Per cent mortality by operation for the UK 1997/98, the north west, and individual centres, with 95% CI
| Operation | UK Cardiac Register | Region | Centre 1 | Centre 2 | Centre 3 | Centre 4 |
| CABG | 2.6 (2.4 to 2.8) | 2.6 (2.3 to 3.1) | 2.8 (1.9 to 3.9) | 2.7 (2.1 to 3.5) | 1.82 (1.4 to 2.9) | 3.0 (2.3 to 4.0) |
| AVR | 4.5 (3.8 to 5.3) | 4.1 (2.8 to 6.0) | 2.1 (0.4 to 7.0) | 4.4 (2.3 to 8.0) | 5.4 (2.0 to 12.7) | 4.1 (2.0 to 7.9) |
| MVR | 6.3 (5.3 to 7.6) | 4.1 (2.4 to 7.0) | 6.4 (1.7 to 18.6) | 4.9 (2.2 to 10.2) | 2.1 (0.1 to 12.7) | 2.9 (0.8 to 8.9) |
| AVR + CABG | 6.4 (5.3 to 7.7) | 7.3 (5.1 to 10.2) | 7.7 (3.2 to 16.6) | 7.1 (4.0 to 12.0) | 6.8 (3.0 to 14.0) | 8.0 (3.5 to 16.2) |
| MVR + CABG | 12.5 (10.1 to 15.4) | 16.1 (10.9 to 23.1) | 16.1 (6.1 to 34.5) | 19.2 (11.2 to 30.4) | 8.7 (1.5 to 29.5) | 14.3 (4.7 to 33.6) |
| DVR +/– CABG | 10.5 (8.2 to 13.3) | 10.8 (6.6 to 16.9) | 14.8 (4.9 to 34.6) | 14.0 (6.3 to 27.4) | 6.8 (1.8 to 19.7) | 8.1 (2.1 to 23.0) |
AVR, aortic valve replacement; CABG, coronary artery bypass graft; DVR, double valve replacement; MVR, mitral valve replacement.