Table 1.

Study population.

	Active endocarditis	Controls
Number of patients, n	20	35
Male sex, n (%)	15 (75)	22 (62.9)
Age, years, median [range]	57 [14–80]	71 [17–83]
Number of valves, n	26	35
Native valves, n (%)	15 (58)	33 (94)
- aortic, n (%)	9 (60)	32 (97)
- mitral, n (%)	4 (27)	1 (3)
- pulmonary, n (%)	1 (7)	0
- tricuspid, n (%)	1 (7)	0 (0)
Prosthetic valves, n (%)	11 (42)	2 (6)
Biological, n (%)	8 (73)	1 (50)
- aortic, n (%)	6 (75)	0 (0)
- mitral, n (%)	1 (13)	0 (0)
- pulmonary, n (%)	1 (13)	1 (100)
Mechanical, n (%)	3 (27)	1 (50)
- aortic, n (%)	3 (100)	1 (100)
Median antimicrobial treatment prior to valve removal, days [range]*	27 [4–54]†	0

n = number; *all patients received prophylactic antibiotics during surgery (standard: cefazoline 3 × 2 gram for 24 hours i.v., with additional doses intraoperatively in case of blood loss >1L, and after 4 hours operation time); ^†three patients did not receive antimicrobial therapy before valve removal.