Longitudinal strain predicts left ventricular mass regression after aortic valve replacement for severe aortic stenosis and preserved left ventricular function

Evaluation of Left Ventricular Function in Patients With Severe Aortic Stenosis Utilizing Automated Cardiac Motion Quantitation Techniques

OBJECTIVE

The objective of this study is to explore the patterns of alteration in left ventricular systolic function among patients with severe aortic stenosis (SAS) through the application of automatic myocardial motion quantification (aCMQ) techniques. Furthermore, we seek to ascertain dependable quantitative markers for the assessment of impaired left ventricular function in patients with SAS and an ejection fraction (EF) ≥ 60%.

METHODS

Seventy patients who underwent echocardiography and received a diagnosis of severe aortic stenosis (SAS) in the hospital from November 2021 to August 2022 were selected for the SAS group and categorized into three subgroups based on ejection fraction (EF)-SAS group with EF ≥ 60%, SAS group with EF ranging from 50% to 59%, and SAS group with EF < 50%. Concurrently, 30 healthy individuals were recruited at the hospital during the same timeframe to serve as the control group. Participants from both groups underwent standard transthoracic echocardiography to assess conventional echocardiographic parameters. Dynamic images were examined using automatic myocardial motion quantification (aCMQ) software to derive longitudinal peak strain (LPS) parameters, which were then subjected to statistical analysis.

RESULTS

In comparison to the control group participants, the measurements of ascending aorta diameter (AoD), left atrium diameter (LAD), interventricular septal end diastolic thickness (IVSd), left ventricular posterior wall end diastolic thickness (LVPWd), peak systolic velocity (Vmax), and mean pressure gradient (MPG) were significantly higher in the SAS groups (p < 0.05). When compared to participants in the SAS group with an EF ≥ 60%, the values of IVSd, LVPWd, Vmax, and MPG in the SAS group with EF ranging from 50% to 59% were significantly elevated (p < 0.05). Similarly, left ventricular end-diastolic diameter (LVEDD), the ratio of early diastolic mitral inflow velocity to early diastolic mitral annular velocity (E/e'), and the ratio of early to late diastolic mitral inflow velocities (E/A) in the SAS group with EF < 50% were significantly elevated (p < 0.05). The absolute values of longitudinal peak strain (LPS) in the SAS groups were significantly lower in comparison to those in the control group (p < 0.05). Furthermore, all measurements of left ventricular global longitudinal systolic peak strain (GLPS) showed a positive correlation with MPG, a moderate negative correlation with aortic valve area index (AVAI), and a moderate positive correlation with E/A.

CONCLUSIONS

Patients with SAS and an EF < 50% exhibited the most profound impairment in left ventricular myocardial function. Utilizing the aCMQ technique enables the precise and quantitative evaluation of the severity of impaired left ventricular systolic function in patients within the SAS group with an EF ≥ 60%.

Strain Assessment in Aortic Stenosis: Pathophysiology and Clinical Utility

Contemporary echocardiographic criteria for grading aortic stenosis severity have remained relatively unchanged, despite significant advances in noninvasive imaging techniques over the last 2 decades. More recently, attention has shifted to the ventricular response to aortic stenosis and how this might be quantified. Global longitudinal strain, semiautomatically calculated from standard two-dimensional echocardiographic images, has been the focus of extensive research. Global longitudinal strain is a sensitive marker of subtle hypertrophy-related impairment in left ventricular function and has shown promise as a relatively robust prognostic marker, both independently and when added to severity classification systems. Herein we review the pathophysiological basis underpinning the potential utility of global longitudinal strain in the assessment of aortic stenosis, as well as its potential role in quantifying myocardial recovery and prognostic discrimination following aortic valve replacement.

Left ventricular myocardial deformation as measure of hemodynamic burden in congenital valvular aortic stenosis

BACKGROUND

Changes in 2D echocardiography (2DE) speckle tracking imaging (STI) derived left ventricular (LV) strain (S) and strain rate (SR) precedes diminution of LV ejection fraction (LVEF) in adult valvular aortic stenosis (AS). We prospectively examined whether 2DE-STI derived multidirectional LV S and SR correlate with AS severity in children using LV mass index (MI) as the principal outcome variable.

