GSTM1 and atrial fibrillation: Univariable factors associated with upper GIB were cirrhosis, coumadin use, lack of proton pump inhibitor use, lower admission hemoglobin (Hb), and greater difference in baseline Hb to pre-procedure Hb (p < .05).The predictors of upper GIB in CKD III/IV were atrial fibrillation diagnosis and in CKD V/ESRD was HD use. The greatest predictor of an upper GIB was a greater difference in baseline Hb to pre-procedure Hb (p < .05).