Patient characteristics by prosthesis type
| Characteristic | Mechanical prosthesis, (n=2239) | Tissue prosthesis, (n=3231) | p Value |
| Perioperative mortality, n (%) yes | 82 (4) | 188 (6) | <0.001 |
| Mean age (SD) | 58.5 (11.6) | 74.1 (7.5) | <0.001 |
| Male gender, n (%) | 1567 (70) | 1836 (57) | <0.001 |
| Concomitant CABG, n (%) | 445 (20) | 1195 (38) | <0.001 |
| Greater than first operation, n (%) | 49 (2) | 22 (1) | <0.001 |
| NYHA, n (%) asymptomatic | 77 (9) | 30 (2) | <0.001 |
| n (%) I | 132 (15) | 130 (10) | |
| n (%) II | 297 (35) | 434 (33) | |
| n (%) III | 287 (34) | 612 (46) | |
| n (%) IV | 61 (7) | 116 (9) | |
| LV function, n (%) normal (>50%) | 1261 (60) | 1899 (61) | 0.64 |
| n (%) moderate impairment (30–50%) | 655 (31) | 917 (30) | |
| n (%) severe impairment (<30%) | 184 (9) | 283 (9) | |
| Diabetes, n (%) no | 2002 (92) | 2855 (89) | <0.001 |
| n (%) IDDM | 60 (3) | 81 (3) | |
| n (%) Non-IDDM | 120 (5) | 275 (9) | |
| AF/flutter, n (%) yes | 277 (16) | 712 (24) | <0.001 |
| Mean creatinine (SD) (mmol/l) | 110 (71) | 111 (49) | 0.51 |
| Mean creatinine clearance (SD) (ml/min) | 78.1 (55.9) | 55.2 (29.2) | <0.001 |
| Mean EuroSCORE (SD) | 4.9 (2.9) | 7.2 (2.7) | <0.001 |
| Mean Parsonnet Score (SD) | 12.1 (7.3) | 20.7 (8.9) | <0.001 |
AF, atrial fibrillation; CABG, coronary artery bypass grafting; IDDM, insulin-dependent diabetes mellitus; LV, left ventricular; NYHA, New York Heart Association. The percentages in this table are not based on the total number in each group.