacement

Background

Cardiovascular magnetic resonance imaging is considered the reference standard for assessing cardiac morphology and function and has demonstrated prognostic utility in patients undergoing transcatheter aortic valve replacement (TAVR). Novel fully automated analyses may facilitate data analyses but have not yet been compared against conventional manual data acquisition in patients with severe aortic stenosis (AS).

Methods

Fully automated and manual biventricular assessments were performed in 139 AS patients scheduled for TAVR using commercially available software (suiteHEART®, Neosoft; QMass®, Medis Medical Imaging Systems). Volumetric assessment included left ventricular (LV) mass, LV/right ventricular (RV) end-diastolic/end-systolic volume, LV/RV stroke volume, and LV/RV ejection fraction (EF). Results of fully automated and manual analyses were compared. Regression analyses and receiver operator characteristics including area under the curve (AUC) calculation for prediction of the primary study endpoint cardiovascular (CV) death were performed.

Results

Fully automated and manual assessment of LVEF revealed similar prediction of CV mortality in univariable (manual: hazard ratio (HR) 0.970 (95% CI 0.943-0.997) p=0.032; automated: HR 0.967 (95% CI 0.939-0.995) p=0.022) and multivariable analyses (model 1: (including significant univariable parameters) manual: HR 0.968 (95% CI 0.938-0.999) p=0.043; automated: HR 0.963 [95% CI 0.933-0.995] p=0.024; model 2: (including CV risk factors) manual: HR 0.962 (95% CI 0.920-0.996) p=0.027; automated: HR 0.954 (95% CI 0.920-0.989) p=0.011). There were no differences in AUC (LVEF fully automated: 0.686; manual: 0.661; p=0.21). Absolute values of LV volumes differed significantly between automated and manual approaches (p < 0.001 for all). Fully automated quantification resulted in a time saving of 10 minutes per patient.

Conclusion

Fully automated biventricular volumetric assessments enable efficient and equal risk prediction compared to conventional manual approaches. In addition to significant time saving, this may provide the tools for optimized clinical management and stratification of patients with severe AS undergoing TAVR.

Pregnancy related changes in Doppler gradients and left ventricular mechanics in women with sub-valvular or valvular aortic stenosis

BACKGROUND

The aim of our study was to characterize echocardiographic changes during pregnancy in women with known LVOT obstruction or AS compared to the healthy pregnancy controls, and to assess the relationship with pregnancy outcomes.

METHODS

We retrospectively studied 34 pregnant patients with congenital LVOT obstruction or AS with healthy age-matched pregnant controls. Patients with other significant valvular lesions, structural heart disease (LVEF < 40%), or prior valve surgery were excluded. All LVOTO/AS patients underwent a minimum of two consecutive echocardiograms between 1 year pre-conception and 1 year postpartum, with at least two studies during the pregnancy. Comprehensive echocardiographic evaluation was performed including speckle-tracking LV global longitudinal strain.

RESULTS

A total of 83 echocardiograms from the study group and 34 echocardiograms from the control group were evaluated. Over the range of LVOTO/AS, a significantly greater increase in the AV gradients and LV and LA volumes were observed as compared with the controls. In the sub-group of LVOTO/AS pregnant women with ≥ moderate (n = 8) versus < moderate LVOTO/AS (n = 26), averaged 2^nd /3^rd trimester LVEF was lower (51 ± 12)% versus (58 ± 4)%, (p = 0.02) and GLS was lower (-19.5 ± 2.8) versus (21.2 ± 2.4), (p = 0.06). Pregnancy was well tolerated despite these changes.

CONCLUSION

Among pregnant women with even milder forms of LVOTO/AS, increases in cardiac volumes and AV gradients can be expected over the course of pregnancy. Significant decreases in LV function and mechanics were only observed in women with moderate or greater LVOTO/AS, although still remained in normal range.