Fructose-1,6-diphosphate (FDP) is used to treat patients who are undergoing coronary artery bypass grafting (CABG) surgery. Before cardiopulmonary bypass begins, a liquid that contains FDP is intravenously infused in the patient, preferably for about 10 to 30 minutes, to allow the FDP to enter the heart and lung tissue while the heart is still beating. FDP can also be added to cardioplegia solution; in addition, FDP can be injected after bypass is terminated, but if post-bypass injection is used, steps should be taken to avoid excess lactic acid accumulation, which appears to increase the risk of atrial fibrillation. To prevent or control lactic acidosis, a buffering or alkalizing agent, such as sodium bicarbonate, or an agent which reduces lactic acid formation, such as dichloroacetate, can be used. In double-blinded trials, this use of FDP substantially reduced heart damage and improved overall outcomes, as shown by lower levels of creatine kinase in blood, improvements in pumping performance, reduced requirements for vasodilator and inotropic drugs, and shorter stays in intensive care units. Certain dosages also reduced the likelihood of atrial fibrillation; however, FDP at high dosages increased the likelihood of A-fib. FDP also helped reduce pulmonary vascular resistance (PVR); this is an important finding, since pulmonary hypertension following cardiopulmonary bypass is a very difficult and often intractable problem, and is a contributing factor in nearly all deaths following CPB surgery.