Global and regional myocardial function and outcomes after transcatheter aortic valve implantation for aortic stenosis and preserved ejection fraction

Transcatheter aortic valve implantation in severe aortic stenosis does not necessarily reverse left ventricular myocardial damage: data of long-term follow-up

AIMS

Aortic stenosis (AS) is causing myocardial damage and replacement is mainly indicated based on symptoms. Non-invasive estimation of myocardial work (MW) provides a less afterload-dependent too for assessing myocardial function. We sought to look at the impact of transcatheter aortic valve implantation (TAVI) on the myocardium at long-term follow-up and according to current indications.

METHODS AND RESULTS

We conducted an observational, cross-sectional, single-centre study. Patients were selected based on the validated indication for a TAVI. Standardized echocardiographies were repeated. A total of 102 patients were included. The mean age was 85 years, 45% were female, 68% had high blood pressure, and 52% had a coronary disease. One-fifth was suffering from low-flow-low-gradient AS. A follow-up was performed at 22 ± 9.5 months after the TAVI. No TAVI dysfunction was observed. Left ventricular (LV) ejection fraction was stable (62 ± 8%), and global longitudinal strain had improved (-14.0 ± 3.7 vs. -16.0 ± 3.6%, P < 0.0001). No improvement of the MW parameters was noticed (LV global work index 2099 ± 692 vs. 2066 ± 706 mmHg%, P = 0.8, LV global constructive 2463 ± 736 vs. 2463 ± 676 mmHg%, P = 0.8). Global wasted work increased [214 (149; 357) vs. 247 (177; 394) mmHg%, P = 0.0008].

CONCLUSION

In a population of severe symptomatic AS patients who had undergone a TAVI, the non-invasive myocardial indices that assess the LV performance at long-term follow-up did not improve. These results are questioning the timing of the intervention and the need for more attention in the pharmacological management of these AS patients.

Left ventricular global work index and prediction of cardiovascular mortality after transcatheter aortic valve implantation

INTRODUCTION

Echocardiography is used for assessment of patients after transcatheter aortic valve implantation (TAVI). Global work index (GWI) integrates LV deformation throughout the cardiac cycle and LV afterload and may be advantageous for long-term follow-up.

METHODS

We analysed 144 patients with severe aortic stenosis who underwent TAVI and echocardiography within two weeks afterwards. GE EchoPAC v2.6 was applied for determining LV ejection fraction, global longitudinal strain (GLS), stroke work (SW), cardiac power output (CPO), and GWI. The endpoint was cardiovascular mortality.

RESULTS

During median follow-up of 625 [IQR: 511-770] days, 20 (14%) patients died. Clinical baseline characteristics were comparable between non-survivors and survivors. GWI (p = 0.003) and LVEF (p = 0.039) were lower in non-survivors, while GLS, SW, and CPO were not different. In Kaplan-Meier analysis patients with GWI ≤1234 mmHg% exhibited a lower survival probability (P = 0.006). In univariable Cox regression, a significant mortality association was identified for GWI (P = 0.004), weaker for LVEF (P = 0.014), but not for the other parameters. In multivariable Cox regression, GWI independently improved an LV systolic function model including LVEF and GLS. Similarly, GWI but not LVEF independently improved outcome association of different clinical models.

CONCLUSIONS

GWI was lower in non-survivors than survivors, differentiated non-survivors from survivors, was associated with mortality independent of clinical or LV parameters, and improved the fitness of clinical or LV prediction models. In contrast, GLS, SW, and CPO did not show any of these properties. GWI provides added value for follow-up after TAVI possibly by integrating LV deformation throughout the cardiac cycle.

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.

Prognostic Value of Preprocedural LV Global Longitudinal Strain for Post-TAVR-Related Morbidity and Mortality: A Meta-Analysis

BACKGROUND

Left ventricular ejection fraction (LVEF) demonstrates limited prognostic value for post-transcatheter aortic valve replacement (TAVR) outcomes. Evidence regarding the potential role of left ventricular global longitudinal strain (LV-GLS) in this setting is inconsistent.

OBJECTIVES

The aim of this systematic review and meta-analysis of aggregated data was to evaluate the prognostic value of preprocedural LV-GLS for post-TAVR-related morbidity and mortality.

METHODS

The authors searched PubMed, Embase, and Web of Science for studies investigating the association between preprocedural 2-dimensional speckle-tracking-derived LV-GLS and post-TAVR clinical outcomes. An inversely weighted random effects meta-analysis was adopted to investigate the association between LV-GLS vs primary (ie, all-cause mortality) and secondary (ie, major cardiovascular events [MACE]) post-TAVR outcomes.

RESULTS

Of the 1,130 identified records, 12 were eligible, all of which had a low-to-moderate risk of bias (Newcastle-Ottawa scale). On average, 2,049 patients demonstrated preserved LVEF (52.6% ± 1.7%), but impaired LV-GLS (-13.6% ± 0.6%). Patients with a lower LV-GLS had a higher all-cause mortality (pooled HR: 2.01; 95% CI: 1.59-2.55) and MACE (pooled odds ratio [OR]: 1.26; 95% CI: 1.08-1.47) risk compared with patients with higher LV-GLS. In addition, each percentage point decrease of LV-GLS (ie, toward 0%) was associated with an increased mortality (HR: 1.06; 95% CI: 1.04-1.08) and MACE risk (OR: 1.08; 95% CI: 1.01-1.15).

CONCLUSIONS

Preprocedural LV-GLS was significantly associated with post-TAVR morbidity and mortality. This suggests a potential clinically important role of pre-TAVR evaluation of LV-GLS for risk stratification of patients with severe aortic stenosis. (Prognostic value of left ventricular global longitudinal strain in patients with aortic stenosis undergoing Transcatheter Aortic Valve Implantation: a meta-analysis; CRD42021289626).

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.