The incidence and severity of AKI in patients undergoing on-pump vs off-pump CABG was AKIN stage 1 : 298 ( 37 % ) vs 329 ( 42 % ) ; AKIN stage 2 : 38 ( 5 % ) vs 43 ( 5 % ) ; and AKIN stage 3 : 44 ( 6 % ) vs 44 ( 6 % ) , which did not differ significantly ( p = 0.174 ) .