An international clinical trial has shown that a drug used to reduce weight and treat diabetes may also help patients with heart failure. The trial of tirzepatide, under the brand name Zepbound, involved 731 patients with diastolic heart failure and obesity who were followed for two years. In nearly half of heart failure cases, the left ventricle of the heart becomes stiff and can no longer pump blood normally. Doctors call this diastolic heart failure or heart failure with preserved ejection fraction. Obesity is the leading cause of heart failure, so a team of scientists wondered if the weight loss drug tirzepatide might help. The new study, the results of which are published in four journals including the New England Journal of Medicine, found that tirzepatide has great benefits in treating heart failure. The results of the study were also published in Nature Medicine, Circulation and the Journal of the American College of Cardiology. According to the study, patients had an improvement in the distance they could walk in six minutes and a significant decrease in a biological marker used to measure inflammation and predict risk of serious heart disease. During the two-year follow-up, 56 participants who received placebo died or had worsened heart failure, compared with 36 participants who took tirzepatide. Those who took tirzepatide also lost weight, losing an average of 11.6 percent of their body weight. The side effects were mostly minor - nausea and diarrhea, the scientists said.