METHODS

52 children (10.4 ± 7.3 years) with isolated congenital AS were included; 13 mild (2.5 m/s < V_max < 3.0 m/s), 25 moderate (3.0 m/s < V_max < 4.0 m/s), and 14 severe (V_max > 4.0 m/s). 2DE including Doppler and STI longitudinal strain (LS), strain rate (LSR), circumferential strain (CS), and strain rate (CSR) were measured. Univariate and multivariable linear regressions identified correlations between LVMI and strain indices.

RESULTS

Three clinical and 2DE variables, and four strain indices were independently associated with LVMI. LVMI correlated positively with systolic blood pressure and aortic regurgitation, and negatively with LVEF. LVMI correlated positively with LSR (four-chamber) and CSR (basal), and negatively with segmental CS in the inferior (basal) and anteroseptal (distal) segments. LVMI showed significant inverse association with LS (P = .05), LSR (P < .001), CS (P < .005), and CSR (P < .0001), independent of AS severity.

CONCLUSIONS

Independent of clinical and 2DE findings including contemporaneous Doppler estimates of AS gradient, both longitudinal and circumferential strain indices correlate with LVMI as a measure of cumulative hemodynamic burden. This association implies subclinical LV dysfunction.

Effects of Aortic Valve Replacement on Left Ventricular Diastolic Function in Patients With Aortic Valve Stenosis

The afterload increase imposed by severe aortic valve stenosis (AS) creates concentric left ventricular (LV) remodeling and diastolic dysfunction (DD), which are both markers of poor clinical outcome. Ideally, a correctly timed surgery for isolated AS can reverse the LV remodeling. However, data on LV DD after aortic valve replacement (AVR) are sparse and contrasting. Aims of the study are to define the markers of a favorable evolution of the DD at follow-up. Patients with severe isolated AS, scheduled for AVR were prospectively enrolled. Transthoracic echocardiography with DD assessment was performed before surgery, and at 12 months after surgery. Global LV longitudinal and circumferential strain, peak atrial longitudinal and contraction strain (PALS, PACS) were obtained at baseline. LV septal biopsy to assess fibrosis was performed at the time of AVR. Sixty-seven patients were enrolled, age 72 ± 8 years, 66% female, ejection fraction 61 ± 8%, E/e' 13 ± 6, PALS 23 ± 7%. Normal estimated left atrial pressure was detected in 19/67 (28%) versus 43/67 (64%) at follow-up (p <0.0001). In the 37 patients with biopsy available, fibrosis was 24 ± 12%. PALS and AS severity were correlated with LV fibrosis (R² = 0.19; p = 0.006, and R² = 0.15; p = 0.02, respectively). PALS (odds ratio: 1.19 [1.05 to 1.41], p = 0.02) and PACS (odds ratio: 1.24 [1.06 to 1.50], p = 0.006) were the only baseline noninvasive parameters independently associated with normal left atrial pressure at follow-up. Mean follow-up time was 791 ± 245 days, and 8 (12%) patients had cardiovascular events (death, hospital admission due to heart failure or ischemic disease, and onset of atrial fibrillation). Myocardial fibrosis (p = 0.05), baseline PALS (p = 0.004), and PACS (p = 0.03) were associated with cardiovascular events. In conclusion, LV diastolic function generally improves after AVR for severe AS. Baseline PALS, PACS, and LV fibrosis were related to the DD and clinical outcome at follow-up; these parameters might cue a better diastolic response to the afterload correction.

Changes in dynamic left ventricular function, assessed by the strain-volume loop, relate to reverse remodeling after aortic valve replacement

Aortic valve replacement (AVR) leads to remodeling of the left ventricle (LV). Adopting a novel technique to examine dynamic LV function, our study explored whether post-AVR changes in dynamic LV function and/or changes in aortic valve characteristics are associated with LV mass regression during follow-up. We retrospectively analyzed 30 participants with severe aortic stenosis who underwent standard transthoracic echocardiographic assessment before AVR [88 (IQR or interquartile range: 22–143) days], post-AVR [13 (6–22) days], and during follow-up [455 (226–907) days]. We assessed standard measures of LV structure, function, and aortic valve characteristics. Novel insight into dynamic LV function was provided through a four-chamber image by examination of the temporal relation between LV longitudinal strain (ε) and volume (ε-volume loops), representing the contribution of LV mechanics to volume change. AVR resulted in immediate changes in structural valve characteristics, alongside a reduced LV longitudinal peak ε and improved coherence between the diastolic and systolic part of the ε-volume loop (all P < 0.05). Follow-up revealed a decrease in LV mass ( P < 0.05) and improvements in LV ejection fraction and LV longitudinal peak ε ( P < 0.05). A significant relationship was present between decline in LV mass during follow-up and post-AVR improvement in coherence of the ε-volume loops ( r = 0.439, P = 0.03), but not with post-AVR changes in aortic valve characteristics or LV function (all P > 0.05). We found that post-AVR improvements in dynamic LV function are related to long-term remodeling of the LV. This highlights the potential importance of assessing dynamic LV function for cardiac adaptations in vivo.

