Myocardial work and aortic valve stenosis cardiac damage stages are predictors of all-cause mortality in patients undergoing transcatheter aortic valve replacement

Abstract In aortic stenosis (AS) patients, assessment of left ventricular (LV) systolic function is complicated due to the significant impact of increased afterload on conventional parameters. Myocardial work (MW) analysis, a novel echocardiographic method adjusts myocardial deformation to instantaneous LV pressure which may better reflect the LV contractile state. Importantly, long-term LV pressure overload has marked backward effects beyond the LV: classification of this extravalvular cardiac damage effectively represents the involvement of the cardiopulmonary system in AS. Both MW and cardiac damage staging could hold remarkable prognostic power in the clinically complex population of transcatheter aortic valve replacement (TAVR) candidates. Accordingly, our aim was to assess the prognostic value of MW analysis and cardiac damage staging in patients undergoing TAVR. We enrolled 289 patients (79±6 years, 41% female) prior to TAVR. Echocardiographic measurements were performed one day before the procedure. We calculated LV ejection fraction (EF) and by speckle-tracking echocardiography global longitudinal strain (GLS), as well. Global constructive work (GCW) was quantified with dedicated software and LV pressure was estimated using transaortic mean gradient and systolic blood pressure. Based on the echocardiographic data, we also determined the extent of cardiac damage associated with AS: patients were classified as Stage 0 (no cardiac damage), Stage 1 (LV damage), Stage 2 (mitral valve or left atrial damage), Stage 3 (pulmonary artery vasculature or tricuspid valve damage), or Stage 4 (right ventricular damage). Our primary outcome was all-cause mortality, reached by 68 patients (median follow-up: 26 months). In our cohort, preprocedural EF was 47±13 %, GLS was -12.3±4 %, while GCW was 2043±791 mmHg%. 14 (5%) patients were classified as Stage 0, 61 (21%) as Stage 1, 128 (44%) as Stage 2, 15 (5%) as Stage 3, and 71 (25%) as Stage 4. GCW showed a continuous decline through the AS Stages (from Stage 0-4: 2963±652 vs. 2154±652 vs. 2168±718 vs. 1988±969 vs. 1552±772 mmHg%; p<0.001). Using univariate Cox analysis GCW (HR 0.968 [95% CI 0.938-0.998] per 100 unit change; p=0.034) and AS Staging (HR 1.236 [95% CI 1.015-1.505]; p=0.035) were both associated with all-cause mortality, while EF (HR 0.984 [95% CI 0.966-1.002]; p=0.085) and GLS (HR 1.042 [95% CI 0.984-1.103]; p=0.160) were not. In multivariate Cox regression models, both GCW (HR 0.957 [95% CI 0.922-0.992] per 100 unit change; p=0.018) and AS cardiac damage staging (HR 1.263 [95% CI 1.029-1.549]; p=0.025) were proven to be significant independent predictors of all-cause mortality. In TAVR patients, preoperative GCW values exhibited a persistent decrease across AS Stages. As opposed to EF and GLS, GCW and AS Staging both showed strong association with all-cause mortality in our cohort. Moreover, GCW had higher prognostic value than any other conventional or advanced measure of LV function.