BACKGROUND: Cardiac resynchronization therapy (CRT) induces segmental left ventricular (LV) remodeling. LV lead position (LV-LP) impacts response to CRT and remodeling.OBJECTIVE: We aimed to assess segmental remodeling concordant, adjacent, and remote to LV-LP using cardiac computed tomography (CT).METHODS: We included patients from the ImagingCRT (Empiric versus Imaging-Guided Left Ventricular Lead Placement in Cardiac Resynchronization Therapy) Trial. A dynamic cardiac CT was performed at baseline and after 6 months. We assessed systolic wall thickening (WT) and exact LV-LP from the CT scans according to a 16 segmental model. Response to CRT was defined as ≥15% reduction in LV end-systolic volume.RESULTS: A total of 107 consecutive patients were included. The change in WT from baseline to follow-up was -19 % (95% CI -25 to -13, pCONCLUSION: During CRT, the systolic WT increases in segments remote to LV-LP, decreases in segments concordant, and remains unchanged in adjacent segments. Only marginal changes occur in wall thickness. In non-responders with non-ischemic cardiomyopathy, deleterious changes in segmental myocardial function occur, and further studies on how to treat these patients best are warranted.