(1) Background: This single-center retrospective study aimed to evaluate whether sodium–glucose cotransporter-2 inhibitors (SGLT2-i) therapy may have a nephroprotective effect to prevent contrast-induced acute kidney injury (CI-AKI) in patients with heart failure (HF) undergoing iodinated contrast medium (ICM) invasive procedures. The gene discussed is SLC5A2; the disease is heart failure.