First-time coronary artery bypass grafting: the anaesthetist as a risk factor

We have investigated the contribution of the anaesthetist and surgeon to outcome after 1301 consecutive coronary artery bypass grafting operations (first operation). The mean + 1 SD aspartate amino transferase concentration on the day after surgery (AST-D1) was 134 u litre-1 (or, after logarithmic transformation, 94 u litre-1). Twenty patients were selected at random from each of three groups having AST-D1 less than 100 u litre-1, 100-134 u litre-1 or greater than 134 u litre-1; positive ECG diagnoses of perioperative myocardial infarction were significantly more frequent with AST-D1 values greater than 100 u litre-1 than with smaller values, but no more frequent with AST-D1 greater than 134 u litre-1. Because several deaths occurred before AST-D1 could be measured, an "adverse outcome" was defined as either hospital death or AST-D1 greater than 100 u litre-1. Univariate analysis implicated both anaesthetist and surgeon as significant predictors of adverse outcome but, after allowing for 12 patient-related factors, only cardiopulmonary bypass time (or ischaemic cross-clamp time) (P less than 0.01) and anaesthetist (P = 0.05) were associated significantly with outcome.