Acute left ventricular mechanics changes after TAVR: The afterload concept revisited

Abstract

Recent studies have emphasized the prognostic value of mild left ventricular ejection fraction (LVEF) impairment in severe aortic stenosis. However, despite adaptive mechanisms to pressure overload, subtle impaired systolic function could be worsened by increased after load and partly reversible immediately after its correction. The aim was to evaluate the short terms effects of transcatheter aortic valve replacement (TAVR) on LV systolic function assessed by global longitudinal strain (GLS). We hypothesized that abrupt decrease of LV after load after TAVR could lead to immediate improvement of LV systolic function. Patients referred to our Department for TAVR were included from January 2018 to July 2018 in this observational prospective single center study. Transthoracic echocardiography (TTE) was performed immediately before and 1–5 days after TAVR by the same operator and reviewed in a blind fashion. Thirty-five symptomatic patients with severe aortic stenosis referred for TAVR (age 84 ± 5 y, 18 male, NYHA 2-3, orifice area 0.7 ± 0.2 cm 2 , LVEF 66 ± 13%, GLS - 15.1 ± 4.7%) were included. Only 9/35 (26%) had a LVEF ≤ 60%. Overall, no significant change in LVEF (65 ± 14%; P = 0.55) or GLS (−16.1 ± 4.8%; P = 0.11) occurred immediately after TAVR despite a dramatic decrease in transoartic mean pressure gradient (44 ± 15 mm Hg versus 6 ± 3 mmHg; P < 0.0001). However in the subgroup of patients with LVEF ≤ 60%, a significant increase in GLS after TAVR was observed (−9.6 ± 4.1% versus −12.1 ± 3.3%; P = 0.0039). Following TAVR, an early improvement in LV systolic function assessed by GLS was observed only in patients with pre-existing mild LV systolic dysfunction. Further studies should evaluate whether this improvement is associated with better long term outcome.