Hemodynamic evaluation of patients with left ventricular assist device during exercise stress echocardiography and cardiopulmonary exercise testing

Left ventricular assist device (LVAD) is highly effective treatment for severe heart failure, with outcomes improving each year. However, the hemodynamic responses of LVAD patients during exercise remain unclear. The present study aimed to investigate hemodynamic changes during exercise using exercise stress echocardiography (ESE) and cardiopulmonary exercise testing (CPX) in patients with LVAD.

In this retrospective study, we analyzed 8 consecutive patients who underwent LVAD implantation at our institution and performed both ESE and CPX. We defined the ratios of exercise to resting left ventricular diastolic diameter (LVDD), right ventricular diastolic diameter (RVDD), and LVAD pump flow (PF) as follows, respectively; LVDDex/LVDDrest, RVDDex/RVDDrest, and PFex/PFrest. Associations between these parameters measured by ESE and exercise capacity assessed with CPX were examined.

The patients had a mean age of 55 ± 11 years, with 3 case of ischemic cardiomyopathy and 5 cases of non-ischemic cardiomyopathy. One patient with the highest exercise tolerance was able to undergo LVAD explantation. The average values for Anaerobic threshold and peak oxygen uptake (VO2)/HR were 2.23 ± 0.56 METs and 6.4 ± 2.0, respectively. LVDDex/LVDDrest showed a positive correlation with peak VO2/HR (r=0.83), while RVDDex/RVDDrest had a negative correlation (r=-0.83). PFex/PFrest demonstrated negative correlations with RVDDex/RVDDrest (r=-0.41).

Increasing right ventricular (RV) size during exercise was associated with reducing peak VO2/HR. This result suggests RV tolerance against exercise assessed with ESE may be strongly correlated with exercise capacity in patients with LVAD. ESE provides prospective insights into the hemodynamics of patients with LVAD during exercise, which may help to adjust LVAD settings and pharmacological therapy for better patient management.