Echo-guided left ventricular assist device speed optimisation for exercise maximisation.

Objective: Current generation left ventricular assist devices (LVADs) operate with a fixed rotation speed and no automated speed adjustment function. This study evaluates the concept of physiological pump speed optimisation based on aortic valve opening (AVO) imaging during a cardiopulmonary exercise test (CPET).

Methods: This prospective crossover study (NCT05063006) enrolled patients with implanted third-generation LVADs with hydrodynamic bearing. After resting speed optimisation, patients were randomised to a fixed-modified speed or modified-fixed speed CPET sequence. Fixed speed CPET maintained baseline pump settings. During the modified speed CPET, the LVAD speed was continuously altered to preserve periodic AVO.

Results: We included 22 patients, the mean age was 58.4±7 years, 4.5% were women and 54.5% had ischaemic cardiomyopathy. Exertional AVO assessment was feasible in all subjects. Maintaining periodic AVO allowed to safely raise the pump speed from 2900 (IQR 2640-3000) to 3440 revolutions per minute (RPM) (IQR 3100-3700; p<0.001). As a result, peak oxygen consumption increased from 11.1±2.4 to 12.8±2.8 mL/kg/min (p<0.001) and maximum workload from 1.1 (IQR 0.9-1.5) to 1.2 W/kg (IQR 0.9-1.7; p=0.028). The Borg scale exertion level decreased from 15.2±1.5 to 13.5±1.2 (p=0.005).

Conclusions: Transthoracic AVO imaging is possible during CPETs in patients with LVAD. Dynamic echo-guided pump speed adjustment based on the AVO improves exercise tolerance and augments peak oxygen consumption and maximum workload.