Prognostic value of left ventricular myocardial work indices in patients with severe aortic stenosis undergoing transcatheter aortic valve replacement

Abstract

Aims: Left ventricular myocardial work (LVMW) is a novel echocardiographic-based method to assess left ventricular (LV) function using pressure-strain loops taking into account LV afterload. The aim of this study was to evaluate the prognostic value of LVMW indices in patients with severe aortic stenosis (AS) undergoing transcatheter aortic valve replacement (TAVR).

Methods and results: LV global work index (LV GWI), LV global constructive work (LV GCW), LV global wasted work (LV GWW), and LV global work efficiency (LV GWE) were calculated in 281 patients with severe AS [age 82, interquartile range (IQR) 78-85 years, 52% male] before the TAVR procedure. LV systolic pressure was derived non-invasively by adding the mean aortic gradient to the brachial systolic pressure to adjust for afterload and calculate LVMW indices. Overall, the average LV GWI was 1872 ± 753 mmHg%, GCW 2240 ± 797 mmHg%, GWW 200 (IQR 127-306) mmHg%, and GWE 89 (IQR 84-93)%. During a median follow-up of 52 (IQR 41-67) months, 64 patients died. While LV GWI was independently associated with all-cause mortality (Hazard ratio per-tertile-increase 0.639; 95%CI 0.463-0.883; P = 0.007), LV GCW, GWW, and GWE were not. When added to a basal model, LV GWI yielded a higher increase in predictivity compared to the left ventricular ejection fraction as well as LV global longitudinal strain and LV GCW, and also across the different haemodynamic categories (including low-flow low-gradient) of AS.

Conclusion: LV GWI is independently associated with all-cause mortality in patients undergoing TAVR and has a higher prognostic value compared to both conventional and advanced parameters of LV systolic function.

Keywords: aortic stenosis; mortality; myocardial work indices.