High-Dose Daptomycin for Cardiac Implantable Electronic Device-Related Infective Endocarditis

Background. Cardiac implantable electronic device (CIED)-related endocarditis is a growing challenge because of increasing incidence and significant mortality. Current treatment is based on complete hardware removal coupled with long-term administration of effective and safe antimicrobials. Daptomycin at the dose of 6 mg/kg/day has been found to be effective in staphylococcal endocarditis, but limited data exist on CIED endocarditis. Moreover, whether higher doses could be more effective but equally safe in this setting is currently unknown. Methods. We report here our experience with high-dose daptomycin in the treatment of 25 cases of CIED endocarditis due to staphylococci. Results. Patients were mostly elderly and male, with large lead vegetations and severe comorbidities. Pathogens were Staphylococcus epidermidis (56%), Staphylococcus aureus (28%), and other coagulase-negative staphylococci (16%). Only 4 patients (16%) had a normal pretreatment renal function. The median daptomycin daily dose was 8.3 mg/kg (range, 6.4-10.7). Daptomycin was administered for a median of 20 days (range, 8-52). Percutaneous lead extraction was performed in 88% of patients. Two patients (8%) failed to clear bacteremia. The overall clinical success of treatment was 80%, whereas a complete microbiological success was observed in 92% of patients. Creatine phosphokinase values were monitored and increased above normal in 5 cases (20%). No serious adverse event related to high-dose daptomycin was observed and no patient required discontinuation because of muscle toxicity. Conclusions. Our experience suggests that high-dose daptomycin may be a safe therapeutic option in staphylococcal CIED endocarditis and may be associated with high microbiological responses and clinical success.