NEW & NOTEWORTHY Combining temporal measures of left ventricular longitudinal strain and volume (strain-volume loop) provides novel insights in dynamic cardiac function. In patients with aortic stenosis who underwent aortic valve replacement, postsurgical changes in the strain-volume loop are associated with regression of left ventricular mass during follow-up. This provides novel insight into the relation between postsurgery changes in cardiac hemodynamics and long-term structural remodeling, but also supports the potential utility of the assessment of dynamic cardiac function.

Latent myopathy is more pronounced in patients with low flow versus normal flow aortic stenosis with normal left ventricular ejection fraction who are undergoing surgical aortic valve replacement: Multicenter study with a brief review of the literature

BACKGROUND

Midwall fibrosis and low stroke volume are independent predictors of mortality in severe aortic stenosis (AS) with preserved LV ejection fraction (LVEF). The role of speckle tracking echocardiography (STE) to identify latent myopathy pre- and post- aortic valve replacement (AVR) in high risk AS patients with normal LVEF is limited.

METHODS

Demographic, 2D echocardiographic, and STE data were analyzed in patients with severe AS and preserved LVEF who underwent tissue AVR. Velocity vector imaging (VVI) was used to assess regional and global peak systolic longitudinal strain (GLS). Low flow (LF) was defined as an indexed LV stroke volume <35 mL/m² .

RESULTS

Between December 2008 and May 2011, 37 patients (75 ± 9 years, 51% male) had both pre- and post-AVR echos within 6.6 ± 6.5 months (median = 4 months; range = 2.5-9.5) of surgery. Compared with pre-AVR, GLS (-6.9 ± 4.9% vs -11.1 ± 4.1%; P < .001) and strain rate (-0.72 ± 0.3s^-1 vs -0.87 ± 0.3s^-1 ; P = .01) improved post-AVR. Pre-AVR mid-segments showed a similar myopathy as the basal segments (-9.5 ± 4.3% vs -9.0 ± 4.2%;P = .3). The 16 (43%) LF patients in this study had lower pre- and post-AVR strain compared to NF patients (GLS Pre-AVR:LF vs NF: -5.1 ± 4.1% vs -8.4 ± 4.9% (P = .04) and GLS Post-AVR:LF vs NF: -9.2 ± 3.7% vs -12.5 ± 3.9% (P = .01)). However, there was no difference in absolute and %change improvement in GLS post-AVR (LF vs NF:∆ -4.2 ± 3.5% vs ∆-4.1 ± 5.3% (P = .90) and 193 ± 214% vs 143 ± 230% change (P = .5)). The lowest GLS was seen in LF/HG AS followed by LF/LG, NF/LG and NF/HG AS; P = .03.

CONCLUSIONS

Latent myopathy is more pronounced in LF AS both pre- and post-AVR. Our study provides evidence of improvement in myopathy in LF AS despite a persistent worse myopathy compared to NF patients post-AVR.

Assessment of reverse remodeling predicted by myocardial deformation on tissue tracking in patients with severe aortic stenosis: a cardiovascular magnetic resonance imaging study

BACKGROUND

The technique of tissue tracking with balanced steady-state free precession cine sequences was introduced, and allowed myocardial strain to be derived directly, offering advantages over traditional myocardial tagging. The aim of this study was to evaluate the correlation between reverse remodeling as an outcome and left ventricular strain using cardiovascular magnetic resonance imaging (CMR) tissue tracking, and to evaluate prediction of reverse remodeling by myocardial deformation in patients with severe aortic stenosis (AS).

