Table 2.
Overview of PCR results and preoperative antibiotic treatment. Crude numbers refer to number of patients; numbers in parentheses indicate the proportion of valve tissue samples versus swabs.
| Tissue samples/swabs1 | ||||
|---|---|---|---|---|
| Number of patients | PCR | |||
| Positive | Negative | |||
| Total | 114 | 40 (28/12) | 74 (42/32) | |
| Preoperative antibiotic treatment | 101 | 33 ∗ND 7 | 68 ∗ND 4 | |
|
| ||||
| IE | Definite | 100 | 36 (25/11) | 64 (35/29) |
| Possible | 4 | 4 (3/1) | 0 | |
| No evidence | 10 | 0 | 10 (7/3) | |
∗ND: no data available; for 2 patients a preoperative antibiotic treatment could be excluded by medical chart.
1Positive tissue/swab cultures were available for 11 specimens that were exceptionally analyzed using broad-range PCR before a negative culture result was obtained. These data were described but not used for the computation of sensitivity, specificity, and positive and negative predictive values of broad-range PCR.