Clinical presentation, microbiology, and prognostic factors of prosthetic valve endocarditis. Lessons learned from a large prospective registry.

BACKGROUND: Prosthetic valve endocarditis (PVE) is a serious infection associated with high mortality that often requires surgical treatment. METHODS: Study on clinical characteristics and prognosis of a large contemporary prospective cohort of prosthetic valve endocarditis (PVE) that included patients diagnosed between January 2008 and December 2020. Univariate and multivariate analysis of factors associated with in-hospital mortality was performed. RESULTS: The study included 1354 cases of PVE. The median age was 71 years with an interquartile range of 62-77 years and 66.9% of the cases were male. Patients diagnosed during the first year after valve implantation (early onset) were characterized by a higher proportion of cases due to coagulase-negative staphylococci and Candida and more perivalvular complications than patients detected after the first year (late onset). In-hospital mortality of PVE in this series was 32.6%; specifically, it was 35.4% in the period 2008-2013 and 29.9% in 2014-2020 (p = 0.031). Variables associated with in-hospital mortality were: Age-adjusted Charlson comorbidity index (OR: 1.15, 95% CI: 1.08-1.23), intracardiac abscess (OR:1.78, 95% CI:1.30-2.44), acute heart failure related to PVE (OR: 3. 11, 95% CI: 2.31-4.19), acute renal failure (OR: 3.11, 95% CI:1.14-2.09), septic shock (OR: 5.56, 95% CI:3.55-8.71), persistent bacteremia (OR: 1.85, 95% CI: 1.21-2.83) and surgery indicated but not performed (OR: 2.08, 95% CI: 1.49-2.89). In-hospital mortality in patients with surgical indication according to guidelines was 31.3% in operated patients and 51.3% in non-operated patients (p<0.001). In the latter group, there were more cases of advanced age, comorbidity, hospital acquired PVE, PVE due to Staphylococcus aureus, septic shock, and stroke. CONCLUSIONS: Not performing cardiac surgery in patients with PVE and surgical indication, according to guidelines, has a significant negative effect on in-hospital mortality. Strategies to better discriminate patients who can benefit most from surgery would be desirable.

Daptomycin treatment in Gram-positive vascular graft infections.

BACKGROUND: Daptomycin is a bactericidal antibiotic approved for the treatment of skin and soft tissue infections and right-side endocarditis. However, there is a lack of published data outlining its usefulness in vascular graft infections (VGI). The aim of this study was to describe the clinical experience of daptomycin use in the treatment of VGI caused by Gram-positive bacteria. METHODS: This was a retrospective cohort study of patients diagnosed with VGI receiving daptomycin at a tertiary care hospital during the period January 2010 to December 2012. RESULTS: Of a total 1066 consecutive patients who had undergone vascular grafts (VG), 25 were diagnosed with VGI. Fifteen of these patients (11 prosthetic VG, three autologous VG, one both types) received daptomycin (median dose 6.7mg/kg/day, range 4.1-7.1mg/kg/day; median age 69 years, range 45-83 years; 80% male). The infected bypass was removed in 13 cases. The most common reason for selecting daptomycin was kidney failure (53%). The Gram-positive organisms isolated were coagulase-negative Staphylococcus (n=10), Staphylococcus aureus (n=3) (two methicillin-resistant S. aureus), Enterococcus faecium (n=2), and Enterococcus faecalis (n=1). The mean follow-up was 69 months (interquartile range 48-72 months). Ten patients (66.7%) achieved complete healing of the VGI. A recurrence of the infection was observed in 100% of patients in whom the bypass was not removed. Among patients who did not achieve complete healing, one needed a supracondylar amputation and one died as a consequence of infection. Five patients received treatment with rifampicin in addition to daptomycin and they were all cured. CONCLUSIONS: The use of daptomycin and surgery for Gram-positive VGI was effective and well tolerated, and this may be a good alternative for the treatment of VGI in patients with peripheral arterial disease in whom renal insufficiency is common.