Significance of leukocytosis after cardiac device implantation

Infection remains a feared complication after cardiac device implantation. Whether early postprocedural leukocytosis, a recognized marker of infection, is an indicator of impending infection is unclear and was the focus of this study. A retrospective chart review of consecutive patients who underwent implantable cardioverter defibrillator or pacemaker implantation was performed. The association between change in white blood cell (WBC) count and development of infection after device implantation was assessed. Infection was defined as pocket or lead infection or as bacteremia or sepsis <60 days after implantation. Pre- and postprocedural WBC counts were obtained within 48 hours of the procedure. Significant leukocytosis was defined as a ≥50% increase in WBC count; 1,245 device implantations met inclusion criteria. Device-related infections occurred in 8 cases (0.6%). A modest 17.6 ± 30.2% increase in WBC count was observed for the entire cohort. Cases resulting in infection demonstrated minimal change in WBC count (mean +5.5 ± 26.5%). No infections occurred in patients with ≥50% increases in WBC count or postprocedural WBC counts >15,000/μl. Subjects with significant leukocytosis were younger (mean age 61.9 ± 16.5 vs 65.6 ± 15.1 years, p <0.01), had longer procedure times (mean 198 ± 97 vs 170 ± 77 minutes, p <0.001), and received biventricular implantable cardioverter-defibrillators (25% vs 13.9%, p <0.001). In conclusion, after device implantation, a ≥50% increase in WBC count occurred in about 10% to 15% of patients. Age, race, type of device, and procedure time influenced the development of significant leukocytosis. Elevation in WBC count after cardiac device implantation was not associated with an increased risk for early infection.