Exercise capacity after mechanical circulatory support compared to heart transplant in advanced heart failure

In patients with advanced heart failure, it is assumed that orthotopic heart transplant (OHTx) results in greater exercise capacity compared to ventricular assist device (VAD), however this has not been formally examined. In this study, we evaluated the exercise capacity of patients following VAD and OHTx after a structured outpatient rehabilitation program.

We performed a retrospective single-center cohort study of patients undergoing OHTx or VAD at a tertiary centre from January 2022 to January 2024. Comorbidities and the option of either intervention was used as inputs in a multivariate linear regression model for prediction of 3-month 6-minute walk test (6MWT). Major factors identified were added as covariates in the combined cohort to determine predictors of 6MWT.

A total of 78 patients were included. The maximal recorded 6MWT was similar between both cohorts (median 6MWT OHTx: 534.0 (478.8-600.3)m; VAD: 608.5 (487.0-643.5)m, p=0.30). Gender was a significant predictor of 6MWT in the OHTx cohort (β=-69.1, p<0.02) with a strong trend in the VAD cohort (β=-199, p<0.09). VAD was not predictive of 3-month 6MWT (p=0.99) in OHTx patients bridged with VAD. VAD or OHTx was also not predictive of 6MWT (p=0.88) while total length of stay was a significant predictor of 6MWT (p<0.0001) in the combined cohort.

In patients with advanced heart failure, VAD and OHTx are associated with a similar level of exercise capacity and does not impact exercise capacity in patients undergoing OHTx who are bridged with a VAD. In patients with OHTx, gender was the strongest predictor of exercise capacity.