Effects of echo-optimization of left ventricular assist devices on functional capacity, a randomized controlled trial

After the implantation of a left ventricular assist device (LVAD), many patients continue to experience exercise intolerance. VAFRACT trial evaluates the additional benefit of LVAD echo-guided optimization (EO) on functional capacity (FC), measured by cardiopulmonary exercise test (CPET), and quality of life (QoL).

Twenty-seven patients were randomized in a 1:1 ratio to EO (EO group) vs. standard settings (CONTROL group) at least after 3 months from LVAD implant procedure. The optimal device speed was defined as the one that allows an intermittent aortic valve opening and a neutral position of the interventricular septum without increasing aortic or tricuspid regurgitation and preserving right ventricular function. The primary endpoint was peak oxygen uptake (VO₂ peak) change after 3 months. Echo-guided optimization significantly improves VO₂ peak (from 13.2 ± 2.5 to 14.2 ± 2.5 mL/kg/min; P < 0.001), oxygen pulse (from 9.75 ± 1.46 to 10.75 ± 2.2 mL; P < 0.001), CPET exercise time (from 490 ± 98 to 526 ± 116 s; P = 0.02), 6 min walk distance (from 363 ± 54 to 391 ± 52 m; P = 0.04), and QoL, using EuroQol Five Dimensions 3L (from 0.796 ± 0.1 to 0.85 ± 0.08; P < 0.001) and the Kansas City Cardiomyopathy Questionnaire (from 81.6 ± 6.9 to 84.6 ± 5.6; P = 0.025).

Echo-guided optimization can significantly influence the FC and the QoL of LVAD patients. This procedure should represent a fundamental step in their clinical management, through the establishment of consolidated follow-up protocols. Our study may represent a starting point for a future, adequately powered clinical trial with a longer term follow-up.