Usefulness of Echocardiographic Parameters of Myocardial Work in Patients with Aortic Stenosis Undergoing Transcatheter Aortic Valve Implantation.

Myocardial work (MW) is a new echocardiographic parameter used in the assessment of cardiac energy expenditure. The aim of the current study was to evaluate changes in left ventricular MW parameters in patients with severe aortic stenosis undergoing transcatheter aortic valve implantation (TAVI). One hundred and thirty five consecutive patients who underwent TAVI at one center were evaluated before and after the procedure using transthoracic echocardiography (TTE) to assess the following MW indices: global constructive work (GCW), global wasted work (GWW), global work index (GWI) and global work efficiency (GWE). The comparison of MW parameters before and an average of 5.9 days after TAVI showed an increase in GCW, GWW and GWI, and no significant change in GWE. A detailed analysis showed an increase in GCW and GWI only in patients with the worst initial global longitudinal strain (GLS) > -8.0%: 845.2 vs. 852.2; < 0.001 and 469.7 vs. 499.0 mmHg%; < 0.001, respectively, whereas in the group of patients with GLS < -16.0%, a reduction in these indices was observed: 2135.8 vs. 2043.0; < 0.001 and 1732.4 vs. 1633.1 mmHg%; < 0.001. The significant increase in GWE was observed in patients with left ventricular ejection fraction (LVEF) < 30%: 77.7 vs. 72.0; = 0.043 and GLS > -8.0%: 74.4 vs. 71.0 mmHg%; < 0.001. The increase in GCW and GWI parameters after TAVI was strongly correlated with LVEF and pressure aortic gradient (PGA) before the procedure. Echocardiographic assessment of myocardial work parameters is a valuable method of documenting hemodynamic changes in patients with severe aortic stenosis before and after TAVI. Long-term left ventricular overload in patients with aortic stenosis results in a global reduction of myocardial work parameters; therefore, in patients with the lowest LVEF and GLS, the increased GCW, GWI and GWE reflect energy reserves enabling a rapid increase in the effective work of the heart.