Is there still a role for preoperative 12-lead electrocardiography?

Twelve-lead electrocardiography is a standard preoperative investigation for patients undergoing major surgery. There is uncertainty and debate over the usefulness of this test for stratifying postoperative cardiac risk. The aim of this study was to investigate the correlation between an abnormal electrocardiogram (ECG) and the postoperative cardiac event rate.

A prospective single-center observational cohort study in patients undergoing major noncardiac surgery was performed. ECGs were analyzed at the end of the study by a cardiologist and a clinician blinded to the clinical outcomes. The primary endpoints were a major adverse cardiac event (MACE), defined as nonfatal myocardial infarction or cardiac death, and perioperative mortality.

A total of 345 patients were included, who had undergone aortic surgery 25.8%, lower limb bypass 29.0%, amputation 25.2%, or laparotomy 20.0%. An abnormal ECG was present in 141 (40.9%) patients. MACE occurred in 46 (13.3%) cases. Patients with an abnormal ECG had a significantly higher incidence of MACE (21.6 vs. 8.3%, P < 0.001). Multivariate analysis showed that left ventricular strain and a prolonged QTc interval (>440 ms) were independent predictors of postoperative adverse events. Among patients with no prior history of ischemic heart disease, those with an abnormal ECG had a higher MACE rate (20.3%) than those patients with a normal ECG (8.6%) (P = 0.01).

Preoperative electrocardiography is a useful screening test for predicting perioperative cardiac events. Patients with an abnormal ECG but without a prior history of heart disease are a high-risk group potentially amenable to intervention and risk reduction.