The impact of contractile reserve on clinical outcomes in patients with left ventricular dysfunction undergoing TAVI

Patients with aortic stenosis (AS) and severe left ventricular (LV) dysfunction, have poor outcomes following transcatheter aortic valve implantation (TAVI). There is limited data regarding the role of dobutamine stress echocardiography (DSE) in patients' selection for TAVI. Our aim was to examine the prognostic value of contractile reserve (CR) and its association with ejection fraction (EF) recovery.

A multicenter registry of consecutive patients with EF ≤ 30 % undergoing TAVI at 17 European centers. Patients were grouped according to those with/without CR, and further stratified by EF recovery post TAVI. The primary endpoint was 3-year mortality. Our cohort included 296 patients who performed DSE, of whom 158 were CR+. After a median follow-up of 2.4 (IQR 2-3) years, 3-year mortality was 43.7 %-vs.34.0 % in the CR- and CR+ groups, respectively (Adjusted HR 1.98,95 % CI[1.21-3.29],p = 0.009). There was no interaction between CR+ and low-flow low-gradient AS. In the entire cohort, EF recovery occurred in 141 (47.6 %) patients, who experienced lower 3-year mortality (29.6 % vs.45.1 % for those without EF recovery; HR 1.68,95 % CI[1.24-2.97],p < 0.01). Following multivariate adjustment, CR+ was an independent predictor of EF recovery (OR 6.06 95 % CI[3.48-10.53],p < 0.001). Stratified by CR status and EF recovery, 3-year mortality was similar in the different EF recovery groups.

CR on DSE is associated with reduced mortality, mediated through its impact on EF recovery. Our results highlight the potential of DSE and CR status in the triage of patients with severe AS and LV dysfunction, and support its routine use in the pre-TAVI assessment.