Figure 2. Study flowchart.

Overview of the study design for all 3 study groups: Ketone/placebo with preceding aspirin, Ketone/placebo without aspirin (from previous study), Niacin/placebo. The interventions were initiated after baseline measurements (0 minutes) and were crossed over to the other intervention at 180 minutes. Invasive measurements using pulmonary artery catheter, echocardiography, and blood samples were conducted hourly during the study period.