Predictors of postoperative myocardial ischaemia  The role of intercurrent arterial hypertension and other cardiovascular risk factors

One hundred and eighty-three patients were studied to examine the role of a number of risk factors in the development of silent ischaemia after general anaesthesia for general and vascular surgery. We collected evidence of cardiovascular risk factors using a binary questionnaire. The patients were monitored pre- and postoperatively using a Holter ECG monitor. Usable data were collected on 140 patients. Pre-operative silent myocardial ischaemia was found to be strongly associated with postoperative silent myocardial ischaemia (odds ratio: 10.8, 95% confidence intervals: 3.8-30.7). A history of hypertension, indicated by treatment with antihypertensive drugs, was associated with increased risk (odds ratio: 2.58, 95% confidence intervals: 1.12-5.96). A linear trend was found for risk associated with increasing admission systolic blood pressure (odds ratio: 1.20 for each 10-mmHg increase in systolic pressure, 95% confidence intervals: 1.01-1.42). An association between vascular surgery and postoperative silent myocardial ischaemia was also confirmed (odds ratio: 2.36, 95% confidence intervals: 1.1-5.1).