Definition of risk factors
| Risk factor | Definition |
|---|---|
| Smoking history | Any history of tobacco use |
| Diabetes | Any history of diabetes regardless of duration |
| Renal failure | Blood creatinine > 140 μmol/l or on dialysis |
| Hypertension | Blood pressure > 140/90 mm Hg or on antihypertensive drugs |
| Cerebrovascular accident | Central neurological deficit persisting > 24 hours or previous cerebrovascular surgery |
| Chronic obstructive pulmonary disease | Pharmacological therapy for COPD or FEV1 < 75% predicted |
| Unstable angina | Myocardial ischaemia requiring hospitalisation and use of iv medication for control |
| Urgent surgery | Surgery within 24 hours of referral |
| Emergency surgery | No delay in providing operative intervention |
| Salvage | Cardiopulmonary resuscitation on route to operating theatre or during anaesthesia |
Definitions as given in the Society of Thoracic Surgeons National Cardiac Surgery database manual for data managers.13