Abstract

Aims: A nested case-control study of 75 patients with cardiac device infections (CDI) and 75 matched controls was conducted to evaluate time course, risk factors, culture results and frequency of CDI.

Methods and results: CDI occurred in 75/3410 (2.2%) device implantation and revision procedures, performed between 2000 and 2007. The time delay between device procedure and infection ranged from 0 to 64 months (mean 14 (SD 16)), 21 patients (28%) had an early infection (<1 month), 26 (35%) a late infection (1–12 months) and 28 (37%) a delayed infection (>12 months). Of interest, 18 (24%) patients presented with an infection >24 months after the device-related procedure. Time delay until infection was significantly shorter when cultures were positive for micro-organisms compared to negative cultures (8 (12) vs 18 (18) months, p = 0.03). Pocket cultures in delayed infections remained more often negative (61% vs 23%, p = 0.01). Independent CDI risk factors were: device revision (odds ratio (OR) 3.67; 95% confidence interval (CI), 1.51 to 8.96), renal dysfunction defined as glomerular filtration rate <60 ml/min (OR 4.64; CI, 1.48 to 14.62) and oral anticoagulation use (OR 2.83; CI 1.20 to 6.68).

Conclusion: CDI occurred in 2.2% of device procedures, with 24% occurring more than two years after the device-related procedure. Renal dysfunction, device revisions and oral anticoagulation are potent risk factors for CDI.