Risk factors for Gram-negative bacterial infection of cardiovascular implantable electronic devices: multicenter observational study (CarDINe Study)

Background: Infections of cardiovascular implantable electronic devices (CIED) are mainly due to gram-positive bacteria (GPB). Data about gram negative bacteria CIED (GNB-CIED) infections are limited. Aims of our work are to investigate risk factors, clinical and diagnostic characteristics, and outcome of patients with GNB-CIED. Methods: Multicenter, international, retrospective, case-control-control study on patients undergoing CIED implantation from 2015 to 2019 in 17 centers across Europe. For each patient diagnosed with GNB-CIED, one matching control with GPB-CIED infection and two matching controls without infection were selected. Results: 236 patients were enrolled: 59 with GNB-CIED infection, 59 with GPB-CIED infection and 118 without infection. No differences regarding clinical presentation, diagnostic and therapeutic managements were found between the groups. A trend toward higher rate of FDG PET/CT positivity was observed among patients with GN than in those with GPB-CIED infection (85.7% vs. 66.7%, p=0.208). Risk factors for GNB-CIED infection were Charlson Comorbidity Index Score (RRR=1.211, P= 0.011), obesity (RRR: 5.122, P=0.008), ventricular-pacing ventricular-sensing inhibited-response pacemaker (PM-VVI) implantation (RRR: 3,027, P=0.006) and the right subclavian vein site of implantation (RRR: 5.014, P=0.004). At 180-day survival analysis GNB-CIED infection was associated with increased mortality risk (HR=1.842, P=0.067). Conclusions: Obesity, high number of comorbidities, and right subclavian vein implantation site are associated with increased risk of GNB-CIED infection. A prompt therapeutic intervention that may be guided by the use of FDG PET/CT is suggested in patients with GNB-CIED infection considering the poorer outcome observed in this group.