The association of myocardial work and cardiac damage stages with outcomes in transcatheter aortic valve replacement patients

Abstract Aortic stenosis (AS) is accompanied by chronically elevated LV afterload, which can lead to severe backward damage. This can be classified into distinct stages, describing the cardiopulmonary system’s involvement in AS. Also, assessing left ventricular (LV) systolic function in AS patients remains difficult even today, because the elevated afterload heavily influences conventional echocardiographic parameters. Myocardial work (MW) analysis is a cutting-edge method combining myocardial strain with instantaneous LV pressure resulting in a more load-independent evaluation of LV contractility. Accordingly, the aim of this study was to investigate the prognostic value of cardiac damage staging and MW parameters in the complex and fragile population undergoing transcatheter aortic valve replacement (TAVR). A total of 319 patients scheduled for TAVR were prospectively enrolled (79 ± 6 years; 40% female). Comprehensive echocardiographic exams were performed one day prior to the intervention. Cardiac damage staging was based on the echocardiographic data: Stage 0 - no damage, Stage 1 - LV damage, Stage 2 - mitral valve / left atrial damage, Stage 3 - pulmonary artery vasculature / tricuspid valve damage, Stage 4 - right ventricular damage. LV ejection fraction (EF) was determined, and using speckle-tracking echocardiography global longitudinal strain (GLS) was assessed. LV pressure was estimated by combining systolic blood pressure with the mean transaortic gradient, and global constructive work (GCW) was derived using dedicated software. The primary outcomes were all-cause mortality and heart failure hospitalization, the composite endpoint consisting of these was reached by 97 patients over a median follow-up of 29 months. Preoperative EF was 47±13 %, GLS was -12.3 ±4.2 %, GCW was 2033±767 mmHg%. Using univariate Cox regression both cardiac damage staging (HR 1.195 [95% CI 1.009-1.415]; p=0.039) and GCW (HR 0.970 [95% CI 0.944-0.996]; per 100-unit change p=0.023) were significant predictors of the composite endpoint. Patients were classified into two categories based on cardiac damage stage: Low Stage (Stages 0–2) and High Stage (Stages 3–4). Similarly, they were divided into Low GCW (< median GCW, 1979 mmHg%) and High GCW (≥ median GCW) groups. This resulted in four subgroups: Low Stage–Low GCW, Low Stage–High GCW, High Stage–Low GCW and High Stage–High GCW. Kaplan-Meier survival curves were generated to compare outcomes across these subgroups. A significant difference was observed among all groups (log-rank p=0.027), with a particularly notable difference between the Low Stage–High GCW and High Stage–High GCW groups (log-rank p=0.006). In our TAVR cohort cardiac damage stages and preoperative GCW values were predictors of the composite endpoint combining all-cause mortality and heart failure hospitalization. Moreover, there was a particularly significant difference between the outcomes of the Low Stage–High GCW and High Stage–High GCW subgroups.Kaplan-Meier curve of the subgroups