Increased apical rotation in severe aortic stenosis is associated with reduced survival: a speckle-tracking study

Impact of aortic valve stenosis on myocardial deformation in different left ventricular levels: A three-dimensional speckle tracking echocardiography study

BACKGROUND

Global systolic left ventricular (LV) myocardial function progressively declines as degenerative aortic valve stenosis (AS) progresses. Whether this results in uniformly distributed deformation changes from base to apex has not been investigated.

METHODS

Eighty-five AS patients underwent three-dimensional (3D) echocardiography in this cross-sectional study. Patients were grouped by peak jet velocity into mild (n = 32), moderate (n = 31), and severe (n = 22) AS. 3D speckle tracking derived strain, rotation, twist, and torsion were obtained to assess global LV function and myocardial function at the apical, mid, and basal levels.

RESULTS

Global longitudinal strain (GLS) was lower in patients with severe AS (-16.1 ± 2.4% in mild, -15.5 ± 2.5% in moderate, and -13.5 ± 3.0% in severe AS [all p < .01]). Peak basal and mid longitudinal strain (LS), basal rotation and twist from apical to basal level followed the same pattern, while peak apical LS was higher in moderate AS compared to severe AS (all p < .05). In multivariate analyses, lower GLS was particularly associated with male sex, higher body mass index and peak aortic jet velocity, lower basal LS with higher filling pressure (E/e') and LV mass, lower mid LS with higher RWT and presence of AS symptoms, and lower apical LS with male sex and higher systolic blood pressure, respectively (all p < .05).

CONCLUSION

Using 3D speckle tracking echocardiography reveals regional and global changes in LV mechanics in AS related to the severity of AS, LV remodeling and presence of cardiovascular risk factors.

Prognostic Value of Lung Ultrasound in Aortic Stenosis

Background: Aortic stenosis (AS) is the most common primary valve lesion requiring intervention in Europe and North America. It has a prolonged subclinical period during which, as AS worsens, left ventricular adaptation becomes inadequate and impaired systolic and/or diastolic dysfunction may lead to overt heart failure (HF). The development of HF is an inflexion point in the natural history of AS. Pulmonary congestion is a cardinal feature in HF, and lung ultrasound (LUS) evaluation of B-lines has been proposed as a simple, noninvasive tool to assess pulmonary congestion.

Aim: To assess the presence and the prognostic value of sonographic pulmonary congestion in patients with moderate or severe AS.

Methods: 75 consecutive patients (39 women, mean age 73.85 ± 7.7 years) with moderate or severe AS were enrolled. All patients underwent comprehensive echocardiography and LUS with the 28 scanning-site assessment. Patients were followed-up for 13.4 ± 6 months to establish the prognostic value of LUS. A composite endpoint of death (of any cause), hospitalization for HF and intensification of loop diuretic therapy was considered.

Results: We found a severe degree of B-lines (≥30) in 29.33% of patients. The number of B-lines correlated with the estimated pulmonary artery systolic pressure (p < 0.001, r = 0.574) and increased along with NYHA class (p < 0.05, rho = 0.383). At multivariable analysis, B-lines ≥30, and mean gradient were the independent predictors of events [B-lines: 2.79 (CI 1.03–7.54), p = 0.04; mean gradient: 1.04 (CI 1.01–1.07), p = 0.004].

Conclusion: Evaluation of B-lines is a simple, highly feasible method to detect pulmonary congestion in AS. The number of B-lines correlates with the hemodynamic changes caused by AS and with the functional status of patients. A severe degree of sonographic pulmonary congestion is associated with an increased risk of adverse events.

Left ventricular twist predicts mortality in severe aortic stenosis

OBJECTIVE

Left ventricular (LV) twist is a major component of ventricular mechanics reflecting the helical orientation of cardiac fibres and compensating for afterload mismatch. However, it is not known whether it determines outcome after transcatheter aortic valve implantation (TAVI). This study sought to investigate TAVI-induced short-term changes of LV twist and to define its role in outcome prediction.

METHODS

A total of 146 patients (median age 81.78 years, 50.7% male) undergoing TAVI for severe aortic stenosis were included. LV rotation and twist were determined by speckle tracking echocardiography within 3 months before and 2 weeks after TAVI. All-cause mortality at 2 years was defined as primary end point.

RESULTS

Patients who survived exhibited a higher apical peak systolic rotation (APSR) (p<0.001), twist (p=0.003) and torsion (p=0.019) pre-TAVI compared with those who died (n=22). Within 2 weeks after TAVI, APSR, twist and torsion decreased in patients who survived (all p<0.001), while no change occurred in those who died. Cox regression analysis showed an association of pre-TAVI APSR (HR 0.92, p=0.010), twist (HR 0.93, p=0.018) and torsion (HR 0.68, p=0.040) with all-cause mortality and an even stronger association of the respective changes after TAVI (∆APSR: HR 1.15, p<0.001; ∆twist: HR 1.14, p<0.001; ∆torsion: HR 2.53, p<0.001). All the parameters determined outcome independently of global longitudinal strain (GLS) and LV ejection fraction (LVEF).

CONCLUSION

APSR, twist and torsion pre-TAVI as well as their change within 2 weeks after TAVI predict 2-year all-cause mortality after TAVI, adding incremental prognostic value to LVEF and GLS.

