Page 35 - Journal of Structural Heart Disease Volume 5, Issue 6

259 Original Scientific Article
Figure 3. Incremental value of GLS, BLS, and MD post-TAVR. Incremental prognostic information by adding strain parame- ters. The C statistic values were obtained from the multivariable Cox proportional hazards regression models. Model 1 in- cludes age, STS score, NYHA IV, renal disease (Cr > 2mg/dL), AV mean gradient and post-TAVR PVL as significant univariates. AV: aortic valve; BLS: basal longitudinal strain; Cr: creatinine; GLS: global longitudinal strain; MD: mechanical dispersion; NYHA: New York Heart Association; PVL: paravalvular leak; TAVR: transcatheter aortic valve replacement.
2D-STE is an emerging tool in detecting myocardial dysfunction prior to a clinically significant decrease in LVEF. When assessing for myocardial fibrosis, 2D-STE is cost-effective in comparison to cardiac MRI and less invasive than myocardial biopsy. Impaired pre-TAVR myocardial strain parameters have been linked to ad- verse outcomes in patients with AS [17]. In this study, we sought to determine if these strain parameters hold a prognostic value even post-TAVR.
Reduction of left ventricular afterload immediate- ly post-TAVR results in improved myocardial strain parameters. In a study done by Delgado et al., a 19% reduction in GLS was noted immediately post-TAVR compared to baseline parameters [40]. In our study, GLS remained an important prognostic variable in multivariate analysis when adjusting for variables in model 1. However, addition of BLS to model 1 + GLS showed a further improvement in incremental prog- nostic value. This may be explained by the fact that
fibrotic changes in AS primarily affect the basal seg- ments and later progress to mid and apical segments [30]. In addition to BLS, MD has also been associated with myocardial fibrosis and heterogeneous myo- cardial contraction in AS [39]. Studies have shown a moderate correlation between the prevalence of myocardial fibrosis as detected on cardiac MR, and MD measured with 2D-STE [41]. In our study, MD was a significant predictor of all cause 1-year mortality in univariate analyses and remained a significant predic- tor in multivariate analysis. Additionally, MD resulted in a significant incremental prognostic value when added to model 1 in combination with BLS and GLS. To our knowledge, this is the first study that describes BLS and MD as important prognostic variables imme- diately post-TAVR. This emphasizes the potential use of 2D-STE in guiding the management of post-TAVR patients.
Hemu M. et al.
Strain Analysis Predicts Mortality in Post-TAVR Patients