<p>Data on the cardiovascular–kidney effects and safety of empagliflozin among patients with acute myocardial infarction are limited. EMPACT-MI (Study to Evaluate the Effect of Empagliflozin on Hospitalization for Heart Failure and Mortality in Patients with Acute Myocardial Infarction) was a double-blind, multicenter clinical trial that randomized 6,522 patients with acute myocardial infarction and risk for heart failure to empagliflozin or placebo. Here we show in this secondary analysis that the mean estimated glomerular filtration rate at baseline was 76.1 ml min⁻¹ 1.73 m⁻² (s.d. = 19.9 ml min⁻¹ 1.73 m⁻²), with longitudinal kidney function data available for 1,152 (17.7%) treated patients from select countries. By 24 months, compared with baseline, the estimated glomerular filtration rate was similar in the empagliflozin group but declined in the placebo group (<i>P</i> = 0.01). Empagliflozin reduced the total adverse events of heart failure or all-cause mortality irrespective of kidney function (<i>P</i>_interaction = 0.30). Thirty-day adverse event rates were similar by treatment group and consistent across baseline kidney function. Empagliflozin had kidney-protective effects, reduced heart failure outcomes and was safe to initiate soon after acute myocardial infarction across baseline kidney function.</p>