Background: Sodium–glucose cotransporter-2 inhibitors (SGLT2i) improve outcomes in heart failure (HF), but baseline characteristics associated with left ventricular (LV) changes after their initiation in routine practice are incompletely defined. Methods: In this retrospective two-centre study, 101 patients with HF (94 HFrEF, 6 HFmrEF, 1 HFpEF) initiating an SGLT2i underwent echocardiography at baseline and 6 months. For the purposes of this study, LV reverse remodelling was defined as a simultaneous reduction in LV end-diastolic (LVEDV) and end-systolic volume (LVESV); LVESV reductions ≥10% and ≥15% were used as stringent definitions. Associations were explored with Firth logistic regression adjusted for age and baseline LVEF. Death or HF hospitalisation after the 6-month visit was analysed in relation to 6-month changes (landmark analysis). Results: Median LVEF increased from 28.8% at baseline to 31.6% at 6 months, and the medians of individual paired changes in LVEDV and LVESV were −13.0% and −16.3% (all p < 0.001). The operational definition was met by 74 patients (73.3%) and an LVESV reduction ≥15% by 56 (55.4%). Higher BMI and larger baseline LVEDV were associated with LV volume reduction, and lower TAPSE with LVEF response, LVESV reduction ≥15% and NYHA improvement. No statistically significant association was observed between 6-month changes in LVEF or LV volumes and subsequent death or HF hospitalisation; confidence intervals were wide. Conclusions: In this uncontrolled cohort, SGLT2i initiation was followed by modest LV volume reduction and a small LVEF increase. These associations are exploratory and hypothesis-generating.