Risk factors associated with early- versus late-onset implantable cardioverter-defibrillator infections

Abstract

Aims: The infection rates of implantable cardioverter-defibrillators systems (ICDs) are higher than that of permanent pacemaker. Risk factors associated with ICD infection have not been characterized and are the subject of the current investigation.

Methods: All patients who had an ICD implanted at Mayo Clinic Rochester between 1991 and 2008 were retrospectively reviewed. Each case of ICD infection was matched with two non-infected controls. Cases of ICD infection were further stratified by early- (≤ 6 months) versus late-onset (>6 months) infection. Multivariable analysis was performed to identify significant risk factors for ICD infection.

Results: Sixty-eight patients with ICD infection and 136 matched controls met the inclusion criteria. Thirty-five cases presented with early-onset infection and 33 had late-onset device infection. Staphylococcal species were the most common pathogens in both groups of patients. Patients with early-onset infection were more likely to present with generator pocket infection (p = 0.02). Patients with multiple comorbid conditions (high Charlson index) tended to have longer hospital stay during implantation admission (p = 0.009). In a multivariable logistic regression model, the presence of epicardial leads (odds ratio (OR) = 9.7, p = 0.03) and postoperative complications at the generator pocket (OR = 27.2, p < 0.001) were significant risk factors for early-onset ICD infection, whereas longer duration of hospitalization at the time of implantation (2 days versus 1 day: OR = 33.1, p < 0.001; ≥ 3 days versus 1 day: OR = 49.0, p < 0.001) and chronic obstructive pulmonary disease (OR = 9.8, p = 0.02) were associated with late-onset infections.

Conclusions: Our study findings suggest that risk factors associated with early- and late-onset ICD infection are different. While circumstances that may increase the chances of pocket contamination in the perioperative period are more likely to be associated with early-onset ICD infection, overall poor health of the host may increase the likelihood of late-onset ICD infection. These factors should be considered when developing strategies to minimize risk of device infection.