Course of platelet count and D-dimer among the 31 patients of the investigation cohort who were within therapeutic ranges already at first monitoring after starting lepirudin. (A) Platelet count; mean values plus or minus 1 SD. ● represent patients with normal renal function (CrCl > 60 mL/min; n = 17); ○, those with moderately impaired renal function (CrCl 30-60 mL/min; n = 7); ▼, those with severely impaired renal function (CrCl < 30 mL/min; n = 7). (B) Box plot of D-dimers in all 31 patients depicting the median value (horizontal line within the box), the 25th and 75th percentiles (bottom and top borders of the box), the 10th and 90th percentiles (bottom and top whiskers), and outliers outside the 10th and 90th percentiles (black dots). Day 0 indicates the day of clinical and laboratory evaluation for suspected HIT and start of lepirudin treatment.