How myocardial work could be relevant in patients with an aortic valve stenosis?

Abstract

Abstract Funding Acknowledgements Type of funding sources: None. Background Speckle tracking based myocardial work calculation is an attractive method to assess left ventricular (LV) myocardial function. In case of aortic stenosis (AS), assessment of work indices is challenging because it requires an accurate evaluation of LV-pressure curves. Therefore, we sought to evaluate the performances of two distinct methods for the estimation of myocardial work indices and to provide a quantitative comparison with invasively measured data. Methods Model-based and template-based methods were defined and applied for the evaluation of LV pressures on 67 AS patients. Global Constructive (GCW), Wasted (GWW), Positive (GPW), Negative (GNW) myocardial work and Global Work Efficiency (GWE) and Index (GWI) parameters were calculated using the available software computing the indices using brachial blood pressure and trans-aortic mean pressure gradient for estimating the LV pressures versus using a model-based and homemade software. A complete comparison was performed with invasive measurements. Results Patients were characterized by mean pressure gradient of 49.8 ± 14.8 mmHg, LV ejection fraction of 59 ± 8%, the global longitudinal strain was -15.0 ± 4.04%, GCW was 2107 ± 800mmHg.% (model-based method) and 2483 ± 1068mmHg.% (template-based method). The root mean square error (RMSE) and correlation were calculated for each patient and for each pressure estimation methods. The mean RMSE are 33.9mmHg and 40.4mmHg and the mean correlation coefficients are 0.81 and 0.72 for the model-based and template-based methods respectively. Correlation coefficient and Bland-Altman analysis were performed for the six work indices. The two methods present correlation coefficient r2 > 0.75 for almost all the indices. Conclusion The two non-invasive methods of LV pressure estimation and the work indices computation correlate with invasive measurements and computations for AS patients. Although the model-based approach requires less information and is associated with slightly better performances, the implementation of template-based method is easier and seems more appropriate in a clinical practice. Abstract Figure. SUMMARY