Background. Extensively drug-resistant (XDR) Acinetobacter baumannii may cause serious infections in critically ill patients. Colistin often remains the only therapeutic option. Addition of rifampicin to colistin may be synergistic in vitro. In this study, we assessed whether the combination of colistin and rifampicin reduced the mortality of XDR A. baumannii infections compared to colistin alone. Methods. This multicenter, parallel, randomized, open-label clinical trial enrolled 210 patients with life-threatening infections due to XDR A. baumannii from intensive care units of 5 tertiary care hospitals. Patients were randomly allocated (1:1) to either colistin alone, 2 MU every 8 hours intravenously, or colistin (as above), plus rifampicin 600 mg every 12 hours intravenously. The primary end point was overall 30-day mortality. Secondary end points were infection-related death, microbiologic eradication, and hospitalization length. Results. Death within 30 days from randomization occurred in 90 (43%) subjects, without difference between treatment arms (P = .95). This was confirmed by multivariable analysis (odds ratio, 0.88 [95% confidence interval, .46–1.69], P = .71). A significant increase of microbiologic eradication rate was observed in the colistin plus rifampicin arm (P = .034). No difference was observed for infection-related death and length of hospitalization. Conclusions. In serious XDR A. baumannii infections, 30-day mortality is not reduced by addition of rifampicin to colistin. These results indicate that, at present, rifampicin should not be routinely combined with colistin in clinical practice. The increased rate of A. baumannii eradication with combination treatment could still imply a clinical benefit. Clinical Trials Registration. NCT01577862.

Prosthetic valve endocarditis (PVE) occurs in approximately 3% to 6% of patients within 5 years of valve implantation and is associated with significant morbidity and mortality.^1-4 Surgical intervention with debridement and valve replacement is recommended by consensus guidelines^5,6 for patients with complications such as valve dysfunction, dehiscence, heart failure, cardiac abscesses, or persistent bacteremia. These guidelines are based largely on expert opinion and limited observational data.⁷ Studies^8-25 comparing survival between patients undergoing surgery vs medical therapy for PVE have reported conflicting results. In addition, retrospective data collection, single-center study design, and small sample sizes of these studies limit the ability to control for treatment selection and survivor bias.

Infective endocarditis (IE) is on the rise in all western countries and in all age groups, and its epidemiologic characteristics have changed significantly in past decades.¹ Despite the great progress in diagnosis and treatment, mortality rates remain high.²

Background—: Use of surgery for the treatment of infective endocarditis (IE) as related to surgical indications and operative risk for mortality has not been well defined. Methods and Results—: The International Collaboration on Endocarditis–PLUS (ICE-PLUS) is a prospective cohort of consecutively enrolled patients with definite IE from 29 centers in 16 countries. We included patients from ICE-PLUS with definite left-sided, non–cardiac device–related IE who were enrolled between September 1, 2008, and December 31, 2012. A total of 1296 patients with left-sided IE were included. Surgical treatment was performed in 57% of the overall cohort and in 76% of patients with a surgical indication. Reasons for nonsurgical treatment included poor prognosis (33.7%), hemodynamic instability (19.8%), death before surgery (23.3%), stroke (22.7%), and sepsis (21%). Among patients with a surgical indication, surgical treatment was independently associated with the presence of severe aortic regurgitation, abscess, embolization before surgical treatment, and transfer from an outside hospital. Variables associated with nonsurgical treatment were a history of moderate/severe liver disease, stroke before surgical decision, and Staphyloccus aureus etiology. The integration of surgical indication, Society of Thoracic Surgeons IE score, and use of surgery was associated with 6-month survival in IE. Conclusions—: Surgical decision making in IE is largely consistent with established guidelines, although nearly one quarter of patients with surgical indications do not undergo surgery. Operative risk assessment by Society of Thoracic Surgeons IE score provides prognostic information for survival beyond the operative period. S aureus IE was significantly associated with nonsurgical management.