Evelyn Hill

(18)F-FDG PET/CT for early detection of embolism and metastatic infection in patients with infective endocarditis.

PurposeIn the acute setting of endocarditis it is very important to assess both the vegetation itself, as well as potential life-threatening complications, in order to decide whether antibiotic therapy will be sufficient or urgent surgery is indicated. A single whole-body scan investigating inflammatory changes could be very helpful to achieve a swift and efficient assessment.MethodsIn this study we assessed whether 18F-FDG can be used to detect and localize peripheral embolism or distant infection. Twenty-four patients with 25 episodes of endocarditis, enrolled between March 2006 and February 2008, underwent 18F-FDG PET/CT imaging on a dedicated PET/CT scanner.ResultsPET/CT imaging revealed a focus of peripheral embolization and/or metastatic infection in 11 episodes (44%). One episode had a positive PET/CT scan result for both embolism and metastatic infection. PET/CT detected seven positive cases (28%) in which there was no clinical suspicion. Valve involvement of endocarditis was seen only in three patients (12%).ConclusionPET/CT may be an important diagnostic tool for tracing peripheral embolism and metastatic infection in the acute setting of infective endocarditis, since a PET/CT scan detected a clinically occult focus in nearly one third of episodes.

Risk Factors for Infective Endocarditis and Outcome of Patients With Staphylococcus aureus Bacteremia

OBJECTIVE To investigate the risk factors for Staphylococcus aureus infective endocarditis (SAIE) and 6-month mortality in patients with S aureus bacteremia (SAB). PATIENTS AND METHODS This study consisted of patients who were diagnosed as having nosocomial or community-acquired SAB or SAIE between June 1, 2000, and December 31, 2005. Clinical characteristics of patients with SAB were compared with those of patients with SAIE, and predictors of mortality in patients with SAB were analyzed. RESULTS The median age of the 132 randomly selected patients with SAB and the 66 patients with SAIE was 66 and 68 years, respectively. Univariable analysis showed that unknown origin of SAB, a valvular prosthesis, a pacemaker, persistent fever, and persistent bacteremia were significantly associated with SAIE. In multivariable analysis, unknown origin of SAB (odds ratio [OR], 4.2; 95% confidence interval [CI], 1.9-9.3; P=.001), a valvular prosthesis (OR, 9.2; 95% CI, 3.2-26.2; P<.001), persistent fever (OR, 3.1; 95% CI, 1.0-9.0; P=.04), and persistent bacteremia (OR, 6.8; 95% CI, 2.3-20.2- P=.001) were independently associated with SAIE. Six- month mortality was 8% in patients with SAB vs 35% in patients with SAIE (OR, 6.5; 95% CI, 2.9- 14.8; P<.001). In univariable analysis, methicillin- resistant S aureus (OR, 7.2; 95% CI, 1.7 - 29.4; P=.005) was significantly associated with 6-month mortality in patients with SAB. CONCLUSION Unknown origin of SAB, a valvular prosthesis, persistent fever, and persistent bacteremia were independently associated with SAIE in patients with SAB. In univariable analysis, methicillin-resistant S aureus was associated with 6-month mortality in patients with SAB. S aureus infective endocarditis had a significantly higher mortality than SAB. The optimal management of SAB and SAIE deserves further study.

Management of Prosthetic Valve Infective Endocarditis

This study analyzed the profile and outcome of surgically versus medically treated patients with prosthetic valve infective endocarditis (PVE). From 2000 to 2006, 80 patients >16 years of age (median 71) with definite PVE according to modified Duke criteria were included. The medically treated group was separated into deliberately conservative and perforce conservative treatments, the latter group including patients with contraindications to a cardiosurgical intervention. The most frequent causative micro-organisms were staphylococci. Forty-six percent of patients were surgically treated, 34% had deliberately conservative treatment, and 20% had perforce conservative treatment. Six-month mortality was 29%; 27% of surgically treated patients died, 4% deliberately conservatively patients died, and 75% perforce conservatively treated patients died. Septic shock, multiorgan failure, and type of treatment were significantly associated with death in univariable analysis. Multivariable analysis revealed that type of treatment (perforce conservative) and septic shock predicted death in patients with PVE. Survival was most favorable in deliberately conservatively treated patients, including PVE due to Staphylococcus aureus. In conclusion, there remains a role for watchful waiting in patients with PVE without evidence of major complications. Moreover, patients with uncomplicated S. aureus PVE can be treated successfully without cardiac surgery. Conversely, patients with major complicated PVE should preferentially undergo surgery. Predictors of mortality in patients with PVE included septic shock and perforce conservative treatment.

