Risk factors for infection of implantable cardiac devices: data from a registry of 2496 patients

The increased use of implantable cardiac devices has been accompanied by an increase in infection. However, risk factors for infection of implanted devices are poorly documented. We aimed to identify risk factors in patients with long-term follow-up after implantation of cardiac devices.

Patients with first implantation of a cardiac device in our centre between October 1996 and July 2007 were entered in a registry. Each confirmed infection of the implanted device was matched to two controls for age, sex, and implantation year. We recorded cardiovascular risk factors (hypertension, diabetes), previous history of heart disease, renal failure, antiplatelet or anticoagulant therapy, as well as pre- and post-procedural characteristics (antibiotic prophylaxis, hyperthermia, number of leads, associated interventions, and early complications). During the study period, 2496 patients underwent implantation of a cardiac device; 35 infections were diagnosed (1.2%). Among these, 75% occurred during the first year after implantation. Early non-infectious complication requiring surgical intervention was observed only in patients with infection (9 of 35, P < 0.001). Factors independently associated with infection were diabetes [odds ratio (OR) 3.5, 95% confidence interval (CI) [1.03, 12.97]], underlying heart disease (OR 3.12, 95% CI [1.13; 8.69]), and use of >1 lead (OR 4.07, 95% CI [1.23, 13.47]). These latter two risk factors were also independently associated with occurrence of infection within 1 year of implantation.

Our data show that the presence of diabetes and underlying heart disease are independent risk factors for infection after cardiac device implantation. As regards procedural characteristics, the use of several leads and early re-intervention are associated with a higher infection rate.