Identifying Cardiac Risk with Laboratory Values

A nurse is reviewing the laboratory results of a client admitted with suspected renal impairment. The nurse notes the following values: Serum Creatinine: 3.2 mg/dL, Blood Urea Nitrogen (BUN): 45 mg/dL, and Potassium: 5.8 mEq/L. The normal ranges for these values are Serum Creatinine: 0.6-1.2 mg/dL, BUN: 7-20 mg/dL, and Potassium: 3.5-5.0 mEq/L. Given these results, which laboratory value indicates a significant risk for the client due to potential cardiac complications?