Long-term outcome of infective endocarditis: a study on patients surviving over one year after the initial episode treated in a Finnish teaching hospital during 25 years.
BACKGROUND
Only a few previous studies have focused on the long-term prognosis of the patients with infective endocarditis (IE). Our purpose was to delineate factors potentially associated with the long-term outcome of IE, recurrences of IE and requirement for late valve surgery.


METHODS
A total of 326 episodes of IE in 303 patients were treated during 1980-2004 in the Turku University Hospital. We evaluated the long-term outcome and requirement for late valve surgery for 243 of these episodes in 226 patients who survived longer than 1 year after the initial admission. Factors associated with recurrences were analysed both for the 1-year survivors and for all 303 patients.


RESULTS
The mean (SD) follow-up time for the 1-year survivors was 11.5 (7.3) years (range 25 days to 25.5 years). The overall survival was 95%, 82%, 66%, 51% and 45% at 2, 5, 10, 15 and 20 years. In age and sex adjusted multivariate analyses, significant predictors for long-term overall mortality were heart failure within 3 months of admission (HR 1.97, 95% CI 1.27 to 3.06; p = 0.003) and collagen disease (HR 2.54, 95% CI 1.25 to 5.19; p = 0.010) or alcohol abuse (HR 2.39, 95% CI 1.30 to 4.40; p = 0.005) as underlying conditions, while early surgery was significantly associated with lower overall mortality rates (HR 0.31, 95% CI 0.17 to 0.58; p < 0.001). Heart failure was also significantly associated with the long-term cardiac mortality (p = 0.032). Of all 303 patients, 20 had more than 1 disease episode. Chronic dialysis (p = 0.002), intravenous drug use (p = 0.002) and diabetes (p = 0.015) were significant risk factors for recurrent episodes of IE, but when analysed separately for the 1-year survivors, only chronic dialysis remained significant (p = 0.017). Recurrences and late valve surgery did not confer a poor prognosis.


CONCLUSIONS
Heart failure during the index episode of IE was the complication, which significantly predicted a poor long-term outcome. Patients who underwent surgery during the initial hospitalisation for IE faired significantly better than those who did not.
Heiro
Maija
M
Department of Medicine, Turku University Hospital, Turku, Finland. maija.heiro@tyks.fi
Helenius
Hans
H
Hurme
Saija
S
Savunen
Timo
T
Metsärinne
Kaj
K
Engblom
Erik
E
Nikoskelainen
Jukka
J
Kotilainen
Pirkko
P
D000437:Alcoholism / Q000150:complications; D003095:Collagen Diseases / Q000150:complications; D003920:Diabetes Mellitus; D003956:Dialysis; D004696:Endocarditis / Q000209:etiology / Q000401:mortality* / Q000601:surgery; D005260:Female; D005387:Finland / Q000453:epidemiology; D006333:Heart Failure / Q000150:complications; D019918:Heart Valve Prosthesis Implantation; D006784:Hospitals, Teaching; D006801:Humans; D008297:Male; D011379:Prognosis; D012008:Recurrence; D012307:Risk Factors; D015819:Substance Abuse, Intravenous; D016019:Survival Analysis; D015996:Survival Rate; D013997:Time Factors; D016896:Treatment Outcome