Biomedical subjects

Vivian H Chu

Publications and source records attributed to Vivian H Chu.

9 recordsLinked to original sources

PubMed2006

Use of vancomycin or first-generation cephalosporins for the treatment of hemodialysis-dependent patients with methicillin-susceptible Staphylococcus aureus bacteremia.

BACKGROUND: Because of its ease of dosing, vancomycin is commonly used to treat methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia in patients undergoing long-term hemodialysis. Clinical outcomes resulting from such a therapeutic strategy have not been well defined. METHODS: We prospectively identified patients undergoing long-term hemodialysis who received a diagnosis of MSSA bacteremia. Clinical outcomes were grouped according to the predominant antibiotic received during their therapy (vancomycin or a first-generation cephalosporin [cefazolin]). Treatment failure (defined as death or recurrent infection) was determined at 12 weeks after the initial positive blood culture results. A multivariable analysis was used to adjust for confounders. RESULTS: During an 84-month period, 123 hemodialysis-dependent patients with MSSA bacteremia were identified. Patients receiving vancomycin (n=77) tended to be younger (51 vs. 57 years; P=.06) and had a lower rates of metastatic complications at presentation (11.7% vs. 36.7%; P=.001) than did those receiving cefazolin (n=46). The 2 groups were similar with regard to Acute Physiology and Chronic Health Evaluation II scores, comorbidities, source of infection, type of hemodialysis access, and access removal rates. Treatment failure was more common among patients receiving vancomycin (31.2% vs. 13%; P=.02). In the multivariable analysis, factors independently associated with treatment failure included vancomycin use (odds ratio, 3.53; 95% confidence interval, 1.15-13.45) and retention of the hemodialysis access (odds ratio, 4.99; 95% confidence interval, 1.89-13.76). CONCLUSIONS: Hemodialysis-dependent patients with MSSA bacteremia treated with vancomycin are at a higher risk of experiencing treatment failure than are those receiving cefazolin. In the absence of patient specific circumstances (e.g., allergy to beta-lactams), vancomycin should not be continued beyond empirical therapy for hemodialysis-dependent patients with MSSA bacteremia.

Adult↗

PubMed2006

Telavancin versus standard therapy for treatment of complicated skin and skin structure infections caused by gram-positive bacteria: FAST 2 study.

Telavancin is a bactericidal lipoglycopeptide with a multifunctional mechanism of action. We conducted a randomized, double blind, active-control phase II trial. Patients > or = 18 years of age with complicated skin and skin structure infections caused by suspected or confirmed gram-positive organisms were randomized to receive either telavancin at 10 mg/kg intravenously every 24 h (q24h) or standard therapy (antistaphylococcal penicillin at 2 g q6h or vancomycin at 1 g q12h). A total of 195 patients were randomized and received at least one dose of study medication. Clinical success rates were similar in all analysis populations at test of cure. In microbiologically evaluable patients with Staphylococcus aureus at baseline (n = 91), 96% of the telavancin group and 90% of the standard-therapy group were cured. Among patients with methicillin-resistant S. aureus (MRSA) at baseline (n = 45), clinical cure rates were also 96% for telavancin and 90% for standard therapy. Microbiologic eradication in patients with S. aureus infection was better with telavancin compared to standard therapy (92% versus 78%, P = 0.07) and significantly better in patients with MRSA (92% versus 68%; P = 0.04). Therapy was discontinued for an adverse event (AE) in 6% and 3% of the patients receiving telavancin and standard therapy, respectively. Except for two cases of rash in the telavancin group, these AEs were similar in type and severity in the two groups. The overall incidences and severities of AEs and laboratory abnormalities were similar between the two groups. These data support the ongoing studies assessing the efficacy and safety of telavancin in the treatment of serious gram-positive infections, particularly involving MRSA.

Adult↗

PubMed2005

Repeat infective endocarditis: differentiating relapse from reinfection.

Repeat infective endocarditis due to the same species can represent relapse of the initial infection or a new infection. We used time-based clinical criteria and pulsed-field gel electrophoresis-based molecular criteria to classify 13 cases of repeat infective endocarditis as either relapse or reinfection. The agreement between clinical and molecular criteria was imperfect (agreement in 10 [77%] of 13 cases).