METHODS

We enrolled 63 patients with severe AS and normal left ventricular (LV) systolic function (ejection fraction > 60%), who underwent both CMR and transthoracic echocardiography (Echo) before surgical aortic valve replacement (AVR). CMR at 1.5 T, including non and post-contrast T1 mapping for extracellular volume (ECV), was carried out to define the amount of myocardial fibrosis. Cardiac Performance Analysis software was used to derive myocardial deformation as strain parameters from three short-axis cine views (basal, mid and apical levels) and apical 2, 3, and 4 chamber views. The primary outcome was reverse remodeling, as evaluated by regression of left ventricular mass index (LVMI).

RESULTS

Median follow-up was 28.8 months (interquartile range 11.3-38.3 months). As evaluated by LVMI between baseline and follow-up, mass regression was significantly improved after AVR (baseline 145.9 ± 37.0 [g/m2] vs. follow-up 97.7 ± 22.2[g/m2], p < 0.001). Statistically significant Pearson's correlations with LVMI regression were observed for longitudinal global strain (r = -0.461, p < 0.001), radial strain (r = 0.391, p = 0.002), and circumferential strain (r = -0.334, p = 0.009). A simple linear regression analysis showed that all strain parameters could predict the amount of LVMI regression (P < 0.05), as well as non-contrast T1 value (beta = -0.314, p < 0.001) and ECV (beta = -2.546, p = 0.038). However, ECV had the lowest predictive power (multiple r2 = 0.071). Multiple regression analysis showed strain could independently predict the amount of LVMI regression and the longitudinal global strain (beta = -3.335, p < 0.001).

CONCLUSION

Longitudinal global strain measured by CMR tissue tracking as a technique was correlated with reverse remodeling as LVMI regression and was predictive of this outcome. As a simple and practical method, tissue tracking is promising to assess strain and predict reverse remodeling in severe AS, especially in patients with suboptimal Echo image quality.

Reversibility of Cardiac Function Predicts Outcome After Transcatheter Aortic Valve Replacement in Patients With Severe Aortic Stenosis

Background

Reversibility of left ventricular (LV) dysfunction in high‐risk aortic stenosis patient and its impact on survival after transcatheter aortic valve replacement (TAVR) are unclear. We aimed to evaluate longitudinal changes of LV structure and function after TAVR and their impact on survival.

Methods and Results

We studied 209 patients with aortic stenosis who underwent TAVR from May 2006 to December 2012. Echocardiograms were used to calculate LV end‐diastolic volume index (LVEDVi), LV ejection fraction, LV mass index (LVMi), and global longitudinal strain before, immediately (<10 days), late (1–3 months), and yearly after TAVR. During a median follow‐up of 1345 days, 118 patients died, with 26 dying within 1 year. Global longitudinal strain, LVEDVi, LV ejection fraction, and LVMi improved during follow‐up. In patients who died during the first year, death was preceded by LVEDVi and LVMi increase. Multivariable longitudinal data analysis showed that aortic regurgitation at baseline, aortic regurgitation at 30 days, and initial LVEDVi were independent predictors of subsequent LVEDVi. In a joint analysis of longitudinal and survival data, baseline Society of Thoracic Surgeons score was predictive of survival, with no additive effect of longitudinal changes in LVEDVi, LVMi, global longitudinal strain, or LV ejection fraction. Presence of aortic regurgitation at 1 month after TAVR was the only predictor of 1‐year survival.

Conclusions

LV reverse remodeling was observed after TAVR, whereas lack of LVEDVi and LVMi improvement was observed in patients who died during the first year after TAVR. Post‐TAVR, aortic regurgitation blocks reverse remodeling and is associated with poor 1‐year survival after TAVR.

Difference in the Prognostic Impact of Left Ventricular Global Longitudinal Strain between Anterior and Nonanterior Myocardial Infarction

BACKGROUND

Speckle tracking-derived global longitudinal strain (GLS) of left ventricle is a potent prognostic marker for patients with ST-segment elevation myocardial infarction (STEMI). The purpose of this study was to investigate the difference of prognostic impact of GLS between anterior and nonanterior myocardial infarction.

METHODS

This study included 686 patients who underwent primary percutaneous coronary intervention for their first STEMI between November 2007 and April 2012. Differences in the prognostic impact of GLS between anterior MI group and nonanterior MI group were evaluated. The composite of all-cause mortality and hospitalization for heart failure in 2 years was investigated for outcome.

