In a heterogeneous population of patients with chronic kidney disease, dapagliflozin significantly reduced left ventricular mass index compared with placebo. These findings provide mechanistic insights into the early treatment benefits of SGLT2 inhibitors seen previously in chronic kidney disease. Further research is needed to replicate and further define these early treatment benefits. (Funded by the Danish Cardiovascular Academy and Novo Nordisk Foundation; ClinicalTrials.gov number, NCT05359263.).