Right heart failure is a potentially devastating complication of mechanical circulatory support, occurring at a rate of 0.49 events per 100 patient-months. Pulmonary vasodilators such as phosphodiesterase-5 inhibitors (PDE5i) have been frequently used to unload the right ventricle in left ventricular assist device (LVAD) patients, but there is scant evidence to support this practice., The purpose of this analysis is to provide additional data regarding the safety and efficacy of the PDE5i sildenafil in a real world population of patients supported with LVADs at Washington University in St. Louis. Sildenafil use was not associated with differences in gastrointestinal (GI) bleeding, stroke, mortality, heart failure (HF) admission, or orthotopic heart transplantation (OHT).