Prognostic value of routine preoperative electrocardiography in patients undergoing noncardiac surgery

Electrocardiography is commonly performed as part of preoperative cardiovascular risk assessment in patients undergoing noncardiac surgery. However, the prognostic value of such electrocardiography is still not clear. This study retrospectively studied 23,036 patients who underwent 28,457 surgical procedures at Erasmus Medical Center from 1991 to 2000. Patients were screened before surgery by type of surgery, cardiovascular risk factors (history of coronary heart disease, heart failure, diabetes mellitus, renal dysfunction, and stroke), and preoperative electrocardiography. Electrocardiographic (ECG) results showing atrial fibrillation, left or right bundle branch block, left ventricular hypertrophy, premature ventricular complexes, pacemaker rhythm, or Q-wave or ST-segment changes were classified as abnormal. Multivariate logistic regression was applied to evaluate the relation between ECG abnormalities and cardiovascular death. In-hospital cardiovascular death was observed in 199 of 28,457 patients (0.7%). Patients with abnormal ECG findings had a greater incidence of cardiovascular death than those with normal ECG results (1.8% vs 0.3%; adjusted odds ratio 4.5, 95% confidence interval 3.3 to 6.0). Adding ECG data to clinical risk factors and the type of surgery resulted in an improved C index for the prediction of cardiovascular death (0.79 vs 0.72). However, in patients who underwent low-risk or low- to intermediate-risk surgery, the absolute difference in the incidence of cardiovascular death between those with and without ECG abnormalities was only 0.5%. In conclusion, preoperative electrocardiography provides prognostic information in addition to clinical characteristics and the type of surgery. However, the usefulness of its routine use in lower risk surgery is questionable.