Clinical profile and outcomes among patients with cardiac implantable electronic device presenting as isolated pocket infection, pocket-related infective endocarditis, or lead-related infective endocarditis

The clinical spectrum of cardiac implantable electronic device (CIED) infections includes isolated pocket infection (IPI), pocket infection complicated by infective endocarditis (PIRIE), and lead-related infective endocarditis (LRIE). The aim of this study was to assess the risk factors, clinical course, and outcomes in patients with CIED infections and to demonstrate differences between PIRIE and LRIE.

The retrospective analysis of data from 3847 patients undergoing transvenous lead extraction for non-infectious (2640; 68.62%) and infectious (1207; 31.38%) indications, including 361 (29.91%) IPI, 472 (39.11%) PIRIE, and 374 (30.99%) LRIE, showed some differences in risk factors, clinical course, and outcomes between the subgroups. Unlike PIRIE, diabetes [hazard ratio (HR) = 1.488; 95% confidence interval (CI; 1.178–1.879), P < 0.001] and lead abrasion [HR = 2.117; 95% CI (1.665–2.691), P < 0.001] increased the risk of LRIE. The risk of pocket infection spread was greater with Staphylococcus aureus infection [HR = 1.596; 95% CI (1.202–2.120), P < 0.001]. Compared with LRIE, patients with PIRIE had lower levels of inflammatory markers and lower prevalence of vegetations. Mortality in PIRIE compared with LRIE patients was lower (53.18 vs. 62.30%; P < 0.001) and comparable to IPI (50.69%; P = 0.162) at long-term [median 1828 (815–3139) days] follow-up.

Cardiac implantable electronic device infections share common risk factors; however, diabetes and intra-cardiac lead abrasion predispose to LRIE, whereas multiple leads and S. aureus in pocket culture are risk factors for pocket infection spread. Compared with LRIE, the clinical course of PIRIE was milder, and short- and long-term mortalities were lower, but comparable with IPI after >1 year. This may be an argument in favour of categorization into primary LRIE and secondary endocarditis, i.e. PIRIE.