Changes in afterload and contractility in patients with severe aortic stenosis after transcatheter aortic valve replacement.

Abstract

Aims: In aortic stenosis (AS), estimation of left ventricular (LV) contractility is difficult as most markers of systolic LV function are load-dependent. The ratio of LV ejection fraction (LVEF) to end-systolic wall stress (ESWS), has been widely accepted as a marker of contractility. However, no studies have evaluated if this ratio is affected by loading conditions. The study describes changes in ESWS and ESWS corrected LVEF after transcatheter aortic valve replacement (TAVR).

Methods and results: In this prospective study, 41 patients with severe AS underwent echocardiography, LV catheterisation, and computed tomography (CT) before and immediately after TAVR. ESWS was estimated from echocardiography alone (ESWS_Echo), combining CT LV dimensions and echocardiographic gradients (ESWS_{CT  +  echo}) and combining CT LV dimensions and invasively measured LV end-systolic pressure (ESWS_{CT  +  Invasive}). ESWS_echo, ESWS_{CT  +  echo} and ESWS_{CT  +  Invasive} all decreased significantly after TAVR (89 ± 48 vs. 57 ± 37 Kdynes/cm², P < 0.01; 69 ± 8 vs. 51 ± 8 Kdynes/cm², P < 0.01, and 197 ± 69 vs. 137 ± 48 Kpa/cm², P < 0.01, respectively). We observed weak to moderate associations between the methods. After TAVR, LVEF corrected to ESWS_echo, ESWS_{CT  +  echo} and ESWS_{CT  +  Invasive} increased (0.93 ± 0.07 vs. 1.91 ± 2.1, P = 0.013; 0.36 ± 0.19 vs. 0.58 ± 0.33, P < 0.01, and 0.3 ± 0.02 vs. 2.5 ± 1.5, P < 0.01, respectively).

Conclusion: ESWS_echo, ESWS_{CT  +  echo} and ESWS_{CT  +  Invasive} decreased significantly after TAVR suggesting they reflect afterload, but independent of method, ESWS corrected LVEF increased slightly post-TAVR, indicating load dependency.