Temporary mechanical circulatory support devices are increasingly used for short-term support in patients with decompensated cardiogenic shock. Recently, a new axial flow pump has become widely available with the Impella System. The Impella has been FDA approved for short term usage. Hemolysis, however, has been a common complication that has increased morbidity and mortality in this patient population. It is hypothesized that a major source of hemolysis in this patient population is shear stress experienced by red blood cells (RBC) as they travel through the pump device. In addition to causing RBC loss and potential anemia, the hemolysis has multiple other downstream consequences including creation of a pro-thrombotic environment leading to clot formation and potential device failure and secondary end organ dysfunction (renal and liver failure). Due to the significant effects of hemolysis in this population, a great deal of interest has been recently focused on addressing this problem, but as of yet no durable solutions exist. Pentoxifylline improves red blood cell deformability and reduces blood viscosity. It is hypothesized here that administering Pentoxifylline to patients in CS who require temporary MCS will decrease the amount of shear stress related hemolysis through the improved deformability and durability of RBCs. We propose to perform a double-blinded randomized controlled trial in patients who undergo an axillary Impella 5.0 insertion for acute decompensated heart failure. There will be a control group who receives a placebo and the treatment group who receives pentoxifylline. Labs will be drawn to monitor hemolysis which is our current standard protocol for the life of the device to determine the efficacy of pentoxifylline in decreasing hemolysis in this patient population.