Pulmonary Function Testing and Outcomes after Left Ventricular Assist Device Implantation

Background: Pulmonary function testing (PFT) is often done during workup prior to left ventricular assist devices (LVAD), but its utility for predicting outcomes and changes in pulmonary function post-LVAD is not well established. We assessed the association of baseline PFT metrics with outcomes after LVAD, and quantified the changes in PFTs post-LVAD. Methods and results: A retrospective study of 178 patients receiving continuous flow LVADs was conducted. A total of 129 subjects had baseline PFT data and 54 of these had repeat tests after LVAD. We collected PFT data (FEV1, FVC, FEV1/FVC ratios, and DLCO) at baseline and post-LVAD, and tested the association with survival, right heart failure, quality of life (Kansas City Cardiomyopathy Questionnaire [KCCQ]) and functional capacity (six-minute walking distance [6MWD]). Proportional hazards and linear regressions determined relationships between baseline PFT data and survival time and functional outcomes, respectively. Paired t-tests compared pre- and post- LVAD PFT variables. There was no association of baseline PFT parameters with survival time post-LVAD (all P > .2), nor the incidence of perioperative RV failure (all P > .15). There were no significant associations of the baseline PFT metrics with the change in KCCQ or 6MWD.  There were statistically significant declines in FEV1, FEV1/FVC ratio, and DLCO after LVAD (P < .05). Conclusion: In this single center study, there was no relationship between baseline PFTs and post-LVAD outcomes, and PFT parameters often worsened after LVAD. Further studies are needed to determine whether PFTs are useful in this setting, and what, if any, impact LVAD therapy has on pulmonary function.