Patterns of Retrosternal Anatomical Change After LVAD Implantation Using Serial CT Imaging
Background:Left ventricular assist devices (LVADs) are increasingly used as a bridge to transplantation in patients with end-stage heart failure. However, re-sternotomy for heart transplantation carries heightened surgical risk due to retrosternal adhesions involving cardiac structures like the ascending aorta (AA), outflow graft (OFG), and right ventricle (RV). This study aimed to quantitatively describe patterns of anatomical changes in sternal proximity over time and discuss potential patient-level predictors of this change.Methods:A retrospective study was conducted at a high-volume cardiac centre, including 101 patients who received HeartWare or HeartMate 3 LVADs via sternotomy between 2013 and 2023. A total of 222 contrast-enhanced CT scans were analysed. Distances from the sternum to the AA, OFG, and RV were measured in the mid-sagittal plane. Mixed-effects regression models assessed longitudinal changes. Univariate regressions explored baseline predictors of anatomical shift within this cohort.Results:The AA and RV demonstrated significant reductions, while OFG demonstrated non-significant reductions in distance from the sternum over time (p = 0.0166 and 0.000918, respectively). Significant baseline predictors of greater anatomical shift included greater body mass index (BMI) and RV enlargement at the time of LVAD implant for AA, and intra-aortic balloon pump implant for the OFG.Conclusions:Serial CT imaging enables longitudinal assessment of retrosternal anatomical changes following LVAD implantation and may assist operative planning prior to heart transplantation. Exploratory univariable analyses identified several patient characteristics associated with greater anatomical change over time. Future prospective multicentre studies, large enough to power multivariate analyses and correlate computed tomography (CT) findings with re-sternotomy outcomes, are required to validate these findings and determine their clinical relevance.