Should High-dose Daptomycin be an Alternative Treatment Regimen for Enterococcal Endocarditis?

Introduction: Previous series on the use of daptomycin in enterococcal infective endocarditis (EIE) have shown various outcomes, including higher mortality rates. We analyzed the effectiveness of high-dose daptomycin for the treatment of EIE. Methods: We performed a prospective study from 2010 to 2018 in a referral center in patients with native (NVE) and prosthetic valve endocarditis (PVE) due to Enterococcus spp. The standard high-dose daptomycin at our institution is 10–12 mg/kg/day (CLCr > 30 ml/min). We compared the efficacy of a daptomycin-based regimen (DBR) versus daptomycin-sparing regimen (DSR) and daptomycin monotherapy versus combination therapy. Primary endpoints of the study were evaluation of risk factors associated with 30-day mortality and failure at end of therapy. Results: We collected 43 EIE cases; 29 were NVE (67.4%). Overall, 16 (37.2%) were treated with DBR, mainly with combination regimens (11, 68.7%), in the majority of cases in association with ß-lactam (7, 43.7%). The mean administered dose of daptomycin was 10.125 mg/kg/day (range 8–12 mg/kg/day). Overall, patients treated with DBR compared with patients treated with DSR had no higher mortality rates and/or failure at end of therapy (6.2% vs. 22. 2%; P 0.41 and MICs 0.25–2 mg/l, 6.2% vs. 3.7%; P 1.0). In the sub-group of patients with NVE and PVE treated with DBR and DSR, no difference was found regarding the primary endpoints on the single or combined use of daptomycin. Conclusion: Our findings suggest that high-dose daptomycin might be used as an alternative treatment regimen in EIE.