Emergence of coagulase-negative staphylococci as a cause of native valve endocarditis.
BACKGROUND
Coagulase-negative staphylococci (CoNS) are an infrequent cause of native valve endocarditis (NVE), and our understanding of NVE caused by CoNS is incomplete.


METHODS
The International Collaboration on Endocarditis-Prospective Cohort Study includes patients with endocarditis from 61 centers in 28 countries. Patients with definite cases of NVE caused by CoNS who were enrolled during the period June 2000-August 2006 were compared with patients with definite cases of NVE caused by Staphylococcus aureus and patients with NVE caused by viridans group streptococci. Multivariable logistic regression was used to determine factors associated with death in patients with NVE caused by CoNS.


RESULTS
Of 1635 patients with definite NVE and no history of injection drug use, 128 (7.8%) had NVE due to CoNS. Health care-associated infection occurred in 63 patients (49%) with NVE caused by CoNS. Comorbidities, long-term intravascular catheter use, and history of recent invasive procedures were similar among patients with NVE caused by CoNS and among patients with NVE caused by S. aureus. Surgical treatment for endocarditis occurred more frequently in patients with NVE due to CoNS (76 patients [60%]) than in patients with NVE due to S. aureus (150 [33%]; P=.01) or in patients with NVE due to viridans group streptococci (149 [44%]; P=.01). Despite the high rate of surgical procedures among patients with NVE due to CoNS, the mortality rates among patients with NVE due to CoNS and among patients with NVE due to S. aureus were similar (32 patients [25%] and 124 patients [27%], respectively; P=.44); the mortality rate among patients with NVE due to CoNS was higher than that among patients with NVE due to viridans group streptococci (24 [7.0%]; P=.01). Persistent bacteremia (odds ratio, 2.65; 95% confidence interval, 1.08-6.51), congestive heart failure (odds ratio, 3.35; 95% confidence interval, 1.57-7.12), and chronic illness (odds ratio, 2.86; 95% confidence interval, 1.34-6.06) were independently associated with death in patients with NVE due to CoNS (c index, 0.73).


CONCLUSIONS
CoNS have emerged as an important cause of NVE in both community and health care settings. Despite high rates of surgical therapy, NVE caused by CoNS is associated with poor outcomes.
Chu
Vivian H
VH
Duke University Medical Center, Durham, North Carolina 27710, USA. chu00009@mc.duke.edu
Woods
Christopher W
CW
Miro
Jose M
JM
Hoen
Bruno
B
Cabell
Christopher H
CH
Pappas
Paul A
PA
Federspiel
Jerome
J
Athan
Eugene
E
Stryjewski
Martin E
ME
Nacinovich
Francisco
F
Marco
Francesc
F
Levine
Donald P
DP
Elliott
Tom S
TS
Fortes
Claudio Q
CQ
Tornos
Pilar
P
Gordon
David L
DL
Utili
Riccardo
R
Delahaye
Francois
F
Corey
G Ralph
GR
Fowler
Vance G
VG
D000328:Adult; D000368:Aged; D003030:Coagulase / Q000172:deficiency; D017714:Community-Acquired Infections / Q000382:microbiology; D003428:Cross Infection / Q000382:microbiology; D004697:Endocarditis, Bacterial / Q000382:microbiology* / Q000601:surgery; D005260:Female; D006333:Heart Failure / Q000382:microbiology; D006349:Heart Valve Diseases / Q000382:microbiology* / Q000601:surgery; D006801:Humans; D008297:Male; D016106:Methicillin Resistance; D008875:Middle Aged; D010138:Pacemaker, Artificial; D011446:Prospective Studies; D013210:Staphylococcus / Q000187:drug effects / Q000201:enzymology / Q000302:isolation & purification*
D003030:Coagulase