Changing patient characteristics and the effect on mortality in endocarditis.
BACKGROUND
Limited data exist on recent demographic and microbiological changes in infective endocarditis (IE) and the impact of these changes on patient survival.


METHODS
Data were collected from all patients with definite or possible IE at Duke University Medical Center, Durham, NC, from 1993 to 1999. Logistic regression analysis was used to identify demographic and microbiological changes that occurred in patients with IE over the study period. The impact of these changes on survival was evaluated using Cox proportional hazards modeling.


RESULTS
Among the 329 study patients, rates of hemodialysis dependence, immunosuppression, and Staphylococcus aureus infection increased during the study period (P=.04, P=.008, and P<.001, respectively), while rates of infection due to viridans group streptococci decreased (P=.007). Hemodialysis was independently associated with S aureus infection (odds ratio, 3.1; 95% confidence interval, 1.6-5.9). Patients with S aureus IE had a higher 1-year mortality rate (43.9% vs 32.5%; P=.04) that persisted after adjustment for other illness severity characteristics (hazard ratio, 1.5; 95% confidence interval, 1.03-2.3).


CONCLUSIONS
The demographic and microbiological characteristics of IE at our institution have changed over the past decade in ways that suggest a link between medical practice and IE characteristics. Staphylococcus aureus has emerged as a dominant cause of IE, and is an independent predictor of mortality. These findings identify clinical settings that may warrant closer surveillance and more aggressive measures in the identification and prevention of endocarditis.
Cabell
Christopher H
CH
Department of Medicine, Duke University Medical Center, Box 31020, Durham, NC 27710. chris.cabell@duke.edu
Jollis
James G
JG
Peterson
Gail E
GE
Corey
G Ralph
GR
Anderson
Deverick J
DJ
Sexton
Daniel J
DJ
Woods
Christopher W
CW
Reller
L Barth
LB
Ryan
Thomas
T
Fowler
Vance G
VG
D000328:Adult; D000368:Aged; D004696:Endocarditis / Q000209:etiology / Q000382:microbiology* / Q000401:mortality*; D005260:Female; D006801:Humans; D007165:Immunosuppression Therapy / Q000009:adverse effects; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D010818:Practice Patterns, Physicians'; D016016:Proportional Hazards Models; D006435:Renal Dialysis / Q000009:adverse effects; D012720:Severity of Illness Index; D013203:Staphylococcal Infections / Q000150:complications; D013211:Staphylococcus aureus / Q000302:isolation & purification; D015996:Survival Rate