Neutrophil count and amputation in critical limb ischaemia

Background. The white blood cell count (WCC) is known to be pre­dic­tive of car­diac and cere­bral vas­cu­lar ­events. No one has yet inves­ti­gat­ed this in crit­i­cal limb ischae­mia (CLI).
Methods. Baseline WCC was exam­ined in rela­tion to lower limb ampu­ta­tion 6 ­months after a 4 week treat­ment peri­od with i.v. pla­ce­bo or i.v. tapros­tene in 366 ­patients with CLI.
Results. The WCC was relat­ed to a sig­nif­i­cant ­increase in ampu­ta­tion, rel­a­tive risk 1.6 (p=0.001, 95% CI: 1.2-2.0) in CLI ­patients with WCC=9×109/l vs ­patients with WCC <9×109/l. Its asso­ci­a­tion with dis­abling ampu­ta­tion per­sist­ed on logis­tic regres­sion anal­y­ses which includ­ed cig­ar­ette smok­ing as a var­i­able and also treat­ment group (p<0.001). The WCC is there­fore an eas­i­ly mea­sur­able prog­nos­tic var­i­able in CLI.
Conclusions. The white blood cell may pro­mote intract­able tis­sue ischae­mia by cap­il­lary plug­ging and/or ­release of toxic chem­i­cals and may have dis­tinct ­effects on tis­sue viabil­ity.