Two weeks of postsurgical therapy may be enough for high-risk cases of endocarditis caused by Streptococcus viridans or Streptococcus bovis

Abstract

The duration of antimicrobial therapy after surgery for infective endocarditis (IE) is controversial. A short course of postsurgical therapy is currently accepted only for patients with negative valve culture. We performed a retrospective (1994-2008) analysis of patients who underwent surgery for IE in our hospital and had a high risk of complications ( one of more of the following: <2 weeks of antibiotic treatment before surgery; embolism; perivalvular extension; and positive valve culture) to compare outcomes of patients who received short-course antimicrobial therapy (SAT) (median 15 days) or long-course antimicrobial therapy (LAT) (median 32 days), irrespective of the results of valve culture. Our endpoints included length of hospital stay, renal and hepatic failure, relapse, re-infection, and mortality rates 1 year after surgery. During the study period, 140 patients underwent surgery for IE (valve replacement, 87.9%). Of these, 133 fulfilled the high-risk group criteria and 92 completed the antimicrobial schedule. Comparison of patients receiving SAT (37) and LAT (55) showed that the SAT group had a shorter length of hospital stay (29 vs. 40 days, p 0.01), and a trend towards lower frequency of renal failure (5.4% vs. 18.2%, p 0.11) and hepatic failure (5.4% vs. 9.1%, p 0.69), whereas mortality (5.4% vs. 3.6%, p 1), relapse (0% vs. 1.8%, p 1) and re-infection (5.4% vs. 3.6%, p 1) rates were similar between both groups. Multivariate analysis showed that IE caused by Streptococcus viridans or Streptococcus bovis was independently associated with SAT. Postsurgical SAT is safe, especially when IE is caused by Streptococcus viridans or Streptococcus bovis, even in patients at high risk of complications.

Infective Endocarditis in Adults: Diagnosis, Antimicrobial Therapy, and Management of Complications

“…If the resected tissue is culture negative, then it may be reasonable for the duration of postoperative treatment given less the number of days of treatment administered for native valve infection before valve replacement. This, however, has been challenged by retrospectively collected data from 2 different medical centers 116,117 that suggest that 2 weeks of antibiotic therapy may be sufficient in patients who undergo valve surgery and have negative valve tissue cultures, particularly in IE cases caused by VGS or Streptococcus gallolyticus (bovis). Whether a 2-week treatment course would be sufficient after valve surgery in patients with positive valve cultures either was not addressed in 1 survey 116 or included only 5 patients in the other.…”

“…Whether a 2-week treatment course would be sufficient after valve surgery in patients with positive valve cultures either was not addressed in 1 survey 116 or included only 5 patients in the other. 117 Histopathological evidence of bacteria with valve tissue Gram staining in patients with negative tissue cultures can represent killed organisms and is not a factor in defining the length of therapy after valve surgery. 110 For patients with NVE who undergo valve resection with prosthetic valve replacement or repair with an annuloplasty ring, there is a lack of consensus as to whether the postoperative treatment regimen should be one that is recommended for prosthetic valve treatment rather than one that is recommended by guest on http://circ.ahajournals.org/ Downloaded from for native valve treatment.…”

Four weeks versus six weeks of ampicillin plus ceftriaxone in Enterococcus faecalis native valve endocarditis: A prospective cohort study

“…The saving in patient complications and hospital stay on account of short-course treatment has already been a common goal of various IE studies. [26,27]. The potential protective effect of shorter courses of beta-lactams, ranging from lower rates of antibiotic-related toxicity to the risk of suffering from C. difficile infections or for the selection of vancomycin-resistant E. faecium [28][29][30].…”

Considerations of antibiotic therapy duration in community- and hospital-acquired bacterial infections

“…The authors observed that a 2 week post-surgical course of AT was not associated with higher relapse rates if valve culture results were negative. 52 More recently, a Spanish retrospective study carried out by Muñoz et al 53 found that short-course (median 15 days) post-operative AT has a similar effectiveness to longer-course (median 32 days) treatment for patients who underwent surgery for IE and had a high risk of complications (short course of AT before surgery, embolic events, extension of infection beyond the valve and positive valve culture). Moreover, on multivariate analysis, IE due to Streptococcus viridans or Streptococcus bovis was independently associated with short-course AT.…”

“…Moreover, on multivariate analysis, IE due to Streptococcus viridans or Streptococcus bovis was independently associated with short-course AT. 53…”