Hypertension and transcatheter aortic valve replacement: parallel or series?

Aortic stenosis (AS) is the most common valvular heart disease in the elderly and it causes significant morbidity and mortality. Hypertension is also highly prevalent in elderly patients with AS, and AS patients with hypertension have worse outcomes. Accurate assessment of AS severity and understanding its relationship with arterial compliance has become increasingly important as the options for valve management, particularly transcatheter interventions, have grown. The parameters used for quantifying stenosis severity have traditionally mainly focused on the valve itself. However, AS is now recognized as a systemic disease involving aging ventricles and stiff arteries rather than one limited solely to the valve. Over the last decade, valvuloarterial impedance, a measure of global ventricular load, has contributed to our understanding of the pathophysiology and course of AS in heterogeneous patients, even when segregated by symptoms and severity. This review summarizes our growing understanding of the interplay between ventricle, valve, and vessel, with a particular emphasis on downstream vascular changes after transcatheter aortic valve replacement and the role of valvuloarterial impedance in predicting left ventricular changes and prognosis in patients with various transvalvular flow patterns.

Newer echocardiographic techniques for aortic-valve imaging: Clinical aids today, clinical practice tomorrow

Increasing life expectancy is expected to lead to a corresponding increase in the prevalence of aortic valve disease (AVD). Further, the number of indications for transcatheter aortic valve replacement (TAVR) as a treatment option for AVD is expanding, with a growing role for echocardiography in its management. In this review we summarize the current literature on some newer echocardiographic modalities and the parameters they generate, with a particular focus on their prognostic and clinical value beyond conventional methods in the management of aortic stenosis, TAVR, and aortic regurgitation. Speckle tracking and 3D echocardiography are now increasingly being used in the management of AVD. For instance, global longitudinal strain, the best-studied speckle tracking echocardiographic parameter, can detect subtle subclinical cardiac dysfunction in patients with AVD that is not apparent using traditional echocardiographic techniques. The emerging technique of 3D full volume color Doppler echocardiography provides more accurate measurement of the severity of aortic regurgitation than 2D-proximal isovelocity surface area. These novel techniques are promising for evaluating and risk stratifying patients to optimize surgical interventions, predict recovery, and improve clinical outcomes.

Increased apical rotation in patients with severe aortic stenosis assessed by three-dimensional speckle tracking imaging

BACKGROUND

Two-dimensional (2D) speckle tracking imaging (STI) is a non-invasive method used to assess subtle changes in left ventricular (LV) function such as strain and rotational dynamics. However, 2D methodology is complicated by issues such as the out-of-plane problem inherent in short-axis imaging. In addition, circumferential rotation contributes to three-dimensional (3D) wall deformations and affects tracking accuracy. By using 3D-STI technique, we evaluated LV global longitudinal strain (GLS) and apical rotation in severe aortic stenosis (AS) patients with preserved LV ejection fraction (EF).

METHODS

LV GLS and apical rotation were evaluated using 3D-STI in 20 severe AS patients (79 ± 8 years old; aortic valve area 0.7 ± 0.2 cm²) with preserved LVEF (68 ± 7%). Data were compared with those of 11 hypertensive LV hypertrophy (LVH) patients (75 ± 10 years old, EF = 66 ± 4%) and 12 controls (healthy individuals: 30 ± 14 years old, EF = 63 ± 6%).

RESULTS

Compared with LVH patients, severe AS patients had significantly decreased values of GLS (-13.0 ± 2.4 vs. -10.4 ± 2.0%, p = 0.008). In contrast, LV rotation was significantly higher in AS than LVH patients (13.9 ± 3.0° vs. 10.8 ± 2.5°, p = 0.007). There was no significant difference in stroke volume index among three groups. In these three groups, severe AS patients had significantly decreased values of GLS [analysis of variance (ANOVA), p < 0.001] and increased LV rotation (ANOVA, p < 0.001).

CONCLUSIONS

In severe AS patients, impaired GLS existed although LVEF was preserved. However, LV rotation was increased in patients with severe AS probably to maintain the LV stroke volume.

Transthoracic Speckle Tracking Echocardiography for the Quantitative Assessment of Left Ventricular Myocardial Deformation

The value of conventional echocardiography is limited by differences in inter-individual image interpretation and therefore largely dependent on the examiners' expertise. Speckle tracking Echocardiography (STE) is a promising but technically challenging method that can be used to quantitatively assess regional and global systolic and diastolic myocardial performance. Myocardial strain and strain rate can be measured in all three dimensions - radial, circumferential, longitudinal - of myocardial deformation. Standard cross-sectional two-dimensional B-mode images are recorded and subsequently postprocessed by automated continuous frame-by-frame tracking and motion analysis of speckles within the myocardium. Images are recorded as digital loops and synchronized to a 3-lead EKG for timing purposes. Longitudinal deformation is assessed in the apical 4-, 3-, and 2-chamber views. Circumferential and radial deformation are measured in the parasternal short axis plane. Optimal image quality and accurate tissue tracking are paramount for the correct determination of myocardial performance parameters. Utilizing transthoracic STE in a healthy volunteer, the present article is a detailed outline of the essential steps and potential pitfalls of quantitative echocardiographic myocardial deformation analysis.