Inflammatory markers in the diagnostic workup of pacemaker- and defibrillator‑related infections in patients referred for transvenous lead extraction
Abstract
Background: Infectious complications can be life‑threatening in patients with permanent transvenous pacemakers and their diagnosis can be challenging.
Aims: The aim of the study was to assess the diagnostic utility of white blood cell (WBC) count and C‑reactive protein (CRP) concentrations in infectious complications in patients with cardiac pacemakers.
Methods: The prospective study included patients who underwent transvenous lead extraction (TLE) due to various indications. The diagnosis of lead‑dependent infective endocarditis (LDIE) was based on the modified Duke criteria, and the diagnosis of local infection was based on symptoms related to device pocket. The study population consisted of 640 patients: 63 (9.9%) with LDIE, 61 (9.5%) with local infection, and 516 controls (80.6%) referred for TLE due to noninfectious indications. We evaluated WBC count and CRP concentrations in each group of patients and assessed the predictive value of these tests for the diagnosis of LDIE and local infection.
Results: Patients with local infection did not differ in terms of median WBC and CRP values compared with controls (P = 0.99 and P = 0.13, respectively), whereas patients with LDIE had higher median WBC count and CRP level (P < 0.001 and P < 0.001, respectively). In the LDIE group, WBC diagnostic test showed 46.0% sensitivity, 95.3% specificity, 90.5% accuracy, 51.8% positive predictive value, and 94.2% negative predictive value. The diagnostic test based on CRP levels showed 84.1% sensitivity, 81.8% specificity, 82.0% accuracy, 33.5% positive predictive value, and 97.9% negative predictive value.
Conclusions: In patients undergoing TLE due to infectious indications, inflammatory markers (WBC count, CRP level) were within normal range in the local‑infection group and markedly elevated in the LDIE group. Inflammatory markers were useful to determine the extent of the infection in patients with local infection.