RESULTS

During the follow-up period, 77 (11.2%) adverse events occurred. The anterior and nonanterior MI groups included 339 and 347 patients, respectively. Among patients with anterior MI, GLS significantly predicted 2-year outcome in an adjusted model (adjusted hazard ratio [HR] 1.186; 95% confidence interval [CI] 1.071-1.314, P = 0.001), whereas the association between GLS and mortality was weaker in the nonanterior MI group (adjusted HR 0.977; 95% CI 0.884-1.081, P = 0.657). The interaction between the infarction territory and GLS was significant (P for interaction = 0.018), indicating that GLS was a more sensitive predictor of mortality in patients with anterior MI than that in those with nonanterior MI.

CONCLUSIONS

Speckle tracking-derived GLS of left ventricle more sensitively predicted clinical outcome in patients with anterior MI than in those with nonanterior MI.

The Early Variation of Left Ventricular Strain after Aortic Valve Replacement by Three-Dimensional Echocardiography

Aortic stenosis (AS) and aortic incompetence (AI) are common aortic valve diseases. Both may deteriorate into irreversible myocardial dysfunction and will increase the risk of sudden death. In this study, we aimed to investigate the early variation trend of left ventricular function by three-dimensional speckle tracking echocardiography (3D-STE) in the patients who underwent cardiac surgeries for aortic valve disease. Twenty patients with severe aortic AS and 16 patients with severe AI were enrolled. All of them underwent the aortic valve replacement (AVR) procedures. The patients’ global longitudinal strain (GLS) and global circumferential strain (GCS) were evaluated by 3D-STE before surgery and at 1 week after surgery. In addition, GLS and GCS were followed at 1 month as well as 3 months after AVR. In AS patients, the GCS after AVR altered little both at 1 week (p = 0.562) and at 1 month (p = 0.953) compared with the data before the surgery. And it increased significantly at 3 months of follow-up observation compared to that before AVR (p<0.05). Meanwhile, GLS increased progressively after AVR and improved significantly at 3 months after surgery (p<0.05). For the AI patients, GLS as well as GCS decreased at 1 week after AVR compared to those data at baseline (p<0.05). However, these two parameters recovered at 1 month after AVR. Furthermore, GLS and GCS improved significantly at 3 months after the surgery (p<0.05). Therefore, both GLS and GCS were influenced by AVR and would be improved at 3 months after surgery both in AS patients or AI patients. GLS and GCS can be finely evaluated by 3D-STE, and they are helpful to determine the variation tendency of left ventricular function in patients with AVR.

Detection of latent anthracycline-induced cardiotoxicity using left ventricular end-systolic wall stress-velocity of circumferential fiber-shortening relationship

Although cardiotoxicity is a well-known side effect of anthracycline, detection of subclinical impairment of myocardial contractility at the latent stage is difficult. The left ventricular end-systolic wall stress (WS)-velocity of circumferential fiber-shortening (VCF) relationship reflects the load-independent myocardial contractility and can detect sensitively intrinsic abnormalities in myocardial contractility. Usefulness of this relationship in detecting subclinical anthracycline-induced cardiotoxicity has not yet been established. We investigated whether latent anthracycline-induced cardiotoxicity at the subclinical state can be detected by using the WS-VCF relationship in patients receiving anthracycline therapy. We studied 45 patients who had received anthracycline therapy and 40 healthy controls. All patients had preserved left ventricular ejection fraction (LVEF). WS and VCF were measured using echocardiography. VCF was corrected by heart rate. The WS-VCF relationship was derived by linear regression. Patients with data points lying below -2 SD derived from controls were regarded as having impaired intrinsic myocardial contractility. Although VCF was within normal limits in all patients, it was significantly reduced in the patient group overall compared with the control group. On the other hand, WS was significantly increased in the patient group overall compared with the control group. The WS-VCF relationship demonstrated impaired intrinsic myocardial contractility in 24 patients (53.3 %). In more than half of patients with preserved LVEF, impairment of intrinsic myocardial contractility was detected using the WS-VCF relationship, suggesting the presence of latent anthracycline-induced cardiotoxicity. The WS-VCF relationship may be able to detect sensitively latent anthracycline-induced cardiotoxicity at the subclinical stage.