Anticoagulation intensity at first laboratory monitoring 4 hours after starting lepirudin infusion (investigation cohort). (A) Patients with normal renal function (CrCl > 60 mL/min, n = 29) classified according to lepirudin starting dose: more than 0.11 mg/kg per hour (n = 2), 0.09 to 0.11 kg/hr (n = 11), 0.03 to 0.089 kg/hr (n = 11), and 0.01 to 0.029 kg/hr (n = 5). (B) Patients with moderately impaired renal function (CrCl 30-60 mL/min, n = 15) classified according to lepirudin starting dose: more than 0.09 mg/kg per hour (n = 4), 0.07 to 0.089 mg/kg per hour (n = 3), 0.03 to 0.069 mg/kg per hour (n = 4), 0.01 to 0.029 mg/kg per hour (n = 4), and less than 0.01 mg/kg per hour (n = 1). (C) Patients with severely impaired renal function (CrCl < 30 mL/min, n = 9) classified according to lepirudin starting dose: 0.03 to 0.069 mg/kg per hour (n = 1), 0.01 to 0.029 mg/kg per hour (n = 4), and less than 0.01 mg/kg per hour (n = 4). ■ represent patients with clotting times greater than therapeutic ranges; ▨, patients with clotting times within therapeutic ranges; □, patients with clotting times less than therapeutic ranges.