Dapagliflozin was shown in a clinical trial to improve survival and reduce the need for hospitalization in adults with heart failure with reduced ejection fraction. The safety and effectiveness of dapagliflozin were evaluated in a randomized, double-blind, placebo-controlled study of 4,744 participants. The average age of participants was 66 years and more participants were male (77%) than female. To determine the drug's effectiveness, investigators examined the occurrence of cardiovascular death, hospitalization for heart failure, and urgent heart failure visits. Participants were randomly assigned to receive a once-daily dose of either 10 milligrams of dapagliflozin or a placebo (inactive treatment). After about 18 months, people who received dapagliflozin had fewer cardiovascular deaths, hospitalizations for heart failure, and urgent heart failure visits than those receiving the placebo.