Endocarditis, Bacterial↗

PubMed2005

Telavancin versus standard therapy for treatment of complicated skin and soft-tissue infections due to gram-positive bacteria.

BACKGROUND: Telavancin, a novel lipoglycopeptide, exerts concentration-dependent, rapid bactericidal activity on account of its multiple mechanisms of action. Telavancin is highly active against gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-intermediate, and vancomycin-resistant strains. METHODS: We conducted a randomized, double-blind, controlled, phase-2 clinical trial. Patients > or = 18 years of age with a diagnosis of complicated skin and soft-tissue infection caused by suspected or confirmed gram-positive organisms were randomized to receive either intravenously administered telavancin once daily or standard therapy (antistaphylococcal penicillin 4 times daily or vancomycin twice daily). RESULTS: For the study, 167 patients were randomized and received at least 1 dose of study medication. Success rates were similar in all analysis populations at the test-of-cure evaluation. Of patients with S. aureus infection at baseline (n = 102), 80% of the telavancin group were cured and 77% of the standard therapy group were cured. For patients with MRSA infection at baseline (n = 48), cure rates were 82% for the telavancin group and 69% for the standard therapy group. Microbiologic eradication in patients with MRSA infection was 84% for the telavancin group versus 74% for the standard therapy group. MIC90 values were lower for telavancin in all tested strains of S. aureus (< or = 0.25 ug/mL) compared with the MIC90 values for vancomycin and oxacillin. Similar proportions of patients discontinued therapy for adverse events in both treatment groups (approximately 5%). Fewer serious adverse events were reported in the telavancin group (4 events) than were for the standard therapy group (9). CONCLUSION: Clinical and microbiological results of this study support the further development of telavancin, especially for treatment of infection due to MRSA.

Adult↗

PubMed2005

Risk of endocarditis among patients with prosthetic valves and Staphylococcus aureus bacteremia.

PURPOSE: Staphylococcus aureus is a common cause of bacteremia and of native valve infective endocarditis. However, the risk of endocarditis in patients with a prosthetic valve who develop S. aureus bacteremia is unclear. The aim of this study was to define the risk of prosthetic valve endocarditis in patients with S. aureus bacteremia. SUBJECTS AND METHODS: All patients with a prosthetic valve or ring who developed S. aureus bacteremia during the 94-month study period were prospectively evaluated. The modified Duke criteria were used for the diagnosis of endocarditis. Patients were followed up for 12 weeks after the initial diagnosis of S. aureus bacteremia. RESULTS: The overall rate of definite prosthetic valve endocarditis among the study patients was 26/51 (51%). The risk of endocarditis was similar in patients with late (>or=12 months after valve implantation) vs. early S. aureus bacteremia (<12 months after prosthetic valve implantation) (50% vs. 52%, P=1.0), mitral vs. aortic prostheses (62% vs. 48%, P=0.24), and mechanical vs. bioprosthetic valves (62% vs. 44%, P=0.29). The 12-week mortality was higher among patients with definite vs. possible endocarditis (62% vs. 28%, P=0.019). CONCLUSION: In this investigation, approximately half of all patients with prosthetic valves who developed S. aureus bacteremia had definite endocarditis. The risk of endocarditis was independent of the type, location, or age of the prosthetic valve. The mortality of prosthetic valve endocarditis is high. All patients with a prosthetic valve who develop S. aureus bacteremia should be aggressively screened and followed for endocarditis.

Bacteremia↗

PubMed2005

Staphylococcus aureus bacteremia in patients with prosthetic devices: costs and outcomes.