Outcome of Patients Requiring Valve Surgery During Active Infective Endocarditis

BACKGROUND The optimal timing of cardiac operations in patients with infective endocarditis continues to be debated. This observational study analyzed the profile and outcome of patients with active infective endocarditis undergoing operations. METHODS Between June 2000 and June 2006, 95 surgically treated patients with definite infective endocarditis by the modified Duke criteria were included. RESULTS Fifty-eight patients were operated on within the first 7 days after diagnosis of infective endocarditis and 37 at more than 7 days after diagnosis up to immediately after completion of antibiotic treatment. Staphylococci predominated and were significantly associated with embolism, abscess, and septic shock. The most frequent indication for operation was severe regurgitation with heart failure. The 6-month mortality was 15%. Early operation showed a trend towards increased mortality vs late operation. In univariable analysis, factors associated with 6-month mortality included staphylococci and septic shock. Multivariable analysis revealed that septic shock predicted 6-month mortality. Despite early operation in patients experiencing septic shock, 57% died. No patients without heart failure died after undergoing (early or late) procedures for severe regurgitation. CONCLUSIONS The prognosis in surgically treated patients was determined by the occurrence of septic shock. The outcome in patients who underwent late operations was favorable compared with the early group. This difference was probably not due to the timing of the surgical intervention but to the severity of infective endocarditis. In patients with severe regurgitation without heart failure, early operation may offer benefit in length of hospitalization and prevention of development of new heart failure.

Infective endocarditis treated with linezolid: case report and literature review

Infective endocarditis (IE) remains a serious disease with mortality rates of 20–25% after 1 year [1]. Antibiotic resistance may limit the therapeutic options and compromise the outcome of infective endocarditis. Linezolid belongs to the oxazolidinone class of antimicrobial agents. It has activity against multidrug-resistant gram-positive organisms, including coagulase-negative staphylococci (CNS), methicillin-resistant Staphylococcus aureus (MRSA), glycopeptide-intermediate S. aureus and vancomycin-resistant Enterococcus [2]. Linezolid has 100% bioavailability, allowing continuation of treatment via the oral route, an elimination half-life of 5–7 h, and good tissue penetration. Linezolid has no cross-resistance with other classes of antibiotics. Due to non-enzymatic oxidation of the morpholine ring, its clearance is not dependent on renal function or hepatic enzyme action. The most common adverse effects are gastrointestinal disturbances, and rarer complications are associated with prolonged linezolid therapy, such as reversible myelosuppression with anemia and thrombocytopenia, and peripheral and optical neuropathy. The oxazolidinones are reversible non-selective monoamine oxidase inhibitors. Therefore, caution is required when prescribing them with adrenergic or serotonergic agents such as pseudoephedrine, phenylpropanolamine, and selective serotonergic reuptake inhibitors [2, 3]. Successes and failures have been reported for IE cases treated with linezolid. We report the case of a patient with prosthetic valve endocarditis who was successfully treated with linezolid. A 46-year-old woman was admitted to hospital with fever and chills. She had not received antibiotics before admission. The only significant aspect of her medical history was rheumatoid arthritis, which was treated with infliximab (an anti-tumor necrosis factor-alpha drug), methotrexate (12.5 mg/week) and prednisone (6 mg per day). Six years previously, she had undergone aortic and mitral valve replacement. Clinical examination at admission was normal. Laboratory results showed an elevated CRP concentration of 49.2 mg/dL. One of six blood cultures showed CNS on admission. One week after admission (without antibiotic treatment), Streptococcus viridans grew in two blood cultures that were obtained on two consecutive days out of multiple sets taken. A transesophageal echocardiograph was performed and vegetations on the prosthetic mitral valve were revealed. The patient was started on a combination of penicillin G and gentamicin. Initially, the patient responded well, but after 1 week, she redeveloped fever and laboratory results showed increasing inflammation. A new transesophageal echocardiograph indicated a possible abscess in the mitral-aortic area. In light of the failed medical treatment, suspicion of an abscess, and the patient’s immunocompromised condition, it was decided that cardiac surgery should be performed. Both valve prostheses were replaced by two new mechanical prostheses. Perioperative valve cultures grew CNS. Antimicrobial susceptibility testing of the isolates showed resistance to methicillin and susceptibility to vancomycin, rifampin, fusidic acid and linezolid. Postoperatively, the patient was treated with vancomycin and rifampin. However, this combination was discontinued after 15 days because of an allergic reaction (a diffuse maculopapular rash). The inflammatory laboratory parameters were still elevated at that time. Antimicrobial therapy was changed to a combination of teicoplanin and E. E. Hill . W. E. Peetermans (*) Department of Internal Medicine, Infectious Diseases, University Hospital Gasthuisberg, Herestraat 49, 3000 Leuven, Belgium e-mail: willy.peetermans@uz.kuleuven.ac.be Tel.: +32-16-344275 Fax: +32-16-344230

Nosocomial infective endocarditis: should the definition be extended to 6 months after discharge

Because the microbiology and patient population of infective endocarditis (IE) have evolved, the traditional definition of nosocomial IE may require revision. The question of whether this definition should be extended to 6 months after discharge was explored, and a high rate of episodes with nosocomial pathogens (coagulase-negative staphylococci) and a low rate of episodes with community pathogens (streptococci) in the extended nosocomial group were found. Therefore, modification of the traditional definition is proposed, distinguishing between early (as traditionally described) and late nosocomial IE (IE in association with a significant invasive procedure performed during a hospitalization between 8 weeks and 6 months before the onset of symptoms).