Abstract 3025: Leiden Device Registry: Delayed Infection Is An Important Issue In Cardiac Device Follow-up.
Background Cardiac device infection (CDI) is a serious complication of cardiac device therapy and negatively influences the risk-benefit ratio, especially in primary prevention. Little data have been published on CDI after a follow-up of more than 2 years, although reports indicate that delayed infections often occur.
Methods We performed a case-control study of 75 patients with CDI and 75 matched controls to evaluate timing, risk factors and types of CDI in a university referral hospital. Multivariate logistic regression was used for comparisons.
Results Of 3410 device procedures performed between Jan 2000 and Dec 2006, 75 CDI (2.2%) occurred. All infected devices were extracted and no deaths occurred. In the cases 37% were ICDs, 15% biventricular and 48% pacemakers vs 47%, 17% and 36% in the controls (p=ns). The delay between device procedure and infection ranged from 0 to 64 months (mean ± SD, 14 ± 16), of which 26 CDI (35%) within 3 months and 18 (24%) after 24 months. Pocket cultures showed mostly Coagulase Negative Staphylococcus (29%) and Staphylococcus aureus (25%). In 29% cultures were non-specific, with 15% skin flora and 14% no micro-organisms.
There was no significant difference in per procedural antibiotic use between cases and controls. Time delay until infection was significantly shorter when cultures were positive for micro-organisms than negative (8 ± 12 vs 21 ± 18 months, p < 0.05). Pocket cultures in delayed infections remained significantly more often negative (56% vs 18%, p = 0,004). Device exchange was significantly more common in the CDI group (60%) than in the control group (33%) (odds ratio (OR) 3.0; 95% confidence interval (CI), 1.5 to 5.8). Also renal dysfunction (Glomerular Filtration Rate < 60 ml/min) appeared to be a risk factor for CDI (OR 3.7; CI, 1.5– 8.9), as was use of oral anti-coagulants (OR 3.4; CI 1.7–7.0). Diabetes was a risk factor for CDI in univariate analysis only (17% vs 5%, p < 0.05).
Conclusion Of all cardiac device infections, 24% occurred more than 2 years after implant or device exchange. Compared to new implants, device exchange tripled the risk for CDI. Cultures in delayed infections were significantly more often negative, suggesting a slow infection with less virulent micro-organisms.