PURPOSE: Although Staphylococcus aureus is a leading cause of nosocomial infection, little is known about the impact of S. aureus bacteremia on patients with prosthetic devices. This investigation sought to define the clinical outcome, health care resource use, and infection-associated costs of S. aureus bacteremia in patients with prostheses. SUBJECTS AND METHODS: All hospitalized patients with a prosthetic device and S. aureus bacteremia during the 96-month study period were identified prospectively. Clinical data were collected at the time of hospitalization. Data regarding infection-related resource utilization and infection-related costs within 12 weeks of the initial bacteremia were also recorded. RESULTS: 298 patients with > or =1 prosthesis and S. aureus bacteremia were identified (cardiovascular device--122 patients, orthopedic device--73 patients, long-term catheter--71 patients, and other devices-32 patients). Overall, 58% of patients underwent surgery as a consequence of the infection. Infection-related complications occurred in 41% and the overall 12-week mortality was 27%. The mean infection-related cost was 67439 dollars for patients with hospital-acquired S. aureus bacteremia and 37868 dollars for community-acquired S. aureus bacteremia (cost difference 29571 dollars; 95% confidence interval, 14370 dollars-49826 dollars). Rates of device infection, complications, 12-week mortality, and mean cost varied by prosthesis type. CONCLUSION: S. aureus bacteremia in patients with prosthetic devices is associated with frequent complications, substantial cost, and significant health care resource utilization.

Adult↗

PubMed2004

Native valve endocarditis due to coagulase-negative staphylococci: report of 99 episodes from the International Collaboration on Endocarditis Merged Database.

Using a large cohort of patients from the International Collaboration on Endocarditis Merged Database, we compared coagulase-negative staphylococcal (CoNS) native-valve endocarditis (NVE) to NVE caused by more common pathogens. Rates of heart failure and mortality were similar between patients with CoNS NVE and patients with Staphylococcus aureus NVE, but rates for both groups were significantly higher than rates for patients with NVE due to viridans streptococci. These results emphasize the importance of CoNS as a cause of NVE and the potential for serious complications with this infection.

Aged↗

PubMed2004

Early predictors of in-hospital death in infective endocarditis.

BACKGROUND: Data on early determinants of outcome in infective endocarditis (IE) are limited. We evaluated the prognostic significance of early clinical characteristics in a large, prospective cohort of patients with IE. METHODS AND RESULTS: Two hundred sixty-seven consecutive patients with definite or possible IE by modified Duke criteria and echocardiography performed within 7 days of presentation were evaluated. Acute physiology was assessed by the Acute Physiology, Age, Chronic Health Evaluation II (APACHE II) score at the time of presentation, and early heart failure was diagnosed by Framingham criteria. In-hospital mortality rate in the cohort was 19% and similar for patients with definite or possible IE (20% versus 16%, respectively; P=0.464). Independent predictors of death determined by logistic regression modeling were diabetes mellitus (OR 2.48; 95% CI, 1.24 to 4.96), Staphylococcus aureus as causative organism (OR, 2.06; 95% CI, 1.01 to 4.20), APACHE II score (OR, 1.07; 95% CI, 1.01 to 1.12), and embolic event (OR, 2.79; 95% CI, 1.15 to 6.80). Early echocardiographic findings of the Duke criteria were not predictive of death. CONCLUSIONS: Early in the course of IE, readily available clinical characteristics that reflect the host-pathogen interaction are predictive of in-hospital death. These factors may identify those patients with IE for more aggressive treatment.

APACHE↗

PubMed2004

Increasing rates of cardiac device infections among Medicare beneficiaries: 1990-1999.

BACKGROUND: Although cardiac devices have been found to reduce symptoms and mortality rates in appropriate patient populations, the implications of certain important risks, such as infection, are incompletely understood. The purpose of this study was to use a large population-based database to define the population that is at risk for cardiac device infections, determine the prevalence of device infections, and study changes in the rates of cardiac device implantation and infection in the past decade. METHODS: Patients with cardiac device implantations and infections were identified with claims files from the Health Care Finance Administration for Medicare beneficiaries from January 1, 1990, through December 31, 1999. Rates of implantation of cardiac devices were determined. Time trend analyses were performed to determine the significance of the observed change in rates. RESULTS: Cardiac device implantation rates increased from 3.26 implantations per 1000 beneficiaries in 1990 to 4.64 implantations per 1000 beneficiaries in 1999, which represents an increase of 42% in 10 years (P for trend <.001). Cardiac device infections showed a larger increase, from 0.94 device infections per 1000 beneficiaries in 1990 to 2.11 device infections per 1000 beneficiaries in 1999, which represents an increase of 124% during the study period (P for trend <.001). CONCLUSIONS: During the previous decade, there was a significant increase in both cardiac device implantations and infections in elderly patients, although the increase in the rates of device infections was substantially higher. Additional studies are needed to better understand the relationship and timing between cardiac device implantation and infection.

